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Hubli M, Leone C. Clinical neurophysiology of neuropathic pain. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2024; 179:125-154. [PMID: 39580211 DOI: 10.1016/bs.irn.2024.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2024]
Abstract
Timely and accurate diagnosis of neuropathic pain is critical for optimizing therapeutic outcomes and minimizing treatment delays. According to current standards, the diagnosis of definite neuropathic pain requires objective confirmation of a lesion or disease affecting the somatosensory nervous system. This can be provided by specialized neurophysiological techniques as conventional methods like nerve conduction studies and somatosensory evoked potentials may not be sufficient as they do not assess pain pathways. These specialized techniques apply various stimuli, such as thermal, electrical, or mechanical, alongside assessments of spinal/cortical potential or electromyographic reflex recordings. The selection of techniques is guided by the patient's clinical history and examination. The most common neurophysiological tests used in clinical practice are pain-related evoked potentials (PREPs) providing an objective evaluation of nociceptive pathways. Four types of PREPs are employed: laser evoked potentials, contact-heat evoked potentials, intra-epidermal electrical stimulation evoked potentials, and pinprick evoked potentials, with the two former ones being the most robust and reliable ones. These techniques investigate small-diameter fibers, primarily Aδ-fibers, and spinothalamic tracts allowing the identification of peripheral or central nervous system lesions. Yet, they are limited in capturing neuronal mechanisms underlying neuropathic pain or in providing objective quantification of pain sensation. Two neurophysiological measures which investigate the pain system beyond its integrity are the nociceptive withdrawal reflex and the N13 component of somatosensory evoked potentials. Both of these methods are more commonly used in research than clinical practice, but they pose interesting approaches to quantify central sensitization, a key underlying mechanism of neuropathic pain. Future investigations in neuropathic pain are therefore warranted.
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Affiliation(s)
- Michèle Hubli
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Caterina Leone
- Department of Human Neuroscience, Sapienza University, Rome, Italy.
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Stoyanova-Piroth G, Milanov I, Stambolieva K. Association between pain threshold and manifested pain assessed using a PD-specific pain scale in Parkinson's disease. Front Neurol 2024; 15:1420696. [PMID: 39131046 PMCID: PMC11312374 DOI: 10.3389/fneur.2024.1420696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Accepted: 06/28/2024] [Indexed: 08/13/2024] Open
Abstract
Background The neurodegenerative process in Parkinson's disease (PD) affects both dopaminergic and non-dopaminergic structures, which determine the wide range of motor and non-motor symptoms (NMS), including different types of pain. Diverse mechanisms contribute to pain in PD. Abnormal nociceptive processing is considered a distinctive feature of the disease. Objective In the present study, we used a validated PD-specific pain assessment tool to investigate self-reported pain in PD patients and to analyze the association with the objective pain threshold. Methods The RIII component of the nociceptive flexor reflex was assessed in 35 patients with PD and was compared to 40 healthy controls. Self-reported pain was measured using the Bulgarian version of the King's Parkinson's Disease Pain Scale (KPPS-BG). A correlation analysis was used to investigate the relationship between the objective nociceptive threshold and PD pain as assessed by KPPS-BG. Results PD patients had a significantly lower RIII threshold than control individuals (the mean SD value was 6.24 ± 1.39 vs. 10.33 ± 1.64) when assessed in the "off" state. A statistically significant (p < 0.05) fairly negative Spearman's correlation was observed between the decreased spinal nociceptive threshold and fluctuation-related pain (-0.31). Domain 4, "nocturnal pain" (-0.21), and the KPPS-BG total score (-0.21) showed a weak negative correlation. An insignificant positive correlation was found between domain 6-"discoloration, edema/swelling"-and the RIII threshold. A higher Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III score and modified Hoehn and Yahr (H&Y) scale are associated with a decreased nociceptive flexor reflex threshold. Conclusion The results of the present study demonstrate the important role of increased spinal nociception in the occurrence of pain, which is associated with fluctuations and, to a lesser extent, nocturnal pain.
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Affiliation(s)
- Galina Stoyanova-Piroth
- St. Naum Hospital of Neurology and Psychiatry, Medical University, Sofia, Bulgaria
- ZURZACH Care, Neurorehabilitation, Rehaklinik Baden Dättwil, Baden, Switzerland
| | - Ivan Milanov
- St. Naum Hospital of Neurology and Psychiatry, Medical University, Sofia, Bulgaria
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Mirra A, Gamez Maidanskaia E, Levionnois OL, Spadavecchia C. How Is the Nociceptive Withdrawal Reflex Influenced by Increasing Doses of Propofol in Pigs? Animals (Basel) 2024; 14:1081. [PMID: 38612320 PMCID: PMC11010981 DOI: 10.3390/ani14071081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/26/2024] [Accepted: 04/01/2024] [Indexed: 04/14/2024] Open
Abstract
The nociceptive withdrawal reflex (NWR) is a physiological, polysynaptic spinal reflex occurring in response to noxious stimulations. Continuous NWR threshold (NWRt) tracking has been shown to be possibly useful in the depth of anesthesia assessment. The primary aim of this study was to describe how propofol modulates the NWRt over time in pigs. Five juvenile pigs (anesthetized three times) were included. An intravenous (IV) infusion of propofol (20 mg/kg/h) was started, and boli were administered to effect until intubation. Afterwards, the infusion was increased every ten minutes by 6 mg/kg/h, together with an IV bolus of 0.5 mg/kg, until reaching an electroencephalographic suppression ratio (SR) of between 10% and 30%. The NWRt was continuously monitored. For data analysis, the time span between 15 min following intubation and the end of propofol infusion was considered. Individual durations of propofol administration were divided into five equal time intervals for each pig (TI1-TI5). A linear regression between NWRt and TI was performed for each pig. Moreover, the baseline NWRt and slopes of the linear regression (b1) were compared among days using a Friedman Repeated Measures Analysis of Variance on Ranks. The NWRt always increased with the propofol dose (b1 = 4.71 ± 3.23; mean ± standard deviation). No significant differences were found between the baseline NWRt and the b1 values. Our results suggest that the NWRt may complement the depth of anesthesia assessment in pigs receiving propofol.
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Affiliation(s)
- Alessandro Mirra
- Section of Anesthesiology and Pain Therapy, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (E.G.M.); (O.L.L.); (C.S.)
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Ser MH, Yılmaz B, Sulu C, Gönen MS, Gunduz A. Nociceptive flexion reflex in small fibers neuropathy and pain assessments†. PAIN MEDICINE (MALDEN, MASS.) 2023; 24:1161-1168. [PMID: 37294833 DOI: 10.1093/pm/pnad077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 05/07/2023] [Accepted: 06/01/2023] [Indexed: 06/11/2023]
Abstract
BACKGROUND The nociceptive flexion reflex (NFR) is a polysynaptic and multisegmental spinal reflex that develops in response to a noxious stimulus and is characterized by the withdrawal of the affected body part. The NFR possesses two excitatory components: early RII and late RIII. Late RIII is derived from high-threshold cutaneous afferent A-delta fibers, which are prone to injury early in the course of diabetes mellitus (DM) and may lead to neuropathic pain. We investigated NFR in patients with DM with different types of polyneuropathies to analyze the role of NFR in small fiber neuropathy (SFN). METHODS We included 37 patients with DM and 20 healthy participants of similar age and sex. We performed the Composite Autonomic Neuropathy Scale-31, modified Toronto Neuropathy Scale, and routine nerve conduction studies. We grouped the patients into large fiber neuropathy (LFN), SFN, and no overt neurological symptom/sign groups. In all participants, NFR was recorded on anterior tibial (AT) and biceps femoris (BF) muscles after train stimuli on the sole of the foot, and NFR-RIII findings were compared. RESULTS We identified 11 patients with LFN, 15 with SFN, and 11 with no overt neurological symptoms or signs. The RIII response on the AT was absent in 22 (60%) patients with DM and 8 (40%) healthy participants. The RIII response on the BF was absent in 31 (73.8%) patients and 7 (35%) healthy participants (P = .001). In DM, the latency of RIII was prolonged, and the magnitude was reduced. Abnormal findings were seen in all subgroups; however, they were more prominent in patients with LFN compared to other groups. CONCLUSIONS The NFR-RIII was abnormal in patients with DM even before the emergence of the neuropathic symptoms. The pattern of involvement before neuropathic symptoms was possibly related to an earlier loss of A-delta fibers.
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Affiliation(s)
- Merve Hazal Ser
- Neurology Department, Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, Istanbul, Fatih 34098, Turkey
| | - Basak Yılmaz
- Neurology Department, Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, Istanbul, Fatih 34098, Turkey
| | - Cem Sulu
- Internal Medicine Department, Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, Istanbul, Fatih 34098, Turkey
| | - Mustafa Sait Gönen
- Internal Medicine Department, Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, Istanbul, Fatih 34098, Turkey
| | - Aysegul Gunduz
- Neurology Department, Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, Istanbul, Fatih 34098, Turkey
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Schaefer LV, Bittmann FN. Case report: Individualized pulsed electromagnetic field therapy in a Long COVID patient using the Adaptive Force as biomarker. Front Med (Lausanne) 2023; 9:879971. [PMID: 36714125 PMCID: PMC9874300 DOI: 10.3389/fmed.2022.879971] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023] Open
Abstract
The increasing prevalence of Long COVID is an imminent public health disaster, and established approaches have not provided adequate diagnostics or treatments. Recently, anesthetic blockade of the stellate ganglion was reported to improve Long COVID symptoms in a small case series, purportedly by "rebooting" the autonomic nervous system. Here, we present a novel diagnostic approach based on the Adaptive Force (AF), and report sustained positive outcome for one severely affected Long COVID patient using individualized pulsed electromagnetic field (PEMF) at the area C7/T1. AF reflects the capacity of the neuromuscular system to adapt adequately to external forces in an isometric holding manner. In case, maximal isometric AF (AFisomax) is exceeded, the muscle merges into eccentric muscle action. Thereby, the force usually increases further until maximal AF (AFmax) is reached. In case adaptation is optimal, AFisomax is ~99-100% of AFmax. This holding capacity (AFisomax) was found to be vulnerable to disruption by unpleasant stimulus and, hence, was regarded as functional parameter. AF was assessed by an objectified manual muscle test using a handheld device. Prior to treatment, AFisomax was considerably lower than AFmax for hip flexors (62 N = ~28% AFmax) and elbow flexors (71 N = ~44% AFmax); i.e., maximal holding capacity was significantly reduced, indicating dysfunctional motor control. We tested PEMF at C7/T1, identified a frequency that improved neuromuscular function, and applied it for ~15 min. Immediately post-treatment, AFisomax increased to ~210 N (~100% AFmax) at hip and 184 N (~100% AFmax) at elbow. Subjective Long COVID symptoms resolved the following day. At 4 weeks post-treatment, maximal holding capacity was still on a similarly high level as for immediately post-treatment (~100% AFmax) and patient was symptom-free. At 6 months the patient's Long COVID symptoms have not returned. This case report suggests (1) AF could be a promising diagnostic for post-infectious illness, (2) AF can be used to test effective treatments for post-infectious illness, and (3) individualized PEMF may resolve post-infectious symptoms.
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Affiliation(s)
- Laura V. Schaefer
- Regulative Physiology and Prevention, Department of Sports and Health Sciences, University Potsdam, Potsdam, Germany
- Practice of Integrative Medicine Bittmann, Potsdam, Germany
| | - Frank N. Bittmann
- Regulative Physiology and Prevention, Department of Sports and Health Sciences, University Potsdam, Potsdam, Germany
- Practice of Integrative Medicine Bittmann, Potsdam, Germany
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Franz S, Heutehaus L, Tappe-Theodor A, Weidner N, Treede RD, Schuh-Hofer S. Noxious radiant heat evokes bi-component nociceptive withdrawal reflexes in spinal cord injured humans-A clinical tool to study neuroplastic changes of spinal neural circuits. Front Hum Neurosci 2023; 17:1141690. [PMID: 37200949 PMCID: PMC10185789 DOI: 10.3389/fnhum.2023.1141690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 04/04/2023] [Indexed: 05/20/2023] Open
Abstract
Investigating nocifensive withdrawal reflexes as potential surrogate marker for the spinal excitation level may widen the understanding of maladaptive nociceptive processing after spinal cord injury (SCI). The aim of this prospective, explorative cross-sectional observational study was to investigate the response behavior of individuals with SCI to noxious radiant heat (laser) stimuli and to assess its relation to spasticity and neuropathic pain, two clinical consequences of spinal hyperexcitability/spinal disinhibition. Laser stimuli were applied at the sole and dorsum of the foot and below the fibula head. Corresponding reflexes were electromyography (EMG) recorded ipsilateral. Motor responses to laser stimuli were analyzed and related to clinical readouts (severity of injury/spasticity/pain), using established clinical assessment tools. Twenty-seven participants, 15 with SCI (age 18-63; 6.5 years post-injury; AIS-A through D) and 12 non-disabled controls, [non-disabled controls (NDC); age 19-63] were included. The percentage of individuals with SCI responding to stimuli (70-77%; p < 0.001), their response rates (16-21%; p < 0.05) and their reflex magnitude (p < 0.05) were significantly higher compared to NDC. SCI-related reflexes clustered in two time-windows, indicating involvement of both A-delta- and C-fibers. Spasticity was associated with facilitated reflexes in SCI (Kendall-tau-b p ≤ 0.05) and inversely associated with the occurrence/severity of neuropathic pain (Fisher's exact p < 0.05; Eta-coefficient p < 0.05). However, neuropathic pain was not related to reflex behavior. Altogether, we found a bi-component motor hyperresponsiveness of SCI to noxious heat, which correlated with spasticity, but not neuropathic pain. Laser-evoked withdrawal reflexes may become a suitable outcome parameter to explore maladaptive spinal circuitries in SCI and to assess the effect of targeted treatment strategies. Registration: https://drks.de/search/de/trial/DRKS00006779.
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Affiliation(s)
- Steffen Franz
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
- Steffen Franz,
| | - Laura Heutehaus
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Anke Tappe-Theodor
- Department of Molecular Pharmacology, Medical Faculty Heidelberg, Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Norbert Weidner
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Rolf-Detlef Treede
- Department of Neurophysiology, Mannheim Center for Translational Neuroscience, Medical Faculty Mannheim, Ruprecht-Karls-University of Heidelberg, Mannheim, Germany
| | - Sigrid Schuh-Hofer
- Department of Neurophysiology, Mannheim Center for Translational Neuroscience, Medical Faculty Mannheim, Ruprecht-Karls-University of Heidelberg, Mannheim, Germany
- Department of Neurology and Epileptology, University of Tübingen, Tübingen, Germany
- *Correspondence: Sigrid Schuh-Hofer,
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Abstract
Spasticity is characterized by an enhanced size and reduced threshold for activation of stretch reflexes and is associated with "positive signs" such as clonus and spasms, as well as "negative features" such as paresis and a loss of automatic postural responses. Spasticity develops over time after a lesion and can be associated with reduced speed of movement, cocontraction, abnormal synergies, and pain. Spasticity is caused by a combination of damage to descending tracts, reductions in inhibitory activity within spinal cord circuits, and adaptive changes within motoneurons. Increased tone, hypertonia, can also be caused by changes in passive stiffness due to, for example, increase in connective tissue and reduction in muscle fascicle length. Understanding the cause of hypertonia is important for determining the management strategy as nonneural, passive causes of stiffness will be more amenable to physical rather than pharmacological interventions. The management of spasticity is determined by the views and goals of the patient, family, and carers, which should be integral to the multidisciplinary assessment. An assessment, and treatment, of trigger factors such as infection and skin breakdown should be made especially in people with a recent change in tone. The choice of management strategies for an individual will vary depending on the severity of spasticity, the distribution of spasticity (i.e., whether it affects multiple muscle groups or is more prominent in one or two groups), the type of lesion, and the potential for recovery. Management options include physical therapy, oral agents; focal therapies such as botulinum injections; and peripheral nerve blocks. Intrathecal baclofen can lead to a reduction in required oral antispasticity medications. When spasticity is severe intrathecal phenol may be an option. Surgical interventions, largely used in the pediatric population, include muscle transfers and lengthening and selective dorsal root rhizotomy.
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Affiliation(s)
- Jonathan Marsden
- School of Health Professions, Faculty of Health, University of Plymouth, Plymouth, United Kingdom.
| | - Valerie Stevenson
- Department of Therapies and Rehabilitation, National Hospital for Neurology and Neurosurgery UCLH, London, United Kingdom
| | - Louise Jarrett
- Department of Neurology, Royal Devon and Exeter Hospital, Exeter, United Kingdom
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Dhondt E, Van Oosterwijck S, Van Branteghem T, Rhudy JL, Danneels L, Van Oosterwijck J. Modulation of the nociceptive flexion reflex by conservative therapy in patients and healthy people: a systematic review and meta-analysis. Pain 2022; 163:1446-1463. [PMID: 34813517 DOI: 10.1097/j.pain.0000000000002499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 09/15/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT The nociceptive flexion reflex (NFR) is a spinally mediated withdrawal response and is used as an electrophysiological marker of descending modulation of spinal nociception. Chemical and pharmacological modulation of nociceptive neurotransmission at the spinal level has been evidenced by direct effects of neurotransmitters and pharmacological agents on the NFR. Largely unexplored are, however, the effects of nonpharmacological noninvasive conservative interventions on the NFR. Therefore, a systematic review and meta-analysis was performed and reported following the PRISMA guidelines to determine whether and to what extent spinal nociception measured through the assessment of the NFR is modulated by conservative therapy in patients and healthy individuals. Five electronic databases were searched to identify relevant articles. Retrieved articles were screened on eligibility using the predefined inclusion criteria. Risk of bias was investigated according to Version 2 of the Cochrane risk-of-bias assessment tool for randomized trials. The evidence synthesis for this review was conducted in accordance with the Grading of Recommendations Assessment, Development and Evaluation. Thirty-six articles were included. Meta-analyses provided low-quality evidence showing that conservative therapy decreases NFR area and NFR magnitude and moderate-quality evidence for increases in NFR latency. This suggests that conservative interventions can exert immediate central effects by activating descending inhibitory pathways to reduce spinal nociception. Such interventions may help prevent and treat chronic pain characterized by enhanced spinal nociception. Furthermore, given the responsiveness of the NFR to conservative interventions, the NFR assessment seems to be an appropriate tool in empirical evaluations of treatment strategies.PROSPERO registration number: CRD42020164495.
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Affiliation(s)
- Evy Dhondt
- Spine, Head and Pain Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Pain in Motion International Research Group
| | - Sophie Van Oosterwijck
- Spine, Head and Pain Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Pain in Motion International Research Group
- Research Foundation-Flanders (FWO), Brussels, Belgium
| | - Thomas Van Branteghem
- Spine, Head and Pain Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Jamie L Rhudy
- Department of Psychology, University of Tulsa, Tulsa, OK, United States
| | - Lieven Danneels
- Spine, Head and Pain Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Jessica Van Oosterwijck
- Spine, Head and Pain Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Pain in Motion International Research Group
- Research Foundation-Flanders (FWO), Brussels, Belgium
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Henrich MC, Steffen Frahm K, Coghill RC, Kæseler Andersen O. Spinal nociception is facilitated during cognitive distraction. Neuroscience 2022; 491:134-145. [DOI: 10.1016/j.neuroscience.2022.03.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 11/25/2022]
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Taniguchi T, Kinukawa TA, Takeuchi N, Sugiyama S, Nishihara M, Nishiwaki K, Inui K. A Minimally Invasive Method for Observing Wind-Up of Flexion Reflex in Humans: Comparison of Electrical and Magnetic Stimulation. Front Neurosci 2022; 16:837340. [PMID: 35281508 PMCID: PMC8904398 DOI: 10.3389/fnins.2022.837340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 01/25/2022] [Indexed: 11/21/2022] Open
Abstract
Wind-up like pain or temporal summation of pain is a phenomenon in which pain sensation is increased in a frequency-dependent manner by applying repeated noxious stimuli of uniform intensity. Temporal summation in humans has been studied by observing the increase in pain or flexion reflex by repetitive electrical or thermal stimulations. Nonetheless, because the measurement is accompanied by severe pain, a minimally invasive method is desirable. Gradual augmentation of flexion reflex and pain induced by repetitive stimulation of the sural nerve was observed using three stimulation methods—namely, bipolar electrical, magnetic, and monopolar electrical stimulation, with 11 healthy male subjects in each group. The effects of frequency, intensity, and number of repetitive stimuli on the increase in the magnitude of flexion reflex and pain rating were compared among the three methods. The reflex was measured using electromyography (EMG) from the short head of the biceps femoris. All three methods produced a frequency- and intensity-dependent progressive increase in reflex and pain; pain scores were significantly lower for magnetic and monopolar stimulations than for bipolar stimulation (P < 0.05). The slope of increase in the reflex was steep during the first 4–6 stimuli but became gentler thereafter. In the initial phase, an increase in the reflex during the time before signals of C-fibers arrived at the spinal cord was observed in experiments using high-frequency stimulation, suggesting that wind-up was caused by inputs of A-fibers without the involvement of C-fibers. Magnetic and monopolar stimulations are minimally invasive and useful methods for observing the wind-up of the flexion reflex in humans. Monopolar stimulation is convenient because it does not require special equipment. There is at least a partial mechanism underlying the wind-up of the flexion reflex that does not require C-fibers.
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Affiliation(s)
- Tomoya Taniguchi
- Department of Anesthesiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
- *Correspondence: Tomoya Taniguchi,
| | - Tomoaki Alex Kinukawa
- Department of Anesthesiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Nobuyuki Takeuchi
- Neuropsychiatric Department, Aichi Medical University, Nagakute, Japan
| | - Shunsuke Sugiyama
- Department of Psychiatry and Psychotherapy, Gifu University, Gifu, Japan
| | - Makoto Nishihara
- Multidisciplinary Pain Center, Aichi Medical University, Nagakute, Japan
| | - Kimitoshi Nishiwaki
- Department of Anesthesiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Koji Inui
- Department of Functioning and Disability, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Japan
- Department of Integrative Physiology, National Institute for Physiological Sciences, Okazaki, Japan
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Mühlemann S, Leandri M, Risberg ÅI, Spadavecchia C. Comparison of Threshold and Tolerance Nociceptive Withdrawal Reflexes in Horses. Animals (Basel) 2021; 11:ani11123380. [PMID: 34944157 PMCID: PMC8698093 DOI: 10.3390/ani11123380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/30/2022] Open
Abstract
Simple Summary Nociception is the physiological basis of the complex experience of pain. An established model for its quantification in equine studies is based on the nociceptive withdrawal reflex evoked by electrical stimulation of a sensory nerve. The reflex is recorded via electromyography and it is common to determine the threshold at which a nociceptive-specific reflex activity can be observed. In the present study, the classical methodology was expanded for a deeper understanding of the physiology of nociceptive reflexes in horses. First, for each individual horse, a threshold was determined as the minimal stimulation intensity able to evoke a nociceptive withdrawal reflex. Second, the stimulation intensity was stepwise increased up to tolerance, which was defined as the stimulus that is able to elicit the maximal tolerable behavioral reaction. The characteristics of the reflex activity on the electromyographic records were compared for threshold and tolerance stimulation intensities. At tolerance, the reflex became faster and wider than at threshold, indicating that either a spinal summation mechanism or the recruitment of faster sensory fibers occurs in response to high-intensity noxious stimuli. A novel endpoint (i.e., tolerance) can now be considered when applying the nociceptive withdrawal reflex model in equine studies. Abstract The nociceptive withdrawal reflex (NWR) is used to investigate nociception in horses. The NWR threshold is a classical model endpoint. The aims of this study were to determine NWR tolerance and to compare threshold and tolerance reflexes in horses. In 12 horses, the NWR was evoked through electrical stimulation of the digital nerve and recorded via electromyography from the deltoid. Behavioral reactions were scored from 0 to 5 (tolerance). First, the individual NWR threshold was defined, then stimulation intensity was increased to tolerance. The median NWR threshold was 7.0 mA, whereas NWR tolerance was 10.7 mA. Upon visual inspection of the records, two main reflex components R1 (median latency 44 ms) and R2 (median latency 81 ms) were identified at threshold. Increasing stimulation intensity to tolerance led to a significant increase in the amplitude and duration of R1 and R2, whereas their latency decreased. At tolerance, a single burst of early, high-amplitude reflex activity, with a median latency of 39 ms, was detected in 15 out of 23 stimulations (65%). The results of this study suggest that (1) it is feasible to determine NWR tolerance in horses and (2) high-intensity stimuli initiate ultrafast bursts of reflex activity, which is well known in practice and has now been quantified using the NWR model.
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Affiliation(s)
- Selina Mühlemann
- Department of Clinical Veterinary Medicine, Anaesthesia Section, Vetsuisse Faculty Bern, 3012 Bern, Switzerland;
| | - Massimo Leandri
- Department of Neuroscience, University of Genova, 16132 Genova, Italy;
| | - Åse Ingvild Risberg
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway;
| | - Claudia Spadavecchia
- Department of Clinical Veterinary Medicine, Anaesthesia Section, Vetsuisse Faculty Bern, 3012 Bern, Switzerland;
- Correspondence: ; Tel.: +41-31-684-29-57
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Henrich MC, Frahm KS, Andersen OK. Spinal spatial integration of nociception and its functional role assessed via the nociceptive withdrawal reflex and psychophysical measures in healthy humans. Physiol Rep 2021; 8:e14648. [PMID: 33217191 PMCID: PMC7679129 DOI: 10.14814/phy2.14648] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 12/11/2022] Open
Abstract
Animal studies have previously shown that deep dorsal horn neurons play a role in the processing of spatial characteristics of nociceptive information in mammals. Human studies have supported the role of the spinal neurons; however, the mechanisms involved, and its significance, remain to be clarified. The aim of this study was to investigate spatial aspects of the spinal integration of concurrent nociceptive electrical stimuli in healthy humans using the Nociceptive Withdrawal Reflex (NWR) as an objective indication of spinal nociceptive processing. Fifteen healthy volunteers participated in the study. Electrical stimuli were delivered, using five electrodes located across the sole of the foot in a mediolateral disposition, as a single or double simultaneous stimuli with varying Inter-Electrode Distances (IEDs). The stimulation intensity was set at 1.5× NWR threshold (TA muscle). The size of the NWR was quantified in the 60-180 ms poststimulus window as a primary outcome measure. Psychophysical measures were secondary outcomes. Single stimulation elicited significantly smaller NWRs and perceived intensity than double stimulation (p < .01), suggesting the presence of spatial summation occurring within the spinal processing. During double stimulation, increasing the inter-electrode distance produced significantly smaller NWR sizes (p < .05) but larger pain intensity ratings (p < .05). By the NWR, spatial summation was shown to affect the nociceptive processing within the spinal cord. The inhibited motor response obtained when simultaneously stimulating the medial and lateral side of the sole of the foot suggests the presence of an inhibitory mechanism with a functional, behaviorally oriented function.
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Affiliation(s)
- Mauricio Carlos Henrich
- Integrative Neuroscience, Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg Ø, Denmark
| | - Ken Steffen Frahm
- Integrative Neuroscience, Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg Ø, Denmark
| | - Ole Kaeseler Andersen
- Integrative Neuroscience, Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg Ø, Denmark
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Linde LD, Bent LR, Dickey JP, Kumbhare DA, Srbely JZ. Exploring the effect of capsaicin-induced central sensitization on the upper limb nociceptive withdrawal reflex threshold. Exp Brain Res 2021; 239:3405-3415. [PMID: 34505162 DOI: 10.1007/s00221-021-06216-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 09/02/2021] [Indexed: 11/29/2022]
Abstract
The nociceptive withdrawal reflex (NWR) threshold is commonly employed in the lower limb to assess clinical and experimentally induced pain. However, no studies to date have investigated changes in spinal nociception in the upper limb, via the NWR threshold, following experimentally induced central sensitization (CS). We tested the hypothesis that experimentally induced CS of the C5-C6 spinal segment significantly reduces NWR thresholds in muscles of the upper limb. Upper limb NWR thresholds from 20 young, healthy adults were assessed by applying noxious electrical stimuli to the right index finger and recording muscle activity from the biceps brachii (BI), triceps brachii (TRI), flexor carpi ulnaris (WF), and extensor carpi radialis longus (WE) muscles via surface electromyography. Topical cream (either 0.075% capsaicin, or control) was applied to the C5-C6 dermatome of the lateral forearm (50 cm2). NWR thresholds were compared at baseline, and four 10-min intervals after topical application. WF muscle NWR thresholds were significantly reduced in the capsaicin session compared to control, while TRI muscle NWR thresholds were significantly reduced 40 min after capsaicin application only (p < 0.05). There were no significant differences for BI or WE muscle NWR thresholds. We observed poor to moderate test-retest reliability for all upper limb NWR thresholds, a key contributor to the selective reduction in NWR thresholds among muscles. Accordingly, while our findings demonstrate some comparability to previously reported lower limb NWR studies, we concurrently report limitations of the upper limb NWR technique. Further exploration of optimal parameters for upper limb NWR acquisition is needed.
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Affiliation(s)
- Lukas D Linde
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada. .,Department of Anesthesiology, Pharmacology & Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. .,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
| | - Leah R Bent
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - James P Dickey
- School of Kinesiology, Western University, London, ON, Canada
| | - Dinesh A Kumbhare
- Department of Medicine, Division of Physical Medicine and Rehabilitation, University of Toronto, Toronto, ON, Canada
| | - John Z Srbely
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
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Dech S, Bittmann FN, Schaefer LV. Assessment of the Adaptive Force of Elbow Extensors in Healthy Subjects Quantified by a Novel Pneumatically Driven Measurement System with Considerations of Its Quality Criteria. Diagnostics (Basel) 2021; 11:diagnostics11060923. [PMID: 34063869 PMCID: PMC8224031 DOI: 10.3390/diagnostics11060923] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/12/2021] [Accepted: 05/17/2021] [Indexed: 01/14/2023] Open
Abstract
Adaptive Force (AF) reflects the capability of the neuromuscular system to adapt adequately to external forces with the intention of maintaining a position or motion. One specific approach to assessing AF is to measure force and limb position during a pneumatically applied increasing external force. Through this method, the highest (AFmax), the maximal isometric (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax) can be determined. The main question of the study was whether the AFisomax is a specific and independent parameter of muscle function compared to other maximal forces. In 13 healthy subjects (9 male and 4 female), the maximal voluntary isometric contraction (pre- and post-MVIC), the three AF parameters and the MVIC with a prior concentric contraction (MVICpri-con) of the elbow extensors were measured 4 times on two days. Arithmetic mean (M) and maximal (Max) torques of all force types were analyzed. Regarding the reliability of the AF parameters between days, the mean changes were 0.31–1.98 Nm (0.61%–5.47%, p = 0.175–0.552), the standard errors of measurements (SEM) were 1.29–5.68 Nm (2.53%–15.70%) and the ICCs(3,1) = 0.896–0.996. M and Max of AFisomax, AFmax and pre-MVIC correlated highly (r = 0.85–0.98). The M and Max of AFisomax were significantly lower (6.12–14.93 Nm; p ≤ 0.001–0.009) and more variable between trials (coefficient of variation (CVs) ≥ 21.95%) compared to those of pre-MVIC and AFmax (CVs ≤ 5.4%). The results suggest the novel measuring procedure is suitable to reliably quantify the AF, whereby the presented measurement errors should be taken into consideration. The AFisomax seems to reflect its own strength capacity and should be detected separately. It is suggested its normalization to the MVIC or AFmax could serve as an indicator of a neuromuscular function.
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Dhondt E, Danneels L, Rijckaert J, Palmans T, Van Oosterwijck S, Van Oosterwijck J. Does muscular or mental fatigue have an influence on the nociceptive flexion reflex? A randomized cross-over study in healthy people. Eur J Pain 2021; 25:1508-1524. [PMID: 33721359 DOI: 10.1002/ejp.1763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 03/06/2021] [Indexed: 11/05/2022]
Abstract
BACKGROUND The nociceptive flexion reflex (NFR) is a spinally-mediated withdrawal reflex occurring in response to noxious stimuli and is used as an electrophysiological marker of spinal nociception. Although it is well-documented that the NFR is subject to powerful modulation of several personal factors, the effects of experimentally induced fatigue on the NFR have not yet been examined. Hence, this study aimed to characterize if and how fatigue affects spinal nociception in healthy adults. METHODS The NFR of 58 healthy people was measured prior to and following rest and two fatiguing tasks performed in randomized order. The NFR was elicited by transcutaneous electrical stimulation of the sural nerve and objectified by electromyographic recordings from the biceps femoris muscle. An isokinetic fatiguing protocol was used to induce localized muscle fatigue of the hamstrings. The modified incongruent Stroop-word task was used to provoke mental fatigue. A linear mixed model analysis was performed to assess the influence of fatigue on the NFR. RESULTS Low-to-moderate levels experimentally induced localized muscle and mental fatigue did not affect the NFR in healthy adults. These results suggest that descending pain inhibitory processes to dampen spinal nociception are resistant to the effects of localized muscle and mental fatigue. CONCLUSIONS The relative robustness of the NFR to fatigue may be beneficial in both clinical and research settings where the influence of confounders complicates interpretation. Furthermore, the findings possibly help enhance our understanding on why even demanding cognitive/physical exercise-based treatment programs form effective treatment strategies for patients with chronic pain. SIGNIFICANCE The present study unraveled that low-to-moderate levels experimentally induced localized muscle and mental fatigue did not affect the NFR. These results suggest that descending pain inhibitory processes to dampen spinal nociception are resistant to the effects of localized muscle and mental fatigue. This relative robustness of the NFR may be beneficial in a clinical setting in which the evaluation of spinal nociception that is unaffected by clinical symptoms of fatigue may be useful (e.g. chronic fatigue syndrome, cancer-related fatigue, etc.).
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Affiliation(s)
- Evy Dhondt
- SPINE Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.,Pain in Motion, International Research Group
| | - Lieven Danneels
- SPINE Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Johan Rijckaert
- SPINE Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.,Department of Audiology, Artevelde University College, Ghent, Belgium
| | - Tanneke Palmans
- SPINE Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Sophie Van Oosterwijck
- SPINE Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.,Pain in Motion, International Research Group.,Research Foundation - Flanders (FWO), Brussels, Belgium
| | - Jessica Van Oosterwijck
- SPINE Research Unit Ghent, Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.,Pain in Motion, International Research Group.,Research Foundation - Flanders (FWO), Brussels, Belgium
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Linde LD, Duarte FCK, Esmaeili H, Hamad A, Masani K, Kumbhare DA. The nociceptive flexion reflex: a scoping review and proposed standardized methodology for acquisition in those affected by chronic pain. Br J Pain 2021; 15:102-113. [PMID: 33633857 PMCID: PMC7882772 DOI: 10.1177/2049463720913289] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The nociceptive flexion reflex (NFR) is used in neurophysiological research as an objective measure of nociception. NFR thresholds are reduced in numerous chronic pain pathologies, which are indicative of common central hyperexcitability within conditions. However, variation exists in both the NFR assessment and determinants of NFR threshold among research groups. Our purpose was to provide a review of the recent literature to (a) confirm the NFR threshold's efficacy in identifying those with chronic pain compared to controls and (b) provide a narrative synthesis on the current methodology used to assess the NFR in clinical populations. We conducted a review of multiple databases (MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Google Scholar and Cochrane Library), including articles that reported controlled clinical studies of humans, in English, comparing NFR thresholds within chronic pain conditions to matched control subjects, published since the last NFR review in 2010. Our search resulted in nine studies included in our narrative synthesis and eight studies included in a meta-analysis. There was a significant pooled standardized mean difference in NFR threshold between chronic pain conditions and controls (-0.94, 95% confidence interval (CI) -1.33 to -0.55, p < 0.0001), with substantial heterogeneity of pooled estimates (I 2 = 87%, τ 2 = 0.41, Q = 76.13, the degrees of freedom (df) = 11, p < 0.0001). Significant variations in participant positioning, stimulation parameters and determinants of the NFR threshold were evident among included studies. We provided a narrative synthesis on the methodologies of included studies, as a recommendation for future studies in the assessment of the NFR in chronic pain.
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Affiliation(s)
- Lukas D Linde
- ICORD, University of British Columbia, Vancouver, British Columbia, Canada
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Felipe CK Duarte
- Division of Research and Innovation, Canadian Memorial Chiropractic College, Toronto, Ontario, Canada
| | - Hamid Esmaeili
- Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada
| | - Abdul Hamad
- Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, University of Toronto, Toronto, Ontario, Canada
| | - Kei Masani
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario, Canada
| | - Dinesh A Kumbhare
- Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, University of Toronto, Toronto, Ontario, Canada
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17
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Effects of Conditioned Pain Modulation on the Nociceptive Flexion Reflex in Healthy People: A Systematic Review. Clin J Pain 2020; 35:794-807. [PMID: 31268892 DOI: 10.1097/ajp.0000000000000724] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVES The nociceptive flexion reflex (NFR) is a spinal reflex induced by painful stimuli resulting in a withdrawal response. Research has shown that the NFR is inhibited through endogenous pain inhibitory mechanisms, which can be assessed by conditioned pain modulation (CPM) paradigms. Although accumulating research suggests that the NFR can be affected by CPM, no clear overview of the current evidence exists. Therefore, the present review aimed at providing such a synthesis of the literature. In addition, the influence of personal factors on the CPM of the NFR was investigated. MATERIALS AND METHODS A systematic review was performed and reported following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Five electronic databases were searched to identify relevant articles. Retrieved articles were screened on eligibility using predefined inclusion criteria. Risk of bias was investigated according to the modified Newcastle-Ottawa Scale. Levels of evidence and strength of conclusion were assigned following the guidelines of the Dutch Institute for Healthcare Improvement. RESULTS Forty articles were included. There is some evidence that CPM produced by thermal or mechanical stimuli induces inhibitory effects on the NFR. However, inconclusive evidence exists with regard to the effect of electrical conditioning stimuli. While several personal factors do not affect CPM of the NFR, increased cognitive interference is associated with reduced NFR inhibition. DISCUSSION The present review demonstrates that certain types of nociceptive conditioning stimuli have the potential to depress, at the spinal level, nociceptive stimuli elicited from distant body regions. Although CPM of the NFR seems to be robust to the influence of several personal factors, it can be affected by cognitive influences.
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18
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Siegenthaler J, Pleyers T, Raillard M, Spadavecchia C, Levionnois OL. Effect of Medetomidine, Dexmedetomidine, and Their Reversal with Atipamezole on the Nociceptive Withdrawal Reflex in Beagles. Animals (Basel) 2020; 10:E1240. [PMID: 32708294 PMCID: PMC7401557 DOI: 10.3390/ani10071240] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/17/2020] [Accepted: 07/17/2020] [Indexed: 11/16/2022] Open
Abstract
The objectives were: (1) to compare the antinociceptive activity of dexmedetomidine and medetomidine, and (2) to investigate its modulation by atipamezole. This prospective, randomized, blinded experimental trial was carried out on eight beagles. During the first session, dogs received either medetomidine (MED) (0.02 mg kg-1 intravenously (IV)] or dexmedetomidine (DEX) [0.01 mg kg-1 IV), followed by either atipamezole (ATI) (0.1 mg kg-1) or an equivalent volume of saline (SAL) administered intramuscularly 45 min later. The opposite treatments were administered in a second session 10-14 days later. The nociceptive withdrawal reflex (NWR) threshold was determined using a continuous tracking approach. Sedation was scored (0 to 21) every 10 min. Both drugs (MED and DEX) increased the NWR thresholds significantly up to 5.0 (3.7-5.9) and 4.4 (3.9-4.8) times the baseline (p = 0.547), at seven (3-11) and six (4-9) minutes (p = 0.938), respectively. Sedation scores were not different between MED and DEX during the first 45 min (15 (12-17), p = 0.67). Atipamezole antagonized sedation within 25 (15-25) minutes (p = 0.008) and antinociception within five (3-6) minutes (p = 0.008). Following atipamezole, additional analgesics may be needed to maintain pain relief.
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Affiliation(s)
- Joëlle Siegenthaler
- Section of Anaesthesiology and Pain Therapy, Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Berne, 3012 Bern, Switzerland; (J.S.); (T.P.); (M.R.); (C.S.)
| | - Tekla Pleyers
- Section of Anaesthesiology and Pain Therapy, Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Berne, 3012 Bern, Switzerland; (J.S.); (T.P.); (M.R.); (C.S.)
| | - Mathieu Raillard
- Section of Anaesthesiology and Pain Therapy, Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Berne, 3012 Bern, Switzerland; (J.S.); (T.P.); (M.R.); (C.S.)
- University Veterinary Teaching Hospital, School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney 2006, Australia
| | - Claudia Spadavecchia
- Section of Anaesthesiology and Pain Therapy, Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Berne, 3012 Bern, Switzerland; (J.S.); (T.P.); (M.R.); (C.S.)
| | - Olivier Louis Levionnois
- Section of Anaesthesiology and Pain Therapy, Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Berne, 3012 Bern, Switzerland; (J.S.); (T.P.); (M.R.); (C.S.)
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19
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Automated Nociceptive Withdrawal Reflex Measurements Reveal Normal Reflex Thresholds and Augmented Pain Ratings in Patients with Fibromyalgia. J Clin Med 2020; 9:jcm9061992. [PMID: 32630430 PMCID: PMC7356211 DOI: 10.3390/jcm9061992] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/11/2020] [Accepted: 06/22/2020] [Indexed: 12/27/2022] Open
Abstract
The nociceptive withdrawal reflex (NWR) is used to probe spinal cord excitability in chronic pain states. Here, we used an automated and unbiased procedure for determining the NWR threshold and compared the reflex thresholds and corresponding pain ratings in a well-characterized cohort of fibromyalgia (n = 29) and matched healthy controls (n = 21). Surface electrical stimuli were delivered to the foot in a stepwise incremental and decremental manner. The surface electromyographic activity was recorded from the ipsilateral tibialis anterior muscle. Fibromyalgia patients reported significantly higher scores for psychological distress and pain-related disability and a significantly lower score for perceived state of health compared to the matched controls. The subjective pain ratings were significantly higher in patients. The NWR thresholds were similar to the controls. In the patients, but not in controls, the NWR thresholds and subjective pain ratings were significantly correlated. Our results showed an increased subjective pain sensitivity in fibromyalgia, but we found no evidence for spinal sensitization based on the reflex measures.
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20
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Swash M, Burke D, Turner MR, Grosskreutz J, Leigh PN, deCarvalho M, Kiernan MC. Occasional essay: Upper motor neuron syndrome in amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 2020; 91:227-234. [PMID: 32054724 DOI: 10.1136/jnnp-2019-321938] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/17/2019] [Accepted: 10/24/2019] [Indexed: 11/04/2022]
Affiliation(s)
- Michael Swash
- Barts and the London School of Medicine, QMUL, Instituto de Medicina Molecular, Faculdade de Medicina, Univeridade de Lisboa, London, UK
| | - David Burke
- University of Sydney and Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Martin R Turner
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Julian Grosskreutz
- Universitätsklinikum Jena, Friedrich-Schiller-University Jena, Jena, Germany
| | - P Nigel Leigh
- Trafford Centre for Biomedical Research, Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, UK
| | - Mamede deCarvalho
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Univeridade de Lisboa, and Department of Neurosciences and Mental Health, Hospital de Santa Maria, Centro Hospitalar Universitário de Lisboa Norte, Lisbon, Portugal
| | - Matthew C Kiernan
- University of Sydney and Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.,Neurology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
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Callister RJ, Brichta AM, Schaefer AT, Graham BA, Stuart DG. Pioneers in CNS inhibition: 2. Charles Sherrington and John Eccles on inhibition in spinal and supraspinal structures. Brain Res 2019; 1734:146540. [PMID: 31704081 DOI: 10.1016/j.brainres.2019.146540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 10/29/2019] [Accepted: 11/01/2019] [Indexed: 12/27/2022]
Abstract
This article reviews the contributions of the English neurophysiologist, Charles Scott Sherrington [1857-1952], and his Australian PhD trainee and collaborator, John Carew Eccles [1903-1997], to the concept of central inhibition in the spinal cord and brain. Both were awarded Nobel Prizes; Sherrington in 1932 for "discoveries regarding the function of neurons," and Eccles in 1963 for "discoveries concerning the ionic mechanisms involved in excitation and inhibition in central portions of the nerve cell membrane." Both spoke about central inhibition at their Nobel Prize Award Ceremonies. The subsequent publications of their talks were entitled "Inhibition as a coordinative factor" and "The ionic mechanism of postsynaptic inhibition", respectively. Sherrington's work on central inhibition spanned 41 years (1893-1934), and for Eccles 49 years (1928-1977). Sherrington first studied central inhibition by observing hind limb muscle responses to electrical (peripheral nerve) and mechanical (muscle) stimulation. He used muscle length and force measurements until the early 1900s and electromyography in the late 1920s. Eccles used these techniques while working with Sherrington, but later employed extracellular microelectrode recording in the spinal cord followed in 1951 by intracellular recording from spinal motoneurons. This considerably advanced our understanding of central inhibition. Sherrington's health was poor during his retirement years but he nonetheless made a small number of largely humanities contributions up to 1951, one year before his death at the age of 94. In contrast, Eccles retained his health and vigor until 3 years before his death and published prolifically on many subjects during his 22 years of official retirement. His last neuroscience article appeared in 1994 when he was 91. Despite poor health he continued thinking about his life-long interest, the mind-brain problem, and was attempting to complete his autobiography in the last years of his life.
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Affiliation(s)
- Robert J Callister
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Newcastle, NSW 2308, Australia.
| | - Alan M Brichta
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Newcastle, NSW 2308, Australia.
| | - Andreas T Schaefer
- Neurophysiology of Behaviour Laboratory, The Francis Crick Institute, London, United Kingdom; Department of Neuroscience, Physiology & Pharmacology, University College, London, United Kingdom.
| | - Brett A Graham
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Newcastle, NSW 2308, Australia.
| | - Douglas G Stuart
- Department of Physiology, University of Arizona, PO Box 210093, Tucson, AZ 85721-0093, USA
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Jure FA, Arguissain FG, Biurrun Manresa JA, Andersen OK. Conditioned pain modulation affects the withdrawal reflex pattern to nociceptive stimulation in humans. Neuroscience 2019; 408:259-271. [DOI: 10.1016/j.neuroscience.2019.04.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/21/2019] [Accepted: 04/08/2019] [Indexed: 12/18/2022]
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23
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Long term reliability of nociceptive withdrawal reflex thresholds. J Neurosci Methods 2019; 320:44-49. [PMID: 30871985 DOI: 10.1016/j.jneumeth.2019.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 03/09/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND The nociceptive withdrawal reflex (NWR) is a polysynaptic spinal reflex protecting the body from harmful stimuli. Two different methods to assess its' threshold (NWR-T) have been part of clinical trials concerning the evaluation of the nociceptive system in the human body. NWR-T's are gathered by stimulation at the sole of the foot and over the sural pathway. Consequently, EMG analyzes the muscle activity over the biceps femoris and tibialis anterior muscle. Past studies favor stimulation at the sole of the foot. NEW METHOD The two methods were compared concerning retest-reliability and subjective pain ratings. The retest-reliability was tested over a period of 21 days using an up-down staircase method. Reliability was evaluated with a Bland Altman agreement analysis. Subjective pain ratings were evaluated with a numeric rating scale (NRS). RESULTS NWR-T assessment was successful for all subjects. The EMG muscle activity had larger reflex amplitudes for measurements of the tibialis anterior muscle. NWR-T values showed greater variability than NRS values. COMPARISON WITH EXISTING METHOD The retest-reliability over a period of 21 days showed stable NWR-T results for both stimulation sites, but superior reliability was gathered with stimulation at the sole of the foot. Subjects rated stimulation over the sural pathway as more painful. CONCLUSIONS The NWR-T upholds reliable measurements over a longer period of time and seems to be a stable measure for pain condition. Reliability estimations, EMG recordings, and subject's rating show stimulation at the sole of the foot could be the better choice.
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Nucera A, Azarpazhooh MR, Cardinali L, Alsubaie R, Chiang TC, Weishaupt N, Hachinski V. Inhibition of the primary motor cortex and the upgoing thumb sign. eNeurologicalSci 2017; 8:31-33. [PMID: 29260033 PMCID: PMC5730890 DOI: 10.1016/j.ensci.2017.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/18/2017] [Indexed: 11/29/2022] Open
Abstract
Background The upgoing thumb sign has been frequently observed in patients with minor strokes and transient ischemic attacks as an indicator of brain involvement. We assessed the effect of primary motor cortex (M1) inhibition in the development of the upgoing thumb sign. Methods Used repetitive Transcranial Magnetic Stimulation (rTMS, 1 Hz frequency for 15 min, 1s ISI, 900 pulses) at 60% of resting motor threshold to inhibit the right or left primary motor cortex of 10 healthy individuals. Participants were examined before and after rTMS by a neurologist who was blind to the site of motor cortex inhibition. Results 10 neurological intact participants (5 women/5 men) were recruited for this study. 2 cases were excluded due to pre-existing possible thumb signs. After the inhibition of the primary motor cortex, in 6 subjects out of 8, we observed a thumb sign contralateral to the site of primary motor cortex inhibition. In one subject an ipsilateral thumbs sign was noted. In another case, we did not find an upgoing thumb sign. Conclusion The upgoing thumb sign is a subtle neurological finding that may be related to the primary motor cortex or corticospinal pathways involvements. After the inhibition of the primary motor cortex, using repetitive Transcranial Magnetic Stimulation 9 (rTMS), in 7 subjects out of 8, the upgoing thumb sign was observed. The upgoing thumb sign is a subtle neurological finding related to the upper motor neuron involvements. The upgoing thumb sign may be seen in the primary motor cortex or corticospinal pathways lesions.
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Affiliation(s)
- Antonia Nucera
- Department of Clinical Neurological Science, University Hospital, University of Western Ontario, Ontario, Canada.,Department of Neurology, Saint Andrea Hospital, Stroke Unit, La Spezia, Italy
| | - Mahmoud Reza Azarpazhooh
- Department of Clinical Neurological Science, University Hospital, University of Western Ontario, Ontario, Canada.,Department of Epidemiology and Biostatistics, University of Western Ontario, Ontario, Canada.,Department of Neurology, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Lucilla Cardinali
- Department of Neurology, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Rasha Alsubaie
- Department of Clinical Neurological Science, University Hospital, University of Western Ontario, Ontario, Canada
| | - Tzu-Ching Chiang
- The Brain and Mind Institute, University of Western Ontario, Ontario, Canada
| | - Nina Weishaupt
- Department of Anatomy and Cell Biology, University of Western Ontario, Ontario, Canada
| | - Vladimir Hachinski
- Department of Clinical Neurological Science, University Hospital, University of Western Ontario, Ontario, Canada.,Department of Epidemiology and Biostatistics, University of Western Ontario, Ontario, Canada
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The Babinski Sign: A comprehensive review. J Neurol Sci 2017; 372:477-481. [DOI: 10.1016/j.jns.2016.10.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/21/2016] [Accepted: 10/25/2016] [Indexed: 11/23/2022]
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Risberg ÅI, Spadavecchia C, Ranheim B, Hendrickson EHS, Lervik A, Haga HA. Antinociceptive effect of buprenorphine and evaluation of the nociceptive withdrawal reflex in foals. Vet Anaesth Analg 2015; 42:329-38. [DOI: 10.1111/vaa.12205] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/02/2014] [Indexed: 11/30/2022]
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Dafkin C, Green A, Kerr S, Raymond A, Veliotes D, Elvin A, Olivier B, McKinon W. Kinematic and kinetic analysis of the inter- and intra-applicator assessment of the Babinski reflex. Neurophysiol Clin 2014; 44:471-7. [DOI: 10.1016/j.neucli.2014.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 10/24/2022] Open
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Peterson CL, Riley ZA, Krepkovich ET, Murray WM, Perreault EJ. Withdrawal reflexes in the upper limb adapt to arm posture and stimulus location. Muscle Nerve 2014; 49:716-23. [PMID: 23929755 DOI: 10.1002/mus.23987] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/29/2013] [Accepted: 07/31/2013] [Indexed: 11/09/2022]
Abstract
INTRODUCTION Withdrawal reflexes in the leg adapt in a context-appropriate manner to remove the limb from noxious stimuli, but the extent to which withdrawal reflexes adapt in the arm remains unknown. METHODS We examined the adaptability of withdrawal reflexes in response to nociceptive stimuli applied in different arm postures and to different digits. Reflexes were elicited at rest, and kinetic and electromyographic responses were recorded under isometric conditions, thereby allowing motorneuron pool excitability to be controlled. RESULTS Endpoint force changed from a posterior-lateral direction in a flexed posture to predominantly a posterior direction in a more extended posture [change in force angle (mean ± standard deviation) 35.6 ± 5.0°], and the force direction changed similarly with digit I stimulation compared with digit V (change = 22.9 ± 2.9°). CONCLUSIONS The withdrawal reflex in the human upper limb adapts in a functionally relevant manner when elicited at rest.
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Affiliation(s)
- Carrie L Peterson
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, 345 East Superior Street, Chicago, Illinois, 60611, USA; Edward Hines, Jr., VA Hospital, Hines, IL, USA
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Cornelissen L, Fabrizi L, Patten D, Worley A, Meek J, Boyd S, Slater R, Fitzgerald M. Postnatal temporal, spatial and modality tuning of nociceptive cutaneous flexion reflexes in human infants. PLoS One 2013; 8:e76470. [PMID: 24124564 PMCID: PMC3790695 DOI: 10.1371/journal.pone.0076470] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 08/28/2013] [Indexed: 12/22/2022] Open
Abstract
Cutaneous flexion reflexes are amongst the first behavioural responses to develop and are essential for the protection and survival of the newborn organism. Despite this, there has been no detailed, quantitative study of their maturation in human neonates. Here we use surface electromyographic (EMG) recording of biceps femoris activity in preterm (<37 weeks gestation, GA) and term (≥ 37 weeks GA) human infants, less than 14 days old, in response to tactile, punctate and clinically required skin-breaking lance stimulation of the heel. We show that all infants display a robust and long duration flexion reflex (>4 seconds) to a single noxious skin lance which decreases significantly with gestational age. This reflex is not restricted to the stimulated limb: heel lance evokes equal ipsilateral and contralateral reflexes in preterm and term infants. We further show that infant flexion withdrawal reflexes are not always nociceptive specific: in 29% of preterm infants, tactile stimulation evokes EMG activity that is indistinguishable from noxious stimulation. In 40% of term infants, tactile responses are also present but significantly smaller than nociceptive reflexes. Infant flexion reflexes are also evoked by application of calibrated punctate von Frey hairs (vFh), 0.8-17.2 g, to the heel. Von Frey hair thresholds increase significantly with gestational age and the magnitude of vFh evoked reflexes are significantly greater in preterm than term infants. Furthermore flexion reflexes in both groups are sensitized by repeated vFh stimulation. Thus human infant flexion reflexes differ in temporal, modality and spatial characteristics from those in adults. Reflex magnitude and tactile sensitivity decreases and nociceptive specificity and spatial organisation increases with gestational age. Strong, relatively non-specific, reflex sensitivity in early life may be important for driving postnatal activity dependent maturation of targeted spinal cord sensory circuits.
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Affiliation(s)
- Laura Cornelissen
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Lorenzo Fabrizi
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Deborah Patten
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Alan Worley
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children, London, United Kingdom
| | - Judith Meek
- Elizabeth Garrett Anderson Obstetric Wing, University College Hospital, London, United Kingdom
| | - Stewart Boyd
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children, London, United Kingdom
| | - Rebeccah Slater
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Maria Fitzgerald
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
- * E-mail:
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van Munster CEP, Weinstein HC, Uitdehaag BMJ, van Gijn J. The plantar reflex: additional value of stroking the lateral border of the foot to provoke an upgoing toe sign and the influence of experience. J Neurol 2012; 259:2424-8. [PMID: 22544298 DOI: 10.1007/s00415-012-6516-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 04/03/2012] [Accepted: 04/07/2012] [Indexed: 11/24/2022]
Abstract
The aim of this work was to determine the value of stroking the lateral dorsal border of the foot, in addition to stroking the sole in patients with a suspected pyramidal tract lesion. In addition, we studied the differences in interpretation between neurologists, residents, and medical students. We included subjects who had weakness of at least one leg and in whom a pyramidal tract lesion was suspected. After testing muscle power, tone, reflexes, and foot tapping, a decision on the presence of a pyramidal syndrome had to be made by each observer. After stimulating the sole as well as the lateral border of the foot, observers made a decision about the presence of a pyramidal syndrome again. Twenty-two legs of 18 patients were examined. Testing the plantar reflex (according to both methods) led to a change of opinion on the presence of a pyramidal syndrome in 45 of 69 (65 %) observations. On analysis according to level of experience, a change of opinion occurred in 19 (86 %) observations by medical students, 15 (65 %) by residents, and 11 (46 %) by neurologists. On eight occasions, the change was prompted by stimulation of the lateral border; in five of these cases the examiner (three medical students and two residents) found a new pathological response. Consecutively stroking the sole and the lateral border may be of added value, especially for less-experienced physicians. It seems that more-experienced physicians need fewer tests in the physical examination in order to identify a pyramidal syndrome of the leg.
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Affiliation(s)
- Caspar E P van Munster
- Department of Neurology, St Lucas Andreas Hospital, Jan Tooropstraat 146, 1006 AE, Amsterdam, The Netherlands.
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Dzheldubayeva ÉR, Chuyan EN, Bogdanova OV, Strizhak LA. Electroneuromyographic studies of pain sensitivity. NEUROPHYSIOLOGY+ 2009. [DOI: 10.1007/s11062-009-9091-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Mutha PK, Sainburg RL. Shared bimanual tasks elicit bimanual reflexes during movement. J Neurophysiol 2009; 102:3142-55. [PMID: 19793874 DOI: 10.1152/jn.91335.2008] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous research has suggested distinct predictive and reactive control mechanisms for bimanual movements compared with unimanual motion. Recent studies have extended these findings by demonstrating that movement corrections during bimanual movements might differ depending on whether or not the task is shared between the arms. We hypothesized that corrective responses during shared bimanual tasks recruit bilateral rapid feedback mechanisms such as reflexes. We tested this hypothesis by perturbing one arm as subjects performed uni- and bimanual movements. Movements were made in a virtual-reality environment in which hand position was displayed as a cursor on a screen. During bimanual motion, we provided cursor feedback either independently for each arm (independent-cursor) or such that one cursor was placed at the average location between the arms (shared-cursor). On random trials, we applied a 40 N force pulse to the right arm 100 ms after movement onset. Our results show that while reflex responses were rapidly elicited in the perturbed arm, electromyographic activity remained close to baseline levels in the unperturbed arm during the independent-cursor trials. In contrast, when the cursor was shared between the arms, reflex responses were reduced in the perturbed arm and were rapidly elicited in the unperturbed arm. Our results thus suggest that when both arms contribute to achieving the task goal, reflex responses are bilaterally elicited in response to unilateral perturbations. These results agree with and extend recent suggestions that bimanual feedback control might be modified depending on task context.
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Affiliation(s)
- Pratik K Mutha
- Department of Kinesiology, Pennsylvania State University, University Park, PA 16802, USA
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Rouaud T, Magot A, Guihéneuc P, Perrouin Verbe B, Truffert A, Péréon Y. Experimental study of a late response recorded from the thoracic wall after phrenic nerve stimulation. Clin Neurophysiol 2009; 120:1543-7. [PMID: 19577512 DOI: 10.1016/j.clinph.2009.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Revised: 06/03/2009] [Accepted: 06/06/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVES The phrenic nerve cervical stimulation induces an early motor diaphragmatic M response that may be recorded from the 7th ipsilateral intercostal space (ICS). Some responses with prolonged latency and of unclear origin can be recorded from the same recording site. The aim of the study was to determine the electrophysiological characteristics and the neuroanatomical pathways underlying the long-latency responses (LLRs) recorded from the 7th ICS. METHODS We studied seven healthy volunteers, five patients with spinal cord injury and five patients with diaphragmatic palsy. All underwent phrenic nerve conduction study. An LLR was sought for at different stimulation sites using various stimulus intensities. RESULTS A polyphasic LLR was recorded from the 7th ICS in all healthy subjects. It was mainly elicited by nociceptive stimulations, not only of the phrenic, but also of the median nerves. Its latency was longer than 70ms, with a wide inter- and intra-individual variability. Amplitude was highly variable and some habituation phenomenon occurred. The LLR was retained in most tetraplegic patients after phrenic nerve stimulation, but absent otherwise. It was present in all patients with diaphragmatic palsy after phrenic nerve stimulation. CONCLUSION The LLR is likely to be produced by both intercostal and diaphragm muscles. It is a polysynaptic and multisegmental spinal response, probably conveyed by small-diameter nociceptive A-delta and/or C fibres and modulated by a supraspinal control. SIGNIFICANCE The LLR recorded from the chest wall may constitute, by analogy with the nociceptive component of the lower limb flexion reflex in humans, a protective and withdrawal spinal reflex response.
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Affiliation(s)
- Tiphaine Rouaud
- CHU Nantes, Laboratoire d'Explorations Fonctionnelles, Nantes, France
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Ertekin C, Bademkiran F, Yalin S, Karapinar N, Uysal H. Withdrawal reflexes in adductor muscles elicited by electrical and magnetic stimulation of the obturator nerve. Muscle Nerve 2008; 38:1490-1497. [PMID: 18816621 DOI: 10.1002/mus.21101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The withdrawal reflex in the short head of the biceps femoris muscle after electrical stimulation of the sural nerve at the ankle has been investigated in numerous studies. These studies have described two distinct responses: early (R-II) and late (R-III). However, withdrawal reflex activity of the adductor muscles in the legs has not been studied systematically. Adductor muscle reflex activity is important because it can produce serious clinical problems, such as adductor spasticity and spasms, during bladder surgery. The present study examined withdrawal reflex features of adductor muscles obtained by electrical and magnetic stimulation of the obturator nerve (ON) in 34 normal healthy subjects. Early adductor muscle withdrawal reflex responses were elicited by ipsilateral ON electrical stimulation with a mean latency of 45.7+/-2.0 ms (responses in 94% of subjects). Reflex responses were also obtained using magnetic stimulation at a similar incidence rate. Contralateral ON electrical stimulation resulted in a similar reflex, but with a lower incidence. ON and femoral nerve electrical and magnetic coil stimulation produced similar low-incidence responses in the vastus medialis. These findings indicate that short latency adductor withdrawal reflexes are easily obtained on both sides following electrical or magnetic stimulation of the ON, and they can be elicited by both nociceptive and nonnociceptive stimuli. These reflexes prepare the body for a proper response to incoming signals and likely serve to protect the pelvic floor and pelvic organs.
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Affiliation(s)
- Cumhur Ertekin
- Ege University, Medical School Hospital, Department of Neurology and Neurophysiology, Bornova, Izmir, 35100, Turkey
| | - Fikret Bademkiran
- Ege University, Medical School Hospital, Department of Neurology and Neurophysiology, Bornova, Izmir, 35100, Turkey
| | - Sevket Yalin
- Ege University, Medical School Hospital, Department of Neurology and Neurophysiology, Bornova, Izmir, 35100, Turkey
| | - Nevin Karapinar
- Ege University, Medical School Hospital, Department of Neurology and Neurophysiology, Bornova, Izmir, 35100, Turkey
| | - Hilmi Uysal
- Akdeniz University, Medical School Hospital, Department of Neurology, Antalya, Turkey
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Don R, Pierelli F, Ranavolo A, Serrao M, Mangone M, Paoloni M, Cacchio A, Sandrini G, Santilli V. Modulation of spinal inhibitory reflex responses to cutaneous nociceptive stimuli during upper limb movement. Eur J Neurosci 2008; 28:559-68. [DOI: 10.1111/j.1460-9568.2008.06330.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
OBJECTIVES The treatment of neuropathic pain is mainly based on antiepileptics, tricyclic antidepressants, and opiates. These drugs have important side effects disturbing the patient's quality of life. Mirtazapine (MTZ) is a new and well-tolerated tricyclic antidepressants with both monoaminergic and opioid properties that might favorably influence pain. The aim of this study was to assess whether MTZ can reduce the pain induced by a standardized stimulus presented to healthy human participants. The nociceptive flexion reflex (NFR) to an electric stimulus was chosen to determine the pain threshold. METHODS The effect of MTZ compared to placebo was assessed on 10 healthy participants in a double-blinded cross-over design. The NFR was measured the day after a single oral dose of drug (30 mg) or placebo. RESULTS A significant increase in upper limb (+29%, P=0.006) NFR threshold was observed. DISCUSSION MTZ increases the pain tolerance in healthy participants. The potential benefit of this effect on pain should be investigated more thoroughly in chronic neuropathic pain patients. The NFR might serve as an additional tool for the monitoring of these patients.
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Edwards L, Ring C, France CR, al'Absi M, McIntyre D, Carroll D, Martin U. Nociceptive flexion reflex thresholds and pain during rest and computer game play in patients with hypertension and individuals at risk for hypertension. Biol Psychol 2007; 76:72-82. [PMID: 17686566 PMCID: PMC2042542 DOI: 10.1016/j.biopsycho.2007.06.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Revised: 06/21/2007] [Accepted: 06/24/2007] [Indexed: 10/23/2022]
Abstract
Supraspinal pain modulation may explain hypertensive hypoalgesia. We compared nociceptive flexion reflex (NFR) thresholds and pain during rest and computer game play in hypertensives and normotensives (Experiment 1) and normotensives with and without hypertensive parents (Experiment 2). The game was selected to modulate activity in pain pathways. NFR thresholds did not differ between groups during rest or game play. Pain ratings never differed between hypertensives and normotensives, whereas individuals with hypertensive parents reported less pain during the first two NFR assessments, compared to those without. NFR thresholds and pain were reduced by game play compared to rest. The failure of game play to differentially modulate NFR thresholds or associated pain reports between groups argues against enhanced supraspinal modulation of nociception and pain in hypertensives and those at increased risk for hypertension.
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Affiliation(s)
- Louisa Edwards
- International Centre for Health and Exercise Research, University of Birmingham, Birmingham B15 2TT, UK.
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Andersen OK. Studies of the organization of the human nociceptive withdrawal reflex. Focus on sensory convergence and stimulation site dependency. Acta Physiol (Oxf) 2007; 189 Suppl 654:1-35. [PMID: 17439638 DOI: 10.1111/j.1748-1716.2007.01706.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- O K Andersen
- Department of Health Science and Technology, Center for Sensory-Motor Interaction (SMI), Aalborg University, Denmark
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Spaich EG, Hinge HH, Arendt-Nielsen L, Andersen OK. Modulation of the withdrawal reflex during hemiplegic gait: effect of stimulation site and gait phase. Clin Neurophysiol 2006; 117:2482-95. [PMID: 16949341 DOI: 10.1016/j.clinph.2006.07.139] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 07/03/2006] [Accepted: 07/17/2006] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The objective of the study was to investigate the sensitivity of the nociceptive withdrawal reflex to stimulation of different locations on the sole of the foot during hemiplegic gait. METHODS Reflexes were evoked by cutaneous electrical stimulation of 4 locations on the sole of the foot of 7 hemiplegic and 6 age-matched healthy persons. The stimuli were delivered at heel-contact, during foot-flat, at heel-off, and during mid-swing. Reflexes were recorded from muscles of the stimulated and the contralateral leg. Ankle, knee, and hip joints angles were recorded using goniometers. RESULTS In the hemiplegic persons, the size of tibialis anterior reflexes, and the latency of soleus reflexes were site- and phase-modulated. In both groups, the tibialis anterior reflexes were significantly smaller with stimulation to the fifth metatarsophalangeal joint and the heel compared with the first metatarsophalangeal joint and the arch of the foot. The tibialis anterior reflexes evoked at heel-off and mid-swing were larger in hemiplegic persons than in healthy persons. Reflexes in the proximal and contralateral limb muscles were not site-modulated during hemiplegic gait. The kinematic response at the ankle joint was also different in the two groups during mid-swing. CONCLUSIONS Hemiplegic and healthy middle-aged people presented different phase-modulation of the kinematic and muscle nociceptive reflex responses evoked by stimulation delivered on the sole of the foot. SIGNIFICANCE The results have potential application in programs to rehabilitate hemiplegic gait.
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Affiliation(s)
- E G Spaich
- Center for Sensory-Motor Interaction (SMI), Aalborg University, Fredrik Bajers Vej 7-D3, DK-9220 Aalborg, Denmark.
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Bergadano A, Andersen OK, Arendt-Nielsen L, Schatzmann U, Spadavecchia C. Quantitative assessment of nociceptive processes in conscious dogs by use of the nociceptive withdrawal reflex. Am J Vet Res 2006; 67:882-9. [PMID: 16649925 DOI: 10.2460/ajvr.67.5.882] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the feasibility of evoking the nociceptive withdrawal reflex (NWR) from fore and hind limbs in conscious dogs, score stimulus-associated behavioral responses, and assess the canine NWR response to suprathreshold stimulations. ANIMALS 8 adult Beagles. PROCEDURE Surface electromyograms evoked by transcutaneous electrical stimulation of ulnaris and digital plantar nerves were recorded from the deltoideus, cleidobrachialis, biceps femoris, and tibialis cranialis muscles. Train-of-five pulses (stimulus(train)) were used; reflex threshold (I(t train)) was determined, and recruitment curves were obtained at 1.2, 1.5, and 2 x I(t train). Additionally, a single pulse (stimulus(single)) was given at 1, 1.2, 1.5, 2, and 3 x I(t train). Latency and amplitude of NWRs were analyzed. Severity of behavioral reactions was subjectively scored. RESULTS Fore- and hind limb I(t train) values (median; 25% to 75% interquartile range) were 2.5 mA (2.0 to 3.6 mA) and 2.1 mA (1.7 to 2.9 mA), respectively. At I(t train), NWR latencies in the deltoideus, cleidobrachialis, biceps femoris, and cranial tibialis muscles were not significantly different (19.6 milliseconds [17.1 to 20.5 milliseconds], 19.5 milliseconds [18.1 to 20.7 milliseconds], 20.5 milliseconds [14.7 to 26.4 milliseconds], and 24.4 milliseconds [17.1 to 40.5 milliseconds], respectively). Latencies obtained with stimulus(train) and stimulus(single) were similar. With increasing stimulation intensities, NWR amplitude increased and correlated positively with behavioral scores. CONCLUSIONS AND CLINICAL RELEVANCE In dogs, the NWR can be evoked from limbs and correlates with behavioral reactions. Results suggest that NWR evaluation may enable quantification of nociceptive system excitability and efficacy of analgesics in individual dogs.
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Affiliation(s)
- Alessandra Bergadano
- Department of Clinical Veterinary Medicine, Anaesthesiology Division, Vetsuisse-Faculty, University of Berne, Länggassstrasse 124, PB 8466, CH-3001 Berne, Switzerland
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Affiliation(s)
- Lars Arendt-Nielsen
- Center for Sensory-Motor Interaction, Laboratory for Experimental Pain Research, Aalborg University, DK-9220 Aalborg, Denmark.
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Sandrini G, Serrao M, Rossi P, Romaniello A, Cruccu G, Willer JC. The lower limb flexion reflex in humans. Prog Neurobiol 2005; 77:353-95. [PMID: 16386347 DOI: 10.1016/j.pneurobio.2005.11.003] [Citation(s) in RCA: 388] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 11/08/2005] [Accepted: 11/09/2005] [Indexed: 10/25/2022]
Abstract
The flexion or flexor reflex (FR) recorded in the lower limbs in humans (LLFR) is a widely investigated neurophysiological tool. It is a polysynaptic and multisegmental spinal response that produces a withdrawal of the stimulated limb and resembles (having several features in common) the hind-paw FR in animals. The FR, in both animals and humans, is mediated by a complex circuitry modulated at spinal and supraspinal level. At rest, the LLFR (usually obtained by stimulating the sural/tibial nerve and by recording from the biceps femoris/tibial anterior muscle) appears as a double burst composed of an early, inconstantly present component, called the RII reflex, and a late, larger and stable component, called the RIII reflex. Numerous studies have shown that the afferents mediating the RII reflex are conveyed by large-diameter, low-threshold, non-nociceptive A-beta fibers, and those mediating the RIII reflex by small-diameter, high-threshold nociceptive A-delta fibers. However, several afferents, including nociceptive and non-nociceptive fibers from skin and muscles, have been found to contribute to LLFR activation. Since the threshold of the RIII reflex has been shown to correspond to the pain threshold and the size of the reflex to be related to the level of pain perception, it has been suggested that the RIII reflex might constitute a useful tool to investigate pain processing at spinal and supraspinal level, pharmacological modulation and pathological pain conditions. As stated in EFNS guidelines, the RIII reflex is the most widely used of all the nociceptive reflexes, and appears to be the most reliable in the assessment of treatment efficacy. However, the RIII reflex use in the clinical evaluation of neuropathic pain is still limited. In addition to its nocifensive function, the LLFR seems to be linked to posture and locomotion. This may be explained by the fact that its neuronal circuitry, made up of a complex pool of interneurons, is interposed in motor control and, during movements, receives both peripheral afferents (flexion reflex afferents, FRAs) and descending commands, forming a multisensorial feedback mechanism and projecting the output to motoneurons. LLFR excitability, mediated by this complex circuitry, is finely modulated in a state- and phase-dependent manner, rather as we observe in the FR in animal models. Several studies have demonstrated that LLFR excitability may be influenced by numerous physiological conditions (menstrual cycle, stress, attention, sleep and so on) and pathological states (spinal lesions, spasticity, Wallenberg's syndrome, fibromyalgia, headaches and so on). Finally, the LLFR is modulated by several drugs and neurotransmitters. In summary, study of the LLFR in humans has proved to be an interesting functional window onto the spinal and supraspinal mechanisms of pain processing and onto the spinal neural control mechanisms operating during posture and locomotion.
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Affiliation(s)
- Giorgio Sandrini
- University Center for Adaptive Disorders and Headache, IRCCS C. Mondino Institute of Neurology Foundation, University of Pavia, Via Mondino 2, 27100 Pavia, Italy.
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Spadavecchia C, Arendt-Nielsen L, Andersen OK, Spadavecchia L, Schatzmann U. Effect of romifidine on the nociceptive withdrawal reflex and temporal summation in conscious horses. Am J Vet Res 2005; 66:1992-8. [PMID: 16334961 DOI: 10.2460/ajvr.2005.66.1992] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the action of a single IV administration of romifidine on the thresholds of the nociceptive withdrawal reflex (NWR) and temporal summation in conscious horses. ANIMALS 10 adult horses. PROCEDURE Single electrical stimulations were applied on the digital nerves to evoke NWR from the left forelimb and hind limb. Repeated electrical stimulations (10 stimuli, 5 Hz) were given to obtain temporal summation. Surface electromyographic reflex activity was recorded from the common digital extensor and cranial tibial muscles. After baseline assessment of NWR and temporal summation thresholds, romifidine (80 microg x kg(-1), IV) was administered. Successive determinations of NWR and temporal summation thresholds were performed 5, 25, and 55 minutes after administration. RESULTS Romifidine significantly increased the current intensities necessary to evoke NWR and temporal summation in forelimbs and hind limbs of horses. Values were significantly higher than baseline values 55 minutes after romifidine administration. After administration of romifidine, a facilitation of reflex components of tactile origin was observed when repeated stimulations were applied. CONCLUSIONS AND CLINICAL RELEVANCE Results confirm antinociceptive activity of romifidine and may represent an objective demonstration of the well-known hypersensitivity to tactile stimuli observed in horses receiving alpha2-adrenoreceptor agonists in clinical practice. Romifidine can be included in analgesic and anesthetic protocols to provide additional analgesia in horses.
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Affiliation(s)
- Claudia Spadavecchia
- Anesthesiology Section, Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Berne, Switzerland
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Andersen OK, Finnerup NB, Spaich EG, Jensen TS, Arendt-Nielsen L. Expansion of nociceptive withdrawal reflex receptive fields in spinal cord injured humans. Clin Neurophysiol 2005; 115:2798-810. [PMID: 15546788 DOI: 10.1016/j.clinph.2004.07.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2004] [Indexed: 11/26/2022]
Abstract
OBJECTIVE In spinal cord injured (SCI) subjects, exaggerated withdrawal reflexes associated with a dominant flexor pattern irrespective of stimulation site have been reported. In the present study, withdrawal reflex receptive field (RRF) was determined in complete SCI subjects (N=9). METHODS Distributed electrical stimulation was applied to the sole of the foot, and reflexes in tibialis anterior, soleus, biceps femoris, and vastus lateralis muscles were recorded together with knee and ankle movement trajectories. A group of spinally intact subjects (N=10) were included as controls. With the subjects in supine position, stimulation was applied to 10 different sites on the foot sole. Based on the tibialis anterior reflex threshold for stimulation on the mid foot sole, two stimulus intensities (1.1 times the reflex threshold and 1.4 times the reflex threshold) were used for all 10 sites. RESULTS In SCI subjects, dorsi-flexion dominated independent of stimulus site and the tibialis anterior RRF covered the entire foot sole in contrast to a well-defined tibialis anterior receptive field at the medial, distal foot sole in the spinally intact subjects. Further, the soleus RRF also covered the entire sole in the SCI subjects. The reflexes in biceps femoris and vastus lateralis muscles were small and associated with weak knee flexion at all 10 sites in the SCI subjects and in the controls. CONCLUSIONS The RRF of the ankle flexor and the ankle extensor muscles both covered the entire sole of the foot indicating an expansion of the RRFs following spinal cord injury. The expansion is most likely due to lack of descending inhibitory control and/or increased sensitivity of the spinal reflex loop in the SCI subjects. SIGNIFICANCE The study improves the understanding of spinal reflex control in spinal intact and spinal cord injured subjects.
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Affiliation(s)
- Ole K Andersen
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7, D3, Aalborg DK-9220, Denmark.
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Spadavecchia C, Andersen OK, Arendt-Nielsen L, Spadavecchia L, Doherr M, Schatzmann U. Investigation of the facilitation of the nociceptive withdrawal reflex evoked by repeated transcutaneous electrical stimulations as a measure of temporal summation in conscious horses. Am J Vet Res 2004; 65:901-8. [PMID: 15281647 DOI: 10.2460/ajvr.2004.65.901] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate whether facilitation of the nociceptive withdrawal reflex (NWR) can be evoked and quantified as a measure of temporal summation from the distal aspect of the left forelimb and hind limb in standing nonsedated horses via repeated stimulations of various subthreshold intensities and frequencies. ANIMALS 10 adult horses. PROCEDURE Surface electromyographic activity evoked by stimulation of the digital palmar and plantar nerves was recorded from the common digital extensor and cranial tibial muscles. For each horse, the NWR threshold intensity to a single stimulus was determined for the forelimb and hind limb. Repeated stimulations were performed at subthreshold intensities and at frequencies of 2, 5, and 10 Hz. The reflex amplitude was quantified, and the behavioral responses accompanying the stimulations were scored. RESULTS Repeated stimulations at subthreshold intensities were able to summate and facilitate the NWR in conscious horses. The reflex facilitation was significantly related to the intensity of the repeated stimuli, whereas no effect of stimulation frequency was found. Reaction scores increased significantly for increasing stimulation intensities. CONCLUSIONS AND CLINICAL RELEVANCE Temporal summation obtained by repeated stimulations of subthreshold intensity appears to represent a new tool for investigating nociceptive pathophysiologic processes in horses; this experimental model may be useful to examine the mode of action and efficacy of analgesic and anesthetic interventions and possibly to assess sensory dysfunction in clinical settings.
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Affiliation(s)
- Claudia Spadavecchia
- Anesthesiology Section, Department of Clinical Veterinary Sciences, University of Berne, Langassstrasse 124, 3012 Berne, Switzerland
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Spaich EG, Arendt-Nielsen L, Andersen OK. Modulation of lower limb withdrawal reflexes during gait: a topographical study. J Neurophysiol 2004; 91:258-66. [PMID: 12968008 DOI: 10.1152/jn.00360.2003] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to investigate the modulation and topography of the nociceptive withdrawal reflex elicited by painful electrical stimulation of the foot sole during gait. Fifteen healthy volunteers participated in this study. Cutaneous electrical stimulation was delivered on five locations of the foot sole after heel-contact, during foot-flat, after heel-off, and during the mid-swing phase of the gait cycle during treadmill walking. Reflexes were recorded from muscles of the ipsilateral and contralateral legs. Furthermore, the kinematic responses in the sagittal plane of the ipsilateral ankle, knee, and hip joints were recorded. Reflexes in the distal muscles showed a site-dependent modulation. The largest responses in tibialis anterior were evoked at the arch of the foot and the smallest at the heel (P < 0.05). The largest soleus responses were also elicited at the arch of the foot (P < 0.04). The EMG responses in flexors and extensors of the knee and extensors of the contralateral leg were generally not dependent on the stimulation site. The response at the three joints showed site dependency, especially during the swing phase where maximal flexion was obtained by stimulation at the arch of the foot (P < 0.05). The withdrawal reflex was modulated during the gait cycle and presented distinctive characteristics for the different muscles studied. Minimal kinematic responses were observed during stance in contrast to swing phase. Modulation of the reflex probably ensures an appropriate withdrawal but primarily secures balance and continuity of movement.
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Affiliation(s)
- Erika G Spaich
- Center for Sensory-Motor Interaction, Aalborg University, Fredrik Bajers Vej 7-D3, DK-9220 Aalborg, Denmark.
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Andersen OK, Sonnenborg F, Matjacić Z, Arendt-Nielsen L. Foot-sole reflex receptive fields for human withdrawal reflexes in symmetrical standing position. Exp Brain Res 2003; 152:434-43. [PMID: 12904932 DOI: 10.1007/s00221-003-1550-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2003] [Accepted: 05/09/2003] [Indexed: 10/26/2022]
Abstract
Human withdrawal-reflex receptive fields were assessed in 10 healthy subjects during standing with even support on both legs. Two electrical-stimulus intensities (1.2 and 2.2 times the pain threshold, PTh) were used. The painful stimuli were delivered in random order to 12 positions distributed over the foot sole. Tibialis anterior (TA), soleus (SO), vastus lateralis (VL), semitendinosus (ST), and iliopsoas (IL) reflexes were recorded. Further, the vertical force was recorded and the center or pressure (CoP) was assessed in the frontal and sagittal planes on both legs. Reflexes were observed at both intensities with the strongest reflexes at the high intensity. Around the ankle joint, SO reflexes dominated, which is in contrast to previous observations for subjects sitting. An unloading of the limb was found on the stimulated leg associated with a simultaneous loading of the contralateral leg. The shift in load was most pronounced for stimulation of the heel. The flexors ST and IL also had strong reflexes with reflex patterns correlated to the pattern of unloading. The shift in vertical force was accomplished by a move of the CoP in the anterior direction on the stimulated limb (contraction of SO), which simultaneously caused a small movement of the CoP in the lateral direction. In the present standing conditions, the ankle extensor played a dominant role in the withdrawal pattern in contrast to previous studies during sitting, relaxed conditions.
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Affiliation(s)
- Ole K Andersen
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7, D3 9220 Aalborg, Denmark.
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Dimitrova A, Kolb FP, Elles HG, Maschke M, Forsting M, Diener HC, Timmann D. Cerebellar responses evoked by nociceptive leg withdrawal reflex as revealed by event-related FMRI. J Neurophysiol 2003; 90:1877-86. [PMID: 12702705 DOI: 10.1152/jn.00053.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of the present study was to examine nociceptive leg withdrawal reflex-related areas in the human cerebellum using event-related functional brain imaging (fMRI). Knowledge about cerebellar areas involved in unconditioned limb withdrawal reflex control has some relevance in understanding data of limb withdrawal reflex conditioning studies. Sixteen healthy adult subjects participated. Nociceptive leg withdrawal reflexes were evoked by electrical stimulation of the left tibial nerve behind the medial malleolus. An event-related fMRI paradigm was applied with a total of 30 stimuli being delivered pseudorandomly during 500 consecutive MR scans. Surface electromyographic (EMG) recordings were performed from the left anterior tibial muscle. Only trials with significant reflex EMG activity were used as active events in fMRI statistical analysis. The specified contrasts compared the active event condition with rest. Leg withdrawal reflex-related areas were located within the vermis, paravermis, and lateral posterior cerebellar hemispheres bilaterally. Vermal and paravermal areas in lobules III/IV in the anterior lobe and in lobule VIII in the posterior lobe agree with the cerebellar representation of climbing and mossy fiber hindlimb afferents and voluntary leg movements. They are likely related to efferent modulation of the leg withdrawal reflex and/or sensory processing of afferent inputs from the reflex and/or the noxious stimulus. Additional activation within vermal lobule VI and hemispheral lobules VI/Crus I may be related to other pain-related processes (e.g., facial grimacing, fear, and startlelike reactions).
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Affiliation(s)
- A Dimitrova
- Department of Neurology, University of Essen, 45122 Essen, Germany
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Spadavecchia C, Arendt-Nielsen L, Andersen OK, Spadavecchia L, Doherr M, Schatzmann U. Comparison of nociceptive withdrawal reflexes and recruitment curves between the forelimbs and hind limbs in conscious horses. Am J Vet Res 2003; 64:700-7. [PMID: 12828255 DOI: 10.2460/ajvr.2003.64.700] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare nociceptive withdrawal reflexes (NWRs) evoked from the distal aspect of the left forelimb and hind limb in conscious standing horses and to investigate NWR recruitment for graded electrical stimulation intensities. ANIMALS 20 adult horses. PROCEDURE Surface electromyographic (EMG) activity evoked by transcutaneous electrical stimulation of the digital palmar (or plantar) nerve was recorded from the common digital extensor and cranial tibial muscles. Stimuli consisted of 25-millisecond train-of-5 constant current pulses. Current intensity was gradually increased until NWR threshold intensity was reached. The EMG signal was analyzed for quantification of the NWR. Behavioral responses accompanying the reflex were scored (scale, 0 to 5). The NWR recruitment curves were determined at 0.9, 1.1, 1.2, and 1.3 times the NWR threshold intensity. RESULTS The NWR threshold was significantly higher for the hind limb (median value, 6.6 mA; range, 3 to 10 mA) than the forelimb (median, 3 mA; range, 1.7 to 5.5 mA). The NWR of the hind limb had a significantly longer latency (median, 122.8 milliseconds; range, 106 to 172 milliseconds), compared with the forelimb (median, 98 milliseconds; range, 86 to 137 milliseconds), and it was associated with significantly stronger behavioral reactions. Gradual increase of NWR amplitude was evident at increasing stimulation intensities and supported by the behavioral observations. CONCLUSIONS AND CLINICAL RELEVANCE We documented NWRs evoked from the forelimb and hind limb and their recruitment with stimuli of increasing intensity in horses. These results provide a basis for use of NWRs in studies on nociceptive modulation in horses.
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Desmeules JA, Cedraschi C, Rapiti E, Baumgartner E, Finckh A, Cohen P, Dayer P, Vischer TL. Neurophysiologic evidence for a central sensitization in patients with fibromyalgia. ARTHRITIS AND RHEUMATISM 2003; 48:1420-9. [PMID: 12746916 DOI: 10.1002/art.10893] [Citation(s) in RCA: 397] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To determine whether abnormalities of peripheral and central nociceptive sensory input processing exist outside areas of spontaneous pain in patients with fibromyalgia (FM) as compared with controls, by using quantitative sensory testing (QST) and a neurophysiologic paradigm independent from subjective reports. METHODS A total of 164 outpatients with FM who were attending a self-management program were invited to participate in the study. Data for 85 patients were available and were compared with those for 40 non-FM controls matched for age and sex. QST was performed using thermal, mechanical, and electrical stimuli at locations of nonspontaneous pain. Pain assessment was 2-fold and included use of subjective scales and the spinal nociceptive flexion reflex (NFR), a specific physiologic correlate for the objective evaluation of central nociceptive pathways. Questionnaires regarding quality of life and the impact of FM were available. RESULTS Participants were mainly middle-aged women, with a mean disease duration of 8 years. Between-group differences were significant for neurophysiologic, clinical, and quality of life measures. In patients with FM, peripheral QST showed significantly altered cold and heat pain thresholds, and tolerance to cold pain was radically reduced. The median NFR threshold in patients with FM (22.7 mA [range 17.5-31.7]) was significantly decreased compared with that in controls (33 mA [range 28.1-41]). A cutoff value of <27.6 mA for NFR provided sensitivity of 73% and specificity of 80% for detecting central allodynia in the setting of FM. CONCLUSION Our results strongly, although indirectly, point to a state of central hyperexcitability of the nociceptive system in patients with FM. The NFR can be used to assess central allodynia in FM. It may also help discriminate patients who may benefit from use of centrally acting analgesics.
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