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Antoine JC. Inflammatory sensory neuronopathies. Rev Neurol (Paris) 2024:S0035-3787(24)00455-7. [PMID: 38472032 DOI: 10.1016/j.neurol.2023.12.012] [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: 07/24/2023] [Revised: 12/15/2023] [Accepted: 12/22/2023] [Indexed: 03/14/2024]
Abstract
Inflammatory sensory neuronopathies are rare disorders mediated by dysimmune mechanisms targeting sensory neurons in the dorsal root ganglia. They constitute a heterogeneous group of disorders with acute, subacute, or chronic courses, and occur with cancer, systemic autoimmune diseases, notably Sjögren syndrome, and viral infections but a noticeable proportion of them remains isolated. Identifying inflammatory sensory neuronopathies is crucial because they have the potential to be stabilized or even to improve with immunomodulatory or immunosuppressant treatments provided that the treatment is applied at an early stage of the disease, before a definitive degeneration of neurons. Biomarkers, and notably antibodies, are crucial for this early identification, which is the first step to develop therapeutic trials.
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Affiliation(s)
- J-C Antoine
- Department of Neurology, University Hospital of Saint-Etienne, 42055 Saint-Étienne cedex, France.
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Corneal Sub-Basal Nerve Plexus in Non-Diabetic Small Fiber Polyneuropathies and the Diagnostic Role of In Vivo Corneal Confocal Microscopy. J Clin Med 2023; 12:jcm12020664. [PMID: 36675593 PMCID: PMC9862881 DOI: 10.3390/jcm12020664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/24/2022] [Accepted: 01/07/2023] [Indexed: 01/18/2023] Open
Abstract
In vivo corneal confocal microscopy (IVCM) allows the immediate analysis of the corneal nerve quantity and morphology. This method became, an indispensable tool for the tropism examination, as it evaluates the small fiber plexus in the cornea. The IVCM provides us with direct information on the health of the sub-basal nerve plexus and indirectly on the peripheral nerve status. It is an important tool used to investigate peripheral polyneuropathies. Small-fiber neuropathy (SFN) is a group of neurological disorders characterized by neuropathic pain symptoms and autonomic complaints due to the selective involvement of thinly myelinated Aδ-fibers and unmyelinated C-fibers. Accurate diagnosis of SFN is important as it provides a basis for etiological work-up and treatment decisions. The diagnosis of SFN is sometimes challenging as the clinical picture can be difficult to interpret and standard electromyography is normal. In cases of suspected SFN, measurement of intraepidermal nerve fiber density through a skin biopsy and/or analysis of quantitative sensory testing can enable diagnosis. The purpose of the present review is to summarize the current knowledge about corneal nerves in different SFN. Specifically, we explore the correlation between nerve density and morphology and type of SFN, disease duration, and follow-up. We will discuss the relationship between cataracts and refractive surgery and iatrogenic dry eye disease. Furthermore, these new paradigms in SFN present an opportunity for neurologists and clinical specialists in the diagnosis and monitoring the peripheral small fiber polyneuropathies.
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Antoine JC. Sensory neuronopathies, diagnostic criteria and causes. Curr Opin Neurol 2022; 35:553-561. [PMID: 35950727 DOI: 10.1097/wco.0000000000001105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW To stress on the diagnostic strategy of sensory neuronopathies (SNN), including new genes and antibodies. RECENT FINDING SNN involve paraneoplastic, dysimmune, toxic, viral and genetic mechanisms. About one-third remains idiopathic. Recently, new antibodies and genes have reduced this proportion. Anti-FGFR3 and anti-AGO antibodies are not specific of SNN, although SNN is predominant and may occur with systemic autoimmune diseases. These antibodies are the only marker of an underlying dysimmune context in two-thirds (anti-FGFR3 antibodies) and one-third of the cases (anti-AGO antibodies), respectively. Patients with anti-AGO antibodies may improve with treatment, which is less clear with anti-FGFR3 antibodies. A biallelic expansion in the RFC1 gene is responsible for the cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) in which SNN is a predominant manifestation. Most of the patients have an adult onset and are sporadic. The RFC1 mutation may represent one-third of idiopathic sensory neuropathies. Finally, the criteria for the diagnosis of paraneoplastic SNN have recently been updated. SUMMARY The diagnostic of SNN relies on criteria distinguishing SNN from other neuropathies. The strategy in search of their cause now needs to include these recent findings.
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Affiliation(s)
- Jean-Christophe Antoine
- University Hospital of Saint-Etienne, European Reference Network for Rare Diseases- Euro-NMD, INSERM U1314/CNRS UMR 5284, Université Claude Bernard Lyon 1, Lyon, France
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Electrodiagnostic Testing of Small Fiber Neuropathies: A Review of Existing Guidelines. J Clin Neurophysiol 2020; 37:288-293. [PMID: 33151659 DOI: 10.1097/wnp.0000000000000681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
This article reviews the literature on neurophysiological techniques for the diagnosis of small fiber neuropathy. The review is focused on clinical approach to suspected small fiber neuropathy, letting aside techniques whose clinical applicability is doubtful. We include, however, the special techniques required to examine C and Aδ fibers, which cannot be evaluated directly with conventional neurophysiological methods. The most relevant publications are summarized and recommendations for the clinical assessment of small fiber neuropathy are provided.
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Abstract
Clinical neurophysiologic investigation of pain pathways in humans is based on specific techniques and approaches, since conventional methods of nerve conduction studies and somatosensory evoked potentials do not explore these pathways. The proposed techniques use various types of painful stimuli (thermal, laser, mechanical, or electrical) and various types of assessments (measurement of sensory thresholds, study of nerve fiber excitability, or recording of electromyographic reflexes or cortical potentials). The two main tests used in clinical practice are quantitative sensory testing and pain-related evoked potentials (PREPs). In particular, PREPs offer the possibility of an objective assessment of nociceptive pathways. Three types of PREPs can be distinguished depending on the type of stimulation used to evoke pain: laser-evoked potentials, contact heat evoked potentials, and intraepidermal electrical stimulation evoked potentials (IEEPs). These three techniques investigate both small-diameter peripheral nociceptive afferents (mainly Aδ nerve fibers) and spinothalamic tracts without theoretically being able to differentiate the level of lesion in the case of abnormal results. In routine clinical practice, PREP recording is a reliable method of investigation for objectifying the existence of a peripheral or central lesion or loss of function concerning the nociceptive pathways, but not the existence of pain. Other methods, such as nerve fiber excitability studies using microneurography, more directly reflect the activities of nociceptive axons in response to provoked pain, but without detecting or quantifying the presence of spontaneous pain. These methods are more often used in research or experimental study design. Thus, it should be kept in mind that most of the results of neurophysiologic investigation performed in clinical practice assess small fiber or spinothalamic tract lesions rather than the neuronal mechanisms directly at the origin of pain and they do not provide objective quantification of pain.
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Affiliation(s)
- Jean-Pascal Lefaucheur
- Excitabilité Nerveuse et Thérapeutique, Faculté de Médecine de Créteil, Université Paris-Est-Créteil, Hôpital Henri Mondor, Créteil, France; Service de Physiologie-Explorations Fonctionnelles, Hôpital Henri Mondor, Créteil, France.
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Bocci T, De Carolis G, Paroli M, Barloscio D, Parenti L, Tollapi L, Valeriani M, Sartucci F. Neurophysiological Comparison Among Tonic, High Frequency, and Burst Spinal Cord Stimulation: Novel Insights Into Spinal and Brain Mechanisms of Action. Neuromodulation 2018; 21:480-488. [PMID: 29314454 DOI: 10.1111/ner.12747] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/16/2017] [Accepted: 10/27/2017] [Indexed: 12/15/2022]
Abstract
RATIONALE Spinal cord stimulation (SCS) is an effective option for neuropathic pain treatment. New technological developments, as high-frequency (HF) and theta burst stimulation (TBS), have shown promising results, although putative mechanisms of action still remain debated. METHODS thirty patients with lower back pain were enrolled and underwent LF, HF, and TBS. Laser evoked potentials (LEPs) were recorded by using a Nd:YAG laser. Amplitudes and latencies of the main two components (N1, N2/P2) were compared among different experimental sessions. Changes in resting motor threshold (RMT), cortical silent period (cSP), short intracortical inhibition (SICI), and intracortical facilitation (ICF) were also evaluated. RESULTS TBS dampened LEP amplitudes compared with LF (N1: p = 0.032; N2/P2: p < 0.0001) and HF stimulation (N1: p = 0.029; N2/P2: p < 0.0001, Holm-Sidak post-hoc test). Concurrently, TBS increased N1 latency, when compared with baseline and LF stimulation (p = 0.009 and 0.0033). Whereas RMT and SICI did not change among experimental conditions, TBS significantly prolonged cSP duration compared with baseline (p = 0.002), LF (p = 0.048), and HF-SCS (p = 0.016); finally, both HF (p = 0.004) and TBS (p = 0.0039) increased ICF. CONCLUSION TBS modulates medial and lateral pain pathways through distinct mechanisms, possibly involving both GABA(a)ergic and Glutamatergic networks at an intracortical level. These results may have implications for therapy and for the choice of best stimulation protocol.
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Affiliation(s)
- Tommaso Bocci
- Department of Clinical and Experimental Medicine, Section of Neurophysiopathology, Pisa University Medical School, Pisa, Italy.,Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
| | | | - Mery Paroli
- Pain Therapy Unit, Azienda Ospedaliera Universitaria Pisana, Pisa, Italy
| | - Davide Barloscio
- Department of Clinical and Experimental Medicine, Section of Neurophysiopathology, Pisa University Medical School, Pisa, Italy
| | - Laura Parenti
- Department of Clinical and Experimental Medicine, Section of Neurophysiopathology, Pisa University Medical School, Pisa, Italy
| | - Lara Tollapi
- Pain Therapy Unit, Azienda Ospedaliera Universitaria Pisana, Pisa, Italy
| | - Massimiliano Valeriani
- Division of Neurology, Ospedale Bambino Gesù, IRCCS, Rome, Italy.,Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark
| | - Ferdinando Sartucci
- Department of Clinical and Experimental Medicine, Section of Neurophysiopathology, Pisa University Medical School, Pisa, Italy.,Neuroscience Institute, National Research Council Pisa, Pisa, Italy
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Bocci T, Santarcangelo E, Vannini B, Torzini A, Carli G, Ferrucci R, Priori A, Valeriani M, Sartucci F. Cerebellar direct current stimulation modulates pain perception in humans. Restor Neurol Neurosci 2016; 33:597-609. [PMID: 25777683 DOI: 10.3233/rnn-140453] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE The cerebellum is involved in a wide number of integrative functions, but its role in pain experience and in the nociceptive information processing is poorly understood. In healthy volunteers we evaluated the effects of transcranial cerebellar direct current stimulation (tcDCS) by studying the changes in the perceptive threshold, pain intensity at given stimulation intensities (VAS:0-10) and laser evoked potentials (LEPs) variables (N1 and N2/P2 amplitudes and latencies). METHODS Fifteen subjects were studied before and after anodal, cathodal and sham tcDCS. LEPs were obtained using a neodymium:yttrium-aluminium-perovskite (Nd:YAP) laser and recorded from the dorsum of the left hand. VAS was evaluated by delivering laser pulses at two different intensities, respectively two and three times the perceptive threshold. RESULTS Cathodal polarization dampened significantly the perceptive threshold and increased the VAS score, while the anodal one had opposite effects. Cathodal tcDCS increased significantly the N1 and N2/P2 amplitudes and decreased their latencies, whereas anodal tcDCS elicited opposite effects. Motor thresholds assessed through transcranial magnetic stimulation were not affected by cerebellar stimulation. CONCLUSIONS tcDCS modulates pain perception and its cortical correlates. Since it is effective on both N1 and N2/P2 components, we speculate that the cerebellum engagement in pain processing modulates the activity of both somatosensory and cingulate cortices. Present findings prompt investigation of the cerebellar direct current polarization as a possible novel and safe therapeutic tool in chronic pain patients.
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Affiliation(s)
- Tommaso Bocci
- Department of Clinical and Experimental Medicine, Unit of Neurology, Pisa University Medical School, Pisa, Italy.,Department of Medical and Surgical Sciences and Neuroscience, University of Siena, Siena, Italy
| | - Enrica Santarcangelo
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Beatrice Vannini
- Department of Clinical and Experimental Medicine, Unit of Neurology, Pisa University Medical School, Pisa, Italy
| | - Antonio Torzini
- Department of Medical and Surgical Sciences and Neuroscience, University of Siena, Siena, Italy.,Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
| | - Giancarlo Carli
- Department of Medical and Surgical Sciences and Neuroscience, University of Siena, Siena, Italy
| | - Roberta Ferrucci
- Department of Neurological Sciences, University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Alberto Priori
- Department of Neurological Sciences, University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Massimiliano Valeriani
- Division of Neurology, Ospedale Bambino Gesù, IRCCS, Rome, Italy.,Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark
| | - Ferdinando Sartucci
- Department of Clinical and Experimental Medicine, Unit of Neurology, Pisa University Medical School, Pisa, Italy.,Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
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Lefaucheur JP, Wahab A, Planté-Bordeneuve V, Sène D, Ménard-Lefaucheur I, Rouie D, Tebbal D, Salhi H, Créange A, Zouari H, Ng Wing Tin S. Diagnosis of small fiber neuropathy: A comparative study of five neurophysiological tests. Neurophysiol Clin 2015; 45:445-55. [DOI: 10.1016/j.neucli.2015.09.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 09/13/2015] [Accepted: 09/14/2015] [Indexed: 01/13/2023] Open
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Neuropathies douloureuses et atteinte des petites fibres. Rev Neurol (Paris) 2014; 170:825-36. [DOI: 10.1016/j.neurol.2014.10.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 10/10/2014] [Indexed: 12/16/2022]
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Sène D, Cacoub P, Authier FJ, Haroche J, Créange A, Saadoun D, Amoura Z, Guillausseau PJ, Lefaucheur JP. Sjögren Syndrome-Associated Small Fiber Neuropathy: Characterization From a Prospective Series of 40 Cases. Medicine (Baltimore) 2013; 92:e10-e18. [PMID: 23982054 PMCID: PMC4553978 DOI: 10.1097/md.0000000000000005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We conducted the current study to analyze the clinical, immunologic, and neurophysiologic features of primary Sjögren syndrome (pSS)-associated sensory small fiber neuropathies (SFNs). Forty consecutive pSS patients with SFN were included. SFN was defined by the presence of suggestive sensory painful symptoms with normal nerve conduction studies and abnormal neurophysiologic tests for small nerve fibers or a low intraepidermal nerve fiber density at skin biopsy. Included patients were compared to 100 pSS patients without peripheral neuropathy.SFN patients were mainly female (92.5%). Age at pSS diagnosis was 55.3 ± 13.1 years, and at SFN diagnosis, 58.9 ± 11.8 years, with a median time to SFN diagnosis after symptom onset of 3.4 years. Clinical symptoms included burning pains (90%), numbness (87.5%), tingling (82.5%), pins and needles (72.5%), electric discharges (70%), and allodynia (55%). Dysautonomia included vasomotor symptoms (66%) and hyperhidrosis (47%). Abnormal neurophysiologic tests included laser evoked potentials (97.5%), thermal quantitative sensory testing (67.5%), and sympathetic skin reflex (40%). A skin biopsy revealed low intraepidermal nerve fiber density in 76% of the 17 tested patients.Compared to the 100 pSS patients without peripheral neuropathy, the 40 pSS-SFN patients were older at pSS diagnosis (55.3 ± 13.1 vs. 49.5 ± 14.9 yr; p = 0.03), and more often had xerostomia (97.5% vs. 81%; p = 0.01) and arthralgia (82.5% vs. 65.0%; p = 0.04). Immunologically, they were characterized by a lower prevalence of serum B-cell activation markers, that is, antinuclear antibodies (65% vs. 85%; p = 0.01), anti-SSA (42.5% vs. 71%; p = 0.002), and anti-SSB (17.5% vs. 39%; p = 0.017); rheumatoid factor (32.5% vs. 66%; p = 0.0005); and hypergammaglobulinemia (35% vs. 62%; p = 0.005).In conclusion, we report the main features of SFN in patients with pSS, the first such study to our knowledge. Our results show that patients with pSS-associated SFN are characterized by an older age at pSS diagnosis and a distinctive immunologic profile hallmarked by a lower frequency of serum B-cell activation markers.
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Affiliation(s)
- Damien Sène
- From the Service de Médecine Interne 2, AP-HP, Hôpital Lariboisière, Université Paris Diderot-Paris 7, Paris (D. Sène, PJG); Service de Médecine Interne 2, AP-HP, Hôpital Pitié-Salpêtrière, Paris, Université, Pierre et Marie Curie-Paris 6, Paris (PC, JH, D. Saadoun, ZA); Centre de Référence des Maladies Neuromusculaire Garches-Necker-Mondor-Hendaye, AP-HP, Hôpital Henri Mondor; INSERM U955, Equipe 10, Université Paris Est-Créteil, Créteil (FJA); and Service de Neurologie (AC) and Service de Physiologie-Explorations Fonctionnelles (JPL), APHP, Hôpital Henri Mondor,Créteil, Université Paris Est-Créteil, Créteil; France
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Maarrawi J, Mertens P, Peyron R, Garcia-Larrea L, Sindou M. Functional exploration for neuropathic pain. Adv Tech Stand Neurosurg 2011:25-63. [PMID: 21997740 DOI: 10.1007/978-3-7091-0673-0_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Neuropathic pain (NP) may become refractory to conservative medical management, necessitating neurosurgical procedures in carefully selected cases. In this context, the functional neurosurgeon must have suitable knowledge of the disease he or she intends to treat, especially its pathophysiology. This latter factor has been studied thanks to advances in the functional exploration of NP, which will be detailed in this review. The study of the flexion reflex is a useful tool for clinical and pharmacological pain assessment and for exploring the mechanisms of pain at multiple levels. The main use of evoked potentials is to confirm clinical, or detect subclinical, dysfunction in peripheral and central somato-sensory pain pathways. LEP and SEP techniques are especially useful when used in combination, allowing the exploration of both pain and somato-sensory pathways. PET scans and fMRI documented rCBF increases to noxious stimuli. In patients with chronic NP, a decreased resting rCBF is observed in the contralateral thalamus, which may be reversed using analgesic procedures. Abnormal pain evoked by innocuous stimuli (allodynia) has been associated with amplification of the thalamic, insular and SII responses, concomitant to a paradoxical CBF decrease in ACC. Multiple PET studies showed that endogenous opioid secretion is very likely to occur as a reaction to pain. In addition, brain opioid receptors (OR) remain relatively untouched in peripheral NP, while a loss of ORs is most likely to occur in central NP, within the medial nociceptive pathways. PET receptor studies have also proved that antalgic Motor Cortex Stimulation (MCS), indicated in severe refractory NP, induces endogenous opioid secretion in key areas of the endogenous opioid system, which may explain one of the mechanisms of action of this procedure, since the secretion is proportional to the analgesic effect.
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Affiliation(s)
- J Maarrawi
- (Faculty of Medicine) and Hôtel-Dieu de France Hospital (Department of Neurosurgery), St Joseph University, Beirut, Lebanon
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Neuropathies sensitives des petites fibres : intérêt des potentiels évoqués laser. Rev Neurol (Paris) 2011; 167:40-5. [DOI: 10.1016/j.neurol.2010.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 07/28/2010] [Accepted: 08/27/2010] [Indexed: 11/19/2022]
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Sène D, Authier FJ, Amoura Z, Cacoub P, Lefaucheur JP. Neuropathie des petites fibres : approche diagnostique et traitement, et place de son association au syndrome de Gougerot-Sjögren primaire. Rev Med Interne 2010; 31:677-84. [DOI: 10.1016/j.revmed.2010.07.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 06/28/2010] [Accepted: 07/28/2010] [Indexed: 12/18/2022]
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Lefaucheur JP, Jarry G, Drouot X, Ménard-Lefaucheur I, Keravel Y, Nguyen JP. Motor cortex rTMS reduces acute pain provoked by laser stimulation in patients with chronic neuropathic pain. Clin Neurophysiol 2010; 121:895-901. [DOI: 10.1016/j.clinph.2009.12.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 12/08/2009] [Accepted: 12/09/2009] [Indexed: 10/19/2022]
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Perchet C, Godinho F, Mazza S, Frot M, Legrain V, Magnin M, Garcia-Larrea L. Evoked potentials to nociceptive stimuli delivered by CO2 or Nd:YAP lasers. Clin Neurophysiol 2008; 119:2615-22. [DOI: 10.1016/j.clinph.2008.06.021] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 06/26/2008] [Accepted: 06/29/2008] [Indexed: 10/21/2022]
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Wydenkeller S, Wirz R, Halder P. Spinothalamic tract conduction velocity estimated using contact heat evoked potentials: What needs to be considered. Clin Neurophysiol 2008; 119:812-21. [DOI: 10.1016/j.clinph.2007.12.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 10/11/2007] [Accepted: 12/08/2007] [Indexed: 11/27/2022]
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Mauguière F, Fischer C, André-Obadia N. Potenziali evocati in neurologia: risposte patologiche e indicazioni. Neurologia 2007. [DOI: 10.1016/s1634-7072(07)70547-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Quante M, Hauck M, Gromoll M, Hille E, Lorenz J. Dermatomal laser-evoked potentials: a diagnostic approach to the dorsal root. Norm data in healthy volunteers and changes in patients with radiculopathy. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2006; 16:943-52. [PMID: 17103230 PMCID: PMC2219653 DOI: 10.1007/s00586-006-0253-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 09/06/2006] [Accepted: 10/21/2006] [Indexed: 10/23/2022]
Abstract
We conducted a cross-sectional study of 40 radiculopathy patients in comparison with norm data from healthy subjects using a new electrophysiological method. Early manifestations of dorsal root impairment escape objective diagnosis by conventional somatosensory-evoked potentials due to the overlapping innervation of the affected dermatome by thickly myelinated mechanoreceptive afferents projecting to adjacent intact roots. Evidence suggested less intersegmental overlap for thermonociceptive afferents rendering laser-evoked potentials (LEP) sensitive to monosegmental dorsal root damage. Therefore we used this new method to study acute manifestations of monosegmental dorsal root pathology. Dorsal root function was tested in 12 healthy subjects and 40 sciatica patients by intraindividual interside comparison. Mechanosensibility and thermosensibility were clinically investigated. LEP were induced by moderately painful laser stimuli. The LEP were evaluated by amplitude and latency of the averaged electroencephalogram. Normal interside differences of LEP for amplitude were +/-22% (lower limb) and +/-35% (upper limb) and +/-15 to +/-16% for latency. Twenty-six patients (65%) showed significant LEP changes, mainly amplitude decreases. Six of these patients exhibited latency prolongations. Clinical testing yielded more frequent pathological results for pain compared to mechanosensibility. The study confirmed our preliminary evidence of LEP sensitivity to objectively document dorsal root impairment in patients suffering from acute monosegmental radiculopathy. This result opens the perspective of electrophysiologically differentiating the presence or absence of dorsal root pathology in patients with similar clinical symptoms but possibly different prognoses, which require different therapies.
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Affiliation(s)
- Markus Quante
- Department of Orthopaedics and Rheumatology, University Hospital Giessen and Marburg, Marburg, Germany.
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Leandri M, Saturno M, Spadavecchia L, Iannetti GD, Cruccu G, Truini A. Measurement of skin temperature after infrared laser stimulation. Neurophysiol Clin 2006; 36:207-18. [PMID: 17095410 DOI: 10.1016/j.neucli.2006.08.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Accepted: 07/17/2006] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES Several types of lasers are available for eliciting laser evoked responses (LEPs). In order to understand advantages and drawbacks of each one, and to use it properly, it is important that the pattern of skin heating is known and duly considered. This study was aimed at assessing the skin temperature during and immediately after irradiation with pulses by Nd:YAP and CO(2) lasers. MATERIALS AND METHODS The back of the non-dominant hand was irradiated in 8 subjects. Temperatures were measured by a fast analogical pyrometer (5 ms response time). Stimuli were tested on natural colour (white) and blackened skin. RESULTS Nd:YAP pulses yielded temperatures that were correlated with pulse energy, but not with pulse duration; much higher temperatures were obtained irradiating blackened skin than white skin (ranges 100-194 degrees C vs 35-46 degrees C). Temperature decay was extremely slow in white skin, reaching its basal value in more than 30 s. CO(2) pulses delivered with power of 3W and 6W yielded temperatures of 69-87 degrees C on white skin, and 138-226 degrees C on blackened skin. Temperature decay was very fast (4-8 ms). CONCLUSIONS Differences in peak temperatures and decay times between lasers and tested conditions depend on energy and volume of heated skin. The highest temperatures are reached with lesser degree of penetration, as in the case of CO(2) laser and blackened skin. Taking into account the temperature decay time of the skin, the minimum interstimulus interval to get reliable LEPs should be no less than 10 s for Nd:YAP and 100 ms for CO(2) laser. Another important practical consequence of the heating pattern is that the Nd:YAP pulses will activate warmth receptors more easily than CO(2).
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Affiliation(s)
- M Leandri
- Interuniversity Centre for Pain Neurophysiology, University of Genova, via Dodecaneso 35, 16146 Genova, Italy
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Stojkovic T. Les neuropathies périphériques : orientations et moyens diagnostiques. Rev Med Interne 2006; 27:302-12. [PMID: 16517027 DOI: 10.1016/j.revmed.2005.10.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2005] [Accepted: 10/24/2005] [Indexed: 01/11/2023]
Abstract
PURPOSES Neuropathies are defined as dysfunction of peripheral nerves, which may show motor, sensory and autonomic symptoms. Although most neuropathies are symmetric, it is important to distinguish a polyneuropathy from a mononeuropathy, a multiple mononeuropathy or a polyradiculoneuropathy. Electrophysiological procedures are helpful in determining the pathological process which may be either an axonopathy, a myelinopathy or a neuronopathy. MAIN POINTS Major progresses have been made in the ten past years in the management and diagnostic approaches of peripheral neuropathy. The history and the physical examination are the first steps to the evaluation of patients with peripheral neuropathy. Electrodiagnostic studies and then laboratory tests are the next step in the diagnostic procedures of peripheral neuropathies. These will lead to a proper identification of the cause of neuropathy, allowing to develop a specific treatment for the patient. However, even after a careful work-up of a patient with neuropathy, 25 to 40% of patients with polyneuropathies remain undiagnosed. PERSPECTIVES Further development are focused in better understanding the pathogenesis and molecular mechanisms of peripheral nerve diseases in order to provide a specific and adequate treatment for each neuropathy.
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Affiliation(s)
- T Stojkovic
- Clinique Neurologique, Service du Professeur Vermersch, Hôpital Roger-Salengro, CHRU de Lille, 59037 Lille cedex, France.
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Garcia-Larrea L. Chapter 30 Evoked potentials in the assessment of pain. HANDBOOK OF CLINICAL NEUROLOGY 2006; 81:439-XI. [PMID: 18808852 DOI: 10.1016/s0072-9752(06)80034-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Abstract
INTRODUCTION Peripheral neuropathies usually include a sensory component of various causes. The diagnosis approach requires careful a clinical assessment and a precise electrophysiological exploration. STATE OF ART Axonal sensory polyneuropathies are classified according to the type of fibers involved (large or small fibers). While there is a large number of causes, current emphasis is placed on glucose intolerance as a source of small-fiber sensory neuropathies. Demyelinating polyneuropathies are often associated with a monoclonal IgM gammapathy with anti-MAG activity. Multiple sensory mononeuropathies are exceptional and suggest possible early-phase vasculities, sensorymotor neuropathy with conduction blocks or leprosy. Sensory neuronopathies can also suggest Sjögren's syndrome or a paraneoplastic syndrome. Finally chronic sensory polyradiculoneuritis constitute a rare subgroup clearly defined as demyelinating inflammatory neuropathy. CONCLUSION The diagnostic approach to sensory neuropathies requires careful nosological electroclinical classification to reduce the number of explorations performed for etiological diagnosis.
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Affiliation(s)
- A Créange
- Service de Neurologie, INSERM E0011, Faculté de Médecine, Créteil, France.
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Lefaucheur JP, Créange A. Neurophysiological testing correlates with clinical examination according to fibre type involvement and severity in sensory neuropathy. J Neurol Neurosurg Psychiatry 2004; 75:417-22. [PMID: 14966158 PMCID: PMC1738954 DOI: 10.1136/jnnp.2003.019208] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To investigate a comprehensive battery of neurophysiological tests for objective evaluation of sensory neuropathies including fibre type involvement and severity, and to determine the relation between neurophysiological data and clinical examination. METHODS 45 patients referred for sensory neuropathy were studied using a standardised clinical evaluation of large and small fibre symptoms and an original neurophysiological battery. Clinical evaluation included: assessment of tactile, vibratory, and pin sensation; tendon reflexes; toe position sense; ataxia score; pain level; and presence of trophic, vasomotor, or sudomotor abnormalities. The neurophysiological battery included: recording of large fibre and small fibre components of the sural sensory nerve action potential; somatosensory evoked cortical potentials and soleus H reflex following tibial nerve electrical stimulation; laser evoked potentials following Nd:YAG laser stimulation of the foot; and plantar sympathetic skin response to median nerve stimulation. Neuropathy was classified according to the predominantly affected fibre type, and a severity score was established based on clinical and neurophysiological abnormalities. RESULTS On clinical examination there were 22 patients with large fibre sensory neuropathy (LFSN), 18 with mixed sensory neuropathy (MSN), and five with small fibre sensory neuropathy (SFSN). Neurophysiological classification identified 25 patients with LFSN, 13 with MSN, and seven with SFSN. Clinical and neurophysiological classifications and severity scores were correlated, whatever the type of neuropathy. CONCLUSIONS The correlation between clinical examination and the results of an original neurophysiological test battery offers a comprehensive clinical and neurophysiological approach to the objective assessment of peripheral neuropathies according to fibre type involvement and overall severity.
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Affiliation(s)
- J-P Lefaucheur
- INSERM E00.11, Hôpital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Créteil, France.
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Cruccu G, García-Larrea L. Chapter 12 Clinical utility of pain - laser evoked potentials. ADVANCES IN CLINICAL NEUROPHYSIOLOGY, PROCEEDINGS OF THE 27TH INTERNATIONAL CONGRESS OF CLINICAL NEUROPHYSIOLOGY, AAEM 50TH ANNIVERSARY AND 57TH ANNUAL MEETING OF THE ACNS JOINT MEETING 2004; 57:101-10. [PMID: 16106611 DOI: 10.1016/s1567-424x(09)70348-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Affiliation(s)
- G Cruccu
- Department of Neurological Sciences, La Sapienza University, Viale Università 20, 00185 Rome, Italy.
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