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Pietro GD, Stefano GD, Leone C, Lionardo AD, Sgrò E, Blockeel AJ, Caspani O, Garcia-Larrea L, Mouraux A, Phillips KG, Treede RD, Valeriani M, Truini A. The N13 spinal component of somatosensory evoked potentials is modulated by heterotopic noxious conditioning stimulation suggesting an involvement of spinal wide dynamic range neurons. Neurophysiol Clin 2021; 51:517-523. [PMID: 34756635 DOI: 10.1016/j.neucli.2021.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/03/2021] [Accepted: 09/03/2021] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Although somatosensory evoked potentials (SEPs) after median nerve stimulation are widely used in clinical practice, the dorsal horn generator of the N13 SEP spinal component is not clearly understood. To verify whether wide dynamic range neurons in the dorsal horn of the spinal cord are involved in the generation of the N13 SEP, we tested the effect of heterotopic noxious conditioning stimulation, which modulates wide dynamic range neurons, on N13 SEP in healthy humans. METHODS In 12 healthy subjects, we performed the cold pressor test on the left foot as a heterotopic noxious conditioning stimulus to modulate wide dynamic range neurons. To verify the effectiveness of heterotopic noxious conditioning stimulation, we tested the pressure pain threshold at the thenar muscles of the right hand and recorded SEPs after right median nerve stimulation before, during and after the cold pressor test. RESULTS The cold pressor test increased pressure pain threshold by 15% (p = 0.04). During the cold pressor test, the amplitude of the N13 component was significantly lower than that recorded at baseline (by 25%, p = 0.04). DISCUSSION In this neurophysiological study in healthy humans, we showed that a heterotopic noxious conditioning stimulus significantly reduced N13 SEP amplitude. This finding suggests that the N13 SEP might be generated by the segmental postsynaptic response of dorsal horn wide dynamic range neurons.
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Affiliation(s)
| | | | - Caterina Leone
- Department of Human Neuroscience, University Sapienza, Rome, Italy
| | | | - Emanuele Sgrò
- Department of Human Neuroscience, University Sapienza, Rome, Italy
| | - Anthony James Blockeel
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Ombretta Caspani
- Department of Neurophysiology, Mannheim Center for translational Neuroscience (MCTN), Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Luis Garcia-Larrea
- Lyon Neurosciences Center Research Unit Inserm U 1028, Pierre Wertheimer Hospital, Hospices Civils de Lyon, Lyon 1 University, Lyon, France; Pain Center, Pierre Wertheimer Hospital, Hospices Civils de Lyon, Lyon 1 University, Lyon, France
| | - André Mouraux
- Université Catholique de Louvain, Institute of Neuroscience (IoNS), Faculty of Medicine, Bruxelles, Belgium
| | - Keith Geoffrey Phillips
- Neuroscience Next Generation Therapeutics, Eli Lilly and Company, Lilly Innovation Center, Cambridge, MA 02142, USA
| | - Rolf-Detlef Treede
- Department of Neurophysiology, Mannheim Center for translational Neuroscience (MCTN), Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Massimiliano Valeriani
- Headache Center, Department of Neuroscience, Bambino Gesù Children's Hospital, Rome, Italy; Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark
| | - Andrea Truini
- Department of Human Neuroscience, University Sapienza, Rome, Italy.
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Defining catastrophic brain injury in children leading to coma and disorders of consciousness and the scope of the problem. Curr Opin Pediatr 2020; 32:750-758. [PMID: 33009124 DOI: 10.1097/mop.0000000000000951] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Severe brain injury in children resulting in coma and disorders of consciousness (DOC) is a catastrophic event for the life and function of children and their families. The present article summarizes the recently published pediatric literature on validated diagnostic assessments, potential predictors of recovery, and outcome measures used in children with catastrophic brain injury (CBI). Literature search terms included variants of consciousness, diagnostic tests, predictors of outcome, and outcome measures. RECENT FINDINGS Developmentally appropriate diagnostic tools, outcome predictors, and outcome measures are lacking for children with CBI leading to coma and DOC. Individual case prognosis relies on serial clinical examinations and experience. Evidence regarding optimal diagnosis of the highest level of consciousness and management of children with CBI is needed. Global efforts through the ongoing Curing Coma Campaign are aimed at: developing common data elements for information capture; streamlining the classification of coma endotypes; describing trajectories with biomarkers to monitor recovery or disease progression; and devising effective treatments for adults and children. SUMMARY Standardized, developmentally appropriate diagnostic and outcome assessments for CBI in children are needed. Future research should use these content standards to update our understanding of children with CBI leading to coma and DOC, and evaluate effective practices using acute adjunctive and rehabilitation therapies.
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Kontio T, Toet MC, Hellström-Westas L, van Handel M, Groenendaal F, Stjerna S, Vanhatalo S, de Vries LS. Early neurophysiology and MRI in predicting neurological outcome at 9-10 years after birth asphyxia. Clin Neurophysiol 2013; 124:1089-94. [PMID: 23403266 DOI: 10.1016/j.clinph.2012.12.045] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 12/18/2012] [Accepted: 12/22/2012] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To assess whether early somatosensory evoked potentials (SEP) predict long-term neurodevelopmental outcome in normothermic, full-term infants with mild to moderate neonatal encephalopathy (NE), and to compare their predictive value to already available amplitude integrated EEG (aEEG) and magnetic resonance imaging (MRI). METHODS Fifty-six infants with post-asphyxia NE were prospectively recruited, and their SEP, aEEG and MRI data were acquired during the first five days. Follow-up continued to 9-10 years for assessment of neuromotor and neurocognitive development. We analysed SEP latency (N1 component), normality of aEEG background pattern, as well as patterns of injury on the neonatal MRI. Neurological outcome measures at 9-10 years included conventional MRI, Movement-ABC and the WISC-III NL. RESULTS A SEP latency <50 ms during the first five days was associated with a normal neuromotor outcome (p < 0.03), and a prolonged day 3 latency was associated with lower childhood IQ (p = 0.02). The presence of multiple seizures in aEEG, as well as a moderate or severe injury on the neonatal MRI was associated with a poor neuromotor score (p = 0.03 and p < 0.01, respectively). Combination of multiple techniques improved prediction of long-term outcome compared to single modality. CONCLUSION Early SEPs provide information that is comparable to the already available aEEG and MRI paradigms in the prediction of long-term outcome of full-term infants with mild to moderate neonatal encephalopathy. SIGNIFICANCE The present results call for further studies using early SEP to aid early assessment of infants treated with hypothermia.
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Affiliation(s)
- T Kontio
- Department of Children's Clinical Neurophysiology, Helsinki University Hospital, and Department of Neurological Sciences, University of Helsinki, Finland.
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Kirkham F. Cardiac arrest and post resuscitation of the brain. Eur J Paediatr Neurol 2011; 15:379-89. [PMID: 21640621 DOI: 10.1016/j.ejpn.2011.04.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 04/17/2011] [Indexed: 10/18/2022]
Abstract
Primary out-of-hospital cardiac arrest in childhood is rare but survival is a little better for children than for adults, although the prognosis for infants is very poor. Hypoxic-ischaemic encephalopathy after in-hospital cardiac arrest in children undergoing complicated treatment for previously untreatable conditions is now a common problem and is probably increasing. An additional ischaemic insult worsens the prognosis for other encephalopathies, such as that occurring after accidental or non-accidental head injury. For near-drowning, the prognosis is often good, provided that cardiopulmonary resuscitation (CPR) is commenced immediately, and the child gasps within 40 minutes of rescue and regains consciousness soon afterwards. The prognosis is much worse for the nearly drowned child admitted to casualty or the emergency room deeply unconscious with fixed dilated pupils, requiring continuing CPR and with an arterial pH <7, especially if there is little recovery by the time of admission to the intensive care unit. The use of adrenaline, sodium bicarbonate and calcium appears to worsen prognosis. Neurophysiology, specifically serial electroencephalography and evoked potentials, is the most useful tool prognostically, although neuroimaging and biomarkers may play a role. In a series of 89 patients studied after cardiac arrest in three London centres between 1982 and 1985, 39% recovered consciousness within one month. Twenty seven percent died a cardiac death whilst in coma, and the outcome in the remainder was either brain death or vegetative state. EEG and initial pH were the best predictors of outcome in this study. Seizures affected one third and were associated with deterioration and worse outcome. The advent of extracorporeal membrane oxygenation (ECMO) and the positive results of hypothermia trials in neonates and adults have rekindled interest in timely management of this important group of patients.
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