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Cunha NSC, Grippe T, Boechat-Barros R, Fernandez RNM, Brandão PRP, Chen R, Cardoso F. Evaluation of the Cutaneous Silent Period in a Healthy Brazilian Population. J Clin Neurophysiol 2023; 40:541-546. [PMID: 35349508 DOI: 10.1097/wnp.0000000000000921] [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] Open
Abstract
PURPOSE To establish cutaneous silent period (CSP) normative values and investigate the variables that may influence them. METHODS We tested 41 healthy subjects. All subjects underwent nerve conduction studies, and we evaluated the CSP in both arms. RESULTS Four subjects did not have CSP and were excluded. The analyses were performed in the healthy group composed of 23 women and 14 men, with a mean age of 35 (range, 19-64) years. The CSP median duration was 23.2 milliseconds (ms), with 2 to 98th percentile at 11.3 and 48.7 ms. The median onset latency was 87.9 (range, 72.9-109) ms, and the median end latency was 112 (range, 93.8-138) ms. The CSP onset latency positively correlated with height, whereas CSP end latency and duration were weakly but significantly associated with age. Some measurements of ulnar nerve conduction study also correlated with CSP measures. The interrater coefficients for the primary measures of onset and end latency demonstrates the reproducibility of the method. CONCLUSIONS The CSP with the fifth digit stimulation and recording from the abductor digiti minimi muscle is a valid diagnostic tool that can be used in clinical practice.
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Affiliation(s)
- Natalia S C Cunha
- Department of Medical Sciences, Universidade de Brasília Brasília, Brazil
- Department of Child Neurology, Hospital da Criança de Brasília José de Alencar Brasília, Brazil
| | - Talyta Grippe
- Department of Neurophysiology, Instituto Hospital de Base do Distrito Federal Brasília, Brazil
- Krembil Research Institute, Toronto, Canada
- Movement Disorders Unit, Internal Medicine Department, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | | | - Rubens N M Fernandez
- Department of Child Neurology, Hospital da Criança de Brasília José de Alencar Brasília, Brazil
- Department of Neurophysiology, Instituto Hospital de Base do Distrito Federal Brasília, Brazil
| | - Pedro Renato P Brandão
- Neuroscience and Behavior Lab, Universidade de Brasília Brasilia, Brazil; and
- Neurology Unit, Hospital Sírio-Libanês Brasilia, Brazil
| | | | - Francisco Cardoso
- Movement Disorders Unit, Internal Medicine Department, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
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Jawad ZY, Hamdan FB, Nema IS. Neurophysiologic evaluation of patients with cervical spondylotic myelopathy. THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2022. [DOI: 10.1186/s41983-022-00595-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Abstract
Background
Cervical spondylotic myelopathy (CSM) is a neurodegenerative disease caused by repetitive spinal cord damage that has resulted in significant clinical morbidity. The clinical evaluation of signs and symptoms, as well as neuroimaging and several neurophysiological tests, are used to make the diagnosis.
Objectives
To investigate changes in the cutaneous silent period (CuSP), cortical silent period (CoSP), and H-reflex in CSM patients, and to correlate these tests with the Japanese Orthopedic Association (JOA) score and Nurick’s grading, as well as to determine the diagnostic value of each of them.
Methods
Twenty patients (14 males and 6 females) with CSM were clinically diagnosed and documented by magnetic resonance imaging (MRI), and they were paired with another 20 healthy volunteers (13 males and 7 females) as a control group. CuSP, CoSP, and H-reflex tests were performed on both groups.
Results
In CSM patients, CuSP latency and duration are substantially longer and shorter in CSM patients, respectively. The degree of changes in CuSP latency is well correlated with the severity of the disease. Further, CoSP duration is significantly shortened. The H-reflex parameters did not differ significantly between the patient and control groups.
Conclusion
The shortened CoSP’s duration and the prolonged CuSP's latency suggest malfunction of the inhibitory and excitatory circuits in the spinal cord. The CuSP is more sensitive and specific than the CoSP in the diagnosis of a patient with CSM.
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Yu Z, Pan W, Chen J, Peng X, Ling Z, Zou X. Application of electrophysiological measures in degenerative cervical myelopathy. Front Cell Dev Biol 2022; 10:834668. [PMID: 36016659 PMCID: PMC9395596 DOI: 10.3389/fcell.2022.834668] [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: 12/13/2021] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Degenerative cervical myelopathy (DCM) is one of the leading causes of progressive spinal cord dysfunction in the elderly. Early diagnosis and treatment of DCM are essential to avoid permanent disability. The pathophysiology of DCM includes chronic ischemia, destruction of the blood–spinal cord barrier, demyelination, and neuronal apoptosis. Electrophysiological studies including electromyography (EMG), nerve conduction study (NCS), motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs) are useful in detecting the presymptomatic pathological changes of the spinal cord, and thus supplementing the early clinical and radiographic examinations in the management of DCM. Preoperatively, they are helpful in detecting DCM and ruling out other diseases, assessing the spinal cord compression level and severity, predicting short- and long-term prognosis, and thus deciding the treatment methods. Intra- and postoperatively, they are also useful in monitoring neurological function change during surgeries and disease progression during follow-up rehabilitation. Here, we reviewed articles from 1979 to 2021, and tried to provide a comprehensive, evidence-based review of electrophysiological examinations in DCM. With this review, we aim to equip spinal surgeons with the basic knowledge to diagnosis and treat DCM using ancillary electrophysiological tests.
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Affiliation(s)
- Zhengran Yu
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- Department of Spine Surgery, Orthopedics Center of Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Wenxu Pan
- Department of Gastroenterology, Guangzhou Women and Children’s Medical Center, Jinan University, Guangzhou, China
| | - Jiacheng Chen
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xinsheng Peng
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zemin Ling
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- *Correspondence: Zemin Ling, ; Xuenong Zou, ,
| | - Xuenong Zou
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- *Correspondence: Zemin Ling, ; Xuenong Zou, ,
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Fava E, Kofler M, Saltuari L. Reversible cutaneous silent period abnormalities in vitamin B12 deficiency: A case report. Clin Neurophysiol Pract 2019; 4:128-132. [PMID: 31249907 PMCID: PMC6586985 DOI: 10.1016/j.cnp.2019.05.002] [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: 02/25/2019] [Revised: 04/29/2019] [Accepted: 05/15/2019] [Indexed: 11/30/2022] Open
Abstract
Polyneuropathy is a frequent neurological manifestation of B12 hypovitaminosis. Thin-myelinated A-delta fibers may be affected in B12 hypovitaminosis. CSP testing is a useful diagnostic tool for A-delta fiber function in B12 deficiency.
Objectives Vitamin B12 deficiency is common in adult and elderly patients and is often underdiagnosed because of its polymorphous manifestations. Neurological symptoms of this condition include subacute combined degeneration and polyneuropathy, with possible affection of thin-myelinated A-delta fibers. Cutaneous silent periods (CSPs) may serve to test small-diameter fiber function non-invasively, using routine electrodiagnostic equipment, but to the best of our knowledge have not been studied so far in vitamin B12 deficiency. Methods We report a 49-year-old male patient suffering from B12 hypovitaminosis due to autoantibodies against gastric parietal cells, who underwent neurophysiological investigation to confirm clinically suspected polyneuropathy during the first month of intramuscular vitamin B12 supplementation. We performed standard electroneurography, needle electromyography in tibialis anterior muscle, quantitative sensory testing, and cutaneous silent periods six months after symptom onset and repeated the electrodiagnostic study 21 months later, after intramuscular vitamin B12 supplementation. Results Standard electroneurography demonstrated axonal sensory polyneuropathy. Needle electromyography (EMG) in tibialis anterior muscle was unremarkable. Cutaneous silent periods in tibialis anterior muscle after noxious electrical sural nerve stimulation were delayed, with incomplete EMG suppression concurring with dysfunction of thin-myelinated A-delta fibers. Quantitative sensory testing revealed altered cold and warm perception thresholds in both upper limbs, but normal values in both lower limbs. A follow-up electrodiagnostic study after 21 months intramuscular vitamin B12 supplementation revealed improvement of all neurophysiological findings, including normalization of cutaneous silent periods. Conclusions Thin-myelinated A-delta fibers may be affected in B12 hypovitaminosis and may show recovery after intramuscular vitamin B12 supplementation. CSP may serve to diagnose small fiber affection in this medical condition and to monitor their recovery after vitamin supplementation. Significance CSP testing represents a useful, non-invasive, rapidly available diagnostic and follow-up tool in vitamin B12 deficiency.
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Affiliation(s)
- Elena Fava
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
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Discrepancy between functional recovery and cutaneous silent period change in surgically treated degenerative cervical myelopathy: a prospective pilot study. Spinal Cord 2019; 57:1076-1083. [DOI: 10.1038/s41393-019-0314-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 06/03/2019] [Accepted: 06/04/2019] [Indexed: 02/05/2023]
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Kofler M, Leis A, Valls-Solé J. Cutaneous silent periods – Part 1: Update on physiological mechanisms. Clin Neurophysiol 2019; 130:588-603. [DOI: 10.1016/j.clinph.2019.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/28/2018] [Accepted: 01/08/2019] [Indexed: 12/14/2022]
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Cutaneous silent periods – Part 2: Update on pathophysiology and clinical utility. Clin Neurophysiol 2019; 130:604-615. [DOI: 10.1016/j.clinph.2019.01.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/28/2018] [Accepted: 01/08/2019] [Indexed: 02/08/2023]
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8
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Versace V, Campostrini S, Sebastianelli L, Saltuari L, Kofler M. Modulation of exteroceptive electromyographic responses in defensive peripersonal space. J Neurophysiol 2019; 121:1111-1124. [PMID: 30811266 DOI: 10.1152/jn.00554.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The cutaneous silent period (CSP) to noxious finger stimulation constitutes a robust spinal inhibitory reflex that protects the hand from injury. In certain conditions, spinal inhibition is interrupted by a brief burst-like electromyographic activity, dividing the CSP into two inhibitory phases (I1 and I2). This excitatory component is termed long-loop reflex (LLR) and is presumed to be transcortical in origin. Efficient defense from environmental threats requires sensorimotor integration between multimodal sensory afferents and planning of defensive movements. In the defensive peripersonal space (DPPS) immediately surrounding the body, we interact with objects and persons with increased alertness. We investigated whether CSP differs when the stimulated hand is in the DPPS of the face compared with a distant position. Furthermore, we investigated the possible role of vision in CSP modulation. Fifteen healthy volunteers underwent CSP testing with the handheld either within 5 cm from the nose (near) or away from the body (far). Recordings were obtained from first dorsal interosseous muscle following index (D2) or little finger (D5) stimulation with varying intensities. A subgroup of subjects underwent CSP recordings in near and far conditions, both with eyes open and with eyes closed. No inhibitory CSP parameter differed between stimulation in near and far conditions. LLRs occurring following D2 stimulation were significantly larger in near than far conditions at all stimulus intensities, irrespective of subjects seeing their hand. Similar to the hand-blink reflex, spinally organized protective reflexes may be modulated by corticospinal facilitatory input when the hand enters the DPPS of the face. NEW & NOTEWORTHY The present findings demonstrate for the first time that a spinally organized protective reflex, the cutaneous silent period (CSP), may be modulated by top-down corticospinal facilitatory input when the stimulated hand enters the defensive peripersonal space (DPPS) of the face. In particular, the cortically mediated excitatory long-loop reflex, which may interrupt the CSP, is facilitated when the stimulated hand is in the DPPS, irrespective of visual control over the hand. No spinal inhibitory CSP parameter differs significantly in or outside the DPPS.
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Affiliation(s)
- Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno/Sterzing and Research Unit for Neurorehabilitation of South Tyrol, Sterzing, Italy
| | - Stefania Campostrini
- Department of Neurorehabilitation, Hospital of Vipiteno/Sterzing and Research Unit for Neurorehabilitation of South Tyrol, Sterzing, Italy
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno/Sterzing and Research Unit for Neurorehabilitation of South Tyrol, Sterzing, Italy
| | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno/Sterzing and Research Unit for Neurorehabilitation of South Tyrol, Sterzing, Italy.,Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
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Zupcic SG, Zupcic M, Duzel V, Šimurina T, Milošević M, Basic S, Vuletic V, Kapural L. Effect of clonidine on the cutaneous silent period during spinal anesthesia. World J Clin Cases 2018; 6:1136-1145. [PMID: 30613672 PMCID: PMC6306629 DOI: 10.12998/wjcc.v6.i16.1136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/17/2018] [Accepted: 11/07/2018] [Indexed: 02/05/2023] Open
Abstract
AIM To investigate the effect of clonidine on the cutaneous silent period (CSP) during spinal anesthesia.
METHODS A total of 67 adult patients were included in this randomized, prospective, single-center, double-blind trial. They did not have neurological disorders and were scheduled for inguinal hernia repair surgery. This trial was registered on ClinicalTrials.gov (NTC03121261). The patients were randomized into two groups with regards to the intrathecally administered solution: (1) 15 mg of 0.5% levobupivacaine with 50 µg of 0.015% clonidine, or (2) 15 mg of 0.5% levobupivacaine alone. There were 34 patients in the levobupivacaine-clonidine (LC) group and 33 patients in the levobupivacaine (L) group. CSP and its latency were measured four times: prior to the subarachnoid block (SAB), after motor block regression to the 0 level of the Bromage scale, with ongoing sensory blockade, and both 6 and 24 h after SAB.
RESULTS Only data from 30 patients in each group were analyzed. There were no significant differences between the groups investigated preoperatively and after 24 h. The CSP of the L group at the time point when the Bromage scale was 0 was 44.8 ± 8.1 ms, while in the LC group it measured 40.2 ± 3.8 ms (P = 0.007). The latency in the L group at the time point when the Bromage scale was 0 was 130.3 ± 10.2 ms, and in the LC group it was 144.7 ± 8.3 ms (P < 0.001). The CSP of the L group after 6 h was 59.6 ± 9.8 ms, while in the LC group it was 44.5 ± 5.0 ms (P < 0.001). The latency in the L group after 6 h was 110.4 ± 10.6 ms, while in LC group it was 132.3 ± 9.7 ms (P < 0.001).
CONCLUSION Intrathecal addition of clonidine to levobupivacaine for SAB in comparison with levobupivacaine alone results in a diminished inhibitory tonus and shortened CSP.
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Affiliation(s)
- Sandra Graf Zupcic
- Clinic of Neurology, Clinical Hospital Centre Rijeka, Rijeka 51000, Croatia
| | - Miroslav Zupcic
- Faculty of Medicine, J. J. Strossmayer University, Osijek 31000, Croatia
- Clinic of Anesthesiology and Intensive Care Medicine, Clinical Hospital Centre Rijeka, Rijeka 51000, Croatia
- Faculty of Medicine, University of Rijeka, Rijeka 51000, Croatia
| | - Viktor Duzel
- Department of Anaesthesia, Barking, Havering and Redbridge University Hospitals NHS Trust, London RM7 0AG, United Kingdom
| | - Tatjana Šimurina
- Faculty of Medicine, J. J. Strossmayer University, Osijek 31000, Croatia
- Department of Health Studies University of Zadar, Zadar 23000, Croatia
- Department of Anesthesiology and Intensive Care Medicine, General Hospital Zadar, Zadar 23000, Croatia
| | - Milan Milošević
- University of Zagreb, School of Medicine, Andrija Stampar School of Public Health WHO Collaborative Centre for Occupational Health, Zagreb 10000, Croatia
| | - Silvio Basic
- Faculty of Medicine, J. J. Strossmayer University, Osijek 31000, Croatia
- Department of Neurology, Clinical Hospital Dubrava, Zagreb 10000, Croatia
| | - Vladimira Vuletic
- Clinic of Neurology, Clinical Hospital Centre Rijeka, Rijeka 51000, Croatia
- Faculty of Medicine, University of Rijeka, Rijeka 51000, Croatia
| | - Leonardo Kapural
- Center for Clinical Research, Winston Salem, NC 27103, United States
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Vasko P, Bocek V, Mencl L, Haninec P, Stetkarova I. Preserved cutaneous silent period in cervical root avulsion. J Spinal Cord Med 2017; 40:175-180. [PMID: 26312387 PMCID: PMC5430474 DOI: 10.1179/2045772315y.0000000053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVE Brachial plexus injuries are usually severe and involve the entire brachial plexus, sometimes occurring with root avulsions. Imaging and electrodiagnostic studies are an essential part of the lesion evaluation; however, the results sometimes show a discrepancy. The cutaneous silent period (SP) is a spinal inhibitory reflex mediated by small-diameter A-delta nociceptive fibers. The aim of the study was to determine if cutaneous SP testing may serve as a useful aid in evaluation of brachial plexus injury and/or in the diagnosis of root avulsion. METHODS In 19 patients with traumatic brachial plexus injury (15 males, age 18-62 years) we performed a clinical examination, CT myelography and neurophysiological testing. A needle EMG was obtained from muscles supplied by C5-T1 myotomes. Cutaneous SP was recorded after painful stimuli were delivered to the thumb (C6 dermatome), middle (C7) and little (C8) fingers while subjects maintained voluntary contraction of intrinsic hand muscles. RESULTS Electrodiagnostic and imaging studies confirmed root avulsion (partial or total) maximally involving C5, C6 roots in 12 patients, whereas only in 4 of them the cutaneous SP was partially absent. In the remaining subjects, the cutaneous SP was preserved. CONCLUSION In brachial plexopathy even with plurisegmental root avulsion, the cutaneous SP was mostly preserved. This method cannot be recommended as a reliable test for diagnosis of single root avulsion; however, it can provide a quick physiological confirmation of functional afferent A-delta fibers through damaged roots and/or trunks. The clinicians may add this test to the diagnosis of spinal cord dysfunction.
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Affiliation(s)
- Peter Vasko
- Department of Neurology, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Vaclav Bocek
- Department of Neurology, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Libor Mencl
- Department of Neurosurgery, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Pavel Haninec
- Department of Neurosurgery, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Ivana Stetkarova
- Department of Neurology, Third Faculty of Medicine, Charles University, Prague, Czech Republic,Correspondence to: Ivana Stetkarova, Head of Department of Neurology, Third Faculty of Medicine, Charles University of Prague, Ruska 87, Prague 10, Czech Republic, 100 00.
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Eckert NR, Poston B, Riley ZA. Modulation of the Cutaneous Silent Period in the Upper-Limb with Whole-Body Instability. PLoS One 2016; 11:e0151520. [PMID: 26981863 PMCID: PMC4794147 DOI: 10.1371/journal.pone.0151520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 02/29/2016] [Indexed: 11/21/2022] Open
Abstract
The silent period induced by cutaneous electrical stimulation of the digits has been shown to be task-dependent, at least in the grasping muscles of the hand. However, it is unknown if the cutaneous silent period is adaptable throughout muscles of the entire upper limb, in particular when the task requirements are substantially altered. The purpose of the present study was to examine the characteristics of the cutaneous silent period in several upper limb muscles when introducing increased whole-body instability. The cutaneous silent period was evoked in 10 healthy individuals with electrical stimulation of digit II of the right hand when the subjects were seated, standing, or standing on a wobble board while maintaining a background elbow extension contraction with the triceps brachii of ~5% of maximal voluntary contraction (MVC) strength. The first excitatory response (E1), first inhibitory response (CSP), and second excitatory response (E2) were quantified as the percent change from baseline and by their individual durations. The results showed that the level of CSP suppression was lessened (47.7 ± 7.7% to 33.8 ± 13.2% of baseline, p = 0.019) and the duration of the CSP inhibition decreased (p = 0.021) in the triceps brachii when comparing the seated and wobble board tasks. For the wobble board task the amount of cutaneous afferent inhibition of EMG activity in the triceps brachii decreased; which is proposed to be due to differential weighting of cutaneous feedback relative to the corticospinal drive, most likely due to presynaptic inhibition, to meet the demands of the unstable task.
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Affiliation(s)
- Nathanial R. Eckert
- Department of Kinesiology, Indiana University, Bloomington, Indiana, United States of America
| | - Brach Poston
- Department of Kinesiology and Nutritional Sciences, University of Nevada-Las Vegas, Las Vegas, Nevada, United States of America
| | - Zachary A. Riley
- Department of Kinesiology, Indiana University-Purdue University, Indianapolis, Indiana, United States of America
- * E-mail:
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Ulrich A, Min K, Curt A. High sensitivity of contact-heat evoked potentials in “snake-eye” appearance myelopathy. Clin Neurophysiol 2015; 126:1994-2003. [DOI: 10.1016/j.clinph.2014.12.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 11/30/2014] [Accepted: 12/10/2014] [Indexed: 12/12/2022]
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13
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Lopergolo D, Isak B, Gabriele M, Onesti E, Ceccanti M, Capua G, Fionda L, Biasiotta A, Di Stefano G, La Cesa S, Frasca V, Inghilleri M. Cutaneous silent period recordings in demyelinating and axonal polyneuropathies. Clin Neurophysiol 2014; 126:1780-9. [PMID: 25497713 DOI: 10.1016/j.clinph.2014.11.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/11/2014] [Accepted: 11/15/2014] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To investigate the cutaneous silent period (CSP), a spinal inhibitory reflex mainly mediated by A-delta fibres, in demyelinating and axonal polyneuropathy (PNP) and evaluate whether CSP parameters differ between patients with and without neuropathic pain. METHODS Eighty-four patients with demyelinating PNP, 178 patients with axonal PNP and 265 controls underwent clinical examination, DN4 questionnaire, standard nerve conduction study, motor-root stimulation and CSP recordings from abductor digiti minimi. We calculated the afferent conduction time of CSP (a-CSP time) with the formula: CSP latency-root motor evoked potential latency. RESULTS In the demyelinating PNP group the a-CSP time was significantly longer; in the axonal PNP group, CSP duration was shorter than the demyelinating group (p=0.010) and controls (p=0.001). CSP parameters were not different between patients with and without neuropathic pain. CONCLUSIONS The abnormality of a-CSP time in the demyelinating PNP group suggests the crucial role of A-delta fibres in the mechanism of CSP; the shorter CSP duration in the axonal PNP group supports the strong influence of the number of axons on this parameter. Our study suggests that neuropathic pain could be related to pathophysiological mechanisms differing from mere A-delta fibre loss. SIGNIFICANCE CSP evaluation is effective in detecting A-delta fibre dysfunction in axonal as well as demyelinating PNP.
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Affiliation(s)
- Diego Lopergolo
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Baris Isak
- Marmara University Hospital School of Medicine, Department of Neurology, Fevzi Cakmak Mah. Mimar Sinan Cad. No: 41, 34899 Ust Kaynarca/Pendik, Istanbul, Turkey; Department of Clinical Neurophysiology, Aarhus Universitets hospital, Nørrebrogade 44, 8000 Aarhus C, Denmark
| | - Maria Gabriele
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Emanuela Onesti
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Marco Ceccanti
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Gelsomina Capua
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Laura Fionda
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Antonella Biasiotta
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Giulia Di Stefano
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Silvia La Cesa
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Vittorio Frasca
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - Maurizio Inghilleri
- Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
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Effects of a selective serotonin reuptake inhibitor escitalopram on the cutaneous silent period: A randomized controlled study in healthy volunteers. Neurosci Lett 2014; 566:17-20. [DOI: 10.1016/j.neulet.2014.02.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 12/14/2022]
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Pujia F, Coppola G, Anastasio MG, Brienza M, Vestrini E, Valente GO, Parisi L, Serrao M, Pierelli F. Cutaneous silent period in hand muscles is lengthened by tramadol: Evidence for monoaminergic modulation? Neurosci Lett 2012; 528:78-82. [PMID: 22981885 DOI: 10.1016/j.neulet.2012.08.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 08/13/2012] [Indexed: 12/12/2022]
Abstract
The purpose of this study was to shed light on the neurochemical modulatory mechanisms of the noxious spinal inhibitory cutaneous silent period (CSP). We study the effects of 100mg of oral tramadol in 11 healthy volunteers. Tramadol has low affinity for opioid receptors and has the ability to inhibit serotonin and noradrenaline reuptake. We elicited CSPs in the first dorsal interosseus muscle and noxious withdrawal flexor reflexes (NWR) in the right biceps femoris muscle before, 30 min and each hour up to the 6th after tramadol. Subjective pain sensation was checked on an 11-point numerical scale. Tramadol increased duration of CSP, and reduced the NWR area under the curve maximally 2h after tramadol and paralleled the reduction of subjective pain perception. We suggest that the monoaminergic action of tramadol reinforces the activity of spinal inhibitory interneurons on α-motoneurons for the hand muscles.
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Affiliation(s)
- Francesco Pujia
- "Sapienza" University of Rome, Department of Medico-surgical Sciences and Biotechnologies, Neurology Section, Rome, Italy.
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Stetkarova I, Kofler M. Differential effect of baclofen on cortical and spinal inhibitory circuits. Clin Neurophysiol 2012; 124:339-45. [PMID: 22877625 DOI: 10.1016/j.clinph.2012.07.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 06/16/2012] [Accepted: 07/01/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVE The cutaneous silent period (SP) is a spinal inhibitory reflex, which suppresses activity in spinal motor nuclei. Transcranial magnetic stimulation (TMS) elicits a cortical SP, which represents GABA(B) receptor-mediated inhibition of cortical excitability. Baclofen as a strong GABA(B) agonist effectively reduces muscle hypertonia, however, it is not known whether intrathecal baclofen (ITB) may modulate spinal inhibitory circuits. METHODS We evaluated clinical and neurophysiological effects of ITB in ten patients with severe spasticity due to spinal cord injury (n = 9) and chronic progressive multiple sclerosis (n = 1). Neurophysiological assessment included H reflex and cutaneous and cortical SPs, before and 15, 30, 60, 90, 120, and 180 min after ITB bolus administration. RESULTS ITB suppressed soleus H reflex as early as 15 min after lumbar bolus injection; MAS scores declined after 1 h. Cortical SP end latency and duration increased progressively with a significant maximum 3h following ITB bolus, whereas cutaneous SP latency and duration did not change significantly. CONCLUSION The present findings suggest that baclofen does not affect the cutaneous SP, but prolongs the cortical SP. SIGNIFICANCE The spinal inhibitory circuitry of the cutaneous SP is not modulated by GABA(B) receptor-mediated activity, in contrast to the cortical inhibitory circuitry of the cortical SP, which is subject to powerful GABA(B) control.
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Affiliation(s)
- Ivana Stetkarova
- Department of Neurology, 3rd Medical Faculty, Charles University, Prague, Czech Republic.
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Rodi Z, Springer C. Influence of muscle contraction and intensity of stimulation on the cutaneous silent period. Muscle Nerve 2010; 43:324-8. [PMID: 21321949 DOI: 10.1002/mus.21868] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2010] [Indexed: 11/09/2022]
Abstract
We evaluated the influence of stimulus intensity (SI) and the amount of voluntary muscle contraction (VMC) on parameters of the cutaneous silent period (CSP). The CSP was measured in 15 healthy subjects at 20%, 40%, and 60% of maximal VMC and after an electric stimulus of 10, 15, and 20 times the sensory threshold. Average EMG amplitudes prior to stimulus and during the CSP increased with the amount of VMC. The CSP duration increased, and suppression index decreased, with increasing SI. The CSP onset and end latencies seemed to shorten and prolong, respectively, with the increasing SI, although this was not statistically significant. Considering the more meaningful temporal parameters of the CSP and the suppression index, it is not necessary to control the VMC, but it is advisable to control the SI.
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Affiliation(s)
- Zoran Rodi
- Institute of Clinical Neurophysiology, University Medical Centre Ljubljana, Zaloska cesta 7, SI-1525 Ljubljana, Slovenia.
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Leis AA, Kofler M, Stetkarova I, Stokic DS. The cutaneous silent period is preserved in cervical radiculopathy: significance for the diagnosis of cervical myelopathy. 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 2010; 20:236-9. [PMID: 21132557 DOI: 10.1007/s00586-010-1627-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2010] [Revised: 09/01/2010] [Accepted: 11/07/2010] [Indexed: 10/18/2022]
Abstract
Electromyographic (EMG) activity from voluntarily contracting hand muscles undergoes transient suppression following nociceptive fingertip stimulation. This suppression is mediated by a spinal inhibitory reflex designated the cutaneous silent period (CSP). The CSP is abolished or altered in a variety of myelopathic conditions. However, before the CSP can gain acceptance as an aid in the diagnosis of myelopathy, the contribution of non-myelopathic conditions that can interrupt the afferent pathways responsible for the CSP needs to be considered. Accordingly, we examined the effect of radiculopathy on the CSP. Nociceptive stimulation was applied to thumb (C6 dermatome), middle (C7) and little (C8) fingers of 23 patients with cervical radiculopathy. Four or more CSP responses were recorded in abductor pollicis brevis muscle following digital stimulation. The patients had C6 (n = 10), C7 (n = 7), or C8 (n = 6) radiculopathy documented by EMG. A complete CSP was elicited in 21 of 23 patients with comparable latencies and durations irrespective of digit stimulated. We conclude that the CSP is preserved in radiculopathy, probably because afferent impulses are carried by smaller, slower conducting 'injury-resistant' A-delta fibers. These results provide important missing evidence that ensures specificity of CSP alterations in the diagnosis of cervical myelopathy. The finding that the CSP is spared in radiculopathy should open the door for investigators and clinicians to adopt this simple spinal inhibitory reflex as a physiologic aid in the diagnosis of spinal cord dysfunction.
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Affiliation(s)
- A Arturo Leis
- Center for Neuroscience and Neurological Recovery, Methodist Rehabilitation Center, Jackson, MS 39216, USA.
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Cutaneous silent period in human FDI motor units. Exp Brain Res 2010; 205:455-63. [DOI: 10.1007/s00221-010-2380-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 07/21/2010] [Indexed: 10/19/2022]
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Cutaneous silent periods are not affected by the antihistaminic drug cetirizine. Clin Neurophysiol 2009; 120:1016-9. [DOI: 10.1016/j.clinph.2009.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 03/12/2009] [Accepted: 03/14/2009] [Indexed: 11/19/2022]
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Abstract
STUDY DESIGN Clinical, neuroradiologic, and neurophysiologic description of 21 patients with compressive cervical spondylotic myelopathy (CCSM). OBJECTIVE To describe the utility of cutaneous silent periods (CSPs) for functional evaluation of mild CCSM. SUMMARY OF BACKGROUND DATA Electroneurography, electromyography, and somatosensory and motor evoked potentials (SEPs, MEPs) are routinely used for comprehensive functional neurophysiological evaluation of CCSM. CSPs have been reported in various intramedullary spinal cord lesions, however, they have not been systematically studied in mild CCSM. METHODS We investigated 21 patients with multilevel CCSM as documented by magnetic resonance imaging. We recorded CSPs in thenar muscles after noxious digit II stimulation and compared them with median and tibial nerve SEPs and MEPs obtained from abductor digiti minimi and tibialis anterior muscles. Electroneurography and electromyography were obtained in affected myotomes. RESULTS CSP onset and end latencies were delayed, and CSP duration was shortened, in CCSM patients. CSP abnormalities were present in 17 patients of whom all, but 1 presented with intramedullary magnetic resonance imaging hyperintensity. All 11 limbs affected by hypalgesia and thermhypesthesia had abnormal CSPs, whereas no spinothalamic deficit was noted in any limb with normal CSPs. CSP onset latency was inversely correlated with JOA score and N13 amplitude, and was positively correlated with central motor conduction time to abductor digiti minimi. CSP duration was inversely correlated with central motor conduction time to tibialis anterior. Electromyographic abnormalities were found in 7 patients. CONCLUSION We confirm the value of neurophysiological evaluation of CCSM. MEPs were more frequently abnormal than SEPs. CSP abnormalities were almost equally sensitive as upper limb MEPs, and were highly associated with spinothalamic dysfunction. The high correlation of CSP abnormalities with corticospinal tract dysfunction suggests supraspinal influence on CSPs. Our findings corroborate the utility of CSP testing in the comprehensive assessment of intramedullary spinal cord dysfunction in CCSM.
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Roser F, Ebner FH, Liebsch M, Dietz K, Tatagiba M. A new concept in the electrophysiological evaluation of syringomyelia. J Neurosurg Spine 2008; 8:517-23. [DOI: 10.3171/spi/2008/8/6/517] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
The current neurophysiological assessment of syringomyelia is inadequate. Early-stage syringomyelia is anatomically predisposed to affect decussating spinothalamic fibers that convey pain and sensation primarily. Silent periods have been proven to be a sensitive tool for detecting alterations in this pathway.
Methods
Thirty-seven patients with syringomyelia were included in this prospective study. Routine electrophysiological measurements were applied including somatosensory evoked potential (SSEP) and motor evoked potential (MEP) recordings for all extremities. The silent periods were recorded from the pollicis brevis muscle, and electrical stimuli were applied to the ipsilateral digiti II. To establish baseline values, the authors had 28 healthy controls undergo monitoring. Sensitivity and specificity values were statistically evaluated according to the main clinical symptoms (paresis, dissociative syndrome, and pain).
Results
All control individuals had normal silent periods in voluntarily activated muscle. In syringomyelia patients, the affected limb showed pathological silent periods with all symptoms (sensitivity 30–50%). Pain was the most specific symptom (90%), despite SSEP and MEP values that were within the normal range.
Conclusions
Silent period testing is a sensitive neurophysiological technique and an invaluable tool for preoperative assessment of syringomyelia. Silent periods are associated with early dysfunction of thin myelinated spinothalamic tract fibers, even when routine electrophysiological measurements still reveal normal values. Conduction abnormalities that selectively abolish the silent periods can distinguish between hydromyelia (a physiologically dilated central canal) and space-occupying syringomyelia.
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Affiliation(s)
| | | | | | - Klaus Dietz
- 2Medical Biometry, University of Tübingen, Germany
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Sensory modulation of voluntary and TMS-induced activation in hand muscles. Exp Brain Res 2008; 188:399-409. [DOI: 10.1007/s00221-008-1372-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 04/02/2008] [Indexed: 11/26/2022]
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Gilio F, Bettolo CM, Conte A, Iacovelli E, Frasca V, Serrao M, Giacomelli E, Gabriele M, Prencipe M, Inghilleri M. Influence of the corticospinal tract on the cutaneous silent period: a study in patients with pyramidal syndrome. Neurosci Lett 2008; 433:109-13. [PMID: 18242857 DOI: 10.1016/j.neulet.2007.12.055] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Revised: 12/17/2007] [Accepted: 12/26/2007] [Indexed: 02/08/2023]
Abstract
The cutaneous silent period (CSP) is a brief transient suppression of the voluntary muscle contraction that follows a noxious cutaneous nerve stimulation. In this study we investigated the influence of the corticospinal tract on this spinal inhibitory reflex. In patients with pyramidal syndrome and in a group of healthy subjects we delivered painful electrical finger stimulation during sustained contraction of the ipsilateral abductor digiti minimi muscle. The CSP latency and duration and the background electromyographic (EMG) activity were measured and compared between-groups. The compound motor action potential amplitude and F-wave latency were also measured after electrical stimulation of the ulnar nerve at the wrist. The CSP latency was significantly longer in patients than in healthy subjects. None of the other variables differed in patients and healthy subjects. Our findings suggest that corticospinal projections influence the CSP latency probably by modulating the balance of excitability in the underlying circuits.
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Affiliation(s)
- Francesca Gilio
- Department of Neurological Sciences, University of Rome Sapienza, Viale dell'Università 30, 00185 Rome, Italy
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Abstract
STUDY DESIGN Clinical, radiologic, and neurophysiologic description of 2 cases. OBJECTIVE To describe 2 cases with spontaneous deep unilateral abdominal pain as the first symptom of thoracic disc herniation at a low thoracic vertebral level, further manifested by unilateral partial paresis of the obliquus abdominis muscle. SUMMARY OF BACKGROUND DATA Clinical manifestation of lateral thoracic disc herniation with electrophysiologic results and conservative therapy as treatment of choice when spinal cord functions are preserved. METHODS Magnetic resonance imaging revealed bilateral paramedian disc protrusions at T12-L1 in Patient 1 and foraminal herniation at T10-T11 and paramedian herniation at T11-T12 in Patient 2. Electromyography (EMG) and evoked potentials were investigated in the acute stage and after 6 months. RESULTS Spontaneous activity on needle EMG confirmed axonal root impairment. Somatosensory and motor-evoked potentials were within normal limits and excluded spinal cord involvement. Nonsteroidal anti-inflammatory drugs and periradicular injection of steroids and local anesthetics rendered both patients pain-free. Normalization of muscle strength within 3 to 6 months was accompanied by EMG findings of reinnervation. CONCLUSION Lateral disc herniation causing compression of a thoracic root associated with unilateral segmental paresis of the abdominal wall is a rare condition. Despite EMG documentation of axonal root lesion, however, a purely conservative therapeutic approach may be considered treatment of choice in cases without spinal cord involvement.
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Kofler M, Kumru H, Stetkarova I, Schindler C, Fuhr P. Muscle force up to 50% of maximum does not affect cutaneous silent periods in thenar muscles. Clin Neurophysiol 2007; 118:2025-30. [PMID: 17644035 DOI: 10.1016/j.clinph.2007.06.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2007] [Revised: 05/28/2007] [Accepted: 06/10/2007] [Indexed: 12/23/2022]
Abstract
OBJECTIVE The cutaneous silent period (CSP) is a spinal inhibitory reflex mediated by A-delta fibers. The amount of muscle contraction has been reported to influence CSPs, but this has not been confirmed in studies applying clinically feasible stimulus parameters. METHODS Fourteen healthy subjects underwent comparison of CSPs while contracting the target muscle at different levels ranging from 10% to 50% of the maximum force, which was continuously monitored with a force transducer. Rectified surface electromyographic (EMG) recordings were obtained from abductor pollicis brevis muscle following ipsilateral recurrent noxious digit 2 and digit 5 stimulation. RESULTS Group average CSP onset and end latency, CSP duration, and the magnitude of EMG suppression were not influenced by volitional muscle contraction ranging from 10% to 50% of the maximum. In contrast, background EMG levels increased significantly with the amount of muscle force. CONCLUSIONS CSPs prove to be robust nociceptive cutaneomuscular reflexes, which are - in contrast to previous reports - not significantly influenced by clinically easily applicable amounts of muscle force. SIGNIFICANCE Non-dependence on the amount of volitional target muscle activation over a range from 10% to 50% of individual maximum force levels renders CSPs particularly suitable for clinical use in patients with peripheral and spinal disorders affecting the A-delta fiber system.
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Affiliation(s)
- Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria.
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Chan YC, Mills KR. The use of transcranial magnetic stimulation in the clinical evaluation of suspected myelopathy. J Clin Neurosci 2005; 12:878-81. [PMID: 16256350 DOI: 10.1016/j.jocn.2005.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2004] [Accepted: 01/14/2005] [Indexed: 11/18/2022]
Abstract
Central motor conduction time (CMCT) and motor evoked potential (MEP) latencies measured by using transcranial magnetic stimulation (TMS) are parameters used to evaluate electrophysiologic function of the corticospinal motor tract. We present 5 cases to illustrate how the use of TMS had contributed to clinical management. CMCT and MEP latency measurements were found to be useful in determining the significance of lesions seen on neuroimaging and helped clinical decisions in the presence of multiple lesions or multiple clinical conditions that cause similar clinical manifestations. TMS study is particularly useful in localizing levels of conduction defect.
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Affiliation(s)
- Y C Chan
- Department of Clinical Neurophysiology, King's College Hospital, London SE5 9RS.
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Kofler M, Poustka K. Interside comparison of cutaneous silent periods in thenar muscles of healthy male and female subjects. Clin Neurophysiol 2004; 115:2123-7. [PMID: 15294214 DOI: 10.1016/j.clinph.2004.04.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2004] [Indexed: 12/27/2022]
Abstract
OBJECTIVE The cutaneous silent period (CSP) is a spinal inhibitory reflex mediated by A-delta fibers. To date, no data are available about normal interside differences. METHODS Twenty healthy subjects underwent comparison of CSPs in the dominant and non-dominant hand. Surface electromyographic (EMG) recordings were obtained from thenar muscles on either side following ipsilateral recurrent nociceptive digit II stimulation. RESULTS Group average CSP onset and end latency, CSP duration, and the magnitude of EMG suppression were not significantly different between both sides. Regression analysis revealed powerful correlations between individual CSP parameters of dominant and non-dominant hands. Calculated upper normal limits of maximum interside differences were 17% for CSP onset latency, 14% for CSP end latency, 22% for CSP duration, and 45% for the index of suppression. CSP parameters in right-handed subjects did not differ significantly from those in left-handed subjects. Female subjects tended to have shorter CSP onset latencies, longer CSP duration, and a smaller index of suppression, resulting in a larger overall suppression. CONCLUSIONS CSPs prove to be robust nociceptive cutaneomuscular reflexes with little side-to-side difference. SIGNIFICANCE The presented normative values of interside differences enable a more thorough comparison with patient data in various conditions.
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Affiliation(s)
- Markus Kofler
- Department of Neurology, Hospital Hochzirl, A-6170 Zirl, Austria.
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