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Arslan BT, Görkem Özyurt M, İşak B, Cecen S, Türker KS. Single motor unit estimation of the cutaneous silent period in ALS. Clin Neurophysiol 2024; 157:110-119. [PMID: 38096766 DOI: 10.1016/j.clinph.2023.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 01/13/2024]
Abstract
OBJECTIVE Recent evidence indicated that amyotrophic lateral sclerosis (ALS) also impairs spinal circuits, including those mediating cutaneous silent period (CSP). However, most studies utilised surface electromyography (sEMG), which needs more resolution to pinpoint changes at the single motoneuron level. We aimed to investigate CSP properties using single motor unit discharges in ALS. METHODS In mild and severe ALS patients and controls, CSP was recorded in the first dorsal interosseus and analysed using the discharge rate method, which accurately shows the inhibitory postsynaptic potentials (IPSPs) profile. RESULTS Our findings confirmed that the CSP latency was prolonged only in severe ALS patients. Moreover, the CSP duration was similar in each group, but late-stage ALS patients tend to have a longer CSP duration. The discharge rate method revealed a significantly longer duration (up to 150 ms) than the duration detected using sEMG. Strikingly, the motoneuron discharge rate - IPSP duration inverse relationship is lost in ALS patients, indicating a possible impairment in the motoneuron integrative properties. CONCLUSIONS Our data support previous findings of prolonged latency, presented input-output modifications of motoneurons, and revealed the entire course of the CSP, representing a much stronger inhibitory event than previously thought. SIGNIFICANCE Motoneuron integrative property modification assessed by CSP could be a new biomarker for ALS.
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Affiliation(s)
| | - M Görkem Özyurt
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Barış İşak
- Marmara University Pendik Training and Research Hospital, Istanbul, Turkey
| | - Serpil Cecen
- Health Science University, Hamidiye Medical Faculty, Istanbul, Turkey
| | - Kemal S Türker
- Istanbul Gelisim University, Faculty of Dentistry, Physiology, Istanbul, Turkey.
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Seok HY, Cho YW. Long-term dopamine agonist treatment fails to restore altered central sensory processing in restless legs syndrome: Evidence from current perception threshold measurements. Sleep Med 2024; 113:1-5. [PMID: 37967484 DOI: 10.1016/j.sleep.2023.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 10/15/2023] [Accepted: 11/03/2023] [Indexed: 11/17/2023]
Abstract
OBJECTIVES Although some studies have examined the impact of short-term dopamine agonist treatment on altered central sensory processing in patients with restless legs syndrome (RLS), there is a scarcity of research investigating the effect of long-term treatment with these drugs. The aim of this study is to investigate the long-term impact of dopamine agonist treatment on altered central sensory processing in RLS patients using current perception threshold (CPT) testing. METHODS We conducted a study of 24 RLS patients, measuring their CPT values before and after dopamine agonist treatment for at least 2 months. Patients were classified as responders or non-responders based on their decrease in International Restless Legs Syndrome (IRLS) score. Clinical parameters were collected and compared pre- and post-treatment. RESULTS The mean duration of treatment with dopamine agonist was 13.6 ± 11.0 months. Our results showed that dopamine agonist treatment significantly improved clinical parameters, including the IRLS score, Visual Analogue Scale, and RLS Quality of Life questionnaire. However, CPT values did not show significant changes for all stimulus frequencies after treatment. Furthermore, we did not find any difference in CPT values before and after treatment in both responders and non-responders. CONCLUSIONS Our study demonstrated that long-term treatment with dopamine agonists effectively reduces RLS symptoms, but does not reverse the altered central sensory processing observed on CPT testing in RLS patients. These results support the notion that the pathophysiology of RLS is multifactorial and not solely driven by dopaminergic dysfunction.
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Affiliation(s)
- Hung Youl Seok
- Department of Neurology, Dongsan Hospital, Keimyung University School of Medicine, Daegu, South Korea
| | - Yong Won Cho
- Department of Neurology, Dongsan Hospital, Keimyung University School of Medicine, Daegu, South Korea.
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Abdulhadi IG, Al-Mahdawi AM, Hamdan FB. Electrophysiological findings in patients with restless legs syndrome. Sleep Med 2021; 87:151-157. [PMID: 34610569 DOI: 10.1016/j.sleep.2021.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/02/2021] [Accepted: 09/14/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Restless legs syndrome (RLS) manifests as an urge to move the body to relieve the discomfortable sensations, primarily when resting, sitting, laying down, or sleeping. Diagnosis of RLS relies on clinical criteria, and the immobilization test was the only instrumental tool with equivocal results. OBJECTIVES To assess different electrophysiological findings in patients with RLS, and compare the diagnostic values of these parameters in the diagnosis of RLS. METHODS 30 patients with primary RLS and 30 controls who were matched for age and gender were studied. Participant's demographics, laboratory findings, and electrophysiological test, namely nerve conduction studies (NCS), cutaneous silent period (CSP), H reflex and sympathetic skin response (SSR), F-wave latency, amplitude, F-wave duration (FWD), and the ratio between FWD and duration of the corresponding compound muscle action potential (FWD/CMAPD) were analyzed. RESULTS None of the patients showed altered NCS data. FWD of upper (12.37 ± 2.77 ms) and lower limb (21.71 ± 5.24 ms) were significantly longer in patients. Also, FWD/CMAP duration of the upper (1.03 ± 0.2) and lower limb (2.02 ± 0.55) was longer in patients. Likewise, they exhibited delayed CSP latency from TA (110.62 ± 13.73 ms) and APB (77.35 ± 12.16 ms) whereas the CSP duration from TA and APB was decreased (37.36 ± 11.59 ms; 42.55 ± 7.97 ms, respectively). The SSR latency was not different, and right-sided H reflex amplitude (5.07 ± 3.98 mV) and H/M ratio (0.65 ± 1.81) were significantly increased in the patient group. CONCLUSION The data suggest that there may be a dysfunction of the inhibitory/excitatory circuits at a spinal level; and no pathology in the peripheral nerves. The unilateral difference of H reflex amplitude and H/M ratio may suggest asymmetrical central inhibitory dysfunction. Further prospective studies with larger cohorts are now needed to evaluate the pathophysiology of RLS with different neurophysiological assessment tools.
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Affiliation(s)
| | | | - Farqad Bader Hamdan
- Department of Physiology, College of Medicine, Al-Nahrain University, Baghdad, Iraq.
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Neurophysiologic assessment of small fibre damage in chemotherapy-induced peripheral neuropathy. Clin Neurophysiol 2021; 132:1947-1956. [PMID: 34034962 DOI: 10.1016/j.clinph.2021.02.406] [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: 08/16/2020] [Revised: 02/16/2021] [Accepted: 02/28/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVE In patients with chemotherapy-induced peripheral neuropathy (CIPN), demonstration of small fibre (SF) damage is important to understand chronic late effects. METHODS Thirty patients having complaints compatible with possible CIPN following treatment with oxaliplatin or docetaxel were compared with 27 healthy subjects. All subjects were evaluated with quantitative sensory testing (QST) assessing SF function and laser evoked potentials (LEP). In addition, SF-damage was assessed using cutaneous silent periods evoked with electrical (El-CSP) and laser (Ls-CSP) stimuli. RESULTS For LEP, N2P2 amplitudes were significantly smaller in patients than controls in both upper (P = 0.007) and lower extremities (P = 0.002), and the N1 amplitude in upper extremities of patients were significantly smaller than in controls (P = 0.001). SF-QST, LEP, Ls-CSP, and El-CSP were abnormal in 10 (33.3%), 16 (53.3%), 19 (63.3%), and 24 (80%) of CIPN patients, respectively. CONCLUSIONS In patients with possible CIPN, El-CSP and Ls-CSP were more often abnormal than LEP and QST. This is probably because El-CSP and Ls-CSP inform mainly about peripheral nociceptive fibres, while LEP and QST inform about peripheral and central nociceptive pathways together. SIGNIFICANCE LEP and QST are established methods to detect SF-damage. El- and Ls-CSP might help clinicians in diagnosing SF-damage.
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Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Agúndez JAG. Association between restless legs syndrome and peripheral neuropathy: A systematic review and meta-analysis. Eur J Neurol 2021; 28:2423-2442. [PMID: 33772991 DOI: 10.1111/ene.14840] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/27/2021] [Accepted: 03/23/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE The coexistence of peripheral neuropathy (PN) and restless legs syndrome (RLS) or Willis-Ekbom disease is relatively frequent, but its prevalence has shown a high variability across studies. In addition, several reports have shown data suggesting the presence of PN in patients with idiopathic RLS. METHODS A search was undertaken using the PubMed, Embase and Web of Science Databases, from 1966 to 6 December 2020, crossing the search term 'restless legs syndrome' with 'neuropathy', 'polyneuropathy' (PNP) and 'peripheral neuropathy', and the references of interest for this topic were identified; a meta-analysis was performed, according to PRISMA guidelines, and a calculation of pooled prevalences, where appropriate, was made using standard methods. RESULTS Restless legs syndrome has been reported in 5.2%-53.7% of patients with PN (average 21.5%; 95% confidence interval 18.6%-24.5%), and PN has been reported in 0%-87.5% of patients with RLS (average 41.8%; 95% confidence interval 39.9%-43.6%), both being significantly more frequent than in controls. The heterogeneity across studies could be due to differences in the diagnostic criteria used for both RLS and PN. RLS is a frequent clinical complaint in patients with PN of different aetiologies, mainly diabetic PN, uraemic PNP, familial amyloid PNP, Charcot-Marie-Tooth disease and chronic dysimmune inflammatory PNP. Recent neurophysiological findings suggest the presence of small sensory fibre loss in patients diagnosed with idiopathic RLS, but it remains to be determined whether RLS associated with small sensory fibre loss and idiopathic RLS are different clinical entities. CONCLUSIONS Future studies including clinical and neurophysiological assessment and skin biopsy involving a large series of patients with PN and RLS are needed for a better understanding of the association between these two entities.
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Affiliation(s)
| | | | - Elena García-Martín
- UNEx, ARADyAL Instituto de Salud Carlos III, University Institute of Molecular Pathology Biomarkers, Cáceres, Spain
| | - José A G Agúndez
- UNEx, ARADyAL Instituto de Salud Carlos III, University Institute of Molecular Pathology Biomarkers, Cáceres, Spain
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Gündüz A, Aydın Ş, Kızıltan M. Cutaneous silent period: A literature review. NEUROL SCI NEUROPHYS 2020. [DOI: 10.4103/nsn.nsn_38_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Seok HY, Do SY, Motamedi GK, Cho YW. Symptom‐related changes in current perception threshold of restless legs syndrome. J Sleep Res 2019; 29:e12890. [DOI: 10.1111/jsr.12890] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/16/2019] [Accepted: 06/02/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Hung Youl Seok
- Department of Neurology Dongsan Medical Center School of Medicine Keimyung University Daegu Republic of Korea
| | - So Young Do
- Department of Neurology Dongsan Medical Center School of Medicine Keimyung University Daegu Republic of Korea
| | - Gholam K. Motamedi
- Department of Neurology Georgetown University Hospital Washington DC USA
| | - Yong Won Cho
- Department of Neurology Dongsan Medical Center School of Medicine Keimyung University Daegu Republic of Korea
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Restless legs syndrome: Clinical changes in nervous system excitability at the spinal cord level. Sleep Med Rev 2019; 47:9-17. [PMID: 31212170 DOI: 10.1016/j.smrv.2019.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/30/2019] [Accepted: 05/27/2019] [Indexed: 12/20/2022]
Abstract
Restless legs syndrome (RLS) is a complex multifactorial disorder whose aetiology has yet to be fully elucidated. Some of the features of RLS, such as processing of sensations and activation of movement, may result from a dysfunction in spinal processing giving rise to a state of spinal hyperexcitability. In the current article we review studies investigating spinal excitability in RLS patients looking specifically at electrophysiological studies of spinal activity, sensory evaluations, and spinal reflex studies. Increased spinal excitability has been shown in RLS patients based on the combined data from electrophysiological studies. Results from studies assessing sensory evaluations in RLS patients show enhanced spinal processing of nociceptive inputs possibly due to central sensitisation. However, not all sensory modalities demonstrate an increase in sensitivity. An increase in nervous system excitability would result in an increase in reflex responses in RLS patients however the data from reflex analyses in RLS patients has failed to consistently show this expected result. Overall changes to RLS spinal excitability have been demonstrated though these changes might be heterogeneous as not all afferent input appears to be affected in the same manner. There may be phase-dependent and modality-dependent alterations in spinal excitability suggesting that the theory of absolute spinal hyperexcitability in RLS patients' needs to be reconsidered.
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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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Kilinc O, Sencan S, Ercalik T, Koytak PK, Alibas H, Gunduz OH, Tanridag T, Uluc K. Cutaneous silent period in myofascial pain syndrome. Muscle Nerve 2017; 57:E24-E28. [PMID: 28877555 DOI: 10.1002/mus.25964] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2017] [Indexed: 12/18/2022]
Abstract
INTRODUCTION An increased response to painful stimuli without spontaneous pain suggests a role of central hyperexcitability of pain pathways in the pathogenesis of myofascial pain syndrome (MPS). In this study we aimed to test the hypothesis that spinal pain pathways are affected in MPS. We used cutaneous silent period (CSP) parameters to demonstrate the hyperexcitability of spinal pain pathways in MPS. METHODS Twenty-nine patients diagnosed with MPS and 30 healthy volunteers were included in the study. The CSP recordings were performed in the right upper and left lower extremities. RESULTS In both upper and lower extremities, patients had prolonged CSP latencies (P = 0.034 and P = 0.049 respectively) and shortened CSP durations (P = 0.009 and P = 0.008, respectively). DISCUSSION Delayed and shortened CSP in MPS patients implies dysfunction in the inhibitory mechanism of the spinal/supraspinal pain pathways, suggesting central sensitization in the pathogenesis of MPS and supporting our research hypothesis. Muscle Nerve 57: E24-E28, 2018.
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Affiliation(s)
- Ozden Kilinc
- Department of Neurology, Marmara University School of Medicine, Fevzi Cakmak Mah. Muhsin Yazicioglu, Cadde No. 10 Pendik Istanbul, 34899, Turkey
| | - Savas Sencan
- Department of Physical Medicine and Rehabilitation, Section of Pain Medicine, Marmara University School of Medicine, Istanbul, Turkey
| | - Tulay Ercalik
- Department of Physical Medicine and Rehabilitation, Section of Pain Medicine, Marmara University School of Medicine, Istanbul, Turkey
| | - Pinar Kahraman Koytak
- Department of Neurology, Marmara University School of Medicine, Fevzi Cakmak Mah. Muhsin Yazicioglu, Cadde No. 10 Pendik Istanbul, 34899, Turkey
| | - Hande Alibas
- Department of Neurology, Marmara University School of Medicine, Fevzi Cakmak Mah. Muhsin Yazicioglu, Cadde No. 10 Pendik Istanbul, 34899, Turkey
| | - Osman Hakan Gunduz
- Department of Physical Medicine and Rehabilitation, Section of Pain Medicine, Marmara University School of Medicine, Istanbul, Turkey
| | - Tulin Tanridag
- Department of Neurology, Marmara University School of Medicine, Fevzi Cakmak Mah. Muhsin Yazicioglu, Cadde No. 10 Pendik Istanbul, 34899, Turkey
| | - Kayihan Uluc
- Department of Neurology, Marmara University School of Medicine, Fevzi Cakmak Mah. Muhsin Yazicioglu, Cadde No. 10 Pendik Istanbul, 34899, Turkey
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Congiu P, Fantini ML, Milioli G, Tacconi P, Figorilli M, Gioi G, Pereira B, Marrosu F, Parrino L, Puligheddu M. F-Wave Duration as a Specific and Sensitive Tool for the Diagnosis of Restless Legs Syndrome/Willis-Ekbom Disease. J Clin Sleep Med 2017; 13:369-375. [PMID: 28095964 DOI: 10.5664/jcsm.6482] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 11/16/2016] [Indexed: 12/14/2022]
Abstract
STUDY OBJECTIVES Restless legs syndrome, also known as Willis-Ekbom disease (RLS/WED), is a frequent condition, though its pathophysiology is not completely understood. The diagnosis of RLS/WED relies on clinical criteria, and the only instrumental tool, the suggested immobilization test, may lead to equivocal results. Recently, neurophysiological parameters related to F-wave duration have been proposed as a diagnostic aid. The aim of this study is to assess and compare the diagnostic values of these parameters in diagnosis of RLS/WED. METHODS Fifteen women affected by primary RLS/WED and 17 age- and sex- matched healthy subjects. A complete electroneurographic evaluation, including nerve conduction studies (NCS), cutaneous silent period (CSP), and F-wave parameters, namely amplitude, F-wave duration (FWD), and the ratio between FWD and duration of the corresponding compound muscle action potential (FWD/CMAPD). RESULTS No subject showed alterations of the NCS. However, FWD and FWD/CMAPD of both upper and lower limbs were significantly longer in patients than controls. Tibial FWD/CMAPD best discriminated RLS/WED patients from controls. A cutoff of 2.06 yielded a sensitivity of 69.2%, a specificity of 94.1%, a positive predictive power of 90%, and a negative predictive power of 80% (area under the curve = 0.817; 95% confidence interval = 0.674-0.959). The combination of ulnar or tibial FWD/CMAPD increases the sensitivity (85.7%) while slightly decreasing the specificity (87.5%, positive predictive value: 85.7%, negative predictive value: 87.5%). CONCLUSIONS Lower limb FWD/CMAPD ratio may represent a supportive diagnostic tool, especially in cases of evening lower leg discomfort of unclear interpretation.
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Affiliation(s)
| | | | | | | | | | - Gioia Gioi
- Sleep Disorders Center, University of Cagliari, Italy
| | - Bruno Pereira
- Biostatistics Unit (DRCI), CHU Clermont-Ferrand, France
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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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Cho YW, Kang MS, Kim KT, Do SY, Lim JG, Lee SY, Motamedi GK. Quantitative sensory test for primary restless legs syndrome/Willis–Ekbom disease using the current perception threshold test. Sleep Med 2017; 30:19-23. [DOI: 10.1016/j.sleep.2016.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/02/2016] [Accepted: 03/01/2016] [Indexed: 10/22/2022]
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Özsimsek A, Koyuncuoglu HR. Electrophysiological findings of Turkish patients with restless legs syndrome. Neuropsychiatr Dis Treat 2017; 13:2005-2010. [PMID: 28794635 PMCID: PMC5538691 DOI: 10.2147/ndt.s132903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
We aimed to investigate changes in electrophysiological findings in Turkish patients with restless legs syndrome (RLS), including F-wave latency (FWL), peripheral silent period (PSP), and Hoffmann reflex. The study took place in a university hospital in Turkey and involved 30 newly diagnosed RLS patients and 30 healthy controls who were matched for age and gender. Participant's demographics (age, gender, weight, and height), laboratory findings, and electrophysiological test outcomes were gathered and analyzed. There was no significant difference in the FWL of the median and ulnar nerves, whereas the H-wave maximum amplitude and H/M ratio were significantly higher in the RLS patients than in the controls at rest. All of the PSP parameters were similar between patients and controls for the abductor pollicis brevis and gastrocnemius muscles. However, for the tibialis anterior muscle, all the PSP duration parameters were shorter in the RLS patients, whereas the PSP latency parameters were similar. The data suggest that there may be a reduction in spinal segmental inhibition at the L4-L5-S1 level, but the mechanisms of inhibition at the L4-L5 and S1 levels may be different; furthermore, there may be no pathology in the peripheral nerves. Further prospective studies with larger cohorts are now needed to evaluate the pathophysiology of RLS with different neurophysiological assessment tools.
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Lanza G, Lanuzza B, Aricò D, Cantone M, Cosentino FII, Pennisi M, Bella R, Pennisi G, Ferri R. Response to the letter to the editor "Cortical excitability in restless legs syndrome". Sleep Med 2016; 21:175. [PMID: 26459686 DOI: 10.1016/j.sleep.2015.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 09/02/2015] [Indexed: 02/07/2023]
Affiliation(s)
- Giuseppe Lanza
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73-94018 Troina, Italy.
| | - Bartolo Lanuzza
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73-94018 Troina, Italy
| | - Debora Aricò
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73-94018 Troina, Italy
| | - Mariagiovanna Cantone
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73-94018 Troina, Italy
| | - Filomena Irene Ilaria Cosentino
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73-94018 Troina, Italy
| | - Manuela Pennisi
- Spinal Unit, Emergency Hospital "Cannizzaro", Via Messina, 829-95126 Catania, Italy
| | - Rita Bella
- Department of Medical and Surgical Sciences and Advanced Technologies, Section of Neurosciences, University of Catania, Via Santa Sofia, 78-95123 Catania, Italy
| | - Giovanni Pennisi
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Via Santa Sofia, 78-95123 Catania, Italy
| | - Raffaele Ferri
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73-94018 Troina, Italy
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Baek SH, Seok HY, Koo YS, Kim BJ. Lengthened Cutaneous Silent Period in Fibromyalgia Suggesting Central Sensitization as a Pathogenesis. PLoS One 2016; 11:e0149248. [PMID: 26871583 PMCID: PMC4752484 DOI: 10.1371/journal.pone.0149248] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 01/28/2016] [Indexed: 11/18/2022] Open
Abstract
The pathogenesis of fibromyalgia (FM) has not been clearly elucidated, but central sensitization, which plays an important role in the development of neuropathic pain, is considered to be the main mechanism. The cutaneous silent period (CSP), which is a spinal reflex mediated by A-delta cutaneous afferents, is useful for the evaluation of sensorimotor integration at the spinal and supraspinal levels. To understand the pathophysiology of FM, we compared CSP patterns between patients with FM and normal healthy subjects. Twenty-four patients with FM diagnosed in accordance with the 1990 American College of Rheumatology classification system and 24 age- and sex-matched healthy volunteers were recruited. The CSP was measured from the abductor pollicis brevis muscle. Demographic data, number of tender points, and visual analog scale and FM impact questionnaire scores were collected. The measured CSP and clinical parameters of the patient and control groups were compared. In addition, possible correlations between the CSP parameters and the other clinical characteristics were analyzed. Mean CSP latencies did not differ between patients (55.50 ± 10.97 ms) and healthy controls (60.23 ± 11.87 ms; p = 0.158), although the mean CSP duration was significantly longer in patients (73.75 ± 15.67 ms) than in controls (63.50 ± 14.05 ms; p = 0.021). CSP variables did not correlate with any clinical variables. The significantly longer CSP duration in FM patients suggests central dysregulation at the spinal and supraspinal levels, rather than peripheral small fiber dysfunction.
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Affiliation(s)
- Seol-Hee Baek
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
| | - Hung Youl Seok
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
| | - Yong Seo Koo
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
| | - Byung-Jo Kim
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
- * E-mail:
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Stetkarova I, Kofler M, Majerova V. Cutaneous silent periods in multiple system atrophy. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2015; 159:327-32. [DOI: 10.5507/bp.2013.081] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 10/15/2013] [Indexed: 12/14/2022] Open
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Mota IA, Fernandes JB, Cardoso MN, Sala-Blanch X, Kofler M, Valls-Solé J. Temporal profile of the effects of regional anesthesia on the cutaneous reflexes of foot muscles. Exp Brain Res 2015; 233:2587-96. [PMID: 26025613 DOI: 10.1007/s00221-015-4329-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/14/2015] [Indexed: 12/23/2022]
Abstract
We analyzed the effects of an anesthetic sciatic nerve block on the cutaneomuscular reflex (cMR) and the cutaneous silent period (cSP) of foot muscles, in order to investigate further the type of fibers involved in their generation. In 14 neurologically normal patients with indication for surgical treatment of hallux valgus, we recorded from the extensor digitorum brevis muscle the reflex responses elicited by high-intensity electrical stimulation of the big toe at various time periods, ranging from 0 to 20 min, after ultrasound-guided sciatic nerve popliteal anesthetic block. The first effect was a delay in cSP onset latency, with no changes in end latency. The cMR remained unaltered up to when subjects were no longer able to maintain the contraction. The effects of local anesthetics on peripheral nerves allow for recognition of the different types of fibers contributing to the cMR and the cSP in muscles of the lower limb.
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Affiliation(s)
- Isabella A Mota
- Hospital Universitario Lauro Wanderley, João Pessoa, Paraiba, Brazil
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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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Effect of pramipexole on cutaneous-silent-period parameters in patients with restless legs syndrome. Clin Neurophysiol 2012; 123:154-9. [DOI: 10.1016/j.clinph.2011.05.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 05/06/2011] [Accepted: 05/29/2011] [Indexed: 11/23/2022]
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Edwards RR, Quartana PJ, Allen RP, Greenbaum S, Earley CJ, Smith MT. Alterations in pain responses in treated and untreated patients with restless legs syndrome: associations with sleep disruption. Sleep Med 2011; 12:603-9. [PMID: 21570347 DOI: 10.1016/j.sleep.2010.09.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 09/03/2010] [Accepted: 09/17/2010] [Indexed: 12/29/2022]
Abstract
OBJECTIVE There has been recent interest in characterizing potential abnormalities of pain processing in patients with sleep disorders such as Restless Legs Syndrome (RLS). The aim of this study was to evaluate psychophysical responses to noxious heat and pressure stimuli in both treated and untreated RLS patients, compared to matched controls. METHODS This study is a cross-sectional group comparison of RLS patients with matched controls. A total of 31 patients (15 treated, 16 untreated) with a confirmed diagnosis of RLS were compared to 18 controls with no history of RLS or related sleep disorders. RESULTS RLS patients (both treated and untreated) demonstrated reduced pain thresholds and reported greater clinical pain relative to controls. Moreover, RLS patients demonstrated enhanced temporal summation of heat pain (p<.05), which may reflect aberrant central nervous system facilitation of pain transmission. Both treated and untreated RLS patients reported disrupted sleep relative to controls, and mediation analyses suggested that the reduced pain thresholds in RLS were attributable to sleep disturbance. However, the effect of RLS on the magnitude of temporal summation of heat pain was independent of sleep disturbance. CONCLUSIONS These findings suggest that central nervous system pain processing may be amplified in RLS, perhaps partially as a consequence of sleep disruption. RLS patients, even those whose symptoms are managed pharmacologically, may be at elevated long-term risk for the development or maintenance of persistent pain conditions. Further studies in larger samples could help to improve the prospects for pain management in RLS patients.
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Affiliation(s)
- Robert R Edwards
- Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School, Brigham & Women's Hospital, Chesnut Hill, MA 02467, USA.
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Koytak PK, Isak B, Borucu D, Uluc K, Tanridag T, Us O. Assessment of symptomatic diabetic patients with normal nerve conduction studies: utility of cutaneous silent periods and autonomic tests. Muscle Nerve 2011; 43:317-23. [PMID: 21321948 DOI: 10.1002/mus.21877] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Established electrophysiological methods have limited clinical utility in the diagnosis of small-fiber neuropathy (SFN). In this study, diabetic patients with clinically diagnosed SFN were evaluated with autonomic tests and cutaneous silent periods (CSPs). Thirty-one diabetic patients with clinically suspected SFN and normal nerve conduction studies were compared with 30 controls. In the upper extremities (UE), the CSP parameters did not differ statistically between the patient and control groups, whereas, in the lower extremities (LE), patients had prolonged CSP latencies (P = 0.018) and shortened CSP durations (P < 0.001). The sensitivity of the CSP duration was 32.6%, and the specificity was 96.7%. The expiration-to-inspiration ratios and amplitudes of the sympathetic skin responses in the lower extremities were also reduced. Our findings indicate that the diagnostic utility of CSPs was higher than that of the autonomic tests to support the clinically suspected diagnosis of SFN.
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Affiliation(s)
- Pinar Kahraman Koytak
- Department of Neurology, Marmara University Hospital, Tophanelioglu Cad. 13/15, Istanbul, Turkey.
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A neurophysiological approach to the complex organisation of the spine: F-wave duration and the cutaneous silent period in restless legs syndrome. Clin Neurophysiol 2011; 122:383-90. [DOI: 10.1016/j.clinph.2010.07.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 07/03/2010] [Accepted: 07/06/2010] [Indexed: 11/20/2022]
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Isak B, Agan K, Ergun A, Cakkalkurt A, Uluc K, Tanridag T, Us O. Where is the core of the volcano? The undetermined origin of primary restless legs syndrome. Int J Neurosci 2010; 121:130-6. [PMID: 21138399 DOI: 10.3109/00207454.2010.537413] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
An association between small fiber neuropathy and primary Restless Legs Syndrome (RLS) is suggested since both of them share common characteristics. Our aim was to investigate the existence of autonomic neuropathy on the basis of autonomic tests. The patients and the age-matched controls were evaluated with Neuropathy Symptom Profile and Autonomic Symptom Profile, nerve conduction studies (NCS), and autonomic tests. Patients suffered from neuropathic and autonomic complaints obviously. There was no significant difference for NCS, heart rate variability tests, and sympathetic skin responses (SSRs) among patients and controls. Since both the NCSs and the autonomic tests were within normal, the complaints were considered to be the consequences of the problem in sensory integration due to the dysfunction of the caudal diencephalic A11 group, rather than a neuropathic process. The cardiac autonomic imbalance possibly emerges as a consequence of arousal periods prior to or during the Periodic Leg Movements (PLM) episodes during sleep, but not due to autonomic neuropathy.
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Affiliation(s)
- Baris Isak
- Department of Neurology, Marmara University Hospital, Istanbul, Turkey
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Utility of the cutaneous silent period in the evaluation of carpal tunnel syndrome. Clin Neurophysiol 2010; 121:1584-1588. [DOI: 10.1016/j.clinph.2010.03.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 03/09/2010] [Accepted: 03/11/2010] [Indexed: 11/19/2022]
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Kim BJ, Kim NH, Kim SG, Roh H, Park HR, Park MH, Park KW, Cho SC, So YT. Utility of the cutaneous silent period in patients with diabetes mellitus. J Neurol Sci 2010; 293:1-5. [PMID: 20417526 DOI: 10.1016/j.jns.2010.03.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 02/09/2010] [Accepted: 03/31/2010] [Indexed: 11/26/2022]
Abstract
We performed this study to evaluate whether or not the cutaneous silent period (CSP) is a useful metric to identify small-fiber neuropathy in diabetic patients. The CSP was measured from the abductor pollicis brevis muscle in 30 healthy controls and 110 diabetic patients, who in turn were divided into 3 subgroups (patients with large-fiber neuropathy, patients with small-fiber neuropathy, and asymptomatic patients). The measured CSP and clinical characteristics were compared among the groups. The power of the CSP in discriminating patients from controls and any correlation with other clinical variables were analyzed. Each patient subgroup had a significantly delayed CSP latency compared to the controls. The latency of patients with large-fiber neuropathy was also significantly prolonged compared to the other subgroups of patients. The CSP latency was the only variable to discriminate patients. The latency showed a significant correlation with the late responses in nerve conduction studies. Thus, the CSP latency may be a useful tool in evaluating small neural fiber function in diabetic patients.
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Affiliation(s)
- Byung-Jo Kim
- Department of Neurology, Korea University College of Medicine, Seoul, Korea
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Tyvaert L, Laureau E, Hurtevent JP, Hurtevent JF, Derambure P, Monaca C. A-delta and C-fibres function in primary restless legs syndrome. Neurophysiol Clin 2009; 39:267-74. [DOI: 10.1016/j.neucli.2009.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 04/20/2009] [Accepted: 06/20/2009] [Indexed: 01/22/2023] Open
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Minimal electrical stimulation intensity and duration to elicit maximal cutaneous silent period in hand. Neurophysiol Clin 2009; 39:291-4. [DOI: 10.1016/j.neucli.2009.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 09/30/2009] [Accepted: 10/25/2009] [Indexed: 11/23/2022] Open
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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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Truini A, Galeotti F, Biasiotta A, Gabriele M, Inghilleri M, Petrucci MT, Cruccu G. Dissociation between cutaneous silent period and laser evoked potentials in assessing neuropathic pain. Muscle Nerve 2008; 39:369-73. [DOI: 10.1002/mus.21162] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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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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