Cutaneous Silent Period in the Evaluation of Small Nerve Fibres

Abstract

Introduction:High intensity cutaneous stimulus transiently suppresses tonic voluntary muscle activity resulting in cutaneous silent period (CSP).Aim:The aim of our study was to evaluate the normal values of an onset latency L1, a late latency L2 and a duration of CSP after stimulating sensory fibres of the median nerve.Material and Methods:This prospective study was performed at the Neurology Department, Clinical Center of Sarajevo University in period from January 1st 2013 to December 1st 2013. In our study we examined 61 subjects. The group included our relatives, coworkers and friends. The informed consent from testing subjects was obtained.Results:The origin of silent period is stimulation of small A-delta nerve fibres. The pre-synaptic or post-synaptic interruption of the electrical volley to motor neurons is discussed. Median values of muscle activity suppression in healthy female is 55.0 ms (45.0-74.0) and 59.0 ms (52.0-67) male subjects. There is a correlation between the onset latency L1and the late L2 latency (p‹0.03). In the on-going study it seems that delay of L1 and shorter muscle activity suppression might provide a sign of small nerve fibres involvement.Conclusion:The use of CSP improves the value of neurophysiology examination.

Update on Cerebellar Ataxia with Neuropathy and Bilateral Vestibular Areflexia Syndrome (CANVAS)

“…Interestingly, we can notice retained H-reflexe despite severe neuronopathy which is congruent with clinical descriptions, although found electrically to a lesser extent (75% of CANVAS cases have clinically retained reflexes in the cohort of Cortese et al [23]). This remains compatible with the hypothesis of relatively selective impairment of small sensory fibres (sparing Ia fibres) as evidenced by pathological cutaneous silent period [34].…”

Early detection of nerve involvement in presymptomatic TTR mutation carriers: exploring potential markers of disease onset

“…CSP is a spinal inhibitory reflex whose afferent arc is mediated almost exclusively by high-threshold, Aδ sensory nerve fibers [ 32 , 45 – 47 ]. Despite the absence of normative data, recent reports suggest an early alteration of CSP in terms of onset latency and duration both in ATTRv patients and presymptomatic carriers [ 37 , 48 ].…”

Vitiligo Hastalarında İnce Lif Nöropatisinin Değerlendirilmesi: Kutanöz Sessiz Periodun Önemi

“…20 It is inevitable to accept a neurological involvement with vitiligo based on these data upcoming from various studies. 4,19,20 Our study is the first study investigating the relation between vitiligo and small fiber neuropathy to our knowledge. Our findings show no association with vitiligo and small fiber neuropathy.…”

“…Th e clinical convenience of CSP appears in evaluating the continuity of nerve fibers which cannot be determined by standard electrophysiologic studies. 4 Vitiligo is a pigmentation disorder presenting with hypopigmented macules; with a prevalence of nearly 1%. Th e exact etiology of vitiligo is unknown, but autoimmune, neurological and auto-toxic mechanisms are focused on studies.…”