The cutaneous silent period in multiple sclerosis

Abstract Background Small fiber neuropathy is a subtype of peripheral neuropathy. Diagnosis of small fiber neuropathy is important for detecting the origin of neuropathic pain in patients with normal standard nerve conduction studies. The cutaneous silent period (CSP) is an inhibitory spinal reflex. It is considered an easily applied, readily available method for the evaluation of small myelinated A-delta fibres. Seventy-six subjects were included; 38 relapsing-remitting multiple sclerosis (RRMS) cases with clinically suspected small fiber neuropathy were compared to 38 healthy controls within an age range of 18–50 years. Patients underwent Expanded Disability Status Scale and were administered Lead’s assessment of neuropathic symptoms and signs pain scale for evaluation of small fiber neuropathy. Results There was a significant delay in CSP onset latency in the lower limbs more than the upper limbs. Also, there was a significant difference in onset latency between upper and lower limbs in cases compared to controls. Conclusion The cutaneous silent period seems to be a promising method for evaluation of small fiber neuropathy in RRMS patients. The potential usefulness of the CSP arises from being a simple, non-invasive method for assessment of small peripheral nerve fibers that standard nerve conduction studies cannot detect.