Routinely performed electrodiagnostic study may be normal in some subjects with mild peripheral neuropathy such as acral dysesthesia and/or weakness and, therefore, fails to confirm the diagnosis at the early stage. Aiming to improve electrodiagnostic sensitivity, we studied critical muscle sampling in electromyography. Subjects with clinical diagnosis of peripheral neuropathy and with normal conventional electrodiagnostic findings were initially recorded. An additional muscle sampling on the first dorsal interosseous pedis was performed. Based on the observation whether there was an absence or presence of abnormal electromyography findings in the muscle of first dorsal interosseous pedis, they were divided into normal group-A or abnormal Group-B. Relationships between the frequency of the abnormal electrodiagnostic study and comorbidities were analyzed. Group-A with 63 subjects (age 45.0 ± 13.0 years old, Male/Female = 16/47) while Group-B with 73 subjects (age 54.2 ± 13.5, M/F = 29/43) were identified based on whether there was the absence or presence of fibrillation potentials and positive sharp waves, an indicator of active denervation process, in the muscle of first dorsal interosseous pedis. More than half of the cohort had abnormal findings, which was increased in frequencies in diabetes, distal weakness, elderly and male populations. Sampling the first dorsal interosseous pedis improves the electrodiagnostic sensitivity for peripheral neuropathy.
Citation: Luo JJ. 2016. Sampling an Intrinsic Foot Muscle Improves Electrodiagnostic Sensitivity for Peripheral Neuropathy. J Neurol Exp Neurosci 2(1): 12-14.