2020 年 37 巻 3 号 p. 287-290
Nerve conduction studies (NCSs) are essential for diagnosis of peripheral neuropathy. NCSs should be performed for the purpose of complementing the findings obtained by detailed neurological examinations. If weakness or numbness is consistent with the territory innervated by a peripheral nerve or spinal nerve, it is more likely to be a peripheral lesion than a central lesion. A fibular NCS is useful for the diagnosis of foot drop. The compound muscle action potential (CMAP) of the fibular nerve is usually recorded on the extensor digitorum brevis, but the CMAP is susceptible to potential damage and may not be suitable for the evaluation of foot drop. In that case, it is recommended to record the CMAP on the tibialis anterior. Sensory conduction studies can distinguish lesions before and after the dorsal root ganglion (L5 radiculopathy vs. fibular neuropathy). It should be noted that conduction block and temporal dispersion are not always demyelinating findings.
