Electrodiagnostic prevalence of accessory peroneal nerve in admitted patients in Shohada hospital

Accessory peroneal nerve (APN) is an anatomic variation which can disturb electrodiagnostic studies. This anomaly is detected when the response CMAP (Compound muscle action potential) of EDB (Extensor digitrum brevis) to peroneal nerve stimulation is measured smaller in distal when compared to proximal. In this study, we have assessed the prevalence of APN in a group of patients admitted to Shohada-Tajrish hospital. CMAP of DPN was measured by Neuro-Screen Toennis instrument. If no CMAP of EDB was detected in ankle, a record was obtained below lateral malleous and the presence of APN was confirmed when CMAP in distal was lesser than proximal. The study population included 143 females (62.7%) and 87 (17.9%) males with a mean age of 42.1±13.5 years. APN was detected in 28 patients, among whom 5 (17.9%) had bilateral APN. Sexual distribution of APN was the same, with half of the cases (14 patients) were females. The prevalence of APN was 12.2%. Approximately, 17.9% of cases were bilateral.