The purpose of this study is to investigate the diagnostic value of using brain stem auditory evoked potentials (BSEP) in patients with the lateral medullary (Wallenberg’s) syndrome. The observed changes included: prolongation of the interpeak latency intervals from wave I to V and III to V; prolongation of the interaural latency difference for wave V; splitting or absence of wave III, and the presence of a broad partly fused wave III-V complex. The present study showed that BSEP can be used to confirm the diagnosis of this syndrome and ascertain the site of the lesio