[Bickerstaff brainstem encephalitis: epidemiology, diagnosis, and therapy].

The author reviewed the epidemiological and clinical aspects of Bickerstaff brainstem encephalitis (BBE) based on the data from the nationwide survey, which was planned in Japanese population between 2006 and 2009. Annual BBE onset was roughly estimated as 100 cases in Japan, which accounted for 43% of brainstem encephalitis, and corresponded to 6.8% of Guillain-Barré syndrome incidence. BBE consisted of typical and atypical cases, and typical BBE had the similar neurological and serological features to Fisher syndrome as well as with good recovery, whereas atypical BBE was characterized by delayed recovery, negative anti-GQ1b antibodies, and abnormal CSF and brain MRI findings with possible other pathogeneses.