[Bickerstaff's brainstem encephalitis and Fisher syndrome: their relationship and treatment].

The nosological position of Bickerstaff's brainstem encephalitis (BBE) was not eatablished, and its etiology was not clear until 1993. Because anti-GQ1b IgG antibody frequently occurs in patients with Fisher syndrome (FS) and there are clinical similarities between FS and BBE, we investigated anti-ganglioside antibodies in sera from three patients with BBE. High anti-GQ1b IgG antibody titers were present in their sera, but decreased with the clinical course of the illness. The findings that BBE and FS shared common autoantibody suggest that autoimmune mechanism common to FS is likely in BBE, and that both conditions form a continuous spectrum. To clarify the clinical features of BBE, we reviewed detailed clinical profiles and laboratory findings for 62 cases of BBE diagnosed by the strict criteria of progressive, relatively symmetric external ophthalmoplegia and ataxia by 4 weeks, and disturbance of consciousness or hyperreflexia. A striking feature was the association with flaccid symmetric tetraparesis seen in 60%. Limb weakness in the BBE cases studied was considered the result of overlap by the axonal subtype of Guillain-Barré syndrome. These indicates that the two disorders are closely related and form a continuous spectrum, and that treatment for Guillain-Barré syndrome should be applied for BBE.