Case of Bickerstaff encephalitis with positive glutamic acid decarboxylase antibodies

Bickerstaff brainstem encephalitis (BBE) is a rare inflammatory demyelinating condition, which is similar to Miller-Fisher syndrome (MFS). Ophthalmoplegia and ataxia are common to these syndromes but unlike MFS, BBE is also characterised by central nervous system involvement, most commonly in the form of altered consciousness. BBE usually has a very good prognosis. We present a case of a young female with BBE. Unlike the majority of BBE patients, she (1) was negative for anti-GBQ1b antibodies but positive for glutamic acid decarboxylase (GAD) antibodies and borderline positive for voltage-gated calcium channel antibodies and (2) had a delayed recovery post treatment with intravenous immunoglobulins and plasma exchange. We contemplate a potential role for GAD antibodies as a marker for longer recovery time in patients with BBE.