Herpes simplex virus (HSV) is a rare, antecedent infectious agent in 
Guillain-Barré syndrome (GBS). We report a patient with overlapping GBS and 
Bickerstaff's brainstem encephalitis (BBE). The patient had a vesicular lesion 
on her nose. Antecedent HSV type 1 (HSV-1) infection was confirmed by isolation 
of the virus and detection of the presence of serum anti-HSV-1 IgM antibody 
during the acute phase. Her serum IgG had high anti-GQ1b antibody titer. 
External ophthalmoplegia has been noted in 2 of 4 reported cases of 
HSV-associated GBS. Herpetic brainstem encephalitis cases of poor prognosis are 
known, but only 2 cases of benign brainstem encephalitis secondary to HSV 
infection, in which there was acute ophthalmoplegia and clinical features 
consistent with those of BBE have been reported.