Bickerstaff's brainstem encephalitis (BBE) is a rare post-infectious neurological disease characterized by the association of external ophthalmoplegia, ataxia, lower limb arreflexia, extensor plantar response and disturbance of consciousness (drowsiness, stupor or coma).

Complete loss of ability to move facial muscles innervated by the facial nerve (i.e., the seventh cranial nerve).