Miller Fisher Syndrome and Bickerstaff's Encephalitis: 2 Sides of the Same Coin

Miller Fisher syndrome (MFS) and Bickerstaff's brainstem encephalitis (BBE) have long been regarded as mutually exclusive disorders of the peripheral (PNS) and central nervous system (CNS), respectively. Recent studies analysing the pathogenesis, course, signs and symptoms of both diseases in large numbers of patients as well as neurophysiological and imaging data contradict this historical nosological classification. MFS and BBE share a common immunopathogenesis and form closely related parts of a continuous spectrum of inflammatory disorders variably involving PNS and CNS. We here present an overview of clinical characteristics, recent pathophysiological findings and therapeutic implications of this disease spectrum.