Treatment for Fisher syndrome, Bickerstaff's brain stem encephalitis and related disorders

Fisher syndrome is an uncommon paralysing illness, usually caused by autoimmune inflammation of nerves following an infection. Fisher syndrome is characterised by impairment of eye movements, abnormal co-ordination and loss of tendon reflexes. It is a variant of Guillain-Barré syndrome. Unlike Guillain-Barré syndrome, it does not cause limb or respiratory muscle weakness. In Western countries Fisher syndrome represents between 5% and 10% of Guillain-Barré syndrome cases, but it is more common in Eastern Asia, for example 25% of cases in Japan. Bickerstaff's brain stem encephalitis shares many clinical features but also includes altered consciousness and signs of central nervous system inflammation. Treatment strategies tried have been immunotherapies such as plasma exchange or intravenous immunoglobulin which are used in Guillain-Barré syndrome. This systematic review found no randomised controlled trials of treatments for Fisher syndrome, Bickerstaff's brain stem encephalitis or their variants. Observational studies suggest that Fisher syndrome always and Bickerstaff's brain stem encephalitis usually recovers completely. Randomised controlled trials are needed to establish the value of immunotherapies or other treatments.