Anti-GQ1b antibodies have been found in two-thirds of patients with this condition. This antibody is also found in almost all cases of Miller Fisher syndrome. The EEG is often abnormal, but shows only slow wave activity, which also occurs in many other conditions, and so is of limited value in diagnosis. Similarly, raised CSF protein levels and pleocytosis are frequent but non-specific. It was originally thought that raised CSF protein without pleocytosis ('albuminocytological dissociation') was a characteristic feature, as it is in Guillain–Barré syndrome, but this has not been supported in more recent work. In only 30% of cases is an MRI brain scan abnormal. Nerve conduction studies may show an axonal polyneuropathy.
Bickerstaff brainstem encephalitis
Powassan encephalitis
Saint Louis encephalitis
La Crosse encephalitis
Viliuisk encephalomyelitis
Rasmussen's encephalitis
Marburg acute multiple sclerosis
Acute disseminated encephalomyelitis