[A case of anti-GQ1b-positive atypical Fisher syndrome with internal ophthalmoplegia but without external ophthalmoplegia].

We report a 21-year-old man who developed an atypical form of Fisher syndrome. One week after having a common cold, he was admitted to our hospital because of a gait disturbance. Neurological examination revealed a somnolent state, cerebellar ataxia, areflexia, limb muscle weakness, and numbness in a glove and stocking like distribution. The patient had internal ophthalmoplegia but did not have external ophthalmoplegia. Brain MRI showed no abnormality in the orbital and the pretegmental brain regions. The protein level in the cerebrospinal fluid was 57 mg/dl and the cell count was 5 mononuclear cells/mm3. His serum titer of anti-GQ1b IgG antibody was markedly elevated. There have been only two previous reports of isolated internal ophthalmoplegia with elevated anti-GQ1b antibody. The present case suggests that anti-GQ1b antibody play an important role in the pathogenesis of patients who present with internal ophthalmoplegia but without external ophthalmoplegia.