Changes in nystagmus on raising body temperature in clinically suspected and proved multiple sclerosis.

Electronystagmography was used to record the appearance or alteration of nystagmus after raising the body temperature by a heat cradle. Nystagmus was increased or provoked in 13 out of 15 patients with clinically proved multiple sclerosis, in eight out of 12 suspected cases, but in no normal controls. No positive results were obtained in 12 patients with other neurological diseases, even when nystagmus was part of the clinical picutre. The technique is simple to use and may have a role in the diagnosis of multiple sclerosis.