Diabetes insipidus in a patient with suspected multiple sclerosis.

A 53-year-old man developed spastic ataxia associated with diabetes insipidus. The patient experienced frequent attacks of stiffness and numbness of the four limbs accompanied by difficulty of speech. During an eight years' follow-up a progressive deterioration of the motor function was observed but no extracerebral manifestations were noticed. The association of spastic ataxia is generally considered as diagnostic of histiocytosis X. In the present case, however, multiple sclerosis seems a more likely diagnosis in view of the late onset and the highly characteristic brain stem seizures.