Severe diaphragm weakness in multiple sclerosis.

A 41 year old caucasian male presented in February 1981 with vertigo, diplopia, paraesthesiae, and urinary retention. He was ataxic and had an internuclear ophthalmoplegia and bilateral extensor responses. Lumbar cerebrospinal fluid showed 41 lymphocytes/mm3 and a protein concentration of 2 g/l. He was treated with dexamethasone and recovered. In March 1982 he presented with typical left optic neuritis responding poorly to corticosteroid treatment. Later that year he had sensory disturbance over the trunk and gait ataxia. In May 1983 he developed