Isolation of virus from the spinal fluid of three patients with multiple sclerosis and one with amyotrophic lateral sclerosis.

A transmissible agent with the properties of a thermolabile filterable virus was isolated from the cerebrospinal fluid (CSF) of 4 Houston patients with chronic central nervous system (CNS) disease. 3 had multiple sclerosis and I had amyotrophic lateral sclerosis. No isolations were made from 27 patients whose CSF was taken for diagnosis of illness unrelated to degenerative CNS disease. Neutralising antibodies to the 4 isolates were present in the serum of each of the 4 patients with virus (14 positive results among 15 tests) but in hardly any of the sera from 8 patients without virus (3 antibody-positive results among 32 tests). The agent is antigenically related to the virus isolated in Japan from cases of subacute myelo-optico-neuropathy.