Cytomegalovirus. Induced demyelination associated with acquired immune deficiency syndrome.

We observed three cases of cytomegalovirus (CMV) infection of the nervous system in association with acquired immune deficiency syndrome. The first patient had demyelinating lesions in the spinal cord with relative preservation of axis cylinders. The second patient had a discrete focus of demyelination in the hypothalamic region associated with well-preserved axons and intact neurons. Microglial nodules were absent in both patients. The third patient had subacute encephalomyelitis principally encephalomyelitis principally characterized by microglial nodule formation in the brain and spinal cord, in addition to necrotizing lesions in the thoracic cord and segmental demyelination in the anterior spinal nerve roots. Perivascular lymphocytic infiltration was minimal and was noted mainly within the peripheral nerves. Typical cytomegalic intranuclear inclusion bodies were seen in the nervous tissue of these three patients who all had evidence of disseminated CMV infection. It is possible that these patients had virus-induced demyelination in the face of altered immunoregulation.