Chronic relapsing experimental allergic encephalomyelitis. Studies in vascular permeability changes.

The vascular permeability in the nervous system to Evans blue-albumin and horseradish peroxidase was studied in chronic relapsing EAE in strain 13 and Hartley guinea pigs. The disease was induced by single sensitization of immature animal and was characterized clinically by remissions and relapses. Recent and old demyelinating plaques in the spinal cord were present. These showed an increased permeability to the protein tracers. The blood-brain barrier in these plaques are therefore disturbed and also in this respect the condition is similar to the multiple sclerosis lesions.