Restraint stress suppresses experimental allergic encephalomyelitis in Lewis rats

We studied the effect of restraint stress on experimental allergic encephalomyelitis (EAE), a model for the human disease multiple sclerosis (MS), in Lewis rats. Rats were subjected to 12 h restraint stress for 3 consecutive nights from the first (day 1) or the eighth day (day 8) after sensitization with the antigen (guinea-pig spinal cord). All controlled rats exhibited clinical and histologic signs of EAE. The mean +/- SD of incubation time, clinical score (0-4) and histologic score (0-3) for this group were 12.8 +/- 1.0 days, 2.7 +/- 0.6, and 2.3 +/- 0.7, respectively. Restraint stress from day 8 significantly suppressed EAE: the mean +/- SD of incubation time, clinical score, and histologic score for this group were 17.2 +/- 2.2 days (p < 0.001), 1.8 +/- 1.3 (p < 0.05), and 1.5 +/- 0.9 (p < 0.02), respectively. Restraint stress from day 1 did not modify EAE. The findings suggest that stressful factors may exert an influence on the clinical course of MS.