Early outbreaks of 'epidemic neuromyasthenia'.

The literature of the outbreaks of 'epidemic neuromyasthenia' (ENM) from 1934 to 1955 has been selected to show that the disease affects other people besides young adult females in hospitals and nursing homes. There have been district epidemics, in which the male: female ratio was almost even and several male outbreaks affecting soldiers in barracks. Some outbreaks appear to have been triggered off by an epidemic of poliomyelitis, and the epidemiology of outbreaks in Iceland in 1948 and 1955 suggests that the normal cytopathological effects of poliomyelitis infection have been suppressed by the new disease. In the Durban epidemic (1955) a toxic metabolite was discovered in the urine of many patients and a markedly increased urinary excretion of creatine was noted in two New York State outbreaks. The results of the transmission of an agent from patients with ENM to monkeys suggest that the neurological disorder might be in the form of mild disseminated lesions scattered throughout the nervous system from the brain to peripheral nerves and associated with perivascular round cell infiltration without significant cellular damage. ENM infection was widespread in the North of England in 1955 and associated with lymphocyte abnormalities, which have persisted in some cases for several years. This suggests a continuous organic process.