MOTOR NEURON DISEASE - PROGNOSIS AND EPIDEMIOLOGY

Abstract

To evaluate the prognosis and possible prognostic factors associated with a benign course, 118 cases of motor neuron disease diagnosed 1948-1975 were followed up. Survival curves, based on the actuarial methods, showed a survival rate of 18.7% (95% confidence limits: 11.4-26.0) and 7.6% (95% confidence limits: 2.7-12.5) after 5 and 10 yr, respectively. Comparing the survival curves of males/females, cases with bulbar/spinal- and upper/lower extremity onset, cases with/without upper motor neuron signs, only bulbar onset was associated with a significantly poorer prognosis. However, cases with bulbar onset had a significantly higher mean age of onset. Based on cases from Funen county [Denmark] with a 1970 population of 432,699 an average annual incidence rate, mortality rate and period prevalence rate of 0.85, 0.86 and 2.5/100,000, respectively, were found. Comparing the incidence per 5 yr period through 1948-1972, no significant deviations indicating a changing environmental factor were found.