Unusual form of motor neuron disease in Kenya

Over the period November 1978 to October 1988, 46 cases of motor neuron disease were seen at Kenyatta National Hospital, Nairobi. One case was seen in private practice. A bimodal age distribution of the disease was identified with a peak in the fourth decade of life and another peak in the sixth decade of life. The disease seen in the fourth decade of life was different as seen in other parts of the world in that the majority of patients tended to present with very rapidly progressive disease despite the primary presentation with limb symptoms and signs. Serum cholinesterase activity in five of these patients and five of the classical motor neuron disease revealed no abnormalities. This unusually rapidly progressive disease in young adults has not been described anywhere. The disease seen in older age groups and especially in patients over fifty years of age was not different from the one seen in other parts of the world.