Observations on the clinical presentations and the neuropathological findings of amyotrophic lateral sclerosis in Australia and Guam.

Among 20 consecutive autopsies of amyotrophic lateral sclerosis (ALS) occurring in Caucasians in Western Australia (WA), 85% were males. The median age of onset was 58.9 years and the average duration of illness was 2.4 years. Twenty-two randomly selected ALS occurring among natives in Guam also showed a male predominance of 75%, younger age of onset (median 48.5 years) and longer survival period (median 3.4 years). 45% of the WA patients presented with bulbar involvement at the time of first examination. These patients had the lowest median survival period of 1.5 years when compared with the other forms of ALS, the classic upper and lower motor system involvement and progressive muscular atrophy. Theneuropathologic lesions of ALS in WA and Guam were similar with the exception that neurofibrillary tangles were frequently present in the Guamanian brains. In 14%, neuronal loss, gliosis and frequency of tangles in the cerebral cortex especially in Ammon's horn, substantia nigra, and locus ceruleus, were sufficiently severe to indicate the coexistence of another disorder, Parkinsonism-Dementia Complex. This condition was not clinically recognized. In the WA cases only one patient had tangles in the brain and he had concurrent Alzheimers disease. While senile plaques were present in this patient they were usually absent in the Guamanian brains.