Recent neuropathologic observations in amyotrophic lateral sclerosis and parkinsonism-dementia of guam

Amyotrophic lateral sclerosis and parkinsonism-dementia apparently continue to occur on Guam at the same high rates as before. We present recent neuropathologic data against the background of studies currently in progress. Brains from 3 United States veterans who served on Guam during the second world war and subsequently died of ALS did not contain neurofibrillary tangles in the characteristic distribution which is invariably found in ALS pa tients on Guam. Follow-up studies of construction workers who resided on Guam between 1945 and 1955 have not revealed a high rate of ALS thus far in this population. A Filipino who resided on Guam for twenty years and died of ALS had very mild neurofibrillary involvement in the areas of the brain where these changes occur among Guamanians. A small number of neurofibrillary changes in subcortical areas is observed among some Guamanians who did not have obvious symptoms of ALS or PD. ALS at approximately the same rate as is encountered on Guam is observed among Guamanians who migrated to California. PD has been verified in a single Guamanian living in California but apparently not among Filipino populations. Idiopathic parkinsonism has not been documented pathologically in a Chamorro on Guam during the years of study. This is surprising since we would have expected no fewer than 20 patients with idiopathic parkinsonism during this time. One Chamorro who moved to California developed signs of parkinsonism approximately six years after arrival. He succumbed eight years later, and at autopsy, the dominant neuropathologic picture was that of idiopathic parkinsonism and not that of PD of Guam. Markedly low levels of monoamines were observed among Guamanian PD patients. Levels in the spinal fluid of ALS patients were higher than those of PD patients but lower than Guamanian controls and were similar to those of ALS patients in the United States. Improvement was observed among PD patients receiving L-dopa. Attempts to isolate slow viruses from ALS and PD patients thus far have been negative, and a simple mendelian mode of inheritance has not been observed. These data are discussed in terms of the etiology of ALS and PD and the relationship between these diseases.