Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex on Guam: Further Pathologic Studies

THE EXTRAORDINARY prevalence of fatal neurological diseases on Guam has evoked the interest of a number of investigators for the last 15 years. The best known diseases affecting the indigenous Chamorro people are a type of amyotrophic lateral sclerosis (ALS), apparently unique to Guam,¹ where, in addition to the classical histological changes of ALS, Alzheimer's neurofibrillary changes are present in specific parts of the central nervous system (CNS); and parkinsonism dementia complex (PD) in which the same neurofibrillary changes are consistently observed.²

At this point one may obviously ask whether these diseases are two distinct entities or are in some way related. This relationship has recently been discussed from the clinical³ and epidemiological⁴ stand-points. In this paper we would like to provide neuropathological evidence for such a relationship. For this purpose we have examined tissues associated with both diseases regardless of the principal clinical