Amyotrophic lateral sclerosis and parkinsonism-dementia among Filipino migrants to Guam.

Amyotrophic lateral sclerosis (ALS) has occurred in 9 Filipino migrants to Guam 1 to 29 years after their arrival and parkinsonism-dementia (PD) in 2 migrants 13 and 26 years after arrival. Seven additional Filipino patients developed more classic Parkinson disease (P) 5 to 24 years after their migration to Guam. Furthermore, 10 part-Filipino patients who were born on Guam of Filipino and Chamorro parentage developed ALS, while 6 such part-Filipino patients developed PD. An estimate of the average annual crude mortality rate for ALS among Filipino migrants was approximately six times that of the continental United States, yet half that currently observed among Chamorros living on Guam. A majority of all migrant patients were born in northwestern Luzon in the Philippine Islands, indicating the desirability of an intensive field epidemiological investigation in that area.