this proposal is based on the association between environmental factors and certain neurodegenerative diseases ( eg , methylphenyltetra-hydropyridine and parkinsonism , poliovirus infection and post-poliomyelitis syndrome , chickling pea ingestion and lathyrism , an unidentified environmental factor and amyotrophic lateral sclerosis-pd complex of guam , and trauma and pugilist 's encephalopathy ) and on the long latent period between exposure to environmental factor and the appearance of symptoms in some of these disorders .
C0524851
neurodegenerative diseases
C0030567
pd