Environmental epidemiology of essential tremor.
BACKGROUND
Essential tremor (ET) is one of the most common neurological disorders. Despite this, the disease mechanisms and etiology are not well understood. While susceptibility genotypes undoubtedly underlie many ET cases, no ET genes have been identified thus far. As with many other progressive, degenerative neurological disorders, it is likely that environmental factors contribute to the etiology of ET. Environmental epidemiology is the study in specific populations or communities of the effect on human health of physical, biologic and chemical factors in the external environment. The purpose of this article is to review current knowledge with regards to the environmental epidemiology of ET.


RESULTS
As will be discussed, a series of preliminary case-control studies in recent years has begun to explore several candidate toxins/exposures, including harmane (1-methyl-9H-pyrido[3,4-b]indole), lead and agricultural exposures/pesticides.


CONCLUSIONS
While several initial results are promising, as will be discussed, additional studies are needed to more definitively establish whether these exposures are associated with ET and if they are of etiological importance.
Louis
Elan D
ED
GH Sergievsky Center, Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Mailman School of Public Health, Columbia University, New York, NY 10032, USA. EDL2@columbia.edu
D003072:Cognition Disorders / Q000453:epidemiology; D004198:Disease Susceptibility / Q000150:complications; D004781:Environmental Exposure; D004782:Environmental Health; D020329:Essential Tremor / Q000453:epidemiology* / Q000209:etiology / Q000523:psychology; D006247:Harmine / Q000031:analogs & derivatives / Q000633:toxicity; D006801:Humans; D007855:Lead Poisoning / Q000150:complications; D010575:Pesticides / Q000633:toxicity; D012307:Risk Factors
D010575:Pesticides; D006247:Harmine; C005010:harman