The biology of dementia due to Parkinson's disease

This article is one of a series focusing on dementias due to an underlying biological factor. The reader should refer to the previous articles in the series (Delieu and Keady, 1996a,b). This article focuses on the normal structures within the brain which are involved in motor control and describes what occurs when this system is disrupted by an inappropriate reduction in the neurotransmitter dopamine. In time, this reduction in dopamine may have deleterious effects on other neuronal systems within the central nervous system, namely the diminished acetylcholine neurones which may lead to a dementional state. Possible causes of Parkinson's disease are discussed and some treatments briefly outlined.