[Alzheimer's disease with secondary Parkinson's syndrome. Case report of a patient with dementia and Parkinson's syndrome after long-term occupational exposure to insecticides, herbicides, and pesticides].

This case report describes long-term occupational exposure to agricultural insecticides, herbicides, and pesticides as possible environmental risk factors of Alzheimer's disease (AD) and Parkinson's syndrome in a 59-year-old man. Initially the patient complained about disturbances in concentration, mnestic deficits, and problems finding words. In the further course of the disease, he developed Parkinson's syndrome with predominant hypokinesia and rigor in addition to mild-to-moderate dementia. Low levels of beta-amyloid 1-42 were found in the CSF. Electroencephalography showed left frontotemporal theta waves. Cranial MRI revealed general brain atrophy with a maximum biparietally. In cerebral positron emission tomography, general hypometabolism was found with maxima biparietally and left frontally. The possible differential diagnosis of AD and Parkinson's syndrome is discussed.