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There has been some discussion as to whether herbicides or insecticides have been implicated in Parkinson's. The following are some abstracts on the subject. The full text versions are probably in your closest medical library. Authors Fleming L. Mann JB. Bean J. Briggle T. Sanchez-Ramos JR. Institution Department of Epidemiology and Public Health, University of Miami School of Medicine, FL 33136. Title Parkinson's disease and brain levels of organochlorine pesticides. Source Annals of Neurology. 36(1):100-3, 1994 Jul. Abstract Epidemiological studies have suggested an etiologic relationship between pesticide exposure and Parkinson's disease (PD). Organochlorine pesticides were assayed in postmortem brain samples from 20 PD, 7 Alzheimer's disease (AD), and 14 nonneurological control cases. The three groups were similar in age at death, sex, and demographic variables. Only two of 16 pesticide residues screened were detected. A long-lasting residue of DDT (pp-DDE) was found in the majority of cases of PD and AD, as well as in all the control cases; pp-DDT was significantly more likely to be found in AD controls than the PD cases (Fisher's exact two-tailed, p = 0.04). Dieldrin was detected in 6 of 20 PD brains, 1 of 7 AD, and in none of 14 control samples. Despite the relatively small number of brains assayed, the association between Dieldrin and the diagnosis of PD was highly significant (p = 0.03). Dieldrin, a lipid-soluble, long-lasting mitochondrial poison, should be investigated as a potential etiological agent of Parkinsonism. Authors Bell IR. Schwartz GE. Amend D. Peterson JM. Kaszniak AW. Miller CS. Institution Department of Psychiatry, University of Arizona Health Sciences Center, Tucson 85724. Title Psychological characteristics and subjective intolerance for xenobiotic agents of normal young adults with trait shyness and defensiveness. A parkinsonian-like personality type?. Source Journal of Nervous & Mental Disease. 182(7):367-74, 1994 Jul. Abstract The present study examines the psychological characteristics and self-reported responses to xenobiotic agents such as tobacco smoke and pesticide of normal young adults with personality traits similar to those claimed for Parkinsonian patients. Previous research, though controversial, has suggested that persons with idiopathic Parkinson's disease (PD) have premorbid personality traits that may include shyness and repressive defensiveness. Other epidemiological evidence indicates that PD patients may have premorbidly increased prevalence of anxiety, affective, and/or somatoform disorders; decreased rates of smoking and alcohol consumption; and elevated exposure to herbicides or pesticides. A total of 783 college students enrolled in an introductory psychology course completed the Cheek-Buss Scale (shyness), the Marlowe-Crowne Social Desirability Scale (defensiveness), Symptom Checklist 90 (revised), the Mastery Scale, a health history checklist, and rating scales for frequency of illness from alcohol and 10 common environmental chemicals. Subjects were divided into four groups on the basis of above- versus below-median scores on the Cheek-Buss and Marlowe-Crowne scales (persons high in shyness and defensiveness, those high only in shyness, those high only in defensiveness, and those low in both shyness and defensiveness). The group high in shyness but low in defensiveness had the highest, whereas the group low in shyness but high in defensiveness had the lowest, total scores on the SCL-90-R; the two shyest groups were lowest in sense of mastery.(ABSTRACT TRUNCATED AT 250 WORDS) Authors Hubble JP. Cao T. Hassanein RE. Neuberger JS. Koller WC. Institution Department of Neurology, University of Kansas Medical Center, Kansas City 66160-7314. Title Risk factors for Parkinson's disease [see comments]. Comments Comment in: Neurology 1993 Sep;43(9):1641-3, Comment in: Neurology 1994 Aug;44(8):1557-8 Source Neurology. 43(9):1693-7, 1993 Sep. Abstract Parkinson's disease (PD) has been associated with rural living, well-water consumption, and pesticide exposure; however, the individual risk contribution of these variables has not been established. We examined social and medical histories of predominantly rural populations to determine relative risk factors for PD. Patients and controls were surveyed regarding residency, occupation, medical history, and social and dietary habits. An initial multiple logistic regression model was confounded by excessive variable colinearity. Principal factor analysis yielded three factors: rural living (including years of rural residency and ground-water use), pesticide use, and male lifestyle (male gender, head trauma, male-dominated occupations). Other variables did not load in factor analysis and were entered separately, with the three factor scores, in a second multiple logistic regression model. Significant predictors of PD emerged (in order of strength): pesticide use, family history of neurologic disease, and history of depression. The predicted probability of PD was 92.3% (odds ratio = 12.0) with all three predictors positive. Pesticide use (distinguishable from rural living) can be considered a risk factor for the development of PD, with family history of neurologic disease and history of depression serving as weaker predictors of PD. Authors Butterfield PG. Valanis BG. Spencer PS. Lindeman CA. Nutt JG. Institution Center for Research on Occupational and Environmental Toxicology, Oregon Health Sciences University, Portland 97201. Title Environmental antecedents of young-onset Parkinson's disease. Source Neurology. 43(6):1150-8, 1993 Jun. Abstract We conducted an exploratory study of young-onset Parkinson's disease (YOPD) to examine occupational and environmental factors associated with disease risk. This case-control study included 63 YOPD patients (diagnosis on or before age 50); controls (n = 68) were diagnosed with rheumatoid arthritis. Crude odds ratios (ORs) were computed to identify exposure variables for logistic regression analyses. After controlling for the variables of race, educational level, sex, age, age at diagnosis, and family history of Parkinson's disease (PD), PD was positively associated with insecticide exposure (OR = 5.75, p < 0.001), past residency in a fumigated house (OR = 5.25, p = 0.046), herbicide exposure (OR = 3.22, p = 0.033), rural residency at time of diagnosis (OR = 2.72, p = 0.027), and nuts and seed eating 10 years before diagnosis (OR = 1.49, p = 0.021). PD was inversely associated with cigarette smoking at 5 years (OR = 0.50, p = 0.027), 10 years (OR = 0.43, p = 0.012), and 15 years (OR = 0.37, p = 0.005) before diagnosis, farm residency (OR = 0.38, p = 0.018), and exposure to dimethyl sulfoxide (OR = 0.10, p < 0.001). These findings are consistent with hypotheses linking PD to exposure to pesticide agents. Authors Semchuk KM. Love EJ. Lee RG. Institution Department of Community Health Sciences, Faculty of Medicine, University of Calgary, AB, Canada. Title Parkinson's disease and exposure to agricultural work and pesticide chemicals. Source Neurology. 42(7):1328-35, 1992 Jul. Abstract This population-based case-control study of 130 Calgary residents with neurologist-confirmed idiopathic Parkinson's disease (PD) and 260 randomly selected age- and sex-matched community controls attempted to determine whether agricultural work or the occupational use of pesticide chemicals is associated with an increased risk for PD. We obtained by personal interviews lifetime occupational histories, including chemical exposure data, and analyzed the data using conditional logistic regression for matched sets. In the univariate analysis, a history of field crop farming, grain farming, herbicide use, or insecticide use resulted in a significantly increased crude estimate of the PD risk, and the data suggested a dose-response relation between the PD risk and the cumulative lifetime exposure to field crop farming and to grain farming. However, in the multivariate analysis, which controlled for potential confounding or interaction between the exposure variables, previous occupational herbicide use was consistently the only significant predictor of PD risk. These results support the hypothesis that the occupational use of herbicides is associated with an increased risk for PD. Authors Wechsler LS. Checkoway H. Franklin GM. Costa LG. Institution Department of Environmental Health, University of Washington, Seattle 98195. Title A pilot study of occupational and environmental risk factors for Parkinson's disease. Source Neurotoxicology. 12(3):387-92, 1991 Fall. Abstract Increasingly, the etiology of Parkinson's disease (PD) has been linked to exposures to environmental toxicants. This epidemiologic pilot study used a self-administered questionnaire among 34 PD cases and 22 other neurology clinic control patients. All subjects were at least 40 years old. Risk factors investigated included occupation, well-water use, pesticide use, metal exposures, medical history, smoking, alcohol consumption, and drug use. Twenty-six percent of the male PD cases reported having been employed in farming versus eleven percent for male controls (OR = 3.1, 95% C.I. = 0.3 to 35). Sixteen percent of male cases versus none of the controls reported employment as welders. No clear trends involving exposure to either occupational or home pesticides emerged. In assessing occupational exposures to metals, aluminum and copper exposures tended to be more common among male cases than male controls. Additionally, as reported in other studies, smoking showed an inverse relationship with PD. Although the findings reported here are provocative, these results are statistically imprecise and must be interpreted cautiously because of the small number of subjects included in the study. Authors Chapman LJ. Sauter SL. Henning RA. Levine RL. Matthews CG. Peters HA. Institution Department of Neurology, University of Wisconsin Medical School, Madison. Title Finger tremor after carbon disulfide-based pesticide exposures. Source Archives of Neurology. 48(8):866-70, 1991 Aug. Abstract Index finger tremor accompanying voluntary movement was studied in 19 age-matched control subjects and in 19 grain industry employees chronically exposed to carbon disulfide-based fumigants. Visual judgments of tremor amplitude made by neurologists during clinical examinations equaled the sensitivity of computerized tremor amplitude measurements. Tremor frequency variations detectable only with computerized measurement were present in grain workers with and without increased tremor amplitudes. Frequency differences discriminated between normal subjects and 74% of the grain workers. The distribution of tremor frequency power in the grain workers was often sequestered at 5 to 7 Hz, reminiscent of tremor in idiopathic Parkinson's disease. These findings suggest that the measurement of subtle tremor frequency changes may provide an early indication of chronic carbon disulfide poisoning. Authors Bachurin SO. Tkachenko SE. Lermontova NN. Institution Institute of Physiologically Active Substances, USSR Academy of Sciences, Chernogolovka, Moscow District. Title Pyridine derivatives: structure-activity relationships causing parkinsonism-like symptoms. [Review] Source Reviews of Environmental Contamination & Toxicology. 122:1-36, 1991. Abstract In recent years, sufficient evidence has surfaced to implicate low-molecular-weight organic compounds in certain known neurological disorders. At this time, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is considered the compound capable of inducing conditions most similar to idiopathic parkinsonism in clinical, biochemical, and histopathological characteristics. Substances containing MPTP-like fragments are used as herbicides, drugs and intermediates in the synthesis of many heterocyclic compounds. The mechanistic study of toxic MPTP action has enabled development of criteria for appraising potential parkinsonogenic properties of similar chemical structures. Key features of MPTP action include the following: 1. Ability to pass through the blood-brain barrier (BBB). 2. Enzymatic biotransformation to the neuroactive form (pyridine metabolites). 3. Transfer to neurons via a neuromediator reuptake system. 4. Action on intracellular targets. This review discusses data concerning the effects of metabolite structure on the major steps in the neurotropic action mechanism of MPTP-like compounds. Special attention is focused on the key steps defining the selectivity of MPTP's neuronal action, i.e., the activation step caused by monoamine oxidase (MAO) and interaction with the dopamine (DA) reuptake system. Most structural MPTP analogs (including certain pesticide preparations) used in our experiments and described in the literature exhibit no degenerative MPTP-like properties. This is probably related to the fact that each consecutive stage in the MPTP neurotoxicity mechanism makes rather stringent demands on metabolite structure. The number of structures which concurrently meet the requirements of all the processes is finite. This, however, does not invalidate the hypotheses concerning the ecotoxic nature of idiopathic parkinsonism. Possible ecotoxins may have only a partial, presymptomatic effect which, however, promotes age-related neurodegenerative processes and accelerates development of parkinsonism. This concept necessitates designing special tests of the possible neurotoxic properties of compounds found in the environment which may be functional MPTP analogs. [References: 147] John Cottingham [log in to unmask] OR [log in to unmask]