It has been postulated that stress is part of the etiological process of Parkinson's disease (PD). The risk of PD was examined in a cohort of patients with adjustment disorders, a diagnosis made in the presence of a severe response to a stressful life event.
Using Danish medical registries, PD occurrence was examined in a nationwide population-based cohort of patients with adjustment disorder diagnosed between 1995 and 2011. The standardized incidence ratio of PD was calculated as the ratio of observed to expected cases, stratified by time and potential risk factors, including depression and anxiety.
Our adjustment disorder cohort (67 786 patients) was followed for a median of 8 years (interquartile range 4, 12.6 years). During follow-up, 119 patients developed PD, versus 64 expected, corresponding to a standardized incidence ratio of 1.84 (95% confidence interval 1.53, 2.20). Consistent results were observed after stratification on potential risk factors, including depression and anxiety.
Adjustment disorder, a diagnosis made in the presence of severe response to stressful life events, was associated with an increased risk of PD.
The modal age at onset of the parkinsonian syndrome during the past thrity years is less than a decade higher than it was in the late 19th and early 20th centuries, suggesting that the same disease entity is affecting parkinsonian patients now as then. The evidence points to the existence of two distinct clinical entities: 1) parkinsonism secondary to encephalitis lethargica, which had its greatest influence on the epidemiology of parkinsonism between 1920 and 1945; and 2) classic parkinsonism, which has undergone little change in the past hundred years.
We have conducted a hospital-based survey of the age-specific prevalence of Parkinson's disease in 551 patients from Helsinki and Vancouver. We conclude that the disorder may be starting earlier than previously and we discuss the implications of this finding for the etiology of Parkinson's disease.
This study examined the possible association between agricultural and horticultural work and the subsequent morbidity of Parkinson's disease.
Fixed cohorts of 2,273,872 men and women aged 20-59 years on 1 January 1981 and identified in the Central Population Register of Denmark were followed, and all first-time hospitalizations with Parkinson's disease as the principal diagnosis during the 13 years until 31 December 1993 were recorded. Standardized hospitalization ratios (SHR) were calculated using all gainfully employed persons as the standard and by multiplying the ratio by 100. Ninety-five percent confidence intervals (95% CI) were calculated on the assumption of a Poisson distribution.
A high risk of Parkinson's disease was found for the men and women in agriculture and horticulture (134 cases, SHR 132, 95% CI 111-156). Statistically significantly high risks were found for farmers (79 cases, SHR 130, 95% CI 103-163) and for all men in agriculture and horticulture (109 cases, SHR 134, 95% CI 109-162).
A consistent pattern of high Parkinson's disease morbidity was found among occupational groups employed in agriculture and horticulture.
This study, based upon data from 40 non-demented Parkinson's disease cases and 101 community controls, and similar data provided by either the spouse (n = 110) or an adult child (n = 31) of each index subject, attempted to assess the usefulness of various demographic data provided by the surrogate respondents for the index subjects. The data were collected by personal interview using a structured questionnaire specifically developed for this study. Ninety-one percent of the index subjects and their surrogates provided information on the annual family income and 98% provided other demographic information. The analysis was done by three groups: the case-surrogates, the control-surrogates and the combined index subject-surrogates, and within each group by the two types of surrogates for the index subjects: the spouse vs adult child. The overall percent agreement between the index subjects and their surrogates varied from moderate for annual family income (54.1%), to good for educational level (61.6%) and to excellent for ethnic origin (82.6%), for age +/- 1 year (97.9%) and for marital status (100.0%). No significant differences in agreement were found for any of these demographic variables either between the case-surrogate group and the control-surrogate group, or between the spouse surrogates and the child surrogates. These findings suggest that spouses and adult children can provide valid information and are equally reliable informants concerning the demographic characteristics of index subjects in a case-control study of Parkinson's disease and, possibly, of other diseases.
A recently described form of Parkinson's disease - PARK8 - is caused by mutations in the novel LRRK2 gene on chromosome 12q12. The most common mutation in this gene is the substitution G2019S and we studied it for the first time in a large group of Russian Slavonic patients (311 patients) with Parkinson's disease including 295 sporadic and 16 familial cases. The mutation LRRK2-G2019S was identified in 1% of patients examined (3 cases) and was not found in a group of population control. The clinical picture of all patients with the LRRK2-G2019S mutation was typical for levodopa-responsive parkinsonism and age of disease onset varied widely (from 39 to 71 years). Two different PARK8-linked haplotypes were found in carriers of the mutation that suggested the independent origin of the G2019S mutation on different chromosomes. The identification of mutations in the LRRK2 gene in patients with "ordinary" sporadic Parkinson's disease has serious implications for medical genetic counseling and prognosis in respective families.
Mutations in DJ-1 are a cause of autosomal recessive parkinsonism. Polymorphism of genes implicated in hereditary forms of parkinsonism may be a predisposing factor in sporadic Parkinson's disease (PD). The authors analyzed whether a polymorphism (g.168_185del) within exon 1 of DJ-1 contributes to the risk of sporadic PD in a Finnish case-control series. This gene does not play a major role in the genetic predisposition to PD in this population.
Comment In: Neurology. 2004 Jun 22;62(12):233515210917
Recent data has demonstrated that mutations in PINK1, encoding PTEN-induced kinase 1, are a cause of early onset recessive parkinsonism (PARK6 locus). Common variability in genes implicated in hereditary forms of parkinsonism may be a predisposing factor in sporadic Parkinson's disease (PD). We analyzed whether six different genetic variants within and surrounding PINK1 contribute to the risk of sporadic PD in a Finnish case-control series. Our results indicate that this gene does not play a major role in the genetic predisposition to PD in this population.
The purpose of this study was to investigate the potential contribution of genetic variants in the estrogen receptor beta gene to the aetiology of Parkinson's disease (PD). Several lines of evidence from human and animal studies suggest a protective role for estrogen in PD. Recently the estrogen receptor beta subtype was reported to be an important mediator of estrogen actions in the nigrostriatal dopamine system. Two single nucleotide polymorphisms at position 1730 and 1082 in the ER beta gene were genotyped, using pyrosequencing, in 260 patients with PD and 308 controls recruited from the Swedish population. Neither of the two estrogen receptor beta polymorphisms was associated with an increased risk for PD. However, the G allele of the A1730G polymorphism was more frequent in patients with an early age of onset than in patients with a late age of onset of PD (P = 0.006). Patients carrying the GG genotype had an odds ratio of 2.2 for having an early onset of PD compared to non-carriers. In conclusion, our results indicate that genetic variation in the estrogen receptor beta gene may influence the age of onset of PD.