Peggy Gray

A meta-analysis of six prospective studies of falling in Parkinson's disease

Recurrent falls are a disabling feature of Parkinsons disease (PD). We have estimated the incidence of falling over a prospective 3 month follow‐up from a large sample size, identified predictors for falling for PD patients repeated this analysis for patients without prior falls, and examined the risk of falling with increasing disease severity. We pooled six prospective studies of falling in PD (n = 473), and examined the predictive power of variables that were common to most studies. The 3‐month fall rate was 46% (95% confidence interval: 38–54%). Interestingly, even among subjects without prior falls, this fall rate was 21% (12–35%). The best predictor of falling was two or more falls in the previous year (sensitivity 68%; specificity 81%). The risk of falling rose as UPDRS increased, to about a 60% chance of falling for UPDRS values 25 to 35, but remained at this level thereafter with a tendency to taper off towards later disease stages. These results confirm the high frequency of falling in PD, as almost 50% of patients fell during a short period of only 3 months. The strongest predictor of falling was prior falls in the preceding year, but even subjects without any prior falls had a considerable risk of sustaining future falls. Disease severity was not a good predictor of falls, possibly due to the complex U‐shaped relation with falls. Early identification of the very first fall therefore remains difficult, and new prediction methods must be developed.

Heterozygosity for a mutation in the parkin gene leads to later onset Parkinson disease

Background: The vast majority of the parkin mutations previously identified have been found in individuals with juvenile or early onset PD. Previous screening of later onset PD cohorts has not identified substantial numbers of parkin mutations. Methods: Families with at least two siblings with PD were ascertained to identify genes contributing to PD susceptibility. Screening of the parkin gene, by both quantitative PCR and exon sequencing, was performed in those families with either early onset PD (age onset ≤50 years) or positive lod score with a marker in intron 7 of the parkin gene. Results: A total of 25 different mutations in the parkin gene were identified in 103 individuals from 47 families. Mutations were found in both parkin alleles in 41 of the individuals, whereas a single mutation in only one of the two parkin alleles was observed in 62 individuals. Thirty-five of the subjects (34%) with a parkin mutation had an age at onset of 60 years or above with 30 of these 35 (86%) having a detectable mutation on only one parkin allele. Few significant clinical differences were observed among the individuals with two, one, or no mutated copies of the parkin gene. Conclusion: Mutations in the parkin gene occur among individuals with PD with an older age at onset (≥60 years) who have a positive family history of the disease. In addition, the clinical findings of parkin-positive individuals are remarkably similar to those without mutations.

Significant Linkage of Parkinson Disease to Chromosome 2q36-37

Parkinson disease (PD) is the second most common neurodegenerative disorder, surpassed in frequency only by Alzheimer disease. Elsewhere we have reported linkage to chromosome 2q in a sample of sibling pairs with PD. We have now expanded our sample to include 150 families meeting our strictest diagnostic definition of verified PD. To further delineate the chromosome 2q linkage, we have performed analyses using only those pedigrees with the strongest family history of PD. Linkage analyses in this subset of 65 pedigrees generated a LOD score of 5.1, which was obtained using an autosomal dominant model of disease transmission. This result strongly suggests that variation in a gene on chromosome 2q36-37 contributes to PD susceptibility.

Rasagiline improves quality of life in patients with early Parkinson's disease

The objective of this study was to determine the effects of rasagiline as monotherapy on quality of life (QOL) in patients with early Parkinsons disease (PD). Rasagiline, a potent, second‐generation, irreversible, selective monoamine oxidase B inhibitor improves PD symptoms in patients with early PD. Patients with early untreated PD were randomly assigned to once‐daily rasagiline 1 mg/day, rasagiline 2 mg/day, or placebo in a 6‐month, double‐blind trial (n = 404). At the end of 6 months, patients entered the preplanned, active‐treatment phase in which those receiving 1 mg/day and 2 mg/day of rasagiline continued on their previously assigned dosages and those receiving placebo switched to rasagiline 2 mg/day, while maintaining blinding to treatment assignments. QOL was measured with the Parkinsons Disease Quality of Life questionnaire (PDQUALIF) at 0, 14, 26, and 52 weeks after randomization. Analysis of the change in PDQUALIF scores from baseline to 6 months showed adjusted treatment effects (with 95% confidence interval) favoring rasagiline over placebo of −2.91 units (−5.19, −0.64, P = 0.01) for the 1 mg/day group and −2.74 units (−5.02, −0.45, P = 0.02) for the 2 mg/day. Subscore analysis attributed most of this benefit to the self‐image/sexuality domain. At 12 months (n = 266), with all groups receiving rasagiline for at least 6 months, no significant differences in PDQUALIF scores were seen between groups. Rasagiline improved QOL compared with placebo. This QOL improvement appears to be accounted for primarily by the symptomatic benefit of rasagiline.

Evaluation of the role of Nurr1 in a large sample of familial Parkinson's disease.

Parkinsons disease (PD) is a common neurodegenerative disorder in humans with wide variability in the age of disease onset. Although the disease has been thought previously to occur sporadically in most patients, there is increasing evidence of a genetic contribution to the disorder. Recently, a polymorphic variant within intron 6 of the Nurr1 gene was reported to be associated with sporadic and familial PD. In an effort to identify susceptibility genes for PD, we have collected 783 PD patients from 372 families and 397 healthy controls from 217 families. PD patients and healthy controls were genotyped for the intron 6 insertion polymorphism by BseRI restriction endonuclease digestion. No significant difference in either homozygosity or heterozygosity for the 7048G7049 (IVS6 1361 +16insG) polymorphism was detected in the PD patient cohort as compared with the panel of healthy controls. Moreover, direct sequencing of exon 1 of the Nurr1 gene in PD patients failed to detect either of the two recently reported Nurr1 mutations identified in a small subset of a PD patient cohort. Taken together, these data suggest that genetic alteration at the Nurr1 locus is not a significant risk factor for the development of Parkinsons disease in our large sample of familial PD patients.