Ethnic background and distribution of clinical phenotypes in patients with probable progressive supranuclear palsy.

BACKGROUND: Progressive Supranuclear Palsy (PSP) is a sporadic neurodegenerative disease without a clear geographic prevalence. Cohorts studied in the UK and India showed no higher prevalence of atypical parkinsonism in South Asian patients. We describe the ethnic and racial background of PSP patients in the Greater Toronto Area (GTA), Canada. METHODS: A prospective observational study of patients with clinically probable PSP evaluated at the dedicated Rossy PSP program. Demographic and clinical data were collected at baseline including PSP phenotype. Results were compared with the latest demographic information from the greater Toronto area. RESULTS: Of the 197 patients screened, 135 had probable PSP and resided within the GTA. The mean age at visit was 71.1 years, disease duration 4.4 years, and disease severity moderate. Compared to our catchment area, there was a higher proportion of patients with a South Asian origin and a lower proportion of patients from East and Southeastern Asia and Africa. A secondary analysis using population census data limited to individuals greater than 65 confirmed the significantly higher representation of South Asians in our clinic but found no differences for other racial and ethnic origins. CONCLUSION: Evaluation of this Toronto cohort found a greater than expected proportion of affected individuals with South Asian ethnic and racial origin. Despite limitations, our results suggest the possibility of a racial and ethnic predisposition to PSP. Further studies are needed to confirm and to address potential associated risk factors, and genome-environmental interactions.

Differences Among Native Hawaiian, Asian, and White Patients with Progressive Supranuclear Palsy.

BACKGROUND: Most studies of progressive supranuclear palsy (PSP) have been conducted in White populations. OBJECTIVE: The objective of this study was to identify whether differences exist for patients with PSP among Whites, East Asians (EAs), and Native Hawaiians/Pacific Islanders (NHPIs) in Hawaii. METHODS: We conducted a single-center, retrospective study of patients meeting Movement Disorder Society probable PSP criteria (2006-2021). Data variables included age of onset and diagnosis, comorbidities, and survival rate. Variables were compared across groups using Fisher's exact test, Kruskal-Wallis rank sum test, and log-rank tests. RESULTS: A total of 94 (59 EAs, 9 NHPIs, 16 Whites, and 10 Others) patients were identified. Mean age ± standard deviation (in years) of symptom onset/diagnosis were both youngest in NHPIs (64.0 ± 7.2/66.3 ± 8.0) followed by Whites (70.8 ± 7.6/73.9 ± 7.8), then EAs (75.9 ± 8.2/79.2 ± 8.3) (P < 0.001). Median survival from diagnosis was significantly lower (P < 0.05) in NHPIs (2 years) compared with EAs (4 years) and Whites (6 years). CONCLUSIONS: There may be racial disparities for PSP, and studies are needed to identify genetic, environmental, and socioeconomic contributions. © 2023 International Parkinson and Movement Disorder Society.

The impact of MRI white matter hyperintensities on dementia in Parkinson's disease in relation to the homocysteine level and other vascular risk factors.

BACKGROUND: The role of white matter hyperintensities (WMH) and homocysteine (Hcy) and other vascular risk factors in the pathogenesis of Parkinson's disease (PD) dementia (PDD) remains unclear. OBJECTIVE: The aim of the study was to assess the impact of WMH, Hcy and other biochemical and vascular risk factors on PDD. METHODS: A total of 192 patients with PD and 184 age- and sex-matched healthy controls were included. A semistructured interview was used to assess demographic and clinical variables with respect to vascular risk factors (arterial hypertension, diabetes mellitus, atrial fibrillation, ischemic heart disease, obliterative atherosclerosis, hypercholesterolemia, smoking, alcohol intake). Unified Parkinson's Disease Rating Scale score, Hoehn-Yahr staging and the Schwab-England activities of daily living scale were used to assess motor abilities and activities of daily living. A complex neuropsychological examination with a battery of tests was used to classify patients into a group with dementia (PDD) and a group without dementia (PD). Neuroradiological examination of MRI scans included visual rating scales for WMH (according to the Wahlund and Erkinjunntti rating scales) and the Scheltens scale for hippocampal atrophy. Blood samples for Hcy, folate, vitamin B12, fibrinogen, lipids, glucose, creatinine, transaminases and thyroid stimulating hormone (TSH) were examined. RESULTS: Among all patients, 57 (29.7%) fulfilled the diagnostic criteria for dementia. Significantly higher Hcy plasma levels were noted in PD and PDD groups compared to controls (p < 0.05) and in PDD when compared to PD (p < 0.05). According to multivariate regression analysis, WMH (Erkinjuntti scale), high Hcy, low vitamin B12 and folate plasma levels were independent risk factors for PDD. Vascular risk factors did not play any role in the pathogenesis of PDD and WMH. CONCLUSIONS: WMH along with Hcy, folate and vitamin B12 may impact cognition in PD. Therapy with vitamin B12, folate and catechol-O-methyltransferase inhibitors may play a potential protective role against PDD.

Ankle-to-brachial index and dementia: the Honolulu-Asia Aging Study.

BACKGROUND: Measurement of the ankle-to-brachial index (ABI) is a noninvasive test to assess peripheral arterial disease. A low ABI is a strong correlate of cardiovascular disease and subsequent mortality. Evidence indicates the existence of vascular components in the pathogenesis of dementia. Here, we examine the association of ABI with dementia and subtypes. METHODS AND RESULTS: Data are from the Honolulu-Asia Aging Study (HAAS), a prospective community-based study of 3734 Japanese American men 71 to 93 years of age at baseline in 1991 to 1993. The analysis included 2588 men who were free of dementia at the first assessment, had an ABI measure, and were examined up to 2 more times for dementia between 1994 and 1999. The sample included 240 incident cases of dementia (144 of Alzheimer's disease, 46 of vascular dementia, and 50 of dementia of other causes). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from Cox proportional-hazards models with age as the time scale after adjustment for education, year of birth, high blood pressure, body mass index, diabetes mellitus, cholesterol concentration, smoking status, alcohol consumption, and apolipoprotein E epsilon4 allele. A low ABI was associated with an increased risk of dementia and vascular dementia (HR, 1.66; 95% CI, 1.16 to 2.37; and HR, 2.25; 95% CI, 1.07 to 4.73, respectively). ABI was weakly associated with Alzheimer's disease (HR, 1.57; 95% CI, 0.98 to 2.53), particularly in the apolipoprotein E epsilon4 carriers (HR, 1.43; 95% CI, 1.02 to 1.96). CONCLUSIONS: These results suggest that ABI, a measure of atherosclerosis, is associated with the incidence of total dementia, vascular dementia, and Alzheimer's disease in carriers of the apolipoprotein E epsilon4 allele.

Prevalence of progressive supranuclear palsy in Yonago, Japan.

There have been few reports of the prevalence of progressive supranuclear palsy (PSP): the present study examines its prevalence in Japan and compares the findings with those in Europe and the United States. The prevalence per 100,000 was 5.82 (men, 9.14; women, 2.75), and the 95% confidence interval was 1.78 to 9.86 (men, 1.82-16.47; women, -1.08-6.65). Our data were comparable to those of studies in Europe and the United States.