RESUMEN
This article reviews evidence for the occurrence of atypical parkinsonism in Afro-Caribbean and Indian ethnic minority subjects living in western countries, particularly the UK. Current information on the frequency, pattern, and prevalence of Parkinson's disease and parkinsonism in these communities is unclear and controversial. While several workers have suggested that there is a low prevalence of Parkinson's disease in populations of African origin, other workers have suggested a higher prevalence of Parkinson's disease in African Americans. Furthermore, little information is available in relation to the pattern of parkinsonism in these subjects. A recent phenomenologic study of parkinsonism in the French West Indies by Caparros-Lefebvre and colleagues has indicated a significantly increased frequency of atypical parkinsonism in local non-white subjects. Since 1995, we have been studying the pattern and frequency of parkinsonism in Afro-Caribbean and Indian (originating from the Indian subcontinent) patients living in the UK, with London serving as the coordinating center. Our results indicate that there is a three- to fourfold increase in the frequency of occurrence of sporadic atypical parkinsonism characterized by levodopa hyporesponsiveness, bradykinesia-dominant disease, and early cognitive dysfunction in these patients even after exclusion of patients with clinically probable multiple system atrophy, progressive supranuclear palsy, and Lewy body dementia. These findings are similar to observations made in the French West Indies. Ongoing studies in India suggest that atypical parkinsonism also affects local patients, and the pattern of parkinsonism tends to differ from Afro-Caribbean subjects in the UK. Studies are currently underway to unravel the mechanism of increased frequency of atypical parkinsonism in these ethnic groups and include genetic studies addressing polymorphisms of enzymes metabolizing levodopa, dietary neurotoxin screen and functional imaging studies of the striatum using positron emission tomography. Furthermore, the contribution of diabetes mellitus and hypertension, commonly seen in these ethnic groups, is also being examined.
Asunto(s)
Población Negra , Emigración e Inmigración , Enfermedad de Parkinson/etnología , Población Blanca , Inglaterra , Humanos , India/etnología , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/etiología , Factores de Riesgo , Indias Occidentales/etnologíaRESUMEN
INTRODUCTION: Although the prevalence and pattern of parkinsonism in white caucasian population have been reported, little is known about the pattern and prevalence of parkinsonism in black and Asian patients (from the Indian subcontinent). We recently reviewed this topic and felt that contrary to popular belief parkinsonism may be commoner in UK. Furthermore, the pattern of parkinsonism appears to be different in this group. METHODS AND RESULTS: Based on this observation we have now set up a worldwide and British study involving Afro-Caribbean and India (patients originating from the Indian subcontinent) subjects. In the first leg of this study, we carried out a door to door knocking assessment for Parkinsonism in one electoral ward in London with a high Afro-Caribbean population and identified three cases of atypical parkinsonism. We have subsequently been reviewing the case files of over 150 patients attending Movement Disorders clinical in areas of London with a high population of the Afro-Caribbean and Indian population. So far, we have identified 18 cases of Parkinsonism in patients of Afro-Caribbean and Asian origin. Fourteen out of 18 cases show non familial atypical parkinsonism with signs of progressive supranuclear palsy in five, probable striato nigral degeneration in four, and a levodopa unresponsive progressive parkinsonism which falls but no dystonia in three, spino-cerebellar atrophy type three in one and autopsy proven Pick's disease in 1.4. High field Magnetic resonance imaging and CT brain scanning have been remarkable apart from non-specific cortical atrophy and signs of vascular disease in some. CONCLUSIONS: Our observations suggest that parkinsonism is probably more common than realized in the Afro-Caribbean and Asian populations and these patients may be more susceptible to atypical parkinsonism. The reason for this is unclear and may reflect genetic or environmental factors as has been postulated in relation to higher incidence of diabetes and ischaemic heart disease in migrant Asian population in UK. Further epidemiological studies addressing this issue are in progress. (AU)