Possible relation of atypical parkinsonism in the French West Indies with consumption of tropical plants: a case-control study

Background In Europe and North America, Parkinson's disease is the major fo rm of parkinsonism; less than 4% of cases are progressive supranuclear pals y (PSP) and about 20% are atypical parkinsonism. The distribution of these subgroups is different in the French West Indies. We aimed to define the cl inical and demographic specificity of these disorders in Guadeloupe and to investigate a postulated link with consumption of herbal tea and fruits fro m the Annonaceae family (Annona muricata and Annona squamosa), which contai n neurotoxic benzyltetrahydroisoquinoline alkaloids. Methods Between September, 1996, and August, 1998, 87 consecutive patients with parkinsonism were referred to the single neurological department in Gu adeloupe. After detailed clinical, neurophysiological, cognitive, and neuro radiological assessment, they were classified by generally accepted criteri a as having Parkinson's disease, PSP, or atypical parkinsonism. We compared the amount of tropical fruits and herbal tea consumed by the various parki nsonian subgroups and by frequency-matched controls (patients with benign s ymptoms and no neurodegenerative disease). Findings Of the 87 patients, 22 had Parkinson's disease, 31 had PSP, 30 had atypical parkinsonism, and four had atypical parkinsonism associated with motor neuron disease, 44 of the patients with PSP or atypical parkinsonism were male. The patients with atypical parkinsonism had symmetrical rigidity and bradykinesia, and no levodopa peak-dose dyskinesias. Patients with PSP differed from those with atypical parkinsonism because they had supranucle ar vertical down-gaze palsy, severe gait and balance problems, and frontal- lobe syndrome. 29 Patients with PSP reported regular consumption of pawpaw fruit, and 26 drank herbal tea. 30 patients with atypical parkinsonism repo rted regular consumption of pawpaw fruit, and 24 drank herbal tea. Both of these groups consumed significantly more fruit and herbal tea than patients with Parkinson's disease (fruit: odds ratio 23.6; herbal tea: 28.2); and c ontrols (fruit: 20.7; herbal tea: 6.48). Both of these groups and herbal te a than Interpretation Our study confirms the over-representation of atypical parki nsonism and PSP in patients with parkinsonism in the French West Indies. Ch ronic exposure to neurotoxic alkaloids could be an important aetiological f actor because these compounds induce parkinsonism in animals. A larger epid emiological study, to clarify the link between these fruits with atypical p arkinsonism and PSP, is proposed.