Atypical Parkinsonism in Guadeloupe: A common risk factor for two closely related phenotypes? Brain 2007

In Guadeloupe, there is an abnormally high frequency of atypical parkinsonism.Only one-third of the patients that develop parkinsonian symptoms were reported to present the classical features of idiopathic Parkinson disease and one-third a syndrome resembling progressive supranuclear palsy (PSP). The others were unclassifiable, according to established criteria. We carried out a cross-sectional study of 160 parkinsonian patients to: (i) define more precisely the clinical phenotypes of the PSP-like syndrome and the parkinsonism that was considered unclassifiable in comparison with previously known disorders; (ii) define the neuropsycho-logical and brain imaging features of these patients; (iii) evaluate to what extent a candidate aetiological factor, the mitochondrial complex I inhibitor annonacin contained in the fruit and leaves of the tropical plant Annona muricata (soursop) plays a role in the neurological syndrome. Neuropsychological tests and MRI were used to classify the patients into those with Parkinson’s disease (31%), Guadeloupean PSP-like syndrome (32%), Guadeloupean parkinsonism^dementia complex (PDC, 31%) and other parkinsonism-related disorders (6%). Patients with a PSP-like syndrome developed levodopa-resistant parkinsonism, associated with early postural instability and supranuclear oculomotor dysfunction.They differed, however, from classical PSP patients by the frequency of tremor (450%), dysautonomia (50%) and the occurrence of hallucinations (59%). PDC patients had levodopa-resistant parkinsonism associated with frontosubcortical dementia, 52 % of these patients had halluci