Guadeloupean parkinsonism: a cluster of progressive supranuclear palsy‐like tauopathy

Abstract

An unusually high frequency of atypical Parkinson syndrome has been delineated over the last 5 years in the French West Indies. Postural instability with early falls, prominent frontal lobe dysfunction and pseudo-bulbar palsy were common and three-quarters of the patients were L-dopa unresponsive. One-third of all patients seen had probable progressive supranuclear palsy (PSP). This new focus of atypical parkinsonism is reminiscent of the one described in Guam and may be linked to exposure to tropical plants containing mitochondrial complex I inhibitors (quinolines, acetogenins, rotenoids). Two hundred and twenty consecutive patients with Parkinson's syndrome seen by the neurology service at Pointe à Pitre, Guadeloupe University Hospital were studied. Currently accepted operational clinical criteria for Parkinson's syndromes were applied. The pathological findings of three patients who came to autopsy are reported. Fifty-eight patients had probable PSP, 96 had undetermined parkinsonism and 50 had Parkinson's disease, 15 had amyotrophic lateral sclerosis with parkinsonism and one had probable multiple system atrophy. All three PSP patients in whom post-mortem study was performed had early postural instability, gaze palsy and parkinsonian symptoms, followed by a frontolimbic dementia and corticobulbar signs. Neuropathological examination showed an accumulation of tau proteins, predominating in the midbrain. There was an exceptionally large accumulation of neuropil threads in Case 1. Biochemical studies detected a major doublet of pathological tau at 64 and 69 kDa in brain tissue homogenates. All cases were homozygous for the H1 tau haplotype, but no mutation of the tau gene was observed. Clinical, neuropathological and biochemical features were compatible with the diagnosis of PSP, although some unusual pathological features were noted in Case 1. A cluster of cases presenting with atypical parkinsonism is reported. Guadeloupean parkinsonism may prove to be a tauopathy identical or closely related to PSP.