Abstract
Our objective was to evaluate the epidemiological and clinical characteristics of amyotrophic lateral sclerosis (ALS) in the Caribbean island of Guadeloupe, using a retrospective study covering 15 years (1996–2011). Sixty-three cases of ALS were reported, with a frequency of 0.93/100,000/year. The incidence was 4.5-fold higher (3.73/100,00/year) on Marie-Galante, a small island in the Guadeloupe archipelago. ALS was associated with Parkinsonism in 23.8% of the cases. Other phenotypes were typical ALS (47.6%), bulbar forms (20.6%), limb-onset variants (6.3%) and ALS associated with frontotemporal dementia (1.6%). Onset of ALS-Parkinsonism was significantly later than in typical forms of ALS (68 vs. 54 years; p = 0.012) and affected males more frequently than did bulbar ALS (80% vs. 23.2%; p = 0.003). After one year of disease duration, the clinical profile of ALS-Parkinsonism included a symmetric akineto-rigid Parkinsonian syndrome unresponsive to levodopa, supranuclear oculomotor palsy (50%), dementia (66.7%) and signs of both lower (100%) and upper (86%) motor neuron involvement, including bulbar signs (100%). In conclusion, a new cluster of ALS-Parkinsonism and a geographical area with a high frequency of ALS were identified in Guadeloupe, suggesting that they result from environmental or genetic factors. Further studies are needed to explore these hypotheses.
Acknowledgements
We thank Alex Mozar and Mohamed Beghdadi for their collaboration and thank Merle Ruberg for her helpful comments and language assistance.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.