MS and neuromyelitis optica in Martinique (French West Indies)

A population-based study is reported of MS in French Afro-Caribbeans (FAC) in Martinique. FAC are descendants of interracial mating that occurred between French Caucasians and black Africans in the 17th and the 18th centuries. The authors surveyed the entire island of Martinique (area 1,128 km(2), population 357,000) between November 1997 and October 1999. Sixty-two patients (46 females, 16 males, ratio 2.9:1) were identified with definite or probable disease by the Poser criteria. Prevalence for all patients on December 31, 1998, was 17.4/10(5) (95% CI 13.1 to 21.7) and 14.3/10(5) (95% CI 10.4 to 18.2) for clinically definite cases (n = 51). Age range of patients on prevalence day was 17 to 73 years (mean +/- SD 39 +/- 11.3 years). Mean age at onset was 31.2 +/- 11 years. Overall, 9.7% had primary progressive disease and 19.4% had benign MS. A low proportion of definite and probable MS cases had oligoclonal bands in CSF (50.9%). Seventeen patients, 13 of whom were alive on prevalence day, had a relapsing form of neuromyelitis optica. The island of Martinique appears to have a low to medium prevalence of MS. MS was almost unknown in FAC in Martinique until the late 1970s. The apparent recent increase may be explained by improved recognition of patients, increased availability of MRI for diagnosis, increased disease awareness among physicians, increased survival of MS patients, or an actual increase in disease frequency.