MS and neuromyelitis optica in Martinique (French West Indies).

BACKGROUND AND OBJECTIVE: 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. METHODS: The authors surveyed the entire island of Martinique (area 1,128 km(2), population 357,000) between November 1997 and October 1999. RESULTS: 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. CONCLUSION: 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.

Autosomal dominant cerebellar ataxia type I in Martinique (French West Indies): genetic analysis of three unrelated SCA2 families.

Autosomal dominant cerebellar ataxias (ADCAs) are a group of neurodegenerative disorders that are clinically and genetically heterogeneous. We report here a genetic linkage study, with five chromosome 12q markers, of three Martinican families with ADCA type 1, for which the spinocerebellar ataxia 1 (SCA1) locus was excluded. Linkage to the SCA2 locus was demonstrated with a maximal lead score of 6.64 at theta = 0.00 with marker D12S354. Recombinational events observed by haplotype reconstruction demonstrated that the SCA2 locus is located in an approximately 7-cM interval flanked by D12S105 and D12S79. Using the z(max)-1 method, multipoint analysis further reduced the candidate interval for SCA2 to a region of 5 cM. Two families shared a common haplotype at loci spanning 7 cM, which suggests a founder effect, whereas a different haplotype segregated with the disease in the third family. Finally, a mean anticipation of 12+/-14 years was found in parent-child couples, with no parental sex effect, suggesting that the disease might be caused by an expanded and unstable triplet repeat.

Autosomal dominant cerebellar ataxia type I in Martinique (French West Indies). Clinical and neuropathological analysis of 53 patients from three unrelated SCA2 families.

Autosomal dominant cerebellar ataxia type I was diagnosed in three unrelated families from Martinique (French West Indies), and linkage to the locus for spinocerebellar ataxia 2 (SCA2) was established. Neuropathological findings in two patients were those of olivopontocerebellar atrophy without oligodendroglial cytoplasmic inclusions. Cerebellar ataxia was associated with hyporeflexia in 68% of 31 examined patients, with slowed and/or limited eye movements in 65% and with dementia in 29%. No patients had optic atrophy, pigmentary retinal degeneration, spasticity or parkinsonism. Mean age at onset was 33 +/- 16 years, and onset before the age of 20 years was correlated with a more rapid and severe course of the disease. Movement disorders, oculomotor disturbances, sphincter disturbances and cognitive impairment were significantly more frequent in early than in late onset patients. This explains why the phenotype was strikingly different in one family, in which mean age at onset was much earlier. Comparison with previously described SCA2 families indicated similarities, such as reduced saccade velocity, supranuclear ophthalmoplegia and decreased reflexes, although phenotypic heterogeneity remains the outstanding feature of this disorder.

Immunological findings in selected aspects of HTLV-1-associated neurological disease - abstract

The discovery in 1985 in Martinique of an association between human T lymphotrophic virus type (HTLV -1) and tropical spastic paraparesis (TSP) (Gessain et al, 1985) opened a new chapter in the search for viruses in chronic human neurological disease. A few HTLV-1 seropositive patients have been reported to present with a clinical picture of a slowly progressive disorder resembling amyotrophic lateral sclerosis (ALS), but with a slower evolution (Vernant et al, 1989). In addition, pathological findings in some TSP cases have included anterior horn neuron depletion (Robertson and Cruickshank, 1972; Arimura et al, 1989). We have monitored selected humoral immune factors as well as levels of inflammatory proteins in asymptomatics and normal controls, using a computer-aided electrophoresis technique. The results showed a significant presence of hypergamma-globulinaemia, predominantly IgC in TSP patients. Interestingly enough, as well, immune complexes, complement cascade activation in those HTLV-1 seropositive patients with anterior horn-like neurological disorders. These data are consistent with the hypothesis of the occurrence of an immune complex-mediated vasculitis phenomenon in the latter subjects. Monitoring of these biological factors may represent a useful tool in the diagnosis and understanding of the physiopathological mechanisms of these disorders (AU)

[Neurologic pathology and HTLV-I virus]. / Pathologie neurologique et virus HTLV-1.

In most cases the only manifestation of nervous system pathology associated with HTLV-1 infection is spastic paraplegia. The virus is transmitted by breast-feeding from mother to child, by transfusion of contaminated blood (or by syringes of intravenous drug addicts) or sexually from husband to wife. Paraplegia usually begins progressively after the age of 30 years by motor and sphincteral disorders, followed by a phase of stabilization. Other clinical entities, such as pseudo-LAS syndromes, polymyositis, lymphocytic alveolitis, vasculitis or meningitis, may coexist or show varying degrees of expression. There is no treatment capable of modifying the course of the disease, but corticosteroids are worth trying, notably in the initial stages of paraplegia and in polymyositis.