Multiple sclerosis, tropical spastic paraparesis and HTLV-1 infection in Afro-Caribbean patients in the United Kingdom.

Forty four consecutive patients of Afro-Caribbean origin resident in the United Kingdom (UK) were studied, based on a provisional diagnosis of myelopathy of unknown cause, tropical spastic paraparesis (TSP) or multiple sclerosis (MS). Of 30 patients with progressive paraparesis 27 had serum antibodies to HTLV-1 and were classified as having TSP. Fourteen patients fulfilled the criteria for MS and none of 12 tested had HTLV-1 antibodies. All the TSP patients and nine of those with MS were born in the West Indies. Five of the West Indianborn MS patients had migrated to the UK after adolescence but the duration of residence in the UK before symptoms of MS developed was similar to those born in the UK (average 18 years). The features that differentiated MS from TSP patients, apart from HTLV-1 status, included clinical evidence of cranial nerve involvement, more extensive abnormalities on the brain and cervical cord MRI and asymmetry of the VEP latency increase, all of which were more frequent in the MS group. Of the three patients without a diagnosis one, born in the UK, had marked abnormalities on MRI of the brain indistinguishable from those seen in MS.