Tropical spastic paraparesis and HTLV-I: a Caribbean perspective - abstract

ABSTRACT

Tropical spastic paraparesis (TSP) is a chronic neurological disease which is probably endemic to the Caribbean for at least the last 100 years. Similar syndromes have also been described in other parts of the world including Japan, North and South America, Africa, and South India. Another chronic syndrome known as tropical ataxic neuropathy (TAN), formerly endemic in Jamiaca, shared some clinical features with TSP and has virtually disappeared. These syndromes have been called by various names, including Jamaican neuropathy, tropical myeloneuropathy and strachen disease, and in Japan TSP is known as HTLV-1 associated myelopathy (HAM). Cyanide toxicity is documented as a cause for both endemic TAN and epidemic TSP in Africa. Cyanide toxin found in improperly prepared cassava, vitamin B12 deficiency and syphilis have all been discounted as a cause of TSP in the Caribbean. The association of the human T-cell lymphotrophic virus (HTLV-1) and TSP was discovered through a combination of serendipity, suspicion and science. Exactly one decade ago the first retrovirus, HTLV-1, to be associated with human disease, was isolated from a patient with a cutaneous T-cell lymphoma. HTLV-1 associated with adult T-Cell lymphoma (ATL) and TSP was subsequently reported throughout the Caribbean by various workers. Gessain et al in 1985 found that 10 out of 17 TSP patients in Martinique were HTLV-1 positive. Bartholomew et al in Trinidad and Tobago and Morgan et al in Jamaica confirmed this association. The prevalence of the virus throughout the Caribbean ranges from 2.0 percent in Martinique to 5.6 percent in Grenada. Other neurological syndromes have since been reported to be associated with HTLV-1. These include polymyositis, Guillain-Barre syndrome, facial nerve palsies, anterior horn cell disease and aseptic meningitis/encephalopathy. Non-neurological associations include pulmonary alveolitis, uveitis, Sjorgen's syndrome and inflammatory skin manifestations. In the last decade, 50 cases of TSP have been identified in Trinidad and Tobago with approximately 17 deaths due primarily to infectious complication. No case of TAN was identified. TSP in Trinidad and Tobago appears to be identical with the syndrome as described regionally. Interestingly, all the cases are of African or mixed-African descent although the population proportion of East Indian to African is approximately 11. HLA studies in Japan have shown evidence for a genetic role in TSP and ATL (AU)