RT Journal Article SR Electronic T1 A 15-year prospective longitudinal study of disease progression in patients with HTLV-1 associated myelopathy in the UK JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 1336 OP 1340 DO 10.1136/jnnp.2009.191239 VO 81 IS 12 A1 Fabiola Martin A1 Alexandra Fedina A1 Silva Youshya A1 Graham P Taylor YR 2010 UL http://jnnp.bmj.com/content/81/12/1336.abstract AB Background The natural history of HTLV-1-associated myelopathy (HAM) has been mainly described in HTLV-1 endemic countries such as Japan, Brazil and Martinique.Objectives The authors describe the natural history of the largest cohort of patients with HAM living in the UK from 1993 to 2007.Methods Prospective, longitudinal study comparing clinical and virological outcome between first and last clinical visit. Incidence and cause of death were documented and the mortality calculated.Results 48 patients were included: 79.2% were female, 79.2% were of Afro-Caribbean origin, and 83.3% acquired HTLV-1 through breastfeeding or unprotected heterosexual intercourse. The mean age of onset was 46 years. The median durations from onset of symptoms to diagnosis and to last follow-up were 2 and 11.6 years. The median time of follow-up was 3.8 years. The most common first recalled symptom was unilateral leg weakness. The median times from onset to unilateral, bilateral walking aid and frame or a wheelchair were 11, 11.2, 11.3 and 18 years. The overall average deterioration in timed walk in patients whose need for aid did not change was 2 s/10 m/year. Three patients progressed rapidly and were unable to walk within 2 years. Six patients were slow/non-progressors. The mortality was 2.4/100 person year follow-up. The median HTLV-1 viral load remained unchanged at 14%.Conclusions HAM is a slowly progressing chronic disease. Timed walk deteriorates by 2 s/10 m/year, and patients remain ambulant for 10 years but become wheelchair-dependent a decade later. HTLV-1 viral load remains high and unchanged over time regardless of clinical progression.