[Neurological symptoms and disability in HTLV-1 associated myelopathy].

INTRODUCTION: The human T cell lymphotropic virus type I (HTLV-I) is a retrovirus that causes tropical spastic paraparesis/HTLV-I associated myelopathy (TSP/HAM). Objectives. To describe neurological characteristics and the severity of disability in a sample of patients with TSP/HAM.
METHODS: All TSP/HAM patients consecutively admitted during 2006 at the Brasilia Sarah Hospital, neurology outpatient clinic were included in the study. HTLV-I infected patient fulfilled criteria for serological positivity at both ELISA and western blot. Ashworth spasticity scale, Barthel index of activities of daily living, kurtzke functional systems and the Expanded Disability Status Scale (EDSS) were applied. All patients performed electrophysiological studies (evoked potentials, electromyogram) and brain/spinal cord magnetic resonance imaging (MRI).
RESULTS: Forty two of 249 paraparetic patients (16.9%; 26 females; mean age: 49.8 years) were diagnosed as having TSP/HAM. Mean time of evolution was 11.2 years. Most common neurological syndrome was a chronic progressive spastic paraparesis with hyperreflexia, ankle clonus and bilateral Babinski sign (97.7 %). Other findings were proximal muscle atrophy in lower limbs (28.6 %) , ataxia (21.4%), and peripheral neuropathy (7.1%). Half of patients were wheel-chair restricted or had a domiciliary walk. EDSS median was 6 and Barthel index mean score was 65. Most common findings on spinal cord MRI were thoracic spinal cord atrophy (66.7%) and white matter hyper-intensity areas in cerebral subcortical (42.8 %) and spinal cord (21.4%) regions.
CONCLUSIONS: TSP/HAM is a very disabilitating disorder. Peripheral neuropathy and ataxia are other syndromes that should be included in the spectrum of HTLV-I infection.