Subcortical dementia in HTLV-I tropical spastic paraparesis. Study of 43 cases

Background: Central nervous system damage associated to HLTV-I does not lim it itself to the spinal cord, but also involves subcortical structures, pro ducing cognitive impairment and behavioral changes which eventually could c onform a new form of subcortical dementia. Aim: To study cognitive changes in patients with HLTV-I associated myelopathy. Patients and methods: Forty three patients (31 female) with Tropical Spastic Paraparesis, aged 52 years old as a mean and with a disease lasting a mean of 7.5 years, were studied . The diagnosis was based on clinical, radiological and neurophysiological changes. The virus was identified with ELISA, indirect immunofluorecence, W estern Blot or proviral DNA identification. Cognitive assessment was done u sing the Wechler Adult Intelligence Scale (WAIS) and Benton Visual Retentio n Test (form D). Patients were grouped according to their motor disability in; 23 patients with independent spastic gait, 11 patients that needed supp ort to walk and 9 patients unable to walk. Results: WAIS test demonstrated cognitive impairment with special deficit in some subtests such as Digit Sp an, Digit Symbol, Picture Arrangement and Object Assembly. Benton Test also disclosed cognitive impairment. There was a positive relationship between cognitive and motor performance. Conclusions: At least 50% of patients with Tropical Spastic Paraparesis have certain degree of intellectual and affec tive impairment.