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

Central nervous system damage associated to HTLV-I does not limit itself to the spinal cord, but also involves subcortical structures, producing cognitive impairment and behavioral changes which eventually could conform a new form of subcortical dementia.

To study cognitive changes in patients with HTLV-I associated myelopathy.

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 immunofluorescence, Western Blot or proviral DNA identification. Cognitive assessment was done using the Wechler Adult Intelligence Scale (WAIS) and Benton Visual Retention Test (form D). Patients were grouped according to their motor disability in; 23 patients with independent spastic gait, 11 patients that needed support to walk and 9 patients unable to walk.

WAIS test demonstrated cognitive impairment with special deficit in some subtests such as Digit Span, Digit Symbol, Picture Arrangement and Object Assembly. Benton Test also disclosed cognitive impairment. There was a positive relationship between cognitive and motor performance.

At least 50% of patients with Tropical Spastic Paraparesis have certain degree of intellectual and affective impairment.