STUDY OF LOWER-LIMB SOMATOSENSORY-EVOKED POTENTIALS IN 96 CASES OF HTLV-I-ASSOCIATED MYELOPATHY TROPICAL SPASTIC PARAPARESIS

Lower limb somatosensory evoked potentials (LSEPs) were performed alon g with neurological evaluation in 96 HTLV-I-associated myelopathy/trop ical spastic paraparesis (HAM/TSP) patients. The N20 latencies were ab normal in 5 cases. Central sensory conduction time (CSCT) was abnormal in 42 cases. A high significant correlation (p < 0.001, r = 0.418) wa s found between CSCT and disability score. Such a correlation was not found between CSCT and other clinical findings, onset of illness, illn ess duration, serum and CSF antibody titer to HTLV-I and vibratory sen sation. There was no difference of the mean of CSCT between the cases with sensory impairment and those without it. This shows that LSEPs ar e useful to estimate the disability of HAM/TSP. Also the cases with de layed CSCT and normal sensation suggest that LSEPs are capable of dete cting subclinical lesions of the spinal cord in HAM/TSP.