We report 10 HTLV-I virus seropositive subjects, eight of them with HT
LV-I associated myelopathy (HAM), two of them also infected with HIV a
s well as two asymptomatic HTLV-I+ relatives of two unrelated patients
. HTLV-I is endemic in several tropical areas, where it causes differe
nt neurological diseases. Only few patients have been reported in our
country since 1994. We studied 8 patients, who fulfilled the clinical
criteria for chronic spastic paraplegia, and 2 other non-symptomatic H
TLV-I seropositive relatives, with electromyography (EMG), motor and s
ensory conduction velocities (NCV), somatosensory, visual and brainste
m auditory evoked potentials (SSEP, VEP and BAEP), Magnetic Resonance
Images (MRI) and cerobrospinal fluid (CSF) analysis. The latter was ca
rried out only in seven symptomatic patients. in every case positive E
LISA tests for HTLV-I/II were confirmed by Western Blot. The two asymp
tomatic persons were clinically and electromyographically assessed, on
e of them was also submitted to SSEPs studies. Three patients were mat
es. Patient's ages ranged from 5 to 65 years old. All symptomatic pati
ents showed muscular weakness, spasticity with pyramidal signs and sph
incter disturbances. Five of them had paresthesias and 2 had burning p
ain on their feet. The EMGs and the NCVs were normal in 7 patients and
in the 2 asymptomatic ones. SSEPs, obtained by stimulating the poster
ior tibial nerves, were impaired in 7 patients and in the asymptomatic
person who received the procedure. The 7 symptomatic patients who und
erwent lumbar puncture had positive tests for HTLV-I in CSF, 3 out of
these 7 patients had also high protein levels and 4 had increased numb
er of lymphocytes. In 2 patients intrathecal IgG production could also
be demonstrated. MRI were normal in 7 patients and in the 2 asymptoma
tics, the exception being a female who had bilateral hyperintense lesi
ons in cerebral white matter in T2. In conclusion, tropical spastic pa
raparesis is apparently a rare disorder in Argentina. However, some ca
ses have been reported recently. Most probably, its prevalence is curr
ently underestimated. Its diagnosis should be considered in every pati
ent with progressive spastic paraplegia.