Clinical electrophysiologic studies of HTLV-I-associated myelopathy
K. Arimura, R. Rosales, M. Osame and A. Igata
Six patients with human T-cell lymphotropic virus type I
(HTLV-I)-associated myelopathy (HAM) were studied by electrophysiologic
methods. Upper-limb short-latency somatosensory evoked potentials showed
slight delay of the N9-N20 interpeak latency in one of 12 limbs, while the
lower-limb short-latency somatosensory evoked potentials showed prolonged
N20-P40 interpeak latency in eight of 12 limbs. Frequent polyphasic
potentials and occasional giant spikes were observed in the distal
extremities. F-wave conduction velocity was delayed in some patients.
Results of the other nerve conduction studies were unremarkable. Our data
provide a valuable extension of the clinical examination of HAM and offer
encouragement for a more extensive electrophysiologic study of this entity,
especially in the spinal cord.
