RESUMEN
By doing MRI of spinal cord and elctrophysiological studies we were going to correlate MRI and electrophysiologi-cal findings with the known pathology of tabes dorsalis. A 45 year old male patient developed gait ataxia with a tin-gling sense in hands and feet in september of 1996. Neurological examination revealed impaired position sense in his great toes and thumbs with profound instability in the Romberg test, and areflexias in his knee and ankle jerks. Serum VDRL and TPHA test results were positive. CSF revealed pleocytosis(WBC : 16/cubic mm), elevated protein level, and reactive VDRL and FTA-ABS tests. Spinal MRI showed high signal intensity in the posterior part of the entire length of the cervical cord without enhancement with Gadolinium. Follow-up spinal MRI of the cervical area, which was taken two years after penicillin treatment did not show any interval change and spinal MRI of thoracolumbar area also showed similar finding to that of the cervical cord. Nerve conduction studies before and after the penicillin trea-ment showed normal findings except absent H-reflexes. However, the somatosensory evoked potentials with posterior tibial nerve stimulation did not show any abnormalities, which were incompatible with previous report and the known pathologic abnormality. Normal somatosensory evoked potentials suggests using any other pathways than the posterior column in conducting somatosensory evoked potentials.