SOMATOSENSORY-EVOKED POTENTIALS IN THE DIFFERENTIAL-DIAGNOSIS BETWEENSPINAL-CORD COMPRESSION AND AMYOTROPHIC-LATERAL-SCLEROSIS

Spinal cord compression (SCC) often presents a similar clinical pictur e to amyotrophic lateral sclerosis (ALS). An early differential diagno sis is important because SCC is a potentially treatable clinical disor der. We carried out a longitudinal study of 43 patients with an initia l diagnosis of ALS, in order to ascertain the percentage of patients w ith SCC, and to evaluate the usefulness of somatosensory evoked potent ials (SEPs) in early diagnosis. Thirty-three patients had a find diagn osis of ALS and 8 of SCC. SEPs central conduction was abnormal in 3 AL S and 7 SCC patients, respectively (Fisher exact test, p<0.05). We con cluded that SEPs investigation is useful in the differential diagnosis between ALS and SCC patients with pure motor signs.