CAN ELECTROMYOGRAPHY PREDICT THE PROGNOSIS OF TRANSVERSE MYELITIS

The role of clinical and magnetic resonance imaging (MRI) features on the prognosis of acute transverse myelitis has been studied, but the r ole of electromyography (EMG) changes, although reported, has not been investigated. Seventeen patients with acute transverse myelitis were subjected to clinical evaluation, MRI scanning and concentric needle E MG. The outcome was defined on the basis of a 3-month Barthel Index (B I) score as good or poor. The EMG changes in these groups were compare d. All of the patients had complete paraplegia (power grade 0), except 1 who had grade LII power. Mild upper limb weakness was present in 6 patients. Joint position and vibration sense were impaired in the lowe r limbs, and a horizontal limit to sensory loss to pinprick was presen t in all of the patients. Spinal MRI was abnormal in 12 of 14 patients . EMG of the lower limb muscles in the acute stage (within 15-30 days of onset) revealed fibrillations or sharp waves or both in 11 patients . At 3-month follow-up, the lower limb power had improved in 8 and upp er limbs in all 6 patients. The EMG changes also improved in 6 patient s; fibrillations either disappeared or were markedly reduced. The moto r unit potentials (MUPs) were of long duration, polyphasic with reduce d recruitment. In 5 patients, however, no MUPs could be recorded and f ibrillations persisted. Lower limb hypotonia and fibrillations on EMG were significantly related to the 3-month outcome. EMG evidence of den ervation in the lower limb muscles in acute transverse myelitis sugges ts a poor outcome as assessed by 3-month Barthel index score.