Evaluation of Role of Electrophysiological Studies in Patients with Lumbar Disc Disease

The role of the electrophysiologic studies in peripheral nerves and muscles of lower limbs (including paraspinal muscles) in prolapsed lumbar intervertebral discs has been studied with equivocal results. Pre- and post-operative electrodiagnostic studies have not been compared much.

To study the role of the electrophysiologic studies in prolapsed lumbar/lumbosacral intervertebral discs for finding the association between clinical findings and electrophysiological changes and to compare the electrophysiologic studies pre- and post-operatively.

The study was conducted from July 2014 to June 2016 on fifty patients who were admitted in the department of neurological surgery with lumbar disc prolapse and all these patients were subjected to surgery. Both pre- and post-operative (from 1 to 6 months after surgery) electrophysiological studies were conducted and compared.

As per the electromyographic (EMG) abnormalities, the most common levels of intervertebral disc prolapse were L4-L5 and L5-S1 accounting for 32% of cases each followed by L5-S1 level which was seen in 28% of patients with L2-L3, L3-L4, and L4-L5 prolapsed intervertebral disc (PIVD) and L3-L4 and L4-L5 PIVD were seen in 4% of cases each. Of the 50 patients, EMG findings correlated with operative findings in 37 (74%) patients, however operative findings did not correlate with EMG findings in 13 (26%) patients.

In compressive lesions of nerve roots (due to disc prolapsed), the EMG method has a high degree of accuracy in determining not only the presence of such lesions but also their exact location. EMG is accurate when correlated with the operative findings.