A prospective study on role of neurophysiological studies in predicting functional outcome after lumbar discectomy

Lumbar intervertebral discs (IVDs) are complex anatomical structures that are essential for the mobility of intervertebral joints. It appears that there are no clear standard clinical or investigation criteria for the diagnosis and selection of patients with lumbar disc herniation for surgery. This study investigates whether Neurophysiological Studies can be used to identify the subgroup with better postoperative outcome.

The current study was conducted on 60 patients with Clinically and neuroimaging diagnosed cases of Lumbar disc herniation. Preoperative radiological assessment involved the flexion and extension lateral radiographs and MRI of the lumbar spine. Preoperative clinical assessment was done by Oswestry Low Back Pain Disability Questionnaire and Visual Analog Scale (VAS). The patients underwent surgery within 1 month of neurophysiologic testing. Surgery was performed at the level suggested by neuroradiology. In all patients we found an abnormal disc, which was removed along with any loose disc material. The patients were followed up for 1 year with interval of 3 months for post-operative assessment.

Statistically significant difference in postoperative percentage fall in visual analogue scale score (95.59%/73.69%) and Oswestry disability score (76.2%/ 65.3%) were observed in patients with normal  preoperative electrodiagnostic studies as compared to abnormal electrodiagnostic studies  at 12 months postoperative period (p=0.993 to 0.002 and p= 0.200 to 0.037 respectively) were observed.

Neurophysiological studies have an important role in predicting the outcome of lumbar spine surgery that can be helpful in better selection of patients and to reduce the incidence of Failed back syndrome.