2024 American Academy of Neurology Abstract Website

Objective:

To illustrate the utility of electromyography (EMG) as an objective measure of success with minimally-invasive interspinous spacer device implantation (ISDI) for the management of concurrent lumbar spinal stenosis (LSS) and radiculopathy (LR).

Background:

Recently, minimally invasive approaches involving ISDI have entered into management algorithms for symptomatic lumbar spinal stenosis (LSS). Vertiflex® ISDI has been used for LSS producing positive results, however, data is lacking for its potential utility in LR. Data is not currently available for EMG changes following ISDI. We report a case of neurogenic claudication with radiculopathy responding to successful ISDI for both LSS and LR with corresponding correction of acute findings on EMG.

Design/Methods:

A retrospective chart review was undertaken. Comparative measurements of acute and chronic EMG changes and clinical outcomes pre- and post-implantation were made.

Results:

A 72 year old male was evaluated in our clinic for progressive back and leg pain symptoms for over 1 year. Qualities of intermittent claudication overlapping LR were observed. EMG findings included spontaneous activity in the form of fibrillation potentials and positive sharp waves in the lumbar paraspinals at L4 and L5, anterior tibialis and extensor digitorum brevis. Post-implant EMG revealed no spontaneous activity or chronic changes at 3 months post-implant. At the end of the 6-month post-implant period, the patient reported more than 80% relief of claudication and 100% relief of radicular symptoms with improved functioning.

Conclusions:

Vertiflex® ISDI has the potential to reduce LR in addition to neurogenic claudication due to LSS. The elimination of spontaneous activity of muscle groups that carry lumbar root innervation corresponding to the treatment level is possible and correlates with clinical improvement as seen in our case. EMG changes may be a reliable marker for objective improvement in patients undergoing ISDI for LR and should be considered in the diagnostic algorithm for LSS. Prospective studies are warranted.