Two cases of lumbar spinal stenosis with lumbar spondylolisthesis in elderly patients who benefited from spinal cord stimulation and an electrophysiological diagnosis

Abstract

Two elderly lumbar spinal stenosis (LSS) patients with spondylolisthesis underused with minimally invasive spinal cord stimulation (SCS) and electrophysiologic study of central motor conduction time (CMCT) and the cauda equina conduction time (CECT) were performed as spinal cord function evaluation. The usefulness of SCS treatment and electrophysiologic studies has been reported. A 68-year-old woman had bilateral leg pain, intermittent claudication, and left extensor hallucis longus (EHL) muscle weakness. The preoperative CMCT was prolonged on both sides, and the CECT was prolonged on the left, so corticospinal tract disorder and cauda equina disorder were suspected. Recovery of the left EHL 2 weeks after the operation and a tendency toward leftside improvement in the CMCT and CECT were seen at 10 weeks after surgery, and analgesics were no longer required by 4 months after surgery. A 79-year-old woman in failed back surgery syndrome had peroneal nerve palsy, lumbago, bilateral leg pain and muscle weakness, and gait disturbance at the first visit, along with bilaterally prolonged CMCT, suggesting corticospinal tract disorder. Two months after surgery, an improving trend in her muscle strength and CMCT were noted, and the peroneal nerve conduction velocity had been restored. In both of these cases, recovery of symptoms and improvement of in the CMCT and CECT were observed following SCS treatment without decompression of the organic compression of the nerve roots or dural canal in the lesion area. Minimally invasive SCS treatment may be useful in elderly patients with spinal diseases, and an electrophysiological diagnosis that can objectively evaluate the spinal cord function may be beneficial.