Correlation of Lateral Stenosis in MRI with Symptoms, Walking Capacity, and EMG Findings in Patients with Surgically Confirmed Lateral Lumbar Spinal Canal Stenosis

Introduction The aim of this study is to evaluate the clinical significance of lateral lumbar spinal canal stenosis (LLSCS), found by magnetic resonance imaging (MRI), through correlating the imaging findings with patient symptoms, walking capacity and electromyographic (EMG) measurements. Materials and Methods A total of 80 patients with symptoms of LSS severe enough to indicate operative treatment were studied with MRI. Of these patients, subjects with distinct lateral LSS were included. Accordingly, 140 roots in 14 patients (mean age, 58 years; range, 48-76 years; male, 43%) were evaluated. In MR images, the entrance and midzones of the lateral lumbar nerve root canal were graded as normal, narrowed but not compressed, or compressed. In quantitative analysis, the minimal widths of the lateral recess and midzone area were measured. Clinical symptoms were recorded with the oswestry disability index (ODI), overall visual analogue scale (VAS), specific low back pain (LBP; NRS-11), specific leg pain (LP NRS-11), beck depression inventory (BDI), and walking distance in the treadmill test. Lumbar paraspinal (L2-S1) and lower limb needle EMG studies were performed. The findings were classified root by root as 1 = normal, 2 = abnormal. The associations between radiological, EMG, and clinical findings were tested with each other. Results LLSCS was confirmed in all patients during surgery. EMG findings were normal in 92 roots and abnormal in 48 roots. All of the patients had at least one abnormal nerve root finding. Severity of the midzone stenosis in MRI correlated with abnormal EMG findings ( p = 0.015). Patients with abnormal EMG had also higher scores in the VAS (41.9 ± 25.7 vs. 31.5 ± 18.1; p = 0.018), NRS leg pain (7.5 ± 1.5 vs. 6.3 ± 2.1; p = 0.000), and BDI (9.8 ± 3.8 vs. 8.0 ± 3.9; p = 0.014). However, no statistically significant correlations between MRI findings and clinical symptoms or walking capacity were found. Conclusion MRI findings correlated with abnormal EMG, indicating that a lateral stenosis seen by MRI is a clinically significant finding. However, no relationships between the MRI findings and symptoms or walking capacity were found, suggesting their multifactorial etiology. MRI and EMG may be useful in the workup of patients with suspected LLSCS. Disclosure of Interest None declared