Nocturnal Leg Cramps and Lumbar Spinal Stenosis: A Cross-Sectional Study in the Community

PURPOSE: Nocturnal leg cramps are considered to be a symptom of lumbar spinal stenosis (LSS). However, the relationship between LSS and nocturnal leg cramps in the general population remains unclear. The purpose of this study was to investigate the prevalence and characteristics of nocturnal leg cramps in LSS in the community. PATIENTS AND METHODS: 328 voluntary participants were enrolled in this study. The presence of LSS was assessed by a validated and self-administered diagnostic support tool. The presence of nocturnal leg cramps and neurological findings were evaluated by one experienced spine surgeon. To investigate the relationship between leg cramps and anatomical factors, the participants underwent an MRI scan, and the dural sac cross-sectional area (DCSA) at each lumbar intervertebral disc level was measured. RESULTS: A total of 214 participants (65.2%) had nocturnal leg cramps, and 94 of 328 participants (28.7%) showed typical LSS symptoms. In the typical LSS symptom group, 31 participants (33.0%) had nocturnal leg cramps. In the atypical LSS symptom group, 83 participants (35.5%) had nocturnal leg cramps. There was no statistically significant difference in the prevalence of nocturnal leg cramps between the two groups. The narrowest DCSA (<25 mm(2) and 25–49.4mm(2)) was statistically related to the presence of nocturnal leg cramp. Statistically significant differences in sensory disturbance and motor weakness were not observed between the subjects with and those without nocturnal leg cramps. Moreover, impaired PTR was statistically related to the presence of nocturnal leg cramp. CONCLUSION: The prevalence of nocturnal leg cramps did not differ with or without typical LSS symptoms in the community. The degree of dural tube compression that is determined by DCSA had a direct effect on the presence of nocturnal leg cramps. Neurological impairment, such as PTR abnormalities, was associated with the presence of nocturnal leg cramps.