Characteristics of Low Back Pain due to Superior Cluneal Nerve Entrapment Neuropathy

Retrospective analysis.

The present study aimed to investigate the features of low back pain (LBP) due to superior cluneal nerve (SCN) entrapment neuropathy (SCN-EN) using the Roland Morris Disability Questionnaire (RMDQ), and to analyze the differences between LBP due to SCN-EN and lumbar spinal canal stenosis (LSS).

The SCN is derived from the cutaneous branches of the dorsal rami of T11-L5 and passes through the thoracolumbar fascia. LBP due to SCN-EN is exacerbated by various types of lumbar movement, and its features remain to be fully elucidated, often resulting in the misdiagnosis of lumbar spine disorder.

The present study included 35 consecutive patients with SCN-EN treated via nerve blocks or surgical release between April 2016 and August 2017 (SCN-EN group; 16 men, 19 women; mean age, 65.5±17.0 years; age range, 19-89 years). During the same period, 33 patients were surgically treated with LSS (LSS group; 19 men, 14 women; mean age, 65.3±12.0 years; age range, 35-84 years). The characteristics of LBP were then compared between patients with SCN-EN and those with LSS using the RMDQ.

The duration of disease was significantly longer in the SCN-EN group than in the LSS group (26.0 vs. 16.0 months, p =0.012). Median RMDQ scores were significantly higher in the SCN-EN group (13 points; interquartile range, 8-15 points) than in the LSS group (7 points; interquartile range, 4-9 points; p <0.001). For seven items (question number 1, 8, 11, and 20-23), the ratio of positive responses was higher in the SCN-EN group than in the LSS group.

Patients with SCN-EN exhibit significantly higher RMDQ scores and greater levels of disability due to LBP than patients with LSS. The findings further demonstrate that SCN-EN may affect physical and psychological function.