Under-recognized Cause of Buttock Pain; Superior Cluneal Neuropathy and Diagnostic Utility of Combined Ultrasonography and Neurostimulation Guidance: Case Series

Background: Superior cluneal neuropathy (SCN) is an under-recognized source of unilateral low back and buttock pain, representing approximately 14% of lower back pain cases. The condition is caused by entrapment or irritation of the superior cluneal nerves. Diagnosis is challenging due to symptom overlap with other spinal and pelvic conditions and the absence of gold-standard diagnostic criteria. Objective: This case series evaluates the utility of ultrasound (US) guidance combined with nerve stimulation for diagnosing and treating SCN, particularly in patients with complex pain histories and overlapping differential diagnoses. Methods: Three patients with unilateral lower back, iliac crest, and buttock pain underwent US-guided superior cluneal nerve injections supplemented by nerve stimulator confirmation. Pain characteristics, physical examination findings, and procedural outcomes were recorded. SCN was identified as hyperechoic structures on US with a honeycomb appearance. Nerve stimulation reproduced patients’ symptoms, followed by therapeutic injection of local anesthetic and corticosteroid. Results: All three patients reported greater than 60% pain relief immediately following the injection. During the follow up evaluations at two and four weeks, excellent pain relief was reported in two patients and moderate relief in one. Conclusion: SCN should be considered in cases of lower back and buttock pain resistant to conventional treatments. This approach of combining US and nerve stimulation improves diagnostic accuracy and therapeutic efficacy, representing a significant advancement in the management of SCN.