Spinal extradural arachnoid cyst presenting with squatting-induced lower extremity symptoms: A case report

Background: Spinal extradural arachnoid cysts (SEACs) may cause progressive myelopathic or cauda equina symptoms but are often asymptomatic and incidentally detected. Determining symptom causality is challenging when radiological compression is mild. Case Description: A 73-year-old female presented with bilateral lower-extremity weakness induced by squatting. The neurological examination was unremarkable except for decreased lower-extremity reflexes. The magnetic resonance imaging revealed a SEAC at the T11–L1 level causing minimal neural compression. Myelography and cystography failed to identify a dural defect. Following direct cyst puncture, her squatting-induced symptoms resolved. She was, therefore, diagnosed with a symptomatic SEAC and successfully underwent cyst excision with dural repair. Postoperatively, her symptoms completely resolved within 1 week, and she was discharged after an uneventful postoperative course. At the 3-month follow-up, she remained symptom-free. Conclusion: In certain cases, symptom resolution after direct spinal cyst puncture may help determine the clinical significance of SEACs. Posture-induced symptoms, such as those triggered by squatting, may provide important diagnostic clues as to how to treat symptomatic SEACs.