A Pediatric Case of Piriformis Syndrome Diagnosed by Trigger Point Injection into Piriformis Muscle

Abstract

A 13-year-old girl presented with left gluteal pain and numbness in the left thigh. Imaging studies and electrophysiological tests revealed no significant abnormalities, and conservative treatment was ineffective. Since persistent pain along the sciatic nerve distribution led us to suspect piriformis syndrome, a diagnostic trigger point injection of 1% mepivacaine into the piriformis muscle was performed under ultrasound guidance, resulting in immediate symptom relief, confirming the diagnosis. Piriformis syndrome is a compressive neuropathy caused by entrapment of the sciatic nerve by the piriformis muscle. While relatively well-documented in adults, it is extremely rare in children. The possibility of piriformis-related nerve compression has not been adequately considered in previously reported pediatric cases of idiopathic sciatica, and undiagnosed piriformis syndrome may have been overlooked. This case, with no infectious or traumatic etiology, represents a rare example of non-infectious piriformis syndrome in a child. The clinical course highlights the diagnostic utility of trigger point injection in suspected cases. Piriformis syndrome should be considered in the differential diagnosis of pediatric sciatica after exclusion of structural abnormalities.