Piriformis muscle syndrome: A diagnostic dilemma

Objective: To evaluate the role of modified H reflexes in confirming a diag nosis of piriformis muscle syndrome. Methods: Six consecutive patients who met stringent inclusion criteria esta blishing the presence of this disorder underwent electrodiagnostic testing including the completion of modified H reflexes as described by Fishman. Results: A positive predictive value of 33% was obtained. Conclusions: This study does not support the role of electrodiagnostic test ing with modified H reflexes in the evaluation of a patient with possible p iriformis muscle syndrome. An algorithmic approach fur the diagnosis of pir iformis syndrome which incorporates examination findings, injection techniq ues, and visual anatomic studies, is offered.