Novel use of CT guided Botulinum toxin infiltration for Pyriformis syndrome –A single centre prospective study from southern India

Introduction: We describe the short term and intermediate efficacy of direct intra-muscular injection of Botulinum toxin in Pyriformis Syndrome, along with its safety profile. Materials and Methods: A diagnosis of pyriformis syndrome was made by exclusion, only after careful clinical assessment & MR Imaging. Patients were selected for Botox infiltration if adequate symptom relief was not noted after conservative management. Patients were placed prone on the CT table with a pillow placed under the lower pelvis for elevation of the hip joints. Subsequently a total of 03 spinal needles (22 G) were placed in the pyriformis muscle belly, at a distance of 1 to 1.5 cm apart. Finally, freshly reconstituted 50U of Botox was injected through each of the needles into the muscle belly (total dose of 150 U). Results: A total of 26 procedures were performed on 25 patients (15 male, 10 female) with one patient receiving a second procedure 15 months after the initial treatment. The mean age of the patient population was 48.6 years. 88.5% (23/26) patients reported very good pain relief when assessed on a Visual analogue scale (VAS) at 3 months, which was sustained at 6 months in 77% (20/26) patients. No procedure related complications were noted. Conclusion: CT guided Botox infiltration into the pyriformis is a safe and effective modality for pain relief in pyriformis syndrome. Three needle technique with infiltration across the length of the muscle appears be more effective in symptom alleviation, as compared to the conventional single site injection. Keywords: Botox, Pyriformis.