Effect of piriformis injection on neuropathic pain.

Abstract

The aim of this study was to investigate the effect of a piriformis injection on neuropathic pain in patients with piriformis syndrome. Thirty patients with unilateral hip and/or leg pain, a positive FAIR test (increased H-reflex latency with Flexion, Adduction and Internal Rotation), and a trigger point at the piriformis muscle were enrolled in this prospective study. All of the patients exhibited neuropathic pain scored according to the Douleur Neuropathique 4 (DN4) of ≥4 for at least 6 months. All of the patients received 4 mL of lidocaine 2%+1 mL of betamethazone to the piriformis muscle under the guidance of ultrasound. The Numeric Rating Scale (NRS), DN4, and the painDETECT (PD) questionnaire were used for outcome assessment. A statistically significant improvement was seen in all scores (p<0.001) when both first week and first month results were compared with the baseline values. Comparison of the first week results with those of the first month revealed a statistically significant improvement in only the NRS and PD scores (p<0.001). The greatest improvement in all scores was seen in the first week after the injection. A mild increase was seen in all scores at the first month compared to the first week. A piriformis injection was found to be effective for both somatic and neuropathic pain in piriformis syndrome patients. Long-term follow-up is needed in order to consider this option alongside other treatment alternatives, like botulinum toxin and myofascial release.