CT-guided percutaneous infiltration for the treatment of Alcock's neuralgia

Abstract

The pudendal nerve may be strained either between the sacrospinous and sacrotuberous ligaments at the ischial spine level or within Alcock's canal. Alcock's neuralgia is a rare, painful condition caused by compression of the pudendal nerve within Alcock's canal (pudendal canal) which is an aponeurotic tunnel that cannot be stretched. Patients usually present with intense, unilateral pain involving anatomic areas along the pudendal nerve's root, genital, anal, and pelvic regions causing mobility impairment. A computed tomography (CT)--guided percutaneous infiltration of the pudendal nerve with a mixture of a local anesthetic and a long-acting corticosteroid is a safe and efficient method that reduces the pain caused by the neuralgia. Corticosteroids and local anesthetics interfere with the neurons, the encoding, and the processing of noxious stimuli; interrupt the pain-spasm cycle; and reduce inflammation. The injected glucocorticosteroid may take 3-5 days to reach its anti-inflammatory effect; therefore, the initial pain relief from the local anesthetic is followed by a baseline pain return and then secondary pain relief at 3-5 days. The procedure is performed under minimal or no anesthesia. In general, at discharge, a responsible person must accompany the patient and ensure a safe return home. Clinical evaluation is performed after 7-10 days. There are 2 types of potential complications that are associated with percutaneous steroid infiltrations: intra-operative (associated with needle placement) and post-operative (infection, bleeding and those associated with the injectate administration). In all cases that steroids were administered within therapeutic doses, no complications were noted. In conclusion, CT-guided percutaneous infiltration with a mixture of long-acting corticosteroid and local anesthetic seems to be a safe and efficient method for the treatment of Alcock's neuralgia.