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.
Key words: Alcock’s canal, neuralgia, corticosteroid, pudendal; nerve,
local anesthetic, computed tomography, infiltration, percutaneous, image
guided.