Abstract
We encountered two patients with intractable perineal pain who were successfully treated with anticonvulsants.
Case 1: A 70-year-old woman had undergone osteotomy of her knee for osteoarthritis under spinal anesthesia in September 1999. One month after the operation, she suffered from perineal shooting pain with a visual analog score of 10/10. Nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, antidepressants and caudal epidural block did not relieve the severe pain. In June 2000, she was admitted to our hospital and received carbamazepine for 2 weeks. Although pain was completely cured, she developed Stevens-Johnson syndrome and then stopped taking carbamazepine. One month later, she again suffered from the perineal pain. Other anticonvulsants, phenytoin, sodium valproate, clonazepam and zonisamide were administered as a trial, and of these clonazepam and zonisamide were effective in controlling the pain. Currently, her visual analog score is 3 to 4/10 while taking zonisamide and amitriptyline hydrochloride.
Case 2: A 52-year-old man was hospitalized for chronic pancreatitis. During hospitalization he had perineal shooting pain with visual analog score of 10/10. Pain could not be controlled with NSAIDs or opioids. In December 2001, he visited our pain clinic and was treated with carbamazepine and amitriptyline for 2 weeks. Although the pain was completely disappeared, he developed syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Three days after discontinuation the drugs, he recovered from SIADH, but again had perineal pain. Zonisamide was then administered. One month after the start of medication, his pain diminished. Currently, he is free of pain under zonisamide.
The efficacy of anticonvulsants for perineal pain has not been reported, but perineal pain in our two patients was successfully treated with carbamazepine. However, our patients had to discontinue carbamazepine because of severe side effects, and other anticonvulsants showed efficacy. We consider that anticonvulsants are effective for intractable perineal shooting pain.
