Persistent Central Neuropathic Pain Caused by Intramedullary Hemorrhage from Spinal Dural Arteriovenous Fistula: A Case Report and Literature Review

Abstract

We describe a patient with persistent central neuropathic pain caused by intramedullary hemorrhage from spinal dural arteriovenous fistula (SDAVF). A 34-year-old woman suffered from sudden severe electric-like pain and paresthesia at the left anterior and posterior chest wall below nipple line, corresponding with T6 dermatome, without muscle weakness or bowel/ bladder dysfunction involving. Magnetic resonance imaging (MRI) revealed intramedullary hemorrhage extending from the level of lower T5 to upper T7 of the left side of the spinal cord with abnormal intradural flow voids along left posterolateral cord surface from the level of T6 to T11. Spinal angiography demonstrated SDAVF, fed by radiculomeningeal branches from the left T5 and T6 intercostal arteries with drainage into ascending and descending prominent and tortuous perimedullary draining veins. There was a venous varix, probably causing hematomyelia. The left T6 intercostal artery not only gave rise the branch to the fistula, but also anterior spinal artery. Therefore, endovascular treatment with liquid embolic material was contraindication for this patient. Due to intractable at-level neuropathic pain, she underwent thoracic laminectomy with microsurgical obliteration of the fistula and dorsal root entry zone lesioning in the same session. The previous chest pain preoperatively was totally relieved for a few days after surgery. Unfortunately, the neuropathic pain gradually returned with stabbing, cramping, and itching sensation. The pain-aggravating factors were premenstrual period, stress, mechanical pressure, and fear of untreatable pain. The pain- relieving factors were warm bath and gentle rub. Intractable neuropathic pain was treated with multi-drug therapy, including opioid, tricyclic antidepressant, and antiepileptic drugs. At 2 years after operation, the pain was controlled in acceptable level with pain score of 2/10. Follow-up spinal angiography and MRI confirmed complete obliteration of the fistula and disappearance of blood components in spinal cord without spinal cord atrophy. From the literature, the authors found another 5 patients suffering from intramedullary hemorrhage caused by SDAVFs. However, there was no persistent neuropathic pain in these patients similar to the present study.