肱動脈偽性動脈瘤壓迫造成類似皰疹感染之正中神經痛

Post-herpetic like Median Nerve Neuralgia by Brachial Artery Pseudoaneurysm Impingement: A case report

肘部動脈穿刺造成肱動脈假性動脈瘤並壓迫正中神經，因此造成神經痛或神經病變的情形十分罕見。我們報告一個63歲男性病例，因自發性蜘蛛膜下腔出血住院，在加護病房於右側肱動脈植入動脈壓監測導管；移除導管後右前臂發生灼熱及麻痛感，符合正中神經分布區，經皮膚科醫師會診後，初步診斷為皰疹性神經痛。後來因右肘部發現一個搏動性腫塊，感覺與運動神經傳導檢查均無反應，經超音波及血管攝影檢查確診為偽性動脈瘤後，行偽動脈瘤切除手術，並用靜脈移植片重建；術後病患麻痛感消失，但留存正中神經病變，手術後一年神經傳導檢查依舊無神經反應。藉由這個罕見病例讓我們學習到，曾經做過肱動脈穿刺的病患，如果出現正中神經病變，應在早期檢查是否是偽性動脈瘤壓迫，如此不僅可以有效解除疼痛，並可避免發生神經永久性傷害。

Brachial artery pseudoaneurysms are exceedingly uncommon but should be considered in the workup of a patient with median neuralgia and/or neuropathy following arterial punctures in the cubital fossa. We reported on a case in which the prodromal symptoms of median nerve compression caused by a brachial artery pseudoaneurysm led to the misdiagnosis of post-herpetic neuralgia before the occurrence of full blown neuropathy symptoms. This 63 year-old male patient, who suffered from spontaneous subarachnoid hemorrhage, received continuous arterial pressure monitoring at right brachial artery in intensive care unit. Following removal of the arterial catheter, the patient developed dysesthetic burning pain in the right forearm along median nerve dermatome, which was initially diagnosed as post-herpetic neuralgia by dermatologists. In the following weeks, a pulsatile swelling at cubital fossa was noticed, and signs of median neuropathy also occurred. Nerve conduction studies (NCS) showed no responses in the median motor and sensory nerves. Both ultrasonography and arterial angiography confirmed the presence of a large pseudoaneurysm. Surgical excision of pseudoaneurysm was then performed, followed by brachial artery reconstruction using interposition basilic vein graft. After surgery, median neuropathy remained, but dysesthetic pain resolved. One year after operation, NCS still failed to show responses in median nerve. Our case demonstrated that, in the presence of median neuralgia following medical procedures in the cubital fossa, the importance of early suspicion and treatment of pseudoaneurysm formation cannot be overemphasized in order to avoid permanent palsies of median nerve.