急速矯正低血鈉症後之橋腦中心和橋腦外脫髓鞘病變－－不尋常之磁振造影表現

Central Pontine and Extrapontine Myelinolysis Following Rapid Correction of Hyponatremia: An Unusual MRI Presentation

一位36歲男性因腹瀉和嘔吐面造成嚴重低血鈉且導致意識模糊。在48小時內補充3%之高鈉點滴後，病人的血鈉值已恢復正常且意識也較為清醒。但是病人卻在隔天發生抽搐而陷入昏迷狀態，此時腦部電腦斷層掃瞄為正常。八日後的腦部磁振造影顯示為橋腦中心脫髓鞘病變；二十四日後的腦部磁振造影則顯示原來的病變區有擴大的現象，並且可見T1和T2影像在被殼處有不正常高訊號強度顯影，可能是為出血的變化。經過文獻的查詢，此現象仍未被報告過。

A healthy man developed progressive lethargy due to severe hyponatremia after nonremitting diarrhea for 2 weeks and vomiting for 2 days. His consciousness improved after rapid correction of the hyponatremia by infusion of 3% saline within 48 hours of hospitalization. Afterwards, he had neurological deterioration with a generalized convulsion and became comatose the following day. Computed tomogram of the brain was normal. The initial magnetic resonance image (MRI) done 8 days after the correction of the hyponatremia suggested central pontine myelinolysis. A follow-up MRI study 24 days after the correction of hyponatremia showed enlargement of the previous pontine myelinolytic lesion. Other significant MRI findings such as abnormal high signal intensities over both putaminal areas on T1-aid T2-weighted images were noted, suggestive of hemorrhagic transformation. This unusual MRI finding in patients with central pontine myelinolysis has not been reported in the literature.