前言：假性腦瘤(pseudotumor cerebri, PTC)，又稱為自發性腦內高血壓(idiopathic intracranialhypertension, IIH)其主要特徵為異常的腦內壓升高(>250mmH2O)，常見症狀有頭痛、視乳突水腫、短暫性視覺障礙與耳鳴等。大約每100 萬人中有9 人會有此症狀，其中以20 至44 歲生育年齡且肥胖的女性發生率最高，但少見於嬰幼兒。本文報告一男嬰疑似因類固醇減量所引發的假性腦瘤案例。
案例報告：一名七個月男嬰，體重7.8 kg，於住院診斷為胰臟血管瘤倂有缺鐵性貧血。住院期間給予高劑量prednisolone 2 mg/kg/day 與鐵劑治療。減量後期以每兩天減量1 mg 的頻次由7mg/day 減量至2 mg/day，兩天後男嬰母親發現其顱部囟門處凸起，活動力降低、昏睡並有四次嘔吐現象，立即送本院住院治療。透過腦脊髓液檢查與腦部核磁共振造影分別排除腦膜炎與腦部病變的可能性，且經由眼底攝影檢查無視乳突水腫現象，但透過腰椎穿刺(lumbar puncture)測得腦內壓高達370 mmH2O (0-2 歲嬰幼兒正常值為75 mmH2O)，故醫師診斷為假性腦瘤，且藉由Naranjo Scale 評估該小兒假性腦瘤「極有可能」與類固醇減量有關(6 分)。藥物上輸注mannitol 20%及給予acetazolamide 125 mg/day 治療並停用prednisolone，另外配合腰椎穿刺引流腦脊髓液減壓。治療後男嬰情況逐漸穩定，囟門處由原先的凸起轉為平坦柔軟且無嘔吐情形。出院後繼續服用acetazolamide 125 mg/day 一星期並持續回診追蹤觀察。
結論：不論由藥物治療或是手術處置，小兒假性腦瘤的治療以降低腦內壓、解除頭痛及防止視乳突水腫而導致視覺喪失為主要目標。
Introduction:Pseudotumor cerebri is also called idiopathic intracranial hypertension. It is characterized by high cerebrospinal fluid pressure with no underlying structural or systemic causes. Idiopathic intracranial hypertension of infant is described without papilledema because of unclosed fontanelles.
Case Report:We reported a 7-month-old infant diagnosed with pancreatic hemangioma to be treated with high-dose corticosteroid (prednisolone 2 mg/kg/day). When pancreatic hemangioma was controlled, the dose of corticosteroid was rapidly tapered in last period. Due to irritability, vomiting, lethargy, and bulging fontanelles, this infant was taken to our emergency department. Intracranial pressure (ICP) was measured as 370 mmH2O (normal range of 0-2 years old infant: 75 mmH2O) without papilledema.Lumbar puncture was performed to drain cerebrospinal fluid for reducing intracranial pressure. Mannitol 10% and acetazolamide 125 mg/day were administered. Finally, the symptoms of idiopathic intracranial hypertension were well-resolved. In this, rapidly tapering high-dose corticosteroids may induce idiopathic intracranial hypertension.
Conclusion:Idiopathic intracranial hypertension of infant could lead to the loss of vision. Dose reduction of corticosteroids after prolonged use should be always slow and clinicians should paid attention to the symptoms of idiopathic intracranial hypertension in pediatric population.
