Vallabhaneni Deepak, Naveed Muhammad Atif, Mangla Rajiv, Zidan Awss, Mehta Rashi I
Department of Internal Medicine, SUNY Upstate Medical University, Syracuse, NY, USA.
Department of Radiology, Shaukat Khanum Memorial Cancer Hospital, Lahore, Pakistan.
Case Rep Radiol. 2018 May 6;2018:3538645. doi: 10.1155/2018/3538645. eCollection 2018.
Encephalitis is characterized by inflammation of brain tissue and has various infectious and noninfectious causes. CSF analysis and MRI usually reveal inflammatory changes although sometimes brain imaging may be normal. Autoimmune encephalitis is caused by antibodies against neuronal synaptic receptors, surface proteins, or intracellular proteins. In this case report, we present a 65-year-old female who presented with a fall and altered mental status. Workup for infectious etiologies was negative and MRI of the brain displayed focal restricted diffusion with corresponding T2-FLAIR hyperintensity involving gray matter structures, making the diagnosis unclear. CT perfusion of the brain demonstrated increased cerebral blood volume and cerebral blood flow in the left parietooccipital gray matter, with corresponding normal mean transit time. Following treatment failure with acyclovir, antibiotics, and steroids, the patient was found to be positive for GAD65 antibodies and diagnosed with autoimmune encephalitis. Symptoms markedly improved with plasmapheresis. Autoimmune encephalitis rarely causes restricted diffusion and this is the first case report to describe corresponding hyperperfusion on CT perfusion study.
脑炎的特征是脑组织炎症，有多种感染性和非感染性病因。脑脊液分析和磁共振成像（MRI）通常显示炎症改变，尽管有时脑部影像学检查可能正常。自身免疫性脑炎由针对神经元突触受体、表面蛋白或细胞内蛋白的抗体引起。在本病例报告中，我们介绍了一名65岁女性，她因跌倒和精神状态改变前来就诊。感染性病因的检查结果为阴性，脑部MRI显示局灶性扩散受限，相应的T2加权液体衰减反转恢复序列（T2-FLAIR）高信号累及灰质结构，这使得诊断不明确。脑部CT灌注显示左侧顶枕叶灰质脑血容量和脑血流量增加，平均通过时间正常。在使用阿昔洛韦、抗生素和类固醇治疗失败后，发现该患者谷氨酸脱羧酶65（GAD65）抗体呈阳性，并被诊断为自身免疫性脑炎。血浆置换后症状明显改善。自身免疫性脑炎很少引起扩散受限，这是第一例描述CT灌注研究中相应高灌注的病例报告。
