Pandeya Anupama, Upadhyay Devansh, Oli Bikram, Parajuli Monika, Silwal Nitesh, Shrestha Aashish, Gautam Niraj, Gajurel Bikram Prasad
Maharajgunj Medical Campus, Tribhuvan University Institute of Medicine, Maharajgunj, 44600, Kathmandu, Nepal.
Department of Radiology and Imaging, Tribhuvan University Institute of Medicine, Maharajgunj, 44600, Kathmandu, Nepal.
Ann Med Surg (Lond). 2022 Jun 5;78:103939. doi: 10.1016/j.amsu.2022.103939. eCollection 2022 Jun.
Dengue is a common febrile illness caused by Dengue virus and spread by mosquitoes. The neurological complications like encephalopathy or encephalitis or immune-mediated neurological syndromes are uncommon though. Discrete neuroimaging findings in this setting are even rarer. We report a case of dengue encephalitis with uncommon MRI features in a young female.
The patient presented with complains of fever, vomiting, weakness in all limbs and difficulty in speech. Neurological examination revealed bilateral horizontal gaze palsy with impaired oculo-cephalic reflex, bulbar dysarthria and quadriplegia with bilateral planters up-going. Laboratory reported anemia, thrombocytopenia and positive NS1 antigen while excluding other tropical and immunological diseases. Brain MRI revealed extensive thalamic involvement as unique "double-doughnut" sign along with lesions in brainstem. The patient received supportive treatment in intensive unit and was discharged following improvement in clinical condition and laboratory reports.
Dengue can infect the central nervous system directly as encephalitis or can have neurological consequences following multi-organ dysfunction and shock as encephalopathy or post-infection immunological syndromes as Guillain-Barré Syndrome or cerebrovascular complications or dengue muscle dysfunction. The MRI appearance of "double-doughnut" sign points towards dengue encephalitis in appropriate setting.
A high index of suspicion is required to make a diagnosis of dengue encephalitis. The "double-doughnut" sign in MRI sequences has the potential to become a diagnostic marker for dengue encephalitis.
登革热是一种由登革病毒引起的常见发热性疾病，通过蚊子传播。然而，诸如脑病、脑炎或免疫介导的神经综合征等神经并发症并不常见。在这种情况下，离散的神经影像学表现更为罕见。我们报告一例年轻女性登革热脑炎，具有不常见的MRI特征。
患者主诉发热、呕吐、四肢无力及言语困难。神经系统检查发现双侧水平凝视麻痹，眼头反射受损，延髓性构音障碍，四肢瘫，双侧巴宾斯基征阳性。实验室检查报告贫血、血小板减少及NS1抗原阳性，同时排除了其他热带和免疫性疾病。脑部MRI显示丘脑广泛受累，呈现独特的“双环”征，同时脑干也有病变。患者在重症监护室接受了支持治疗，随着临床状况和实验室报告的改善而出院。
登革热可直接感染中枢神经系统导致脑炎，或在多器官功能障碍和休克后引发脑病，或出现感染后免疫综合征如格林-巴利综合征、脑血管并发症或登革热肌肉功能障碍等神经后果。在适当的情况下，MRI上的“双环”征提示登革热脑炎。
诊断登革热脑炎需要高度的怀疑指数。MRI序列中的“双环”征有可能成为登革热脑炎的诊断标志物。
