Supplementary Material for: Virus Induced Voracity: Uncovering Hyperphagia Post Herpes Simplex Virus Type 1

Herpes simplex virus type 1 (HSV-1) is the leading cause of sporadic fatal encephalitis, typically presenting with temporal lobe abnormalities. We report a 25-year-old woman with a 10-day history of fever, headache, and vomiting, progressing to confusion, visual hallucinations and drowsiness. She had a history of meningoencephalitis at age eight and well-controlled focal seizures. Upon admission, her GCS score was E3V5M3, and the MRI showed hyperintensities in both temporal lobes with diffusion restriction. EEG indicated generalised slowing, and CSF analysis revealed lymphocytic pleocytosis with elevated protein levels. Viral encephalitis was suspected, and intravenous acyclovir was initiated. CSF PCR confirmed HSV-1. By the end of 1st week, she became afebrile and showed improved awareness but developed hyperphagia for both edible and non-edible objects. She received 21 days of acyclovir with significant improvement in consciousness but only partial improvement in over eating. HSV-1 affects the bilateral medial temporal lobes, insular cortex, and cingulate gyrus. An MRI confirmed these findings in this patient. Hyperphagia, a rare complication of HSV encephalitis, is a part of Kluver-Bucy Syndrome (KBS), typically associated with other cognitive dysfunctions. Despite early treatment, hyperphagia persisted partially, emphasising the need for rapid diagnosis and treatment to prevent severe outcomes. The case highlights that acute onset hyperphagia can be an isolated complication of HSV encephalitis, requiring tailored therapeutic strategies. Follow-up showed significant weight gain with moderate improvement in hyperphagia, underscoring the challenges in managing this condition.

单纯疱疹病毒1型（Herpes simplex virus type 1, HSV-1）是散发性致死性脑炎的首要致病原，典型临床表现为颞叶异常。本文报告1例25岁女性患者，其病程长达10天，初始症状为发热、头痛与呕吐，随后进展为意识模糊、视幻觉及嗜睡。患者8岁时曾罹患脑膜脑炎，且存在经良好控制的局灶性癫痫病史。入院时，其格拉斯哥昏迷量表（Glasgow Coma Scale, GCS）评分为E3V5M3；头颅磁共振成像（Magnetic Resonance Imaging, MRI）显示双侧颞叶存在高信号伴弥散受限。脑电图（Electroencephalogram, EEG）提示广泛性慢波，脑脊液（Cerebrospinal fluid, CSF）检查显示淋巴细胞增多伴蛋白水平升高。临床怀疑为病毒性脑炎，遂启动静脉注射阿昔洛韦治疗。脑脊液聚合酶链式反应（Polymerase Chain Reaction, PCR）检测确诊为HSV-1感染。治疗至第1周末，患者体温恢复正常，意识状态有所改善，但出现贪食症状，可进食可食用与不可食用物品。患者接受了21天的阿昔洛韦治疗，意识状态显著好转，但贪食症状仅获得部分缓解。HSV-1可累及双侧内侧颞叶、岛叶皮层及扣带回，本次患者的头颅MRI检查证实了上述受累部位。贪食是HSV脑炎的罕见并发症，属于克鲁伊夫-布西综合征（Kluver-Bucy Syndrome, KBS）的表现之一，该综合征通常伴随其他认知功能障碍。尽管及早启动治疗，患者的贪食症状仍部分持续，这凸显了快速诊断与治疗对预防严重不良结局的必要性。本病例提示，急性起病的贪食可作为HSV脑炎的孤立性并发症，需制定针对性的治疗策略。随访结果显示患者体重显著增加，贪食症状得到中度改善，这也凸显了该病症管理的挑战性。