MedPeer Publisher

From Subtle Insular Changes to Cerebral Circulatory Arrest: Serial CT Evolution of Fulminant Herpes Simplex Virus Type 1 Encephalitis

Authors

Samia Amar, Yahya Sqalli Houssaini, Boutaina Essaher, Ihssane Laasri, Hassan Ennouali, Mohammed Ennmer

Journal Information

Journal: Medpeer Publisher

ISSN: 3066-2737

Volume: 3

Issue: 8

Date of Publication: 2026/08/31

DOI: 10.70780/medpeer.000QGVY

Abstract

Herpes simplex virus type 1 (HSV-1) encephalitis is a major cause of sporadic viral encephalitis in adults and may initially present with subtle or nonspecific findings on computed tomography (CT). We report the case of a 69-year-old man presenting with a seizure and persistent impairment of consciousness, without fever or other overt clinical features suggesting infection. Initial non-contrast CT demonstrated subtle isolated loss of the left insular ribbon, raising the possibility of early ischemia but remaining nonspecific in this clinical setting. HSV-1 encephalitis was subsequently confirmed by cerebrospinal fluid analysis, and antiviral therapy was initiated. Despite treatment, the patient remained unconscious, and serial CT demonstrated rapid progression to extensive bilateral, left-predominant encephalitic involvement with severe cerebral edema, intracranial hypertension, and mass effect, ultimately followed by cerebral circulatory arrest. This case highlights the diagnostic challenge of early HSV-1 encephalitis, as an isolated subtle insular abnormality may overlap with ischemic or peri-ictal abnormalities. HSV encephalitis should therefore remain in the differential diagnosis in patients presenting with seizures and persistent impairment of consciousness, even in the absence of fever or other overt infectious features and before the characteristic temporo-limbic imaging pattern becomes apparent.

Keywords

Herpes Simplex Encephalitis, HSV-1, Intracranial Hypertension, Cerebral Circulatory Arrest, Encephalitis

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