Herpes Simplex Virus Encephalitis: Atypical Presentation as a Right Middle Cerebral Artery Stroke

Abstract

Herpes simplex virus encephalitis (HSVE) is a medical emergency associated with high mortality and morbidity. Definitive diagnosis is established by history, clinical examination, neuroimaging studies, supportive electroencephalogram (EEG) findings, and cerebrospinal fluid (CSF) analysis.We report a case of HSVE presenting as a stroke mimic in a 76-year-old female with a history of atrial fibrillation on warfarin. She was admitted to our medical intensive care unit with intermittent fever, lethargy, and new onset left-sided hemiparesis. A computed tomography (CT) of the head showed a right middle cerebral artery (MCA) acute ischemic stroke with midline shift and a dense right MCA sign. Brain magnetic resonance imaging (MRI) showed evidence of acute stroke with consideration of herpes encephalitis. CSF analysis was positive for herpes simplex virus (HSV) type one. She recovered with high-dose intravenous acyclovir therapy.Our patient was a diagnostic dilemma, initially being diagnosed with an acute ischemic stroke and yet found to have HSVE, which mimicked an acute ischemic stroke. Delay in treatment may result in devastating clinical outcomes that may include severe cognitive, focal neurological deficits, persistent seizures, and even death. This case highlights the importance of a multidisciplinary approach and the need for increased awareness of an atypical presentation of HSVE among emergency physicians, neurologist, intensivists, and radiologists.

Herpes Simplex Encephalitis Presenting with Isolated Ninth Cranial Nerve Palsy: A Case Report

“…This sign is critical for distinguishing HSV from the other types of encephalitis. Another radiological finding is the unilateral involvement of the temporal lobe with the ganglia preserved [3][4][5]. The findings of cranial MRI performed in the present case on the first day of hospitalization confirmed the diagnosis.…”

“…CSF contains erythrocytes in hemorrhagic encephalitis caused by herpes virus. This is helpful in diagnosis, but not diagnostic (2)(3)(4)(5)8,9). In the present case, the CSF was clear in appearance with slightly elevated pressure.…”

“…Focal or generalized seizures may also occur. There may be severe neurological condition progressing from psychotic behavioral disorders, hemiplegia, speech disorders and amnesia to stupor and coma (4)(5)(6)(7)(8)(9). Here we present the case with herpes encephalitis who presented with dysphagia and loss of sense of taste and improved without complication with acyclovir therapy after diagnosed with herpes encephalitis, we have shown that it is possible to present with 9th cranial nerve paralysis for the first time in herpes encephalitis cases that may present with atypical admissions.…”

“…The virus needs to reach to the central nervous system via hematogeneous route or via olfactory nerves to cause encephalitis. While encephalitis clinic occurs due to primary disease in children and young adults, it occurs due to retrograde spread of the virus from the peripheral neurons to the brain in advanced ages (3)(4)(5)8,9). Laboratory findings are not specific to herpes encephalitis.…”

“…Herpetic encephalitis is the most common and the highest mortality of encephalitis (1)(2)(3)(4)(5). It is clinically characterized by high fever, headache, and confusion.…”