Case Report/Case SeriesSubacute Herpes Simplex Type 1 Encephalitis Case Report With Literature ReviewElshony, Hosna MD; Idris, Abdelrahman FRCP; Al-Ghamdi, Abdulazuiz FRCP; Alharbi, Bashaer; Almalki, Abdulrahman; Alharbi, Ahmed; Faqih, NorahAuthor Information Department of Neurology/Internal Medicine, Security Forces Hospital, Makkah, Saudi Arabia Written informed consent was obtained from the patient for publication of this case report and any accompanying images. H.E.: study design, manuscript writing, literature review, editing. A.I.: manuscript reviewing and editing. B.A., A. Almalki, A. Alharbi, and N.F.: literature review, manuscript writing. The authors declare no conflict of interest. Correspondence to: Hosna Elshony, MD, Department of Neuropsychiatry, Faculty of medicine, Menoufiya University, Egypt. E-mail: [email protected]. The Neurologist: September 2021 - Volume 26 - Issue 5 - p 178-184 doi: 10.1097/NRL.0000000000000343 Buy Metrics Abstract Introduction: The typical herpes simplex viral encephalitis (HSVE) course is an acute illness, less commonly it may present as a chronic course, mainly in children, and rarely may it be subacute. Subacute HSVE is rarely described in the literature being reported 4 times only. Case Report: We here report 2 cases of subacute HSV1 encephalitis diagnosed based on cerebrospinal fluid polymerase chain reaction and magnetic resonance imaging findings and review the literature trying to find any specific clinical, laboratory, radiologic diagnostic or prognostic criteria regarding this subacute form of HSVE. Conclusion: There is subacute form of HSVE and should be suspected with any subacute febrile illness with nonspecific cognitive impairment even in the absence of focal neurological symptoms and in cases with rapidly progressive dementia. This form has similar radiologic finding and good response to acyclovir but carry even better prognosis than that the acute HSVE. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.