Abstract
Herpes simplex virus encephalitis can sometimes lead to sinus node dysfunction. A 72-year-old Japanese man was admitted with faintness, and normal head computed tomography (CT) findings were observed. After hospitalization, the patient was diagnosed with sick sinus syndrome and experienced an Adams-Stokes attack. As a result, a permanent pacemaker was implanted. Subsequently, the patient began experiencing seizures intermittently. A repeat head CT scan revealed low-density areas in the left temporal lobe and insular cortex, and polymerase chain reaction revealed herpes simplex DNA in the cerebrospinal fluid. Therefore, intravenous acyclovir was administered immediately. However, the low-density areas on the head CT extended to both temporal lobes, and consciousness was not restored. Unfortunately, the patient developed aspiration pneumonia and died. Hence, it is important to consider the potential of herpes encephalitis in patients with sinus node dysfunction. LEARNING OBJECTIVE: When encountering a patient with sinus node dysfunction, it is necessary to consider the possibility of herpes encephalitis as one of the differential diagnoses, especially in atypical cases. Early diagnosis of herpes encephalitis can reduce the risk of death and the need for permanent pacemaker implantation.