(489) Delays in Herpes Encephalitis Diagnosis

Introduction: Herpes simplex encephalitis (HSE) is rare, affecting only 1-4 per million worldwide. HSE initially presents with fevers and nausea. Later, neurologic symptoms manifest, e.g. short-term amnesia, and word-finding difficulty. If diagnosis is delayed, seizures occur and are associated with worse outcomes. Since early symptoms are nonspecific, HSE diagnosis is often delayed, a retrospective study of 2667 patients estimated 45% of patients experience at least 1 missed opportunity, with 22% having >7 day delay. Our case depicts the difficulty of recognizing HSE, and emphasizes the need to keep HSE in the differential when evaluating encephalopathy, especially in the elderly.

Description: A 70 YOF, who had been independent, presented for altered mentation. She had felt unwell due to a ‘stomach bug’, afterwards, she developed blurry vision, memory loss and difficulty finding her words. The next day, her family found her unresponsive. Patient’s labs showed leukocytosis (14), and a urinalysis indicating infection. Noncontrast tomography of her head was normal. Encephalopathy was concluded to be due to urinary tract infection and she was started on ceftriaxone. After less than 24 hours, she had a seizure and difficulty breathing. Rapid response was called, she was intubated and transferred to the intensive care unit. Suspicion arose for a central nervous system infection, and she was started on vancomycin, ampicillin, acyclovir, and steroids. Lumbar puncture showed elevated white blood cell count (36), glucose (120) and protein (90). Serology was positive for HSV 1. MRI showed restricted diffusion involving the left temporal lobe and left insular cortex, confirming HSE. Acyclovir was continued. The patient recovered, was extubated and downgraded to the floor.

Discussion: Although this patient’s symptoms were reasonably explained by having a urinary tract infection, it led to delaying her diagnosis, which is a common phenomenon. It is paramount that we treat patients with acyclovir as soon as HSE is suspected without waiting for imaging or lumbar puncture. Herpes encephalitis has seventy percent mortality rate and delays in diagnosis increase mortality and morbidity. Hence, vigilance in recognizing HSE symptoms is crucial, even if they can be explained by another more benign cause.