Abstracts

Rationale: Herpes simplex virus (HSV) is the most common cause of sporadic encephalitis throughout the world. Sporadic encephalitis is considered to be the result of reactivation of latent infection with virus located in cranial nerve ganglia or the result of CNS invasion through the olfactory pathways. Without antiviral therapy, mortality from HSV encephalitis is greater than 70%, with a high rate of severe neurologic sequelae. Acyclovir reduced mortality to 28% and rapid institution of antiviral therapy has further reduced 1-year mortality to 14%. The occurrence of HSV encephalitis after neurosurgery is rare and is associated with an unfavorable outcome [1]. We report a case with an unique clinical presentation that occurred after head trauma requiring left cranioplasty eight years prior to admission, in whom HSV affected the same hemisphere. A literature review revealed cases immediately post-surgery[2],[3],[4] but predisposition to the same hemispheric involvement after years of surgical intervention has not been reported. This is a 50 year old afebrile African-American male who presented with episodic right facial twitching and tongue tremors for one week, prior to admission. He had difficulty talking in between twitching episodes. Initial laboratory values were significant only for an elevated blood glucose level of 362, and mildly elevated creatinine of 1.3. The physical examination was significant only for episodic right facial twitching and deviation, with tremors of the tongue. The patient was started on Levetiracetam with a differential diagnosis that included focal seizures and hemifacial spasms. An EEG confirmed left brain periodic lateralized epileptiform discharges (PLEDS). Imaging studies consisting of a CT Scan of the head followed by MRI of the brain showed encephalomalacia underlying the left cranioplasty. Contrast MRI demonstrated leptomeningeal enhancement in the same region as the encephalomalacia. Two days after admission the patient became febrile at 102.9 F and developed severe aphasia. The same day Vancomycin, Ceftriaxone and Acyclovir were started empirically. On the third day one episode of focal clonic seizure was witnessed involving the right arm and leg and he also suffered an episode of respiratory failure requiring transfer to the MICU and intubation for the next six days. A dense monoplegia of the right upper extremity and paresis of the right lower extremity were noticed on the second day of MICU stay. CSF studies came back positive for HSV 1 PCR and Acyclovir was continued for a total of three weeks. Interval EEGs continued to show electrical PLEDS which did not resolve for almost 3 weeks. The presentation and course of HSV encephalitis is unique in this patient and will be further discussed.Methods: .Results: .Conclusions: .