ABSENT MRI FINDING OF HERPES SIMPLEX VIRAL EECEPHALITIS IN RENAL TRANSPLANT PATIENT

Abstract

SESSION TITLE: Tuesday Fellows Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Herpes simplex viral encephalitis (HSVE) is typically associated with a constellation of frontotemporal features and MRI findings showing increased signal intensity in the temporal lobe, with characteristic sparing of the lentiform nuclei. We report a case of HSVE with profound neurological manifestations without MRI findings in an immunosuppressed adult after kidney transplant. CASE PRESENTATION: 58 year old man with history of renal transplant in 2012 presented with profound ataxia, generalized fatigue for 3 days. He was compliant with Tacrolimus and Mycophenolate without any adverse events. On physical exam the patient was afebrile, normotensive with temporal wasting. His neurological, cardiovascular, chest and abdominal examination were benign. CT head was unremarkable. CT abdomen/pelvis/chest showed numerous hepatic cysts, and transplanted kidney. During the hospitalization he had no resolution of symptoms and had a seizure requiring intubation for airway protection. He was empirically started on Vancomycin and Meropenem . MRI head on day 4 was unremarkable. Tacrolimus level was therapeutic. LP was performed and showed lymphocytic pleocytosis CSF and elevated protein with high RBC count 70. The patient was started on ganciclovir for high clinical suspension of HSV or CMV encephalitis. EEG was abnormal with severe diffuse background slowing. After initiation of antiviral therapy pt demonstrated marked clinical improvement. CSF analysis revealed a positive HSV–2 PCR. The patient was successfully extubated and completed a course of oral acyclovir. DISCUSSION: HSVE is a neurological emergency with high morbidity and mortality. It is caused by herpes simplex virus type one (90%), followed by type two (10%). The presentation is usually nonspecific and may include acute febrile illness with headache, progressive altered mental status, hemiparesis, and seizures. In the immunocompetent adult patient, the pattern is quite typical and MRI usually shows bilateral asymmetrical involvement of the limbic system, medial temporal lobes, and inferolateral frontal lobes. The basal ganglia are typically spared. In immunocompromised patients, involvement can be more diffuse, and more likely to involve the brainstem, but normal MRI findings is highly unusual in HSVE. Our case reinforces the importance of consideration of HSVE in the differential of patient's with suggestive clinical features even with absent MRI finding. CONCLUSIONS: As clinicians, our index of suspicion should remain high in patients presenting with the typical features of encephalitis such as fever, headache, confusion, and clouding of consciousness. Although this case was not a classic presentation for HSVE and MRI was unremarkable, neurologic manifestations in an immunosuppressed host should prompt further exploration. The diagnosis of HSVE is usually established from the combination of the clinical and investigative features. Reference #1: Kaya A, Mert A, et al. Herpes simplex virus encephalitis: clinical manifestations, diagnosis and outcome in 106 adult patients. Sili U, J Clin Virol. 2014;60:112–118. Reference #2: Bulakbasi N, Kocaoglu M Central nervous system infections of herpesvirus family. Neuroimaging Clin N Am. 2008;18:53–84. Reference #3: Croll, Benjamin J et al. “MRI diagnosis of herpes simplex encephalitis in an elderly man with nonspecific symptoms” Radiology case reports vol. 12,1 159-160. 22 Dec. 2016, https://doi.org/10.1016/j.radcr.2016.11.021 DISCLOSURES: No relevant relationships by Mona Alipour, source=Web Response no disclosure on file for Farhad Arjomand; no disclosure on file for Louis Gerolemou; No relevant relationships by Nabil Mesiha, source=Web Response No relevant relationships by Jose Orsini, source=Web Response Speaker/Speaker's Bureau relationship with Allergan Please note: $20001 - $100000 Added 03/18/2019 by Joshua Rosenberg, source=Web Response, value=Honoraria No relevant relationships by Sahar Takkouche, source=Web Response