SESSION TYPE: Critical Care Student/Resident Case Report Posters II
PRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PM
INTRODUCTION: Etiologies for Status Epilepticus (SE) are broad, but encephalitis is a unique trigger for refractory SE. We present a case of HHV6 encephalitis in an immunocompetent male who developed severe refractory SE from HHV6B.
CASE PRESENTATION: A previously healthy 21 year old male was admitted with signs of confusion and disorientation. The patient had had a febrile episode with some non-specific cervical lymphadenopathy that resolved with Augmentin. His history was benign, with no falls, trauma, exposures, travels, drug use or previous episodes. After admission, the patient developed status epilepticus that was not controlled with IV Valproate, Phenytoin, Levetiracetam, Lorazepam and Midazolam, and necessitated mechanical ventilation. Extensive CSF testing was negative, except for HHV6-type B PCR positivity. Admission MRI was normal but progressed to bilateral hippocampal enhancement and then hyperintense bihemispheric signal (without laminar necrosis). Clinically, the patient deteriorated in spite of optimal treatment; burst suppression was achieved with IV Pentobarbitol and IV Propofol with heroic doses of IV Midazolam (>100mg/hr), but relapsed when drug therapy was marginally deescalated. Repeat LP showed persistent HHV6B, which was treated with Ganciclovir and later Cidofovir along with IV Methylprednisone. The patient showed signs of vasomotor instability at day 21, in spite of vasopressor support, and at the family’s wishes care was withdrawn.
DISCUSSION: It has been published that HHV6 has known epileptogenic properties. This virus usually affects young patients with immunosuppression, but recently has been found in immunocompetent adults. The diagnosis is usually made via HHV6 (A/B) lab titers, given the fact that clinical presentation is highly variable. Imaging is not specific for this syndrome but bilateral hippocampal enhancement may offer an early clue to HHV6 encephalitis. Other MRI findings include increased mesial temporal lobe signal and cortical laminar necrosis. The current standards of care in encephalitis/ meningitis do not address the increasing incidence of a highly epileptogenic virus such as HHV6. As the seizures in HHV6 encephalitis are resistant to conventional treatment, a delayed diagnosis frequently leads to an often fatal, refractory SE.
CONCLUSIONS: HHV6 should be sought early in immunocompetent adults with undiagnosed encephalitis and seizures, with Ganciclovir/Cidofovir and Methyprednisone added empirically along with aggressive management of seizures to prevent progression to catastrophic SE.
1) Birnbaum et al. Severe meningoencephalitis caused by human herpesvirus 6 type B in an immunocompetent woman treated with ganciclovir. Clin Infect Dis. 2005 Mar 15;40(6):887-9.
2) Provenzale et al. Extrahippocampal involvement in human herpesvirus 6 encephalitis depicted at MR imaging. Radiology. 2008 Dec;249(3):955-63.
3) Theodore et al. Human herpes virus 6B: a possible role in epilepsy? Epilepsia. 2008 Nov;49(11):1828-37.
DISCLOSURE: The following authors have nothing to disclose: Aaron Persinger, Amol Patil, Susanna Von Essen
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