We present a case of human herpes virus 6 (HHV-6) encephalitis presenting as New onset status epilepticus (NORSE) in an immunocompetent adult.
Reactivation of HHV-6 virus, particularly in immunocompromised patients, has been associated with various neurological disorders including encephalitis. However, there are anecdotal case reports of HHV-6 encephalitis presenting with status epilepticus (SE) in immunocompetent adults.
A 46-year-old male with past medical history significant for hypertension, congestive heart failure, and type-2 diabetes mellitus presented with new onset recurrent episodes of generalized tonic-clonic seizures, non-responsive to benzodiazepines. Patient was started on broad spectrum IV antibiotics (vancomycin, ceftriaxone and acyclovir). Continuous EEG monitoring showed multiple seizures with onset in right temporal region and meeting the criteria for SE. Lumbar puncture revealed neutrophil predominant pleocytosis (138 WBC/mm3) with normal glucose and protein levels. Patient continued to remain in SE despite loading with IV levetiracetam and lacosamide. IV midazolam infusion was initiated after intubating the patient for airway protection. MRI brain demonstrated hyper intensities on T2/FLAIR sequences in bilateral hippocampi with subtle enhancement on T1 post contrast images with IV gadolinium. Patient was in super-refractory SE with no response to IV continuous anesthetics (midazolam and ketamine). IV pentobarbital infusion was started subsequently and continued for 48 hours. Patient was found positive for HHV-6 on CSF by multiplex PCR testing. Seizures resolved after starting IV ganciclovir and patient was able to be weaned of pentobarbital within 24 hours with no recurrence of seizures. Patient was successfully extubated and went on to complete a 3-week course of ganciclovir and returned to near neurological baseline with only residual left upper extremity weakness (mRS 1).
This case highlights HHV-6 as an important consideration in patients with new onset refractory status epilepticus (NORSE), including immunocompetent adults. Prompt treatment with suitable antiviral agents (ganciclovir or foscarnet) can improve outcomes.