It’s a typical busy Saturday night in the main ER, with your alcoholics and K2-smokers causing a ruckus, when you pick up a 32yo woman brought in by her friend for ‘acting strange.’ You think maybe she joined the K2-bandwagon of Brooklyn, but her friend adamantly denies any drug use, saying that she prefers sex to drugs & rock’n’roll. You get more history from her friend, who says she has been very confused, thinks it is 1976, and is having difficulty expressing herself in the last 2 days. She has no psychiatric or medical history but her friend her blurts out, “Oh, she did have a nasty blister on her lip last week”

You glance her vitals: T 100.3, otherwise normal. Exam is relatively unremarkable except for nuchal rigidity and the neuro findings mentioned by her friend.

What's the most likely diagnosis?
Viral Encephalitis, specifically HSV.  It almost always coexists with a viral meningitis, but by definition includes focal neurologic deficits. HSV has an affinity for the medial temporal lobe, which will effect behavior and memory and can present with psych symptoms, confusion, aphasia, amnesia, seizures, coma.  It is extremely fatal if not treated promptly. 

 

What do you want to do next?
  Labs and CT Scan to rule out any other emergent causes of AMS, followed by LP. CT usually won’t show an encephalitis (an MRI will), but is necessary both to rule out abscess or other space-occupying lesion and  risk of herniation before an LP in an altered patient. 

 

What do you expect to see in the CSF?
CSF will show a viral meningitis picture

1. Mildly elevated WBC with lymphocyte predominance 2. normal glucose 3. slightly elevated protein  4. normal opening pressure

Ultimately, diagnosis is made by viral culture or PCR

 

Treatment?
 Acyclovir 10mg/kg IV q 8hours. 

 

What other viruses cause encephalitis?
Arbovirus including west nile virus (ask about tick bites and mosquitos), HZV, CMV, EBV, and rabies 

 

Tintinalli’s 7th Ed.

Uptodate

 

By Dr. Kylie Birnbaum

Special thanks to Dr. Willis

 

 

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Kylie Birnbaum

Emergency Medicine Resident at Kings County Hospital / SUNY Downstate @KBirnbaumMD
Categories: EM Principles

Kylie Birnbaum

Emergency Medicine Resident at Kings County Hospital / SUNY Downstate

@KBirnbaumMD

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