Noon conference jan 10

1. © 2016 Virginia Mason Medical Center 1
Case
67 year old woman who doesn’t go to the doctor
very often. Last time was after a hysterectomy 8
years ago for endometrial cancer. She has a hx of
smoking (25 pack years), and high blood pressure.
She was found by her husband to be aphasic and
have right sided weakness. He was concerned and
called 911. She was airlifted to HMC, but their CT
was broken, so she was diverted to VMMC.

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Case
In the ED she was found to be moving all limbs
spontaneously, and very agitated. When asked to
perform simple tasks she would respond with “I
don’t understand” repeatedly.
Husband tells you that “she has not been acting like
herself”

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Case
In the ED she developed fever, tachycardia, urinary
retention, somnolence and became unresponsive to
painful stimuli on the right side.

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Hybrid Matrix Table
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Case
Vitals
T 39.2
HR 117
BP 172/85
Labs:
Wbc 4.2, Hb 11.8, plt 232, normal diff.
CMP: wnl
Csf: pleocytosis (24 leuks/uL), increased protein (855 mg/L), glucose 83, opening pressure of 150
mmH2O, and no oligoclonal bands.
EEG: diffuse slow waves intermittently
MRI showed bilateral fluid-attenuated inversion recovery (FLAIR) hyperintensities into adjacent
mesiotemporal, temporopolar, and frontobasal areas with regional gadolinium enhancement

6. Noon Conference
Jonathon Sargent, MD
Internal Medicine, R3

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Objectives
• Presentation of viral encephalitis
• Diagnosis
• Diagnostic pitfalls
• Management
• Complications

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Terminology
Aseptic meningitis – cerebral function is intact
Encephalopathy – deficits in cerebral function,
Encephalitis – encephalopathy with evidence of
inflammation
Meningoencephalopathy – mixed picture

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Etiologies
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• Viral encephalitis
• Invasion of the CNS.
• Virus can be cultured from brain tissue
• Post infectious
• Virus cannot be detected
• Neurons spared
• Perivascular inflammation and demyelination

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Viral pathogens
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• HSV-1 – most common cause of sporadic
encephalitis
• Arbovirus
• West nile
• Eastern equine, Western equine, Venezuela equine
• Zika
• St. Louis
• Tick borne –
• Colorado tick fever, Powassan virus

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Patholgens
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Clues on physical exam:
Parotitis, no history of vaccine – think mumps
Flaccid paralysis with rash – you might be thinking
Guaillan-Barre, think West Nile
Hydrophobia, pharyngeal spasms – think Rabies
Grouped vesicles in dermatoid pattern – think VZV

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Herpes
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HHV1
HHV2
HHV3
HHV4
HHV5
HHV6
HHV7
HHV8

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Herpes
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HHV1 HSV1
HHV2 HSV2
HHV3 VZV
HHV4 EBV
HHV5 CMV
HHV6 Roseola
HHV7
HHV8 KSHV

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HSV-1 Encephalitis
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Presentation: Fevers, confused, agitated,
obtunded, seizures, focal neurological
abnormalities, meningismus possible
In 106 cases of HSVE, primary reason for
hospitalization was:
• Seizure (32%)
• Abnormal behavior (23%)
• Loss of consciousness (13%)
• Confusion and disorientation (13%)

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Illness script
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Pathophysiology
Epidemiology
Time course
Clinical presentation
Diagnostics
Therapeutics
HSVE Bacterial Meningitis
Clinical presentation Fever
AMS
Focal Neuro Sx
Fever
Nuchal rigidity
AMS (lethargic)
Diagnostics Lymphocytic pleocytosis
Elevated protein
MRI – temporal lobe
abnormalities
Pleocytosis 1k-5k
Neut > 80%
Protein > 200
Glucose < 40 (ratio<0.4)
Therapeutics acyclovir Ceftriaxone
Vanc
If age >50 – amp
+/- dexamethasone

16. © 2016 Virginia Mason Medical Center
HSV-1 Encephalitis Imaging
CT:
• Subtle hypodense lesions
• Temporal lobe (typically)
• edema
• Contrast enhancement – uncommon in first
week
• Normal scan should not dissuade
diagnosis early in course.
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HSV-1 Encephalitis Imaging
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18. © 2016 Virginia Mason Medical Center
HSV-1 Encephalitis Imaging
MRI
• Most sensitive and specific
• Hyperintense lesions on T2-weighted
sequences
• Mesiotemporal, orbitofrontal lobes
• DWI more sensitive than T2-weighted
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HSV-1 Encephalitis Imaging
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Differential Diagnosis
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• Viruses (Arbo,
Herpes,
miscellaneous)
• Brain abscess,
subdural empyema
• Vascular disease
• Subarachnoid
hemorrhage
• Post infectious
• malignancy
• Neurosyphillis
• Paraneoplastic and
autoimmune
• Toxins
• SLE, vasculitis
• PRES
• Alcohol, drugs,
trauma

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Diagnosis
• PCR of CSF
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Diagnosis
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Diagnostic pitfalls
1. Failure to recognize encephalitis
2. Absence of pleocytosis
3. False negative pcr.
When suspicion is high, repeat in 3-7
days
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Treatment
Indication for CCU
• Decreased level of consciousness
• Severe comorbidities
• Autonomic dysfunction
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Treatment
• Acyclovir 10 mg/kg q8hrs 14-21
days
• Recommend broad spectrum abx
until bacterial infection is excluded
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Outcomes
• Untreated – mortality is 70%
• Treated – mortality 20-30%
• Survivors have significant long term morbidity
• Seizure disorder, neuropsychiatric illness,
thromboembolic disease, amnesia and
learning disabilities
• Autoimmune encephalitis – autoantibodies
against NMDAR
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