Encephalitis

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Introduction

Encephalitis, or inflammation affecting the brain matter, is a serious condition with a number of viral and nonviral infectious causes.

It is important to watch for HSV encephalitis, as this is a treatable, yet often lethal, condition.

a simple case introducing clincial presentation and calling for a differential diagnosis. To get students thinking.

Many viruses can be transmitted via insects. These include:

Viruses enter the brain via peripheral nerves or across the blood-brain barrier.

Encephalitis typically causes:

Seasonal patterns can help determine pathogen.

HSV encephalitis is typically preceded by an upper respiratory infection, followed by acute onset headache and fever.

With HSV encephalitis, CSF can reveal:

Viral cultures or PCR can be done on stool, throat, WBC cells, CSF, and brain biopsy. CSF titres may also be done.

EEG can be diagnostic for HSV

Other diagnoses to consider include:

acute encephalomyelitis
infective endocarditis, with brain embolization
meningoencephalitis caused by
- Cryptococcus neoformans
- Mycobacterium tuberculosis
acute bacterial abscess
TTP
cerebral venous thrombosis
vascular disease
primary or metastatic malignancy
Taenia solium cysticercosis
Toxoplasma gondii

Due to the potential benefit, acyclovir should be instituted with a low threshold of suspicion.

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