Red Book - Encephaltis

Question 1

Define encephalitis

Answer 1

Inflammation of the brain parenchyma.

Pathogens gain access to CSF via haematogenous spread.

Some invade via direct neuronal transport

Question 2

How do encephalitis present

Answer 2

Over a number of days
Prodromal illness

Personality change
Headaches
Confusion
Seizures and status
Focal
COMA

Question 3

Causes of encephalitis

Answer 3

Viral
Bacterial
Fungal
TB

Auto-immune —> anti NMDA recepted
Anti GABA-B receptor

Question 4

Name some viruses

Answer 4

HSV1
Entero
VZV
EBV
Rabies
CMV

Question 5

How to diagnose

Answer 5

History, Exam, Bloods, LP, Imaging, EEG

Hx:
From patient with collaterol
O/E - neuro exam and focals

Bloods - FBC, (WCC and differential (bacterial from viral))
CRP
U&E, LFT, TFT (other causes)
CLotting (coag prior to LP)
Autoimmune serology
HIV test

Image - CT/MRI

EEG

LP - NOT if raised ICP or coagulopathy
	Cell count and gram stain
	Cytology
	Viral PCR
	Biochem glucose and protein
	Culture
	Antibodies

Question 6

Differentials

Answer 6

1) other infection
Meningitis, cerebral abscess, sepsis (confusion), HIV

2) Vascular —> stroke TIA, ICH, PRES (assoc with hypertension)
3) Malignancy —> primary lymphoma, mets

4)toxins and metabolic
Hepatic, uraemia, thyroid crisis, electrolytes
MDMA, amphet, LSD, TCA, SSRI,
Serotonin syndrome and NMS

5) autoimmune - NMDA, GABA-B, vasculitis, lupus, ADEM
6) non convulsive status

Question 7

Treatment

Answer 7

ABCDE etc

Anti viral - aciclovir 10mg/kg tds two weeks

Bacterial cover - ceftriaxone 2g tds

Steroids/?? May be a role in children

Question 8

Prognosis

Answer 8

Mort 10%
80% if untreated

Complications are high —> memory loss, behaviour, persona, speech, epilepsy

Question 9

If immunocomprimised

Answer 9

HIV testing

Consider opportunistic infection — fungal cryptococcus

Question 10

Opening pressures

Answer 10

Normal 10-20 cmH2O

Bact: High
Viral: Normal high
Fung: VERY HIGH
TB High

Question 11

CSF apprearence

Answer 11

Normal: Clear
Bacter:   Turbid
Viral:	    Gin clear
Fungal	     Fibrin web
TB:L		TurBid

Question 12

Protein in CSF

Answer 12

Normal: <	0.45g/L
BactL		High >1
Viral		Normal
Funal		High 0.2-5
TB		       High 1-5

Question 13

CSF:plasma glucose ratioCSF

Answer 13

Normal:L 50-66%
Low	      <50%
Viral		Normal
Fungal 	Low/normal
TB			Very low <30%

Question 14

Cell count

Answer 14

Normal <5 mm3
Bact >1000
Viral < 500
Fungal 100-500
TB 50-1500

Question 15

WCC differential

Answer 15

Normal Lymphocytes
Bacterial Polymorphs
Viral funal TB lymph