Neuro - Encephalitis

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 daysProdromal illness

Personality changeHeadachesConfusionSeizures and statusFocalCOMA

Question 3

Causes of encephalitis

Answer 3

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

Question 4

Name some viruses

Answer 4

HSV1EnteroVZVEBVRabiesCMV

Question 5

How to diagnose

Answer 5

History, Exam, Bloods, LP, Imaging, EEGHx:From patient with collaterolO/E - neuro exam and focalsBloods - FBC, (WCC and differential (bacterial from viral)) CRP U&E, LFT, TFT (other causes) CLotting (coag prior to LP) Autoimmune serology HIV testImage - CT/MRIEEG

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), HIV2) Vascular —> stroke TIA, ICH, PRES (assoc with hypertension)3) Malignancy —> primary lymphoma, mets4)toxins and metabolic Hepatic, uraemia, thyroid crisis, electrolytes MDMA, amphet, LSD, TCA, SSRI, Serotonin syndrome and NMS5) autoimmune - NMDA, GABA-B, vasculitis, lupus, ADEM6) non convulsive status

Question 7

Treatment

Answer 7

ABCDE etcAnti viral - aciclovir 10mg/kg tds two weeksBacterial cover - ceftriaxone 2g tdsSteroids/?? May be a role in children

Question 8

Prognosis

Answer 8

Mort 10%80% if untreatedComplications 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 cmH2OBact: HighViral: Normal highFung: VERY HIGHTB High

Question 11

CSF apprearence

Answer 11

Normal: ClearBacter:   TurbidViral:	    Gin clearFungal	     Fibrin webTB:L		TurBid

Question 12

Protein in CSF

Answer 12

Normal: <	0.45g/LBactL		High >1Viral		NormalFunal		High 0.2-5TB		       High 1-5

Question 13

CSF:plasma glucose ratioCSF

Answer 13

Normal:L 50-66%Low	      <50%Viral		NormalFungal 	Low/normalTB			Very low <30%

Question 14

Cell count

Answer 14

Normal <5 mm3Bact >1000Viral < 500Fungal 100-500TB 50-1500

Question 15

WCC differential

Answer 15

Normal LymphocytesBacterial PolymorphsViral funal TB lymph