Encephalitis - Dr. P. Soundararajan
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Transcript of Encephalitis - Dr. P. Soundararajan
ACUTE ENCEPHALITIS
DR. P. SOUNDARARAJAN,PROFESSOR OF PEDIATRICS,
MGMCRI.
Terms to understand
• Encephalitis• Encephalopathy• Meningitis• Meningism • Myelitis
Meningoencephalitis
• Acute inflammation of meninges & brain tissue
• CSF – pleocytosis• Gram stain & culture negative• Changes in MRI brain • Mostly self limiting
Etiology
• Enterovirus; coxsackie, polio, echo• Arbovirus; JEV, WNV, Dengue• Herpes virus; HSV1&2, VZ, EBV, CMV.• Others; mumps, measles, rabies, adenoV.• Bacteria; TB, mycoplasma, rickettsiae• Protozoa; acanthameba, toxoplasma
JEV
JEV
• Annual incidence : 16/100 000 in children [4-8 /100 000 in adults]
• HSV; 22%• VZV; 21%• Adeno V; 4%• JBE in asia; 35000 – 50000 cases / year. 1/3 die , june to september.
JEV
• Flavivirus• Spread by culex• Single stranded RNAV• 1955 in pondicherry; 1st case• 2005; 1400 deaths in UP & Bihar• 2014; WB, UP, assam; ~ 300deaths
Pathogenesis • Direct invasion & destruction by virus• Host reaction to viral antigens• Meningeal congestion• Mononuclear infiltration• Neuronal disruption• Neuronophagia, vasculitis• Demyelination [ADEM]
Structures affected
• HSV; temporal lobe• Arbovirus; entire brain• Rabies; basal parts• Varicella; cerebellum
4 stages
• 0-3d ; prodrome• 4-7d; acute• 8-10d; subacute• 1-4wk; recovery
Clinical features• Depends on parenchymal involvement• Preceding mild febrile illness & exantheme• Acute onset of high fever, headache, irritability,
lethargy, nausea, myalgia• Convulsions, stupor, coma• Fluctuating FND, emotional outburst• Ant.horn cell injuryflaccid paralysis [west nile,
entero virus]
Clues in history
• Travel to endemic places
Clues in examination • Cranial N palsy; HSV, EBV, TB.• Ataxia; VZV, • AFP; polio, enteroV, tick borne.• Rash; VZV, typhus, mycoplasma• Parotitis; mumps,• LN; HIV, EBV, CMV, Rubella.• Hydrophobia; rabies.
Diagnosis CSF: lymphocytic predominance
Protein: normal, high in HSV Glucose: normal, low in mumps Hemorrhagic; measles Viral antigen by PCR Blood: Culture from NP swab, vesicle, feces, urine IgM, IgG titre
EEG in HSV
Bilateral asymmetric thalamic hyper intensity
Substantia nigra involvement
Management in ICU
Management
• Monitor GCS• ABC• Restrict IVF• Anticovulsants, antipyresis ,• Treat ICT• Moitor; glucose, BUN, elect, ABG, LFT,
Infant < 1 yr Child 1-4 yrs > 4 yearsEYES
4 Open Open Open
3 To voice To voice To voice
2 To pain To pain To pain
1 No response No response No response
VERBAL5 Coos, babbles Oriented, speaks,
interacts, socialOriented and Alert
4 Irritable cry, consolable
Confused speech, disoriented, consolable
Disoriented
3 Cries persistently to pain
Inappropriate words, inconsolable
Nonsensical speech
2 Moans to pain Incomprehensible, agitated
Moans, unintelligible
1 No response No response No response
MOTOR6 Normal spontaneous
movementNormal spontaneous movement
Follows commands
5 Withdraws to touch Localizes pain Localizes pain
4 Withdraws to pain Withdraws to pain Withdraws to pain
3 Decorticate flexion Decorticate flexion Decorticate flexion
2 Decerebrate extension Decerebrate extension Decerebrate extension
1 No response No response No response
Bad Prognosis
• <3 yrs• GCS <6 for 4days• Hyponatremia
• 50-60% sequalae
Prevention
Thank you