Is an inflammatory process of brain parenchyma. Occurs most often in the first year of life M/C in world and in INDIA _ Japanese encephalitis In immunocompetent host- Vaicella , EBV, herpes

1. ENCEPHALITIS
_SANTHOSHI

2. ◦Is an inflammatory process of brain parenchyma.
◦Occurs most often in the first year of life
◦M/C in world and in INDIA _ Japanese encephalitis
◦In immunocompetent host- Vaicella , EBV, herpes

3. Etiology
◦RNA viruses- mumps, measles,
rubella,enteroviruses
◦DNA viruses- herpes simplex, cytomegalovirus,
Epstein barre virus
◦ARTHROPOD BORNE viruses- Japanese Bvirus,
west Nile, equine viruses
◦HIV, Rabies, lymphocytic choriomeningitis, dengue
virus

4. Cont…
◦Rickettsia, fungi (cryptococcus), protozoa (T gondii),
bacteria(tb meninges, listeria )
◦Non infectious causes- ADEM( ac. Disseminated
encephalomyelitis) allergy( post vaccine), Heat
hyperpyrexia, antibody associated encephalitis ,
electrolyte imbalance, toxins, metabolic disorders

5. Mode of transmission
◦Respiratory droplets
◦ contaminated food&
drinK
◦Mosquito, tick & other
insect bites
◦Skin contact

6. Pathogenesis
◦Neural damage is caused by direct invasion & destruction
of neural tissue or by host reactions to the antigens.
◦The damage leads to parenchyma & meningeal
inflammation , oedema & necrosis
◦HSV- affects temporal lobe
◦Arbo virus_ entire brain
◦Rabies virus- hippocampus

7. Pathological changes
◦Gross- brain shows diffuse oedema, congestion,
hemorrhages

8. ◦Microscopic- perivascular cuffing with
lymphocytes & neutrophils
◦Necrosis & degeneration of neurons with
neuronophagocytosis.

9. Clinical features
◦Features depends on- severity of infection
-host susceptibility
- agent localization
- presence of raised
Intracranial pressure

10. Initial symptoms
◦Onset- sudden but may be gradual.
◦ High fever, head ache, mental confusion, vomiting,
irritability, loss of consciousness, seizures.
◦Ocular palsies, hemiplegia, speech dysfunction,
&cerebellar symptons

11. ◦Raised ICT –decerebration
- cardiorespiratory insufficiency
-hyperventilation
- autonomic dysfunction
◦Extrapyramidal symptoms are common with JE
◦Lateralization to one side with temporalorfrontal
involvement- Herpes encephalitis

12. ◦Brain swelling leads to herniation at tentorial
hiatus.
◦Compression of midbrain cause deterioration in
consciousness, ptosis, pupillary abnormalities,
6th palsy , ophthalmoplegia, cheynestoke
breathing hyperventilation & bradycardia.

13. Symptoms-in newborn & infants
◦Irritability
◦Body stiffness
◦Poor feeding
◦Bulging fontanellE
◦Vomiting

14. Emergency symptoms
◦Loss of consciousness, stupor, coma.
◦Muscle weakness, paralysis, seizures.
◦Severe head ache,high fever.
◦Sudden change in mental function Like flat
mood , loss of interest in daily activities,
memory loss