Encephalitis

Question 1

what is encephalitis?

Answer 1

Encephalitis is an acute inflammatory process affecting the brain parenchyma

Question 2

what is encephalitis most commonly caused by?

Answer 2

Viral infection is the most common and important cause, with over 100 viruses implicated worldwide

Question 3

What are the symptoms of encephalitis?

Answer 3

Fever
Headache
Behavioral changes
Altered level of consciousness
Focal neurologic deficits
Seizures

Question 4

What are the causes of viral encephalitis?

Answer 4

Herpes viruses – HSV-1, HSV-2, Varicella Zoster virus, Cytomegalovirus, Epstein-Barr virus, Human Herpes virus 6

Adenoviruses

Influenza A

Enteroviruses, Poliovirus
Measles, Mumps, and Rubella viruses

Rabies

Arboviruses : Japanese encephalitis; St. Louis encephalitis virus; West Nile encephalitis virus

Question 5

sporadic encephalitis in previously healthy is most commonly caused by

Answer 5

herpes encephalitis

Question 6

What may herpes encephalitis present as?

Answer 6

severe haemorrhagic encephalitis affecting the temporal lobe

focal signs and epilepsy features

Acute infection or more commonly reactivation of latent infection (trigeminal nerve ganglion)

Question 7

survival rate of herpes encephalitis

Answer 7

30% mortality with treatment

70% mortality without treatment

Question 8

what is rabies?

Answer 8

Acute, progressive viral encephalitis

Highest case fatality of any infectious disease

Question 9

Transmission of rabies

Answer 9

Virus enters through bite, grows at trauma site for a week and multiplies.

Then enters nerve endings and advances toward the ganglia, spinal cord and brain.

Question 10

What are the clinical phases of rabies?

Answer 10

Prodromal phase – fever, nausea, vomiting, headache, fatigue; some experience pain, burning, tingling sensations at site of wound

Furious phase – agitation, disorientation, seizures, twitching, hydrophobia

Dumb phase – paralyzed, disoriented, stuporous

Coma phase - results in death