Viral infection of CNS - DONE

Question 1

Encephalitis def:

Answer 1

Encephalitis is defined by the presence of an inflammatory process of the brain in association with clinical evidence of neurologic dysfunction

Question 2

Viral encephalitis - symptoms:

Answer 2

• fever
• altered level of consciousness (confusion, behavioral abnormalities)
• depressed level of consciousness (lethargy, coma)
• focal or diffuse neurologic signs and symptoms
• seizures

Question 3

Viral encephalitis - etiology:

Answer 3

Majority of cases are unknown (32%-75%)

Question 4

Viral encephalitis - etiology - What are the common causes of sporadic cases?

Answer 4

• Herpesviruses:
  
  • HSV-1
  • VZV
  • EBV

Question 5

What are endemic encephalitis caused by?

Answer 5

arthropod-borne viruses

Question 6

Viral encephalitis - diagnosis:

Answer 6

• MRI : is the most sensitive neuroimaging test to evaluate patients with encephalitis
• CT : with or without contrast enhancement, should be used to evaluate patients with encephalitis if MRI is unavailable or cannot be performed because of its low sensitivity
• CSF analysis is essential and should be performed (unless contraindicated) in all patients with encephalitis.

Question 7

What is the most sensitive neuroimaging test to evaluate patients with encephalitis?

Answer 7

MRI

Question 8

Viral encephalitis - diagnosis - findings:

Answer 8

• Focal findings in a patient with encephalitis should always raise the possibility of HSV encephalitis:
  
  • 80% will have abnormalitis in the temporal lobe.
• Normal MRI does not exclude the HSV etiology:
  
  • 10% of patients will have no abnormalitis on MRI

Question 9

Viral encephalitis - diagnosis - Electroencephalography (EEG)

Answer 9

• rarely helpful in establishing an etiology in patients with encephalitis
• has a role in identifying patients with non-convulsive seizure activity who are confused, obtunded, or comatose
• should be performed in all patients with encephalitis

Question 10

persistent neutrophilic pleocytosis has been observed in…..

Answer 10

patients with West Nile virus encephalitis.

Question 11

Nucleic acid amplification tests example:

Answer 11

PCR

Question 12

Viral encephalitis - empirical treatment:

Answer 12

acyclovir should be initiated in all patients with suspected viral encephalitis, especially if focal features are present

Question 13

Viral encephalitis -treatment - Empirical therapy

Answer 13

• acyclovir should be initiated in all patients with suspected viral encephalitis, especially if focal features are present

Question 14

Viral encephalitis -treatment - Supportive therapy:

Answer 14

• careful monitoring of ICP
• antipiretics
• anticonvulsant drugs
• prophylaxis of aspiration pneumonia, stasis ulcers, decubiti, deep venous thrombosis

Question 15

What is the treatment of choice for patients with herpes simplex encephalitis?

Answer 15

acyclovir

Question 16

Acute viral meningitides:

Answer 16

Inflammation caused by infection is limited to meninges.

Question 17

Patients with Acute viral meningitides have:

Answer 17

• no signs of altered consciousness
• no seizures
• no focal neurologic symptoms

Question 18

Acute viral meningitides - symptoms:

Answer 18

• headache- often in frontal or retro-orbital area
• photophobi
• pain on moving the eyes
• signs of meningeal irritation, mostly neck stiffness
• fever
• malase, mialgia
• nausea and vomiting

Question 19

Acute viral meningitides - etiology:

Answer 19

Enteroviruses (including echoviruses and coxsackieviruses) are the most common cause, more than 85%

Question 20

What is probably the 2nd cause of viral meningitides?

Answer 20

HSV-2

- about 5% of cases

Question 21

Most cases of recurrent viral/aseptic meningitis (Mollaret’s meninigitis) are due to…..

Answer 21

HSV

Question 22

When should VZV be suspected?

Answer 22

VZV should be suspected in the presence of concurrent chickenpox or shingles

Question 23

EBV:

Answer 23

• may be accompanied by symptoms of infectious mononucleosis

- presence of atypical lymphocytes in peripheral blood and CSF should suggest this etiology

Question 24

HIV:

Answer 24

• should always be suspected in patients with meningitis

- may follow primary infection in 5-15% of cases

Question 25

MUMS:

Answer 25

• may be accompanied by symptoms of infectious mononucleosis presence of atypical lymphocytes in peripheral blood and CSF should suggest this etiology
• documented history of previous infection excludes this diagnosis

Question 26

Viruses with high seroprevalence rate:

Answer 26

• HSV

- VZV

Question 27

When is neuroimaging studies (MRI) not necessary?

Answer 27

In patients with uncomplicated viral meningitidis neuroimaging studies (MRI) are not necessery

Question 28

Viral meningitis - treatment:

Answer 28

• Symptomatic:
  
  • analgesics
  • antipyretics
  • antiemetics
• Acyclovir in HSV or VZV meningitis
• Antyretroviral treatment in HIV meningitis