CNS infections

Question 1

What is the most common anti-viral?

Answer 1

Aciclovir

Question 2

What are the most common meningitis causing organisms?

Answer 2

Neisseria meningitidis
Haemophilus influenzae
Streptococcus pneumoniae
(herpes simplex virus)

Question 3

What type of organism is neisseria meningitidis?

Answer 3

• gram negative coccus bacteria

- commensal organism in upper respiratory tract

Question 4

How is neisseria meningitidis spread?

Answer 4

person to person

Question 5

What type of organism is Haemophilus influenzae?

Answer 5

• gram negative cocco-bacillus

- commensal organism in upper respiratory tract

Question 6

What structure do lots of CNS infections possess?

Answer 6

capsule to protect themselves against immune system

Question 7

What type of organism is Streptococcus pneumoniae?

Answer 7

gram postitive diplococcus

Question 8

What are the most common meningitis causing organisms in neonates?

Answer 8

• Listeria monocytogenes
• E.Coli
• streptococcus agalacticae (group B streptococcus)

Question 9

How is listeria monocytogenes spread?

Answer 9

• can colonise food and vagina

- can therefore be transmitted to baby at birth

Question 10

What other organisms can cause meningitis in immunocompromised patients?

Answer 10

• cryptococcus neoformans (yeast)
• Toxoplasma gondii (protozoa)
• Listeria monocytogenes (food borne)

Question 11

What viruses can cause encephalitis?

Answer 11

• Herpes simplex virus
• Varicella-zoster virus

almost always these^

• polio, measles and mumps (vaccine preventable)
• zoonotic and vector borne (rabies, zika and Japanese encephalitis)

Question 12

What are the symptoms of meningtis?

Answer 12

Headache 
fever
neck stiffness 
photophobia 
non-blanching purpuric rash

Question 13

What are the symptoms of meningtis?

Answer 13

• Headache
• fever
• neck stiffness
• photophobia
• non-blanching purpuric rash

Question 14

What are the symptoms of progressed meningitis infection?

Answer 14

• neurological deficits
• upper respiratory tract symptoms
• AKI, disseminated intravascular coagulation
• shock, peripheral ischemia

Question 15

What is the diagnostic approach for meningitis?

Answer 15

• antibacterials given even before culture
• imaging to check for raised intracranial pressure
• lumbar puncture (only if no intracranial pressure) check cell count, chemistry and microbiology
• blood culture
• throat swob, blood and CSF

Question 16

What is the treatment of meningitis?

Answer 16

• ceftriaxone
• steroids to reduce pressure
• amoxicillin to cover listeria
• ciprofloxacin to eradicate carriage

Question 17

What medication is given to treat meningitis in neonates?

Answer 17

cefotaxime

Question 18

What are the symptoms of encephalitis?

Answer 18

• altered behaviour
• altered consciousness
• neurological symptoms
• fever
• rash for VZV

Question 19

How is encephalitis diagnosed?

Answer 19

• CT and MRI
• Lumbar puncture
• PCR from throat, blood and CSF
• EEG

Question 20

How is encephalitis treated?

Answer 20

• sedation if agitated
• ventilation if in coma
• hydration
• seizure management
• osmotherapy for raised intracranial pressure
• steroids to reduce pressure
• antivirals

Question 21

What is the MoA of aciclovir?

Answer 21

• prodrug (only activated in virally infected cells)
• competitively inhibits DNA synthesis by competing with deoxyguanosine
• get aciclovir in DNA chain instead of deoxyguanosine which will terminate the chain

Question 22

What are the side effects of aciclovir?

Answer 22

disturbances

• GI
• Skin
• neurological
• renal

Question 23

What is aciclavir used for?

Answer 23

• Herpes labialis (lips) and eye infections
• orally for Herpes genital infections and varicella virus
• IV for life threatening HSV and VSV

Question 24

Which drug can be given instead of aciclavir?

Answer 24

valaciclovir - easier to give orally

Question 25

What antiviral can be used to treat cytomegalovirus?

Answer 25

Ganciclovir