Viral & Bacterial CNS Infections

Question 1

What part of the brain has resistanec to ifnection?

Answer 1

Cerebral tissue

Question 2

What part of the nervou system is never infected by blood-borne pathogens?

Answer 2

Cranial epidural and subdural spaces

Question 3

What are the 2 pathways of pathogen infection?

Answer 3

Diploic vein flow = from diploic sinuses to meningeal veins then brain

Erosion of osteomyelitis focus = ostoeomyelitic focus erros the inner table of bone & invade the dura, subdural space, pia-arachnoid and even the brain

Question 4

What are the most common neonates causing bacterial CNS infection?

Answer 4

E coli
Group B Strep

Question 5

What is the most common pathogen causing CNS infection in infants & unvax child?

Answer 5

H influenzae

Question 6

What are common pathogens causing bacterial CNS infeciton in adults?

Answer 6

Pneuococcus (Streptococcus pneumoniae)
Meningococcus (Neisseria meningitidis)
Group B Strep
Listeria monocytogenes
Staphylococcus

Question 7

What condition is caused by inflammatory reaction in the pia and arachnoid in the CSF

Question 8

How can an infection reach the ventricles?

Answer 8

1. Directly from CHOOROID PLEXUSES
2. Reflux through FORMAINA OF MAGENDIA AND LUSCHKA

Question 9

What type of acute meningeal inflammation can acuse Kernig and Brudzinski signs?

Answer 9

Pure pia-arachnoiditis

Question 10

What are the signs & symtoms of Hydrocephalus?

Answer 10

• at first = purulent exudate around the baes of the brain
• later = meningeal fibrosis w/c impairs CSF reabsorption
• rarely = aqueductal stensosis as complication of meningitis

Question 11

What are signs & symptoms seen in those suspected of acute bacterial meningitis?

Answer 11

Fever
Headache (usually severe)
Stiffness of the neck
(+) Brudzinski sign & Kernig signs

Question 12

Memorize or familiarize empiric therapy of bacterial meningitis!!!!!

Answer 12

Cefoxatime + Ampicillin = 0-4 weeks

Headtrauma; neurosurgery = Vancomycine + Ceftazidime

Question 13

What is the Osler Triad?

Answer 13

Pneumococcal meningitis + pneumonia + endocarditis

Question 14

In wha tcases do u see Osler triad?

Answer 14

Leptomeningitis (acute bacterial meningitis)

Question 15

What is the tx of childhood meningitis?

Answer 15

Corticosteroids + high dose of Dexamethasone

Question 16

What is the tx of meningitis in adults?

Answer 16

Dexamethasone just before the 1st dose of antibiotics

Question 17

What are the common location of brain abscess?

Answer 17

1/3 = anterolateral part of the cerebellar hemisphere
2/3 = middle and inferior parts of the temporal lobe

Question 18

What is the most common location of brain abscess?

Answer 18

Abscess originaitng in the ear

Question 19

What location is indicated if sinuses are implicated in brain abscess?

Answer 19

Frontal = abscess in the frontal lobe
Sphenoid = abscess in the temporal lobe

Question 20

What is the most common anomaly of brain abscess?

Answer 20

Tetralogy of fallot

Question 21

What is the most comon organism causing brain abscess?

Answer 21

Streptoccci

Question 22

What are the focal neurologic deficits of brain abscess?

Answer 22

Motor
Sensory
Speech disorders

Other:
Fever, leukocytosis
Elevated ESR

Question 23

What is the appearance of brain abscess in CT scan and MRI?

Answer 23

CT = ring enhancing lesion with HYPODENSE center

MRI = ring enhancing lesion with HYPOINTENSE center

Question 24

What is the most comon cause of Acute Aseptic Meningitis?

Answer 24

Enterovirus
- Echovirus
- Coxsackie virus

Question 25

What are the best tests used to detect Acute Aseptic Meningitis in active stage & later stage of the infection?

Answer 25

PCR = active stage of viral replication
Serological stage = later stage

Question 26

What is the tx for HSV encephalitis?

Answer 26

Acyclovir

Question 27

In HSV encephalitis, if there is brain edema, what is the tx given?

Answer 27

Mannitol and hypertonic saline

Question 28

What are subacute and chronic viral infections of the CNS?

Answer 28

Subacute sclerosing panencephalitis = measles virus
Progressive rubella panencephalitis = rubella
Progressive multifocal leukoecenphalpathy = JC virus

Question 29

What are late manifestations of Progressive multifocal leukoencephalopathy?

Answer 29

Hemiparesis
Quadriparesis
Visual defects
Cortical blindness
Aphasia
Ataxia
Dysarthria
Dementia
Confusional states
Coma

Question 30

What is the gold std of Progressive multifocal leukoencephalopathy?

Answer 30

Viral DNA isolation from CSF by PCR

Question 31

What are the diff tx for PML?

Answer 31

Cytosine arabinoside
Cidofovir
Mirtazapine
Interferon
Topotecan

Question 32

What are the 2 stages of pathogenesis of Tuberculous meningitis?

Answer 32

1st = bacterial seeding
2nd = rupture of 1 or more of the tubercles

Question 33

What are early manifesatstions of TB meningitis?

Answer 33

Low-grade fever
Malaise
Headache
Lethargy
Confusion
Stiff neck with Kernig and Brudzinski signs

Question 34

What are the most frequent intracranial tumors in children?

Answer 34

Cerebellar tuberculomas

Question 35

What are the diff drugs for TB meningitis?

Answer 35

Isoniazid
Rifampin
Ethambutol
Pyrazinamide

Question 36

What are the principal type sof neurosyphilis?

Answer 36

Asymptomatic neurosyphili
Meningeal syphilis

Question 37

What is the characteristic sign of asymptomatic neurosyphilis?

Answer 37

Argyll robertson pupils = pupils accomodate with convergence but do not react to light

Question 38

What are signs of meningeal syphilis?

Answer 38

Headache
Stiff neck
Cranial nerve palsies
Convulsions
Mental confusion
Afebrile

Question 39

What is the most common form of neurosyphilis?

Answer 39

Meningovascular syphilis

Question 40

What is the tertiary neursyphilis?

Answer 40

Tabes dorsalis or Tabetic neurosyphilis
- develops 15-20 yrs afer onset of infection
- spreads to the spinal cord

Question 41

What aer major symptoms of Tabetic neurosyphilis?

Answer 41

Lightining pains
Ataxia
Urinary incontinence