MICRO: CNS Infections

Question 1

Layers of the Skull?

Answer 1

Question 2

Viral vs. Bacterial Meningitis?

Answer 2

Viral (Aseptic) Meningitis:

• Commonest Type of Meningitis
• Self-limiting (<1 Week)
• Most Mild/Inapparent

Bacterial Meningitis:

• Acute: onset over hours to days. Medical Emergency. High Mortality (Meningococcus, S. pneumoniae) Case fatality rate of pneumococcal meningitis increases with age
• Chronic: onset over weeks to months (Mycobacterium tuberculosis)

Question 3

Complications of Bacterial Meningitis?

Answer 3

Complications:

• Abscesses
• Ventriculitis
• Hydrocephalus
• Cranial nerve palsies (sensorineural hearing loss)
• Seizures
• Hemiplegia
• Spasticity
• Mental retardation/ Learning difficulties

COMPLICATIONS PREVENTABLE W/ EARLY TREATMENT

Question 4

Causes of Acture Bacterial Meningitis?

Answer 4

Question 5

Causes of Chronic Bacterial Menigitis?

Answer 5

Question 6

Pathogenesis of Bacterial Meningitis?

Answer 6

Question 7

Pathophysiologic Mechanisms of Bacterial Meningitis

Answer 7

Bacterial invasion of BBB => intense inflammation in sub-arachnoid space. CSF is an area of immune deficiency. Lacks phagocytes, minimal leucocytes. If bacteria are able to make it across the BBB can replicate unchecked

Question 8

Presentation of Acute Bacterial Meningitis

Answer 8

Question 9

Presentation of Acute Bacterial Meningitis in Neonates?

Answer 9

Question 10

Presentation of Acute Bacterial Meningitis in Elderly?

Answer 10

Question 11

Investigations for Bacterial Meningitis?

Indications for CT scan prior to LP?

Answer 11

CT Scan Prior for those with signs of Raised intracranial pressure:

• depressed consciousness
• papilloedema
• focal neurological signs

MUST ALSO DO A CT SCAN PRIOR TO LP IN THOSE WITH:

• IMMUNOCOMPROMISED STATE
• HISTORY OF CNS DISEASE
• NEW ONSET SEIZURE

Question 12

Normal Opening Pressured for Lumbar Puncture?

Answer 12

<18cm H20

Question 13

Normal CSF Composition vs. Acute Bacterial Meningitis

• Aperance
• Cell Count
• Protein
• Glucose

Answer 13

Question 14

Empirical antibiotics for treating Acute bacterial meningitis?

• Neonate - 3 moths
• 3 months - 50 Years old
• > 50 Years old
• CNS shunt

Answer 14

• Neonate to 3 months: ampicillin + cefotaxime
• 3 months to 50 years: vancomycin + cefotaxime
• Over 50 years: vancomycin + ampicillin + cefotaxime
• CNS shunt: vancomycin + ceftazidime

Question 15

Antibiotic Treapy of Meningococcal Meningitis?

Answer 15

Question 16

Chemoprophylaxis of Meningococcal Meningitis for close contacts of infected?

Answer 16

Question 17

Meningococcal MENC Vaccine: Polysaccharide vs. Conjugate

Answer 17

Question 18

Antigenic components (4) of MenB Vaccine

Answer 18

Question 19

Management of H. influenzae Meningitis

Answer 19

• 3rd generation cephalosporin
• dexamethasone => decreases incidence of nerve deafness

Question 20

Chemoprophylaxis of H. influenzae Meningitis close contacts

Answer 20

Rifampicin for 4 days

Question 21

Treatment/Preventionof Pntioneumococcal Meningitis

Answer 21

Question 22

Presentation of Tuberculous meningitis?

Answer 22

Question 23

Treatment of Tuberculous meningitis?

Answer 23

Question 24

CSF findings in Meningitis?

Answer 24

Question 25

Clinical Presentation of Encephalitis

Answer 25

Question 26

CSF findings in Encephalitis?

Answer 26

Question 27

Herpes Simplex Encephalitis Presentation/Diagnosis?

Answer 27

Question 28

Brain Abscess Pathogenesis

Answer 28

Question 29

How does site of presentation of a brain abscess give insight to its origns?

Answer 29

Question 30

Clinical Features of a brain absess?

Answer 30

Question 31

Diagnosis of Brain Abcess?

Answer 31

Question 32

Management of Brain Abcess?

Answer 32