Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A13AMC @ UoN > L15 - Infections of the CNS (Meningitis & Brain Abscess) > Flashcards

L15 - Infections of the CNS (Meningitis & Brain Abscess) Flashcards

1
Q

Define Meningitis

A

Inflammation of the meninges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the four possible routes of infection by which meningitis might arise?

A

Blood-borne
Paraminingeal suppuration
Direct spread through dural defect
Direct spread through cribriform plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give several examples of the possible complications of meningitis

A 
Death
Subdural collection
Cerebral vein thrombosis
Hydrocephalus
9-15% Deafness (Hib)
Convulsions
Visual/Motor/Sensory deficit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the five causative organisms most commonly implicated in meningitis?

A 
Neisseria meningitidis
Streptococcus pneumoniae
Haemophilius influenzae type B
Escherichia coli
Listeria monocytogenes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In what group is N. meningitidis most common?

A

Children

Young adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In what groups is S. pneumoniae most common?

A

Elderly

Children <2yrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In what group is H. influenzae type B most common?

A

Children <5yrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

In what group is E. coli most common?

A

Neonates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In what group is L. monocytogenes most common?

A

Neonates

Immunocompromised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the characteristics of normal cerebrospinal fluid

A

Low protein
Low IgG
No lymphatics
BBB so only lipophilic compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What bacterial factors act as inflammatory mediators?

A

Endotoxins of Gram-ve bacteria
Lipoteichoic peptidoglycan components of Gram+ve cell walls
TNF, IL-1/6/8, NO, PAF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What immune cells migrate to the CSF following the effect of these inflammatory mediators?

A

Neutrophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What effect does the migration of neutrophils to the CSF have?

A

Release of proteolytic products (Ox radicals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What effect do Ox radicals have?

A

They damage the vascular endothelium
Changes BBB permeability
Alters CSF dynamics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the pathogenesis of bacterial meningitis

A

Nasopharynx to
Bloodstream to
Choroid Plexus to
CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the most common route of infection?

A

Blood-borne from a respiratory site (nasopharynx)

Across the choroid plexus into the subarachnoid space and into the CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which three organisms can easily colonise the nasopharynx and penetrate vascular tight junctions?

A

S. pneumoniae
N. meningitidis
H. influenzae type B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What bacterial factors enable colonisation of the nasopharynx?

A

IgA protease

Pili

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What bacterial factors enable bacteraemia?

A

Endocytosis across tight junctions

Capsules to resist lysis/phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What factors cause the slow immune response in the subarachnoid space?

A

No Immunoglobulin, C3/C4 or phagocytes

Delayed response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the classic symptoms of Meningitis?

A

Global headache
Neck and back stiffness
Nausea/Vomiting
Photophobia (non-specific)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the symptoms of Meningitis in infants?

A 
Flaccid/Opisthotonus
Bulging fontanelle (increased ICP)
Fever/Vomiting
Strange cry
Convulsions
Typical signs are often not present <18mo
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What common conditions present similarly to Meningitis?

A

Sub-arachnoid haemmorhage
Malignancy
Other infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the physical signs of Meningitis?

A

Fever
Petechial/purpuric rash
Photphobia
Irritation of the motor roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What physical effect does irritation of the motor roots have?
Kernig's +ve (hamstring spasm) Neck stiffness Brudzinskis sign (flexion of neck causes hip/knee flexion)
26
What is the best diagnostic test in Meningitis?
Lumbar puncture
27
What are the pros/cons of an LP?
Pros - Distinguish between bacterial/viral, rapid | Cons - Risk of herniation (longer history, focal neurology, drowsy, decreased clotting)
28
What are the normal CSF values?
``` Leukocytes - <5 Polymorphs - x Lymphoycytes - x Glucose - 60-80% BG Protein - 0.1-0.4g ```
29
Describe the CSF changes present in Meningitis
``` Increased leukocytes (B>T>V) Presence of neutrophils (B>T>V) Presence of lymphocytes (V>T>B) Decreased glucose (T>B) Raised protein (B>T>V) ```
30
What are the most common possible complications of Meningococcal disease?
Death 13% (40% in septicaemia) Necrotic lesions Reactive arthrtis (young adults) Serositis
31
What are rarer complications of Meningococcal disease?
Neurological sequelae | Abscess formation
32
What are risk factors for a poor outcome?
``` Age Presence of otitis media/sinusitis Absence of rash Tachycardia Low GCS +ve Blood culture Thrombocytopenia Low CSF leukocyte count ```
33
How should meningitis be managed?
``` Antibiotics Oxygenation Prevention of hypoglycaemia/hyponatraemia Anticonvulsants Decrease ICP ```
34
What are the ideal antibiotic characteristics for meningitis?
Bactericidal Sufficient penetration into CSF (non-toxic) Good activity against pathogens Little endotoxin released on organism death
35
What six factors can increase antibiotic penetration of the BBB?
``` High lipid solubility Low molecular weight Low ionisation High serum concentration Low protein binding Meningeal inflammation ```
36
Describe the pros of Chloramphenicol for treating Meningitis
Good CSF penetration (i.v. and oral) | Active against organisms
37
Describe the cons of Chloramphenicol for treating Meningitis
Bacteriostiatic Resistance in Hib/Pneumococci Causes aplastic anaemia/Grey baby syndrome
38
How is Chloramphenicol used to treat meningitis?
Reserve agent for allergic patients
39
Describe the pros of Ceftoaxime/Ceftriaxone for treating Meningitis
Good penetration into inflamed CSF Active against organisms Active against penicillin resistant pneumococci AND ampicillin resistant Hib
40
How are Cefotaxime/Ceftriaxone used to treat meningitis?
First line treatment in adults AND children Cefotaxime - 6 hourly Ceftriaxone - 12 hourly
41
Describe the pros of Benzylpenicillin to treat meningitis
Most active agent for penumococcal meningitis | Penetration of inflamed meninges
42
Describe the cons of Benzylpenicillin to treat meningitis
Short half life (4 hourly dosing) High serum levels increase risk of epileptic fits Increasing incidence of resistance
43
How is Benzylpenicillin used to treat meningitis?
Treatment for known sensitive organisms | 4 hourly dosing
44
What is the penetration ratio for Chloramphenicol?
9:1
45
What is the penetration ratio for Cefotaxime/Ceftriaxone?
1:10
46
What is the penetration ratio for Benzylpenicillin?
1:23
47
What is the antimicrobial therapy for N. meningitidis?
Benzylpenicillin if sensitive | Cefotaxime/Ceftriaxone if not
48
What is the antimicrobial therapy for S. pneumoniae?
Benzylpenicillin if sensitive Cefotaxime/Ceftriaxone if not Add Vancomycin if strain may be resistant
49
What is the antimicrobial therapy for Hib?
Cefotaxime/Ceftriaxone
50
What is the antimicrobial therapy for an unknown organism? - Child >2mo and adults
Cefotaxime/Ceftriaxome | Add Amoxicillin if >50 or immunocompromised
51
What is the antimicrobial therapy for an unknown organism? - Child <2mo
Benzylpenicillin AND Gentamicin
52
What is the length of treatment for N. meningitidis?
7 days
53
What is the length of treatment for S. pneumoniae?
14 days
54
What is the length of treatment for Hib?
7 days
55
What is the length of treatment for L. monocytogenes?
>21 days
56
What is the length of treatment for unknown organisms?
7-14 days i.v. treatment
57
When does giving steroids improve long-term morbidity?
Hib meningitis in children | Steroids given prior to antibiotics
58
What three vaccines are available for meningitis?
Conjugated Hib and Meningococcal group C Pneumococcal vaccine (<2 yrs) Men B vaccine Polyvalent pneumococcal polysaccharide vaccine
59
What chemoprophylaxis is available for meningitis?
Rifampicin OR Ciprofloxacin
60
Define a brain abscess
An abscess caused by inflammation and collection of infected material from local/remote infectious sources within the brain
61
What are the clinical signs of a Brain abscess?
``` Focal neurological signs Raised ICP Headache (70-95%, short duration) Fever (variable) Raised CRP/ESR ```
62
What are the possible routes of infection for brain abscess causing organisms?
Direct spread (venous connections) Haematogenous spread Direct implantation
63
What organisms cause brain abscesses?
``` Streptococcus milleri (60-70%) Anaerobes (65%) Enterobacteriaceae (25%) Staphylococcus aureus (10%) Polymicrobial (30-60%) ```
64
Describe the pathophysiology of brain abscesses
1-3 days - Cerebritis with central inflammation 4-9 days - Ring of cerebritis surrounding necrotic centre (+/- mass effect) 10-13 days - Capsule formation 14 days - Capsule helps to limit spread
65
What is the surgical treatment for brain abscess treatment?
Drainage (Burr-hole under LA/Craniotomy) | Excision (Craniotomy)
66
What is the medical treatment for brain abscess treatment?
Extensive antibiotic coverage
67
What antibiotic treatment is best if the source is likely dental/sinus/haematogenous? (brain abscess)
Ceftriaxone + Metronidazole | If streptococcal/anaerobic narrow to Benzylpenicillin + Metronidazole
68
What antibiotic treatment is best if the source is likely otogenic? (brain abscess)
Ceftazidime + Benzylpenicilin + Metronidazole OR | Meropenem
69
What antibiotic treatment is best for post-operative/post-traumatic treatment? (brain abscess)
Vancomycin + Meropenem
70
What is the general structure of antibiotic therapy? (brain abscess)
High dose 6-8 wks 3 wks i.v. then oral
71
What possible side effects are associated with the high doses used for treatment? - Brain Abscesses
Bone marrow suppression | Antibiotic fever

A13AMC @ UoN (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions