Infection

Question 1

Define “brain abscess” and “subdural empyema”

Answer 1

Brain abscess - localised area of pus within the brain

Subdural empyema - a thin layer of pus between the dura and arachnoid membranes over the surface of the brain

Question 2

What are the clinical features associated with a brain abscess?

Answer 2

Fever
Headache
Focal symptoms (seizures, dysphasia, hemiparesis)
Signs of raised intracranial pressure (papilloedema, depressed consciousness)
Features of an underlying source (dental/sinus/ear infection)
Meningism

Question 3

What are the two main differentials for when a patient presents with symptoms of a brain abscess (apart from abscess!)

Answer 3

Any focal lesion, commonly a tumour

Subdural haematoma

Question 4

List some possible causes of a brain abscess

Answer 4

Penetrating head injury
Spread from adjacent infection
Neurosurgical procedure
Blood-borne infection (e.g. bacterial endocarditis)

Question 5

Which organisms can cause brain abscesses?

Answer 5

There is often a mixture of organisms present but depends on the predisposing condition

Common organisms include:

• Streptococci, particularly the strep milleri group
  
  • strep anginosus
  • strep intermedius
  • strep constellatus
• Anaerobes e.g. bacteriodes, prevotella

Question 6

Describe the management of brain abscesses

Answer 6

Surgical drainage if possible
Treat strep with penicillin and ceftriaxone
Treat anaerobes with metronidazole
High doses required to penetrate the brain

Question 7

Which brain infections/diseases are more common in HIV patients? (patients with low CD4 counts)

Answer 7

Cryptococcus neoformans (fungi)
Toxoplasma gondi
Progressive multifocal leukoencephalopathy
Cytomegalovirus (CMV)
HIV-encephalopathy (HIV-associated dementia)

Question 8

How do spirochaetes appear under the microscope?

Answer 8

Helical coils

Question 9

Give three types of spirochaetes and the diseases that they cause

Answer 9

Borrelia burgdorferi - Lyme disease
Treponema pallidum - (neuro)syphilis
Leptospirosis

Question 10

Describe the neurological signs/symptoms associated with late stage lyme disease

Answer 10

PNS is affected more than the CNS
Mononeuropathy
Mononeuritis multiplex
Painful radiculopathy
Cranial neuropathy
Myelitis, meningio-encephalitis

Question 11

Which drugs are used to treat lyme disease?

Answer 11

IV ceftriaxone

Oral doxycycline

Question 12

How is (neuro)syphilis treated?

Answer 12

High dose penicillin

Question 13

What neurological symptoms can present in patients with syphilis?

Answer 13

Headache
Behavioural changes
Movement problems (can look like Parkinson's or Huntingdon's disease)

Question 14

How many types of poliovirus are there? How are they transmitted?

Answer 14

3

Transmitted by the faecal-oral route

Question 15

What age group is most affected by the polio virus? What disease does this cause?

Answer 15

Children under 5

Poliomyelitis

Question 16

Describe the initial presentation of poliomyelitis

Answer 16

Fever
Fatigue
Headache
Vomiting
Neck stiffness
Pain in limbs

Question 17

What happens when the poliovirus invades the nervous system?

Answer 17

Ascending, asymetric, flaccid paralysis, especially in the legs
- often permenent but can sometimes be reversed
Death occurs in 5-10% of those paralysed dues to paralysis of respiratory muscles
No sensory features

Question 18

Which parts of the nervous system does poliovirus infect?

Answer 18

Anterior horn cells of lower motor neurones

Question 19

Describe the symptoms of rabies encephalitis

Answer 19

Anorexia
Irritability and agitation
Inspiratory spasms
Cough
Autonomic dysfunction
Altered mental status
Hydrophobia
Aerophobia
Hypersalivation

Question 20

Describe the type of paralysis that can be caused by rabies

Answer 20

Ascending paralysis

Question 21

Which bacteria cause tetanus and botulism?

Answer 21

Clostridium;

• tetanus: clostridium tetani
• botulism: clostridium botulinum

Question 22

How are clostridium bacterial infections treated?

Answer 22

Antitoxin
Penicillin
Metronidazole

Question 23

What is CJD?

Answer 23

Creutzfeld-Jakob disease

Neural disease caused by prion

Question 24

What are the main two types of CJD?

Answer 24

Sporadic CJD - presents as a rapidly progressing dementia, causes death within 6 months
New variant CJD - linked to bovine spongiform encephalopathy (cattle), usually has younger onset but longer course than sporadic

Question 25

How might sporadic CJD show up on MRI?

Answer 25

increased intensity in caudate and putamen

Question 26

Which type of CJD can produce an abnormal ECG?

Answer 26

Sporadic CJd

Question 27

Describe the clostridium bacteria

Answer 27

gram positive, anaerobic, spore-forming bacillus