Infection of the nervous system Flashcards Preview

Neurology > Infection of the nervous system > Flashcards

Flashcards in Infection of the nervous system Deck (45):
1

 

 

What is encephalitis?

 

 

Encephalitis means acute inflammation of brain parenchyma, usually viral

2

 

 

What is the most common cause of encephalitis?

 

 

Viral

3

 

 

What are viral causes of encephalitis?

  • HSV 1 + 2
  • Arbovirus
  • CMV
  • EBV
  • VZV
  • HIV
  • Measles
  • Mumps
  • Rabies
  • West nile virus
  • Tick-borne encephalitis

4

 

 

What are non-viral causes of encephalitis?

  • Any bacterial meningitis
  • TB
  • Malaria
  • Listeria
  • Lyme disease
  • Legionella
  • Leptospirosis
  • Aspergillosis
  • Crytococcus
  • Schistosomiasis
  • Typhus

5

 

 

What would be your differential diagnosis for someone with features of encephalitis?

If no infectious prodrome, think encephalopathy

  • Hypoglycaemia
  • Hepatic encephalopathy
  • Diabetic ketoacidosis
  • Drugs
  • Hypoxic brain injury
  • Uraemia
  • SLE
  • Wernicke's encephalopathy

6

 

 

What are autoimmune causes of encephalitis?

Limbic encephalites

  • Paraneoplastic limbic encephalitis
  • Voltage gated potassium channel limbic encephalitis
  • Anti-NMDA receptor antiobody panencephalitis

7

 

 

What are signs and symptoms of encephalitis?

 

  • Bizarre encephalopathic behaviour or confusion
  • Decreased GCS/Coma
  • Fever
  • Headache
  • Focal neurological signs
  • Seizures

8

 

 

When should you suspect encephalitis?

 

Whenever someone presents with odd behaviour, decreased consciousness focal neurology or seizure which was preceded by an infectious prodrome

9

 

 

What kind of infectious prodromes would you want to find out about in someone presenting with features of encephalitis?

 

  • Pyrexia
  • Rash
  • Lymphadenopathy
  • Cold sores
  • Conjunctivitis
  • Meningeal signs

10

 

 

What might cold sore indicate about the cause of a presentation of encephalitis?

 

 

Caused by Herpes Simplex virus

11

 

 

What might parotid gland swelling indicate as to the cause of encephalitis?

 

 

Caused by mumps

12

 

 

What might be the cause of someone presenting with features of encephalitis, hydrophobia, delusions, hallucinations and anxiety?

 

 

Rabies

13

 

 

What investigations would you consider doing in someone with features of encephalitis?

 

  • Bloods - Blood cultures, Viral PCR, Malaria film, Toxoplasma IgM titre, HIV test, Mantoux test
  • Contrast enhanced CT
  • LP
  • EEG

14

 

 

In someone with features of encephalitis, what would focal bilateral temproal lobe involvement on Contrast-enhanced CT indicate ?

 

 

HSV encephalitis

15

 

 

What would meningeal enhancement on contrast-enhanced CT suggest in someone with features of encephalitis?

 

 

Meningeal involvemnent

16

 

 

What should you do before doing an LP?

 

 

CT scan to rule out coning

17

 

 

What are features seen on LP in someone with encephalitis?

 

  • Increased CSF protein
  • Increased lymphocytes
  • Decreased glucose

18

 

 

What is important to remember when interpreting LP CSF results for someone with suspected encephalitis?

 

 

Normal CSF does not exclude ecnephalitis

19

 

 

How would you manage someone with encephalitis?

 

  • Start aciclovir within 30 mins arrival
  • Supportive therapy in HDU
  • Anticonvulsants for seizures
  • Dexamethaose - if raised ICP

 

20

 

 

What is mortality rate in untreated encephalitis?

 

 

70%

21

 

 

What is the mortality rate in treated encephalitis?

 

 

10-30%

22

 

 

What are causes of a cerebral abscess?

 

  • Ear/Sinus/dental/peridontal infection
  • Skull fracture
  • Congenital heart disease
  • Endocarditis
  • Bronchiectasis

23

 

 

What are the typical causative bacteria implicated in brain abscesses?

 

  • Staph. angiosus (sinus/teeth)
  • Bacteriodes (sinus/teeth)
  • Staphylococci (penetrating trauma)

24

 

 

What are symptoms of a brain abscess?

 

 

  • Dull persistent headache
  • Symptoms of raised intracranial pressure (e.g., vomiting, papilledema, altered mental status)
  • Focal neurological deficits
  • Fever
  • Generalized or focal seizures

 

25

 

 

What are signs seen in someone with a cerebral abscess?

 

  • Decreased GCS/Coma
  • Signs of sepsis elsewhere
  • Fever
  • Focal neruology
  • Signs of increased ICP
  • Meningism may be present

26

 

 

What investigations might you consider doing in someone with a cerebral abscess?

 

  • CT/MRI
  • Bloods - FBC, ESR
  • Biopsy

27

 

 

What might you see on FBC in someone with a cerebral abscess?

 

 

Increased WCC

28

 

 

What might you see on investigation of ESR in someone with a cerebral abscess?

 

 

Raised ESR

29

 

 

How would you manage someone with a cerebral abscess?

Urgent neurosurgical referral

  • Treat ICP
  • High dose ABx - 6-8 weeks
  • Surgical resection/decompression

30

 

 

What dose of aciclovir would you start someone on if they presented with encephalitis?

IV acicolvir 10mg/kg 8 hrly for 14-21 days

31

 

 

What antibiotics would you use to treat a cerebral abscess?

 

  • Penicillin/ceftraixone - cover streps
  • Metranidazole - anaerobes

32

 

 

What is the morality rate in those with a cerebral abscess?

 

 

Treated - 25%

33

 

 

What cerebral problems can occur in those with HIV infection?

 

  • Cerebral toxoplasmosis
  • Aseptic meningitis/encephalitis
  • Primary cerebral lymphoma
  • Cerebral abscess
  • Cryptococcal meningitis
  • SOL of unkown cause
  • Dementia
  • Leucoencephalopathy

34

 

 

What infectious organisms can infect the CNS in those with chronic HIV infection?

 

  • Cryptococcus neoformans
  • Toxoplasma gondii
  • Cytomegalovirus

35

 

 

What is acute disseminated encephalomyelitis?

 

 A rare autoimmune disease marked by a sudden, widespread attack of inflammation in the brain and spinal cord that often follows many types of infection (measles, mycoplasma, mumps, rubella). As well as causing the brain and spinal cord to become inflamed, ADEM also attacks the nerves of the central nervous system and damages their myelin insulation, which, as a result, destroys the white matter.

36

 

 

What are neurological manifestations of lyme disease?

 

  • Mononeuropathy
  • Mononeuritis multiplex
  • Painful radiculopathy
  • Cranial neuropathy
  • Myelitis
  • Meningoencephalitis
  • Encephalomyelitis

37

 

 

What are the main forms of neurosyphillis?

 

  • Asymptomatic neurosyphillis
  • Meningovascular syphillis
  • Tabes dorsalis
  • General paralysis of the insane

38

 

 

What is Meningovascular Neurosyphillis?

Syphillitic infection which causes:

  • Subacute meningitis with cranial nerve palsies and papilloedema
  • A gumma – a chronic expanding intracranial mass
  • Paraparesis – a spinal meningovasculitis.

39

 

 

What is asymptomatic neurosyphillis?

 

 

Neurosyphillis with positive CSF but no neurological signs

40

 

 

What is tabes dorslis?

Demyelination in dorsal roots causes a complex deafferentation syndrome. The elements of tabes:

  • Lightning pains 
  • Ataxia, stamping gait, reflex/sensory loss, wasting
  • Neuropathic (Charcot) joints
  • Argyll Robertson pupils 
  • Ptosis and optic atrophy

41

 

 

What is general paralysis of the insane?

Dementia and weakness associated with neurosyphillis, in addition to:

  • Seizures
  • Brisk reflexes
  • Extensor plantar reflexes
  • Tremor
  • Argyll-Robertson pupils

42

 

 

How would you manage someone with neurosyphillis?

 

 

Benzylpenicillin

43

 

 

What are features of Sporadic/Variant CJD?

 

  • Rapidly progressive dementia with early behavioural abnormalities
  • Myoclonus
  • Cerebellar ataxia
  • Extrapyramidal and pyramidal signs
  • Cortical blindness
  • Seizures

44

 

 

What is variant CJD linked to?

 

 

Bovine spungiform encephalopathy

45

 

What is the following?

 

 

Cerebral abscess