Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

2ND YEAR SYSTEMS: Neuro > Infections of the nervous system > Flashcards

Infections of the nervous system Flashcards

1
Q

What is Encephalitis?

A

inflammation/infection of the brain substance

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

What is myelitis?

A

inflammation/infection of the spinal cord

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

What is the ‘classical triad’ of symptoms for Meningitis?

A

Fever
Neck stiffness
Altered mental status

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

What are meningisms?

A

collective term for neck stiffness, photophobia, nausea and vomiting

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

What sorts of cerebral dysfunction appear in Meningitis patients?

A

confusion
delirium
declining conscious level - GCS <14 in 69%

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

What is the hallmark sign of meningococcal meningitis?

A

petechial skin rash - do tumbler test - if you can still see the rash through the glass then this is likely meningitis

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

What 4 types of meningitis can you get?

A

Infective - bacterial, viral or fungal

Inflammatory - sarcoidosis

Drug induced - NSAIDs, IVIG

Malignant - metastatic, haematological (leukemia, lymphoma, myeloma)

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

Name 2 common bacterium that cause bacterial meningitis

A

Neisseria meningitidis (meningococcus)

Streptococcus pneumoniae (pneumococcus)

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

Cause of viral meningitis?

A

enteroviruses

viral meningitis is much milder than bacterial

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

Clinical features of Encephalitis? (5)

A

Flu-like early symptoms (4-10days)

Progressive Headache associated with fever
+/- meningism

Progressive cerebral dysfunction

Seizures

Focal symptoms / signs

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

How is viral encephalitis different to the bacterial form?

A

viral encephalitis has a generally slower onset and cerebral dysfunction is a more prominent feature

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

Types of Encephalitis/ differential diagnosis? (6)

A

Infective - viral most common is HSV

Inflammatory - limbic encephalitis, ADEM

Metabolic - hepatic, uraemic, hyperglycaemic

Malignant - metastatic

Migraine

Post ictal (after repeated seizures - don’t fully recover)

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

What are the 2 important antibodies associated with auto-immune Encephalitis?

A

Anti-VGKC - (Voltage Gated Potassium Channel) causes frequent seizures, amnesia and altered mental state

Anti-NMDA receptor - causes prominent psychiatric features, altered mental state and seizures progressing to a movement disorder and coma

Person with auto-immune Encephalitis mistakenly attacks healthy brain cells

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

Investigations for Meningitis (3)

A

Blood cultures (bacteraemia)

Lumbar puncture (CSF culture/microscopy)

No need for imaging if no contraindications to LP

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

Investigations for Encephalitis?

A

Blood cultures

Imaging (CT scan +/- MRI)

Lumbar puncture

EEG - electroencephalogram

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

What are contraindications to Lumbar puncture? In these cases you should do a CT scan first.

A

If patient has:-

focal symptoms or signs suggest a focal brain mass

If they have reduced conscious level which suggests raised intracranial pressure

If you take CSF away from LP then you may cause focal mass to herniate if you alter the fluid balance

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

What are the CSF findings for Bacterial Meningitis. Mention:- cell count
glucose level
protein level

A

Cell count - high, mainly neutrophils

Glucose - reduced (bacteria use it up)

Protein - high

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

What are the CSF findings for Viral Meningitis and Encephalitis. Mention:- cell count
glucose level
protein level

A

Cell count - High, mainly lymphocytes

Glucose - Normal (60% of blood glucose - must compare CSF with blood sample)

Protein - slightly increased

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

Herpes simplex (HSV) encephalitis

A

rare but commonest type of encephalitis in europe

Lab diagnosis by PCR of CSF for viral DNA

treat with aciclovir

over 70% mortality and high morbidity if untreated

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

What do types 1 and 2 Herpes simplex cause?

A

cold sores - 1>2

Genital herpes - both

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

How does the Herpes virus act in the body?

A

Virus remains latent in the trigeminal or sacral dorsal root ganglion after primary infection

can become reactivated due to stress

(as with all herpes viruses, once infected, always infected)

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

Enteroviruses

A

Tendency to cause CNS infections (neurotropic) Human infections, no animal reservoir

Spread by the faecal-oral route
Many can cause non-paralytic meningitis

They do not cause gastroenteritis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Arbovirus encephalitis

A

Variety of virus groups

Geographical distribution. Vector – not present all over the world - need to take travel history.

transmitted to man by vector (mosquito or tick)

Called Arbo as ARthropod BOrne

24
Q

What is a brain abscess

A

localised area of pus within the brain

Fever if abscess bursts and get meningitis

25
Q

What is Empyema of the brain?

A

A collection of fluid around the brain – sub dural or extra dural

26
Q

Clinical features of brain abscess or empyema?

A

Fever, Headache

Focal symptoms / signs - Seizures, dysphasia, hemiparesis, etc

Signs of raised intracranial pressure - papilloedema (optic disc swelling), depressed conscious level

Meningism may be present, particularly with empyema

Features of underlying source
e.g dental, sinus or ear infection or endocarditis

27
Q

Causes of brain abscess and empyema?

A

Any focal lesion, but most commonly tumour

Subdural haematoma

Penetrating head injury

Spread from adjacent infection - sinusitis, dental, otitis media

Blood borne infection
e.g. Bacterial endocarditis

Neurosurgical procedure

28
Q

How do you diagnose a brain abscess or empyema? What tests/imaging are done? (4)

A

Imaging: CT or MRI

investigate source

blood cultures

Biopsy (drainage of pus) – sample of abscess itself - this depends on where the problem is - if in brainstem then may not be able to take sample

29
Q

Causative organisms for brain abscess?

A

Often mixtures of organisms present due to closed space (polymicrobial) - depends on predisposing condition

Streptococci in 70% of cases

Anaerobes in 40 - 100% of cases

30
Q

Management of brain abscess? (4)

A

Surgical drainage if possible

Penicillin or ceftriaxone to cover streps, Metronidazole for anaerobes

High doses required for penetration

Culture and sensitivity tests on aspirate provide useful guide

31
Q

What does a low CD4 count mean?

A

Patient’s HIV is not well managed

32
Q

Diagnostic tests for HIV?

A

Cryptococcal antigen

Toxoplasmosis serology

CMV PCR - cytomegalovirus

HIV PCR

33
Q

Spirochates: cause which diseases affecting the CNS (3)

A

Lyme Disease
Syphilis
Leptospirosis

34
Q

Describe Lyme disease: including the 3 stages

A

spirochaete - Borrelia burgdorferi

multi-system - skin, rheumatological, neurological, cardiac and ophthalmological involvement

stage 1 - target rash, 505 flu like symptoms

stage 2 - one or more organ systems become involved (blood or lymphatic spread)

stage 3 - chronic infection, can take months to years

35
Q

Which 2 systems are most commonly involved first in Lyme’s disease ?

A

Musculoskeletal

neurological

36
Q

Neurological involvement in Lyme disease: examples

A

Subacute encephalopathy

Encephalomyelitis

Mononeuropathy - one nerve

Mononeuritis multiplex - multiple nerves

Painful radiculoneuropathy

Cranial neuropathy

Myelitis

Meningo-encephalitis

37
Q

Investigations for Lyme disease (4)

A

Complex range of serological tests

CSF lymphocytosis - bacteria produce a more viral picture so lymphocytes are raised which you wouldn’t expect

MRI brain / spine (if CNS involvement)

Nerve conduction studies / EMG (if PNS involvement)

38
Q

Treatment for Lyme disease

A

Prolonged antibiotic treatment – 3-4 weeks at least

intravenous ceftriaxone
oral doxycycline

39
Q

Neurosyphilis

A

Syphilis (Treponema pallidum) has a similar 3 stage presentation - primary, secondary, latent

Test CSF for antibodies:- Treponema specific and non-treponemal specific antibody tests

Expect to see CSF lymphocytes raised

treat with high dose penicillin

40
Q

Poliomyelitis

A

99% of infections are asymptomatic

caused by poliovirus types 1, 2 or 3

Asymmetric, flaccid paralysis, esp legs

No sensory features

41
Q

Rabies

A

Acute infectious disease of CNS affecting almost all mammals

Transmitted to human by bite or salivary contamination of open lesion

Neurotropic - virus enters peripheral nerves and migrates to CNS

Ascending paralysis and encephalitis

42
Q

Rabies encephalitis

A

No useful diagnostic tests before clinical disease apparent - Once this disease is in place, it is very difficult to treat

Diagnosis: PCR and Serology

Important sources of human infection:
Dogs in Africa/Asia
Bats in the developed world.

43
Q

Who is the rabies vaccine given to in UK

A

bat handlers

regular handlers of
imported animals

selected travelers to enzootic areas

44
Q

Post-exposure treatment for rabies?

A

Wash wound
Give active rabies immunisation
Give human rabies immunoglobulin (passive immunisation) if high risk

If you just give the active vaccine then the body takes weeks to develop an antibody. Need to give active and passive for rabies immunoglobulin

45
Q

Tetanus

A

Infection with c tetani

anaerobic Gram positive bacillus, spore forming

toxin acts at neuro-muscular junction
blocks inhibition of motor neurones
rigidity and spasm (risus sardonicus) – makes you very stiff

46
Q

Prevention of tetanus?

A

Immunisation (toxoid)
given combined with other antigens (DTaP)

Penicillin and immunoglobulin for high risk wounds/patients

47
Q

Botulism (clostridium botulinum) 3 modes of infection

A

Infantile (intestinal colonization) –
Immature gut

Food-borne (outbreaks) – canned food

Wound: Almost exclusively injecting or “popping” drug users

48
Q

Presentation of botulsim

A

Incubation period 4-14 days

Descending symmetrical flaccid paralysis

Pure motor

Respiratory failure

Autonomic dysfunction

Usually pupil dilation

49
Q

Diagnosis of botulism

A

Nerve conduction studies

Mouse neutralisation bioassay for toxin in blood – ethical? Need to be sure of diagnosis before testing on mouse

Culture from debrided wound

50
Q

Treatment for botulism

A

Anti-toxin (A,B,E)

Penicillin / Metronidazole (prolonged treatment)

Radical wound debridement

51
Q

Creutzfeldt-Jakob Disease (CJD)

A

a rare and fatal condition caused by an abnormal infectious protein in the brain called a prion.

It can be sporadic, new variant, familial or acquired (blood transfusion etc)

No treatment

52
Q

When should you consider sporadic CJD as the diagnosis?

A

Consider in any rapidly progressive dementia

Clinical features:- 
Insidious onset (usually older than 60)

Early behavioural abnormalities

Rapidly progressive dementia

Myoclonus - quick, involuntary muscle jerk

53
Q

What diagnoses are you thinking for sporadic CJD? (4)

A

Alzheimer’s disease with myoclonus

Subacute sclerosing panencephalitis (SSPE)
Very rare, chronic infection with defective measles virus

CNS vasculitis

Inflammatory
encephalopathies

54
Q

Prognosis of sporadic CJD

A

death often within 6 months

55
Q

New variant CJD

A

Younger onset <40

Linked to Bovine Spongiform Encephalopathy in Cattle
ie eating infected material

2ND YEAR SYSTEMS: Neuro (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions