Infections of CNS Flashcards
1
Q
what area of the CNS is infection during Encephalitis ?
A
inflammation / infection of brain substance
2
Q
what area of the CNS is infection during Meningitis ?
A
inflammation / infection of meninges
3
Q
what area of the CNS is infection during Myelitis ?
A
inflammation / infection of spinal cord
4
Q
what is the classical triad of meningitis ?
A
fever
neck stiffness
altered mental state
5
Q
what the of rash do people get during a meningitis ?
A
Petechial skin rash
6
Q
what test is done to test for the petechial skin rash?
A
tumbler test
- non blanching
7
Q
what type of meningitis is the petechial rash commonly seen?
A
the bacteria meningitis
8
Q
as well as the classical triad of symptoms, what other symptoms can be seen during meningitis ?
A
confusion declining consciousness cranial nerve palsy seizures focal symptoms
9
Q
what are the four main categories of aetiology for meningitis ?
A
infective
inflammatory
drug induced
malignant
10
Q
what drugs can induce meningitis ?
A
NSAIDs and IVIG (Intravenous Immunoglobulin)
11
Q
what are the three infective agents that can cause meningitis ?
A
bacterial
viral
fungal
12
Q
what group of people usually are infected by fungal meningitis ?
A
immunosuppressed people
13
Q
what is the virus that causes viral meningitis ?
A
enteroviruses
14
Q
what two bacteria can cause bacterial meningitis ?
A
Neisseria meningitidis (meningococcus) Streptococcus pneumoniae (pneumococcus)
15
Q
what are the symptoms of meningitis ?
A
fever headache neck stiffness petechial skin rash confusion
16
Q
what are the symptoms of encephalitis ?
A
flu like stage in first couple of weeks
confusion
abnormal behaviour
seizures
focal symptoms (vision, hearing)
17
Q
is the onset of viral encephalitis faster or slower than bacterial meningitis ?
A
viral encephalitis is slower
18
Q
is cerebral dysfunction more prominent in viral encephalitis or bacterial meningitis ?
A
viral encephalitis
19
Q
what are the four main categories of the aetiology of encephalitis ?
A
infective
inflammatory
metabolic
malignant
20
Q
what is an inflammatory cause of encephalitis ?
A
limbic encephalitis
21
Q
what is the most common infective cause of encephalitis ?
A
herpes simplex virus
22
Q
what three metabolic problems could cause encephalitis ?
A
hepatic
uraemia
hyperglycaemic
23
Q
what are the two antibodies that can cause autoimmune encephalitis ?
A
anti - VGKC (voltage dated K channels)
anti - NMDA
24
Q
what are the clinical signs of anti-VGKC encephalitis ?
A
frequent seizures
amnesia
altered mental state
25
what are the clinical signs of anti-NMDA encephalitis ?
flu like stage
prominent psychiatric features
altered mental state
result in coma
26
what investigations would be done for meningitis ?
blood cultures
| lumbar puncture
27
should the blood tests and lumbar puncture be done as soon as possible?
yes
| - they want to be done before antibiotics have started to be given
28
when should a CT scan be done for meningitis ?
if there is a contraindication for lumbar puncture
29
what are the investigations that should be done for encephalitis ?
blood cultures
imaging (CT/MRI)
lumbar puncture
EEG
30
what two tests can be done on the CSF from a lumbar puncture ?
CSF microscopy
| CSF culture
31
what are some contraindications for lumbar puncture ?
```
papilloedema
GCS <10
severe immunocompromised
new onset seizures
focal neurological deficit
```
32
what does focal symptoms suggest about the brain?
suggest a focal brain mass/tumour
33
what does reduced conscious level suggest?
raised intracranial pressure
34
is the opening pressure of the CSF increased, decreased or normal with bacterial meningitis ?
increased
35
is the opening pressure of the CSF increased, decreased or normal with viral meningitis or encephalitis ?
normal/increased
36
what WBC is high in CSF of bacterial meningitis?
neutrophils
37
what WBC is high in CSF of viral meningitis/ encephalitis ?
lymphocytes
38
is glucose levels in CSF increased, decreased or normal with bacterial meningitis?
decreased
| - sometimes zero
39
is glucose levels in CSF increased, decreased or normal with viral meningitis/ encephalitis ?
normal
40
is protein levels in CSF increased, decreased or normal with bacterial meningitis?
high
41
is protein levels in CSF increased, decreased or normal with viral meningitis/ encephalitis ?
slightly increased
42
what type and shape of bacteria causes bacterial meningitis ?
gram positive cocci in chains
43
what is the commonest cause of encephalitis in europe ?
herpes simplex virus
44
should treatment of encephalitis be started on suspicion ?
yes
| - even if the lumbar puncture results aren't back yet
45
what is the mortality of herpes simplex encephalitis ?
70%
46
what antibiotic should be started for herpes simplex virus?
aciclovir
47
are HSV encephalitis and bacterial meningitis easy to treat in the early stages ?
yes
48
how many types of HSV are there?
two types
| - type 1 and 2
49
once someone is infected with herpes group of viruses can they be cured?
no they are always infected
50
where abouts does the herpes virus lie latent to cause cold sores and genital herpes ?
trigeminal and sacral ganglion
51
what type of herpes simplex virus causes encephalitis ?
type 1
52
are enteroviruses DNA or RNA viruses ?
RNA
53
how are enteroviruses spread?
faecal oral route
54
do enteroviruses cause GI symptoms ?
no
55
what part of the history is very important to ask about when talking about CNS infections ?
travel history
| sexual history
56
how are arbovirus encephalitides transmitted ?
by a vector such as a mosquito or ticks
57
give some examples of arbovirus encephalitides?
```
West Nile virus
St Louis Encephalitis
Western Equine Encephalitis
Tick Borne Encephalitis
Japanese B Encephalitis
```
58
what is an important factor when thinking about uncommon infections from other countries ?
immigration
59
what is a brain abscess?
localised area of pus within the brain
60
what is a sub dural empyema ?
thin layer of pus between the dura and arachnoid membranes over the surface of the brain
61
what symptoms can be caused by a brain abscess?
increased intracranial pressure
decreased conscious level
focal symptoms dependant on the area of brain affected
62
what are the clinical symptoms of a brain abscess?
```
fever
headache
seizures
hemiparesis
decreased conscious level
```
63
what are three underlying causes of a brain abscess?
poor dentition
sinusitis
(middle) ear infection
64
what are two differential diagnoses of a brain abscess or empyema ?
```
subdural haematoma
focal lesson (tumour)
```
65
what are some causes of a brain abscess?
penetrating head injury
spread of infection from adjacent structures
blood borne infection
post surgery
66
what investigations should be done for a brain abscess?
CT/ MRI
examination of head/neck
blood cultures
biopsy (drainage of pus)
67
is drainage of a abscess always possible?
no
| - if the abscess was in the brain stem then the risks of damage would not be worth it
68
what type and group of bacteria are usually found in brain abscesses?
streptococci bacteria
| - strep milleri group
69
what group of antibiotics are the strep milleri group of bacteria found in brain abscesses sensitive to?
penicillin
70
what percentage of brain abscesses contain strepococci bacteria ?
70%
71
what are three bacteria in the strep milleri group?
Strep anginosus,
Strep intermedius,
Strep constellatus
72
what antibiotics should be given to aerobic bacteria in brain abscesses?
Penicillin or ceftriaxone
73
is strep bacteria aerobic or anaerobic ?
aerobic
74
what antibiotic should be given to anaerobic bacteria in brain abscesses?
metronidazole
75
why are antibiotics sometimes not effective for brain abscesses?
sometimes the antibiotic can't penetrate the abscess properly so high doses are required for penetration
76
what system in the brain reduces the effect of drugs on the brain ?
blood brain barrier
77
with which conditions should the patient be offered a HIV test?
```
Cerebral toxoplasmosis
Aseptic meningitis /encephalitis
Primary cerebral lymphoma
Cerebral abscess
Cryptococcal meningitis
Space occupying lesion of unknown cause
Dementia
Leucoencephalopathy
```
78
what brain infections are common in HIV patients with low CD4 counts ?
```
Cryptococcus neoformans
Toxoplasma gondii
Progressive multifocal leukoencephalopathy (PML)
Cytomegalovirus (CMV)
HIV-encephalopathy
```
79
are PCR tests specific ?
yes very specific
80
what tests should be done to investigate infections associated with HIV?
```
India Ink
Toxoplasmosis serology (IgG)
JC virus PCR
CMV PCR
HIV PCR
```
81
what bacterial antigen is detected using the india ink test?
cryptococcal antigen
82
what type of organism is cryptococcal ?
fungi
83
what is the transmission route for fungi?
inhalation from dust
84
form what object do immunocompromised people in aberdeen commonly get a fungal brain infection?
opening brown bins full of compost
85
what bacteria causes lyme disease ?
Borrelia burgorferi
86
what bacteria causes syphilis ?
Trepomena pallidum
87
what bacteria causes leptospirosis ?
Leptospira interrogans
88
how many stages are there for lames disease?
3
89
how is lyme disease transmitted?
vector borne
| - ticks
90
what type of rash is seen in stage 1 lyme disease ?
erythema migrans
91
where is the erythema migrans rash seen on the patient ?
where the tick bite was
92
what type of symptoms are seen in stage 1 lyme disease ?
flu like symptoms
- fatigue
- headache
- fever
- chills
- neck stiffness
93
how long does stage 1 lyme disease last for ?
1 month
94
how does the bacteria form the tick spread around the body after the initial bite?
blood and lymphatics
95
what are the common symptoms in stage 2 lyme disease ?
joint and muscle pain
| neurological involvement
96
during lyme disease, is the PNS or CNS more effected ?
PNS
97
how long does stage 2 lyme disease last for?
weeks - months
98
how long does stage 3 of lyme disease last for?
months - years
99
does lyme disease cause chronic fatigue syndrome ?
no
100
what two conditions of neurological involvement is seen in stage 3 lyme disease
Subacute encephalopathy
| Encephalomyelitis
101
what investigations should be done for lyme disease ?
```
serology
CSF lymphocytosis
PCR of CSF
MRI spine and brain
nerve conducting studies
```
102
what is the treatment for stage 1 and 2 lyme disease
oral doxycycline
103
what is the treatment for stage 3 lyme disease ?
1 month IV ceftriaxone
104
how many stages of presentations are there for syphilis ?
3
105
what is syphilis treated with?
high dose penicillin
106
what blood tests can be done for syphilis ?
Treponema specific and non-treponemal specific (VDRL) antibody tests
107
what type of virus is poliovirus ?
enteroviruses
108
what symptoms does polio cause ?
flaccid paralysis
| - no sensory features
109
what can the polio vaccine be given ?
injection
| orally
110
what part of the nervous system does the polio virus affect?
anterior horn cells of lower motor neurones
111
how is rabies transmitted to humans ?
bite
| saliva
112
what part of the nervous system does the rabies virus affect?
infects the peripheral nerves and migrates to CNS
113
what are the clinical symptoms of rabies ?
ascending paralysis and encephalitis
114
how is the rabies infection managed ?
sedation
intensive care
death
115
what mammals commonly transmit the rabies virus ?
dogs and bats
116
in what form is the rabies virus given in the vaccine ?
killed vaccine
117
who should be given the rabies vaccine?
people travelling abroad to areas where rabies incidence is high
bat handlers
regular handlers of imported animal s
118
what are the three steps of suspected rabies from a dog bite ?
1. wash wound
2. give active rabies immunisation
3. give human rabies immunoglobulin
119
what type of bacteria is clostridium tetani?
anaerobic gram positive bacillus, spore forming
120
where about does the toxin of tetanus act in the nervous system ?
acts at the NMJ
121
what are the clinical symptoms of tetanus?
rigidity
spasm
risus sardonicus
122
what is risus sardonicus ?
highly characteristic, abnormal, sustained spasm of the facial muscles that appears to produce grinning
123
What two medications should be given to suspected tetanus patients ?
penicillin
| immunoglobulin
124
what bacteria causes botulism ?
clostridium botulinum
125
what type of bacteria is clostridium botulinum ?
Anaerobic spore producing gram positive bacillus
126
What are the three routes of infection of botulism ?
infant intestinal colonisation
food borne
wound - common in drug users
127
why are drug users high risk for botulism ?
when they inject the drugs, if they miss the vein then the drugs can cause an abscess to form and the bacteria to colonise
128
what are the common clinical signs of botulism ?
pupil dilation
| descending symmetrical flaccid paralysis
129
does botulism affect the sensory and motor fibres ?
just the motor fibres
130
how is botulism diagnosed ?
culture from debrided wound
| nerve conduction study
131
what are the three treatment options for botulism ?
1. anti-toxin (A,B,E)
2. penicillin/ metronidazole (prolonged treatment)
3. radical wound debridement
132
state two post infective inflammatory syndrome which can occur after an infection?
1. CNS
2. PNS
CNS
- Acute disseminated encephalomyelitis (ADEM)
PNS
- Guillain Barre Syndrome (GBS)
133
what type of condition is post infective inflammatory syndrome?
autoimmune
134
state some symptoms of Guillain Barre Syndrome (GBS)?
pain, tingling and numbness
progressive muscle weakness
co-ordination problems and unsteadiness
135
what is the most common cause of CJD ?
sporadic CJD
136
is CJD disease common?
no very rare
| 1 per million
137
is the presentation of sporadic CJD all the same ?
no it varies
138
what age range is CJD most common?
>60yrs
139
what substance causes CJD ?
Transmissible Proteinaceous particle – Prion
140
what symptoms would someone with CJD experience ?
```
myoclonus (jerks)
weakness
hyper reflexia
blindness
seizures
confusion
tremor
```
141
what disease should be considered in someone over 60yrs who has rapidly progressive dementia ?
sporadic CJD
142
what is the prognosis and survival time for sporadic CJD?
- poor due to rapid progression
| - death within 6 months
143
what are some differential diagnoses of sporadic CJD?
```
Alzheimers with myoclonus
Subacute sclerosing panencephalitis (SSPE)
CNS vasculitis
Non-convulsive status
Inflammatory encephalopathies
```
144
what three investigations should be done to test for CJD?
MRI
EEG
Lumbar puncture
145
for CJD infection will the protein in the CSF be normal ?
normal or raised
146
what would be seen on a MRI with a patient who has variant CJD?
pulvinar sign
147
what age range is at most risk for new variant CJD?
younger onset <40yrs
148
what is a common way for people to become infected with new variant CJD?
eating infected meat
149
does new variant or sporadic CJD have a longer course and therefore less severe?
new variant has a longer course
150
is Guillain Barr syndrome anaerobic or aerobic infection ?
aerobic
151
which infection would have flu like symptoms before neurological signs ?
viral encephalitis
| lymes disease
152
should antibiotics be started while waiting for a CT and a lumbar puncture for viral encephalitis ?
yes
153
what infection are drug users high risk for contracting ?
botulism
154
what rash is seen during lymes disease ?
erythema migrans
155
what virus is the most common cause for viral encephalitis ?
herpes simplex
156
what group of bacteria is most common in brain abscesses?
strep milleri
157
can poliomyelitis be vaccinated against ?
yes
158
does bacterial meningitis increase CSF opening pressure?
yes
159
does viral encephalitis increase CSF opening pressure?
no
