Neuro Flashcards
(223 cards)
1
Q
What do contusions involve?
A
The surface of the brain
2
Q
2 types of contusions?
A
Coup (contusion at the site of impact)
Contrecoup (contusion at the opposite to the site of impact)
3
Q
Common scenario for epidural haemorrhage?
A
Parietal/squamous temporal bone fracture with middle meningeal artery rupture
4
Q
What is a ‘lucid interval’ in epidural haemorrhage?
A
initial consciousness level appears normal
progressive pain and LOC hours later
5
Q
What causes subdural haemorrhage?
A
rupture of bridging veins causing haemorrhage into the potential space between the brain and the dura
6
Q
Causes of subdural haemorrhage?
A
injury/impact (most common)
spontaneous or following trivial impact (coagulopathy)
chronic hydrocephalus
7
Q
Features of chronic subdural haemorrhage?
A
weeks or months following injury
slowly progressive symptoms
older patients
8
Q
Causes of subarachnoid haemorrhage?
A
Can be spontaneous (rupture of berry aneurysm)
can be caused by single punch (stretching and tearing of artery consequent to impact)
9
Q
Features of intracerebral haemorrhage?
A
Usually associated with other trauma manifestations
take time to develop
10
Q
What are deep seated haemorrhages associated with?
A
High-velocity blunt force trauma
11
Q
What causes traumatic diffuse axonal injury (DAI)?
A
rotational forces leading to shearing of neuronal processes
patients have immediate prolonged coma
12
Q
What is seen microscopically in DAI?
A
white matter haemorrhages
corpus callosum lesions
axonal retraction balls
13
Q
Examples of secondary brain injury?
A
intracranial haemorrhage may extend brain swelling intracranial herniation syndromes global ischaemic brain damage infections
14
Q
What causes ‘ring’ haemorrhages in the brain?
A
Fat embolism
15
Q
How does a fat embolism reach the brain?
A
if pulmonary trapping capacity is exceeded
via a v-shunt
16
Q
Consequences of head injury?
A
post-traumatic hydrocephalus
post-traumatic epilepsy
chronic infections or late-presenting infection
chronic traumatic encephalopathy
17
Q
3 determinants of ICP?
A
blood brain barrier
pressure volume equilibrium
cerebrovascular autoregulation
18
Q
What is average intra-cranial volume in adults?
A
1700ml
19
Q
What is the Monroe-Kellie doctrine?
A
ICP can only be held stable if an increase in one component is compensated for by the other two
20
Q
What are the three components of ICP?
A
brain tissue, blood, CSF
21
Q
What is cerebral perfusion pressure?
A
The difference between ICP and mean arterial pressure
22
Q
What does an elevated ICP that approaches MAP mean?
A
this results in reduced cerebral perfusion pressure- ischaemic injury to cerebral tissue
23
Q
What is the major consequence of BBB failure?
A
Cerebral oedema
24
Q
What is cerebral oedema?
A
a state where there is a local or diffuse increase in brain water
25
Causes of cerebral oedema?
```
Physical injury
Tumours (especially mets)
Inflammatory disease
Pseudotumor cerebri
Vascular disease
Drugs and chemicals
Metabolic disease
```
26
Appearance of cerebral oedema?
Increased brain weight and swelling
| Possible discolorations
27
Where is CSF formed?
In the choroid plexus
28
What happens if there is increased CSF and venous pressure?
may be transmitted to the eye and cause venous distension and optic disc swelling
29
Herniation syndromes include?
subfalcine herniation
transtentorial herniation
cerebellar tonsillar herniation
30
What becomes compressed in subfalcine herniation?
the anterior cerebral arterty
31
What becomes compressed in transtentorial herniation?
CN III
| posterior cerebral artery
32
What becomes compressed in cerebellar tonsillar herniation?
brainstem compression
33
What is a Duret haemorrhage?
Haemorrhage within the brainstem
34
What name is given to a haemorrhage within the brainstem?
Duret haemorrhage
35
Clinical manifestations of increased ICP?
```
Headache (worse when lying down)
Nausea
Vomiting
Confusion
LOC
Localising signs due to herniation effects
```
36
What is a hydrocephalus?
accumulation of excessive CSF in the ventricular system
37
Causes of hydrocephalus?
overproduction due to tumour of choroid plexus (rare)
| reabsorption limited by altered flow due to obstruction
38
Clinical features of hydrocephalus?
```
headache
nausea and vomiting
drowsiness and LOC
ocular palsies and pupal dilation
papilledema
```
39
Outcome of hydrocephalus?
Acute- no time for compensation- collapse/death
| Chronic- time for compensation- CSF pressure can return to normal limits
40
Where are most CNS tumours located in children?
Posterior fossa (70%)
41
Where are most CNS tumours located in adults?
Cerebral hemispheres (70%)
42
How do CNS tumours typically present?
with signs of increased ICP
43
Are diffuse gliomas amenable to surgical resection?
No- they typically infiltrate large volumes of brain tissue
44
What are the commonest primary CNS tumours in adults?
Diffuse Gliomas
| Meningiomas
45
What are the commonest CNS tumours in children?
```
Gliomas
Embryonal tumours (medulloblastomas)
```
46
What percent of primary brain tumours in adults are diffuse gliomas?
80%
47
What are ependymomas?
slow growing neoplasms that arise from an ependymal surface, usually the 4th ventricle
commonest neoplasm of the spinal cord
48
In who are ependymomas commonly seen?
Young children (adverse prognosis)
49
Where do medulloblastomas arise?
In the cerebellum in children
50
Features of medulloblastomas?
Present with headache and vomiting
growth rate is rapid
extensive local infiltration
spread via CSF pathways
51
Who do primary CNS lymphomas occur in?
middle-age
| primarily in the immunosuppressed
52
Features of primary CNS lymphomas?
primary high grade B cell lymphomas
radiosensitive
steroid responsive
53
How common are meningiomas?
20% of primary brain tumours in adults
| more common in women
54
Prognosis of meningiomas?
Usually low-grade tumours
| Outcome related to completeness of surgical resection
55
Most common sites for mets to the brain?
breast, lung, kidney and malignant melanoma
56
Examples of familial brain tumours?
Turcot syndrome
Li-Fraumeni syndrome
Cowden syndrome
57
What is Turcot syndrome associated with?
medulloblastoma or glioblastoma
| APC gene
58
What is Li-Fraumeni syndrome associated with?
medulloblastoma, TP53 mutations
59
What is Cowden syndrome associated with?
Lhermitte Duclos disease
| PTEN mutations
60
What is the inheritance pattern of tuberous sclerosis?
Autosomal Dominance
61
What is tuberous sclerosis associated with?
seizures, mental retardation and autism
| hamartomas and benign tumours of brain and other tissues
62
Translocation associated with tuberous sclerosis?
TSC1 (9q) and TSC2 (16p)
63
What does von Hippel Landau disease cause?
hemangioblastomas of CNS
cysts of liver, pancreas and kidneys
propensity to develop RCC and pheochromocytoma
64
Pattern of inheritance of vHL?
autosomal dominant
| mutations of VHL 3p
65
Neurofibromatosis 1 features?
more common
| neurofibromas of peripheral nerves, cafe au lait spots, Lisch nodules, optic nerve gliomas
66
Neurofibromatosis 2 features?
less common
| bilateral acoustic neuromas, multiple meningiomas
67
Two major causes of CVAs?
Thrombosis
| Haemorrhage
68
Why is it important to establish the cause of a CVA?
to determine treatment
| thrombolysis vs anticoagulants
69
Why is treatment urgent in a CVA?
possibility of limiting ischaemia and secondary damage to penumbra
managing ICP
70
Causes of thrombotic CVA?
```
atherosclerosis
antiphospholipid syndrome
arteritis
arteriopathy
coagulopathy, smoking
```
71
Causes of a haemorrhagic CVA?
```
aneurysm
arterio-venous malformation
arterial HTN
anticoagulants
amyloid angiopathy
arteritis
anaplastic tumour
```
72
3 main sources of thromboembolism causing CVA?
Heart (A Fib)
Carotid bifurcation (atherosclerosis)
Aorta (spine)
73
What does occlusion result in?
Infarction and liquefactive necrosis
74
'Pale' infarct vs 'Red' infarct?
'Pale' infarct comes from complete infarction
| 'Red' infarct occurs when there is reperfusion
75
What causes hypoxic/ischaemic encephalopathy?
cardiac arrest
| shock
76
Pathophysiology behind HIE?
glutamate release from neurons
calcium influx
free radicals and catabolic enzymes
neuronal necrosis
77
Which section of the brain is particularly vulnerable to HIE?
Ammon's horn in the hippocampus
78
What is multi-infarct dementia?
impairment in multiple cognitive functions due to a vascular cause
79
Risk factors for multi-infarct dementia?
Elderly
DM
smoking
HTN
80
Where does a hypertensive haemorrhage most affect?
the basal ganglia and the brainstem
81
What occurs in hypertension?
Fibrinoid degeneration of the arteries
82
What does cerebral amyloid angiopathy occur with?
Alzheimer's disease
83
Which lobes are most affected by cerebral amyloid angiopathy?
Occipital lobes
84
What stain is used in cerebral amyloid angiopathy?
Congo Red
85
What is a Congo Red stain used to identify?
Amyloid
86
How do neurodegenerative diseases manifest macroscopically and microscopically?
Macroscopically - atrophy
| Microscopically - neuronal loss and accumulation of abnormal proteins
87
Other names for Motor Neuron Disease?
Amyotrophic lateral sclerosis
| Lou Gehrig's Disease
88
Macroscopic pathology of ALS?
atrophy of motor cortex
| atrophy of motor nerves
89
MND prognosis?
Death within 5 years due to respiratory failure or aspiration
90
Histology of MND?
```
loss of motor neurons
loss of myelinated axons
gliosis
Bunina bodies
spherical inclusions
variety of proteins (most contain TDP43)
```
91
What are akinetic-rigid disorders?
extrapyramidal
| characterised by rigidity, bradykinesia and resting tremor (Parkinsonism)
92
Examples of akinetic-rigid disorders?
```
Parkinson's
Multiple System Atrophy
Progressive Supranuclear Palsy
Corticobasal degeneration
Wilson's disease, drug-induced parkinsonism, vascular parkinsonism
```
93
What causes Parkinson's Disease?
loss of dopaminergic neurons of the nigrostriatal system
| loss of melanised neurons from the substantia niagra
94
What protein is accumulated in Parkinson's disease?
alpha-synuclein
95
Familial forms of Parkinson's?
SNCA, PARK2, PINK1, UCHL1, DJ1, LRRK2
96
Hyperkinetic movement disorders are characterised by?
Chorea
Ballismus
Myoclonus
Dystonia
97
What is ballismus caused by?
Damage to the subthalamic nucleus
98
Huntington's Disease features?
involuntary movements
psychiatric symptoms
dementia
99
Gross appearance of Huntington's Disease?
cerebral atrophy
| atrophy of caudate, putamen and globus pallidus
100
Microscopic appearance of HD?
neuronal loss and gliosis in basal ganglia
| ubiquitin and huntingtin
101
Inheritance pattern of HD?
AD
'CAG' expansion- longer expansion = earlier onset
huntingtin gene on chromosome 4
102
Examples of degenerative ataxias?
Spinocerebellar ataxia
Friedrich ataxia
Ataxia-telangiectasia
103
When does Friedrich's ataxia present?
pre-adolescence
104
What other diseases are associated with Friedrich's ataxia?
```
Hypertrophic Cardiomyopathy (60%)
Diabetes Mellitus (10%)
```
105
Friedrich's ataxia inheritance pattern?
Autosomal recessive
| chromosome 9, frataxin, GAA expansion
106
Features of temporoparietal, frontotemporal and subcortical dementias?
Temporoparietal - impairment of memory, later dysphasia and dyspraxia
Frontotemporal- behavioural disturbances, later memory loss
Subcortical- slowing of thought process, basal ganglia related
107
What is the most common form of dementia?
Alzheimer's Disease
108
Where does Alzheimer's disease occur?
Frontotemporal
| Temporoparietal
109
What percentage of Alzheimer's has a positive family history?
10%
110
Which proteins accumulate in Alzheimer's?
Tau (tangles)
| Beta-amyloid (plaques)
111
Macroscopic pathology of AD?
atrophy
shrinkage of gyri, widening of sulci
hydrocephalus ex vacuo
112
Early-onset AD forms of AD?
APP, PSEN1, PSEN2
113
Connection between APOE gene and Alzheimer's?
e2 isoform is protective
| e4 isoform increases risk
114
Classifications of human prion diseases?
Idiopathic/sporadic
Genetic
Acquired
115
Idiopathic prion diseases?
Creutzfeldt-Jacob disease
Fatal insomnia
protease-sensitive prionopathy
116
Genetic prion diseases?
Creutzfeldt-Jacob disease
Fatal insomnia
Gerstmann-Straussler-Scheinker
117
Acquired prion disease?
From cows- BSE, mad cow disease
iatrogenic CJD
from humans- Kuru
118
Causes of secondary CNS malformations?
```
ischaemia/infarction
congenital/intrauterine infections
maternal factors (folic acid deficiency, toxins, diabetes)
```
119
Early malformations are more likely _______ than later in gestation?
Genetic
| Fatal
120
Malformations related to early in gestation?
```
neural tube defects
disorders of cerebral development
disorders of cerebellar, hindbrain and spinal cord development
vascular disorders
hydrocephalus
```
121
Range of neural tube defects?
Open NTDs- craniorachischisis, anencephaly, spina bifida cystica
Closed NTDs- encephalocele, spina bifida occulta
122
What is raised in open NTDs?
maternal serum alpha-fetoprotein
123
What is folic acid important in preventing?
Neural tube defects
124
What is holoprosencephaly?
failure of the forebrain to develop properly
125
What can cause holoprosencephaly?
maternal infection, diabetes, foetal alcohol syndrome
126
What forms CNS and PNS myelin?
CNS - oligodendrocytes
| PNS- Schwann Cells
127
What is demyelination?
destruction of normally formed myelin with relative preservation of axons
128
What is dysmyelination?
failure to form myelin normally
129
Primary vs. secondary demyelination?
Primary- myelin exhibits the initial and most marked damage and axons are relatively preserved
Secondary- degeneration of myelin as a result of axonal or neuronal injury
130
Effects of demyelination?
slowing of conduction velocity
conduction block
'cross talk' due to unstable demyelinated nerves
131
What is 'cross talk'?
miscommunication between unstable demyelinated nerves
| i.e., sensory events result in motor phenomenon (unable to move after a hot bath, positional change causes pain)
132
General aetiologies of demyelination?
Infective
Immune/inflammatory
Metabolic/toxic
Neoplastic
133
General aetiologies of dysmyelination?
Genetics
134
What HLA types are susceptible to MS?
A3, B7, DR2, DQ1
135
When does MS have its onset?
usually in twenties
136
Progression of MS?
exacerbations and remissions
visual or motor signs
slow progressive disability over decades
137
Diagnosis of MS?
history
MRI (multiple lesions in space and time)
CSF
Visual Evoked Responses
138
What causes death in patients with MS?
secondary complications
| infection
139
What is the key pathology behind MS?
Demyelinating plaques (Active, Inactive, Shadow)
140
Where do demyelinating plaques occur?
Mostly in white matter
| optic nerve, periventricular regions and spinal cord most common sites
141
What is found in acute and chronic demyelinating plaques?
Acute- macrophages
| Chronic- astrocytic gliosis
142
What inflammation is seen around demyelinating plaques?
T lymphocytic perivenous inflammation
143
What causes neuromyelitis Optica? (Devic's disease)
inflammation and demyelination of the optic nerve and the spinal cord
distinct from MS
144
2 types of NMO/Devic's Disease?
Autoimmune (AQP4 positive)
| Idiopathic (AQP4 negative)
145
Symptoms of NMO/Devic's Disease?
limb weakness, paralysis, bladder dysfunction
| visual blurring, blindness
146
Who is NMO/ Devic's most common in?
women
| African origin
147
What is the likelihood of recurrence in NMO?
>90%
148
Outcome of NMO if left untreated?
50% are blind and wheelchair bound by 5 years
149
Treatment for NMO?
mycophenolate mofetil
rituximab
azathioprine
150
What is acute disseminated encephalomyelitis preceded by?
systemic viral illness or vaccination (few days- few weeks)
151
Symptoms of acute disseminated encephalomyelitis?
acute onset
headache, vomiting, weakness, stupor, seizures, pyrexia
5-20% mortality
152
Who does acute disseminated encephalomyelitis usually occur in?
young people
153
What type of reaction is involved in acute disseminated encephalomyelitis?
T-cell mediated hypersensitivity reaction
154
What is the name given to the more severe, hyperacute Acute disseminated encephalomyelitis?
Acute haemorrhagic leukoencephalopathy
155
Main infective cause of demyelination?
Progressive Multifocal Leukoencephalopathy (PML)
156
What is involved in progressive multifocal leukoencephalopathy?
subacute viral infection of oligodendrocytes
| latent in host- reactivated in T-cell deficiency
157
Treatment and outcome of Progressive Multifocal Leukoencephalopathy?
resistant to therapy
treatment aims to reduce immune suppression
usually fatal within 6 months
158
Histology of Progressive Multifocal Leukoencephalopathy?
multiple demyelinated foci
inclusions in oligodendrocytes nuclei
enlarged 'giant' astrocytes
159
What causes central pontine myelinolysis?
rapid correction of hyponatremia due to metabolic disorders
| alcoholism, malnutrition, hyperemesis
160
Symptoms of central pontine myelinolysis?
```
rapid onset confusion
limb weakness
conjugate gaze palsies
hypotension
most cases fatal within weeks
```
161
What are leukodystrophies?
genetic disorders of myelin formation
162
How does X linked leukodystrophy present?
seizures
abnormal behaviour
muscle spasms
163
What is involved is adrenoleukodystrophy?
adrenal insufficiency and dysmyelination
164
Name 3 myelin proteins and state whether involved in CNS or PNS?
Proteolipid Protein (PLP)- >50% in CNS, minimal in PNS
Peripheral myelin protein 22 (PMP22)- 5% of PNS, not in CNS
Myelin Basic Protein (MBP)- in both CNS and PNS
165
What is Guillain-Barre syndrome?
acute inflammatory demyelinating polyneuropathy (AIDP)
166
Symptoms of Guillain-Barre syndrome?
acute onset
ascending flaccid paralysis
usually 2 weeks after viral or infective illness
167
What antibodies are circulating in Guillain-Barre syndrome?
anti-myelin
| antiganglioside
168
What classifies chronic inflammatory demyelinating polyneuropathy?
> 2 months
| recurring episodes of demyelination with remyelination and inflammation
169
What percentage of patients with vasculitis also have peripheral neuropathy?
33%
170
What is neurogenic muscle disease and what causes it?
denervation of muscle leads to muscle atrophy
| caused by any process that affects the anterior horn cell or its axon (MND, spinal muscular atrophy)
171
Causes of myopathies?
Acquired (inflammatory, toxins/drugs, paraneoplastic)
| Genetic (dystrophies, congenital myopathies, protein inclusion myopathies)
172
Types of inflammatory myopathies (myositis)?
inclusion body myositis
polymyositis
dermatomyositis
173
Features of inflammatory myopathies?
```
myalgia
muscle weakness
muscle tenderness
elevated inflammatory markers
muscle biopsy useful
```
174
Two types of skeletal muscle dystrophinopathy?
Duchenne muscular dystrophy
| Becker muscular dystrophy
175
What cardiac disease is related to dystrophinopathy?
X-linked dilated cardiomyopathy
176
What will be raised in muscle dystrophy?
muscle creatinine kinase (CK) due to muscle necrosis
177
Structural abnormalities associated with congenital myopathies?
central nuclei
defects of the sarcomere network
nemaline rods
178
When do symptoms of congenital myopathies usually present?
At birth or in early childhood
179
Metabolic myopathies include defects in?
Glycogen storage/ glucose metabolism
Lipid metabolism
mitochondrial myopathies/cytopathies
180
Glycogen storage disorders symptoms are induced by?
Exercise
181
Most common enzymes involved in glycogen storage disorders are?
myophosphorylase (mcArdles)
| phosphofructokinase
182
What do 90% of Myasthenia Gravis patients have and what do the remaining 10% have?
anti-ACh receptor antibodies
| remaining 10% have anti-tyrosine kinase receptor antibodies
183
Symptoms of myasthenia gravis?
fatigable muscles
ptosis
painless muscle weakness
thymic hyperplasia
184
Which HLAs are associated with myasthenia gravis?
A1, B7, DRW3
185
What is acted on in Lambert-Eaton myasthenic syndrome?
Voltage-gated Calcium channels
186
What is the major cause of Lambert-Eaton myasthenic syndrome?
Underlying malignancy
| particularly Small Cell Lung Cancer
187
Which is the most common form of meningitis?
Viral > bacteria
| but viral is less severe also
188
Most common bacterial cause of meningitis?
Neisseria meningitides
189
Three ages of meningitis?
Infant (most common)
Toddler (second most common)
Over 4s- adult
190
Causes of meningitis in an infant?
Group B strep
E coli
Listeria
191
Causes of meningitis in a toddler and adult?
N. meningitidis
| S. pneumoniae
192
3 'NHS bacteria' for meningitis?
Neisseria meningitidis
Haemophilus influenza B
Streptococcus pneumoniae
193
What is the bacterial meningitis paradox?
mucosal pathogens commonly colonise the oropharynx but rarely go on to cause bacterial meningitis
194
How much of the population's nasopharynx is colonised by N. meningitidis?
5-30%
195
What is the most major risk for bacterial meningitis?
Close contact (household contact) inc. 400x
196
Clinical features of meningococcal sepsis?
headache, fever, vomiting, drowsiness
haemorrhagic rash, neck stiffness
infants- poor feeding, bulging fontanelle
neonates- respiratory distress
197
Meningococcal septicaemia vs meningitis?
Sepsis- rash, bleeding, hypotension, 20% fatal, +/- meningism
Meningitis- no/mild rash, no bleeding, normotensive, 5% fatal, meningism and raised ICP
198
How do people present with meningococcal syndromes?
55% present with septicaemia and meningitis
20% present with meningitis alone
25% present with septicaemia alone
199
Contraindications of lumbar puncture in suspected meningitis?
Raised ICP
Shock
Respiratory distress
200
Treatment of bacterial meningitis?
Early antibiotics
fluid resuscitation
10mg dexamethasone
201
Is there evidence of increased risk in close contacts in NHS meningitis?
N- yes, 400x
| S- no, no need for prophylaxis
202
Types of CNS infection?
```
bacterial (brain abscess)
viral (herpes, polio, measles)
fungal
parasitic
prion (CJD)
```
203
Bacteria behind brain abscesses?
60% aerobic- staph, strep, gram neg bacilli
| 32% anaerobic- Bacteroides, fusarium
204
Routes of infection for brain abscesses?
Direct (N.B., head injury, skull fracture)
Blood spread
Iatrogenic
site of abscess reflects route of entry
205
Mortality from brain abscesses?
10%
206
Who are at risk for a CNS Tuberculous infection?
children and immunosuppressed
207
Features of CNS Tuberculous infection?
```
caseous necrosis with granulomas
subacute onset
meningitic signs
drowsiness
cranial nerve palsies
increased ICP
```
208
Where are tuberculomas endemic?
Indian subcontinent
209
What bacteria causes syphilis?
Treponema pallidum
210
What causes Lyme disease?
Borrelia burgdorferi spirochete
| transmitted by ticks
211
3 stages of Lyme disease?
1st - skin, erythema marginatum
2nd- weeks or months later- neurological or cardiac signs
3rd- years later, CNS and arthritis
212
What can Lyme disease be confirmed by?
Western blot
213
What accounts for over 80% of aseptic meningitis?
Enteroviruses
214
What can cause viral encephalitis?
```
Herpes simplex
Herpes zoster
Enteroviruses
Rabies
Measles
Cytomegaloviruses
Polyoma viruses
HIV
```
215
What are poliomyelitis and polio-encephalitis?
Poliomyelitis- inflammation of the grey matter of the spinal cord
Polio-encephalitis- inflammation of the grey matter of the brain
216
2 types of cytomegalovirus?
Congenital (maternal infection usually asymptomatic)
| Acquired (usually complicates immunosuppression)
217
Main complications of congenital cytomegalovirus?
deafness, convulsions, mental retardation, seizures, chorioretinitis
218
What percentage of AIDs patients have CNS involvement?
80%
219
3 causes of brain disease in AIDs patients?
direct HIV infection
opportunistic infections
tumours (cerebral non-Hodgkin lymphoma)
220
Toxoplasmosis is carried by?
Cats
221
When does transplacental spread of toxoplasmosis occur?
when the infection occurs during pregnancy, greatest risk between 10-24 weeks
222
Commonest site involved in toxoplasmosis?
Basal ganglia
223
What causes cerebral malaria?
Plasmodium falciparum
