neuropathology Flashcards
1
Q
what structure is contained within the internal capsule
A
cortical spinal tract
2
Q
why are neurons highly sensitive cells (destruction)
A
they have a high metabolic demand and so are sensitive to metabolic changes
3
Q
can mature neurons undergo cell division
A
no
4
Q
what is gliosis
A
proliferation of astrocytes (in response to injury)
5
Q
function of astrocytes (2)
A
preserve CSF barriers, gliosis
6
Q
role of oligodendrogytes
A
myelination
7
Q
role of empendymal cells
A
help csf movement via use of cillia
8
Q
role of microglia
A
immune system (turn into mobile phagocytes)
9
Q
where are the most sensitive cells in the brain
A
pyramidal cells in CA1 (hipp.)
10
Q
what type of cells are commonly seen in the cerebellum
A
purkinje cells
11
Q
when might laminar necrosis occur
A
when there is damage to layers III,V,VI of the neo cortex
12
Q
what is cerebral vascular disease
A
a neurological defecit due to cerebrovascular compromise
13
Q
what causes the majority of cerebral vascular disease
A
ischaemia (85%)
14
Q
what are the 2 most common causes of global hypoxia
A
severe hypotension; cardiac arrest
15
Q
what type of necrosis is seen in ischaemic stroke
A
liquefactive necrosis
16
Q
what are red neurons
A
eosinophillic neurons that are dying (degredation of nucelus and nissel bodies) as a result of ischemia
17
Q
6 most common causes of intercerebral haemorrhages
A
- hypertension
- cerebral amyloid angiopathy
- saccular aneursms
- vascular malformations
- tumours
- vasculitis
18
Q
what 4 brain areas are the most common for ICH to occurwhen due to HTN
A
- putamen
- thalamus
- cerebellum
- pons
19
Q
what are the layers surroudning the brain (inner to out - 7)
A
- pia mater
- arachnoid mater
- dura mater
- bone
- periosteum
- aponeurosis
- skin
20
Q
after passing under what structure does the anterior middle meningeal artery split
A
pterion
21
Q
what is the pterion
A
junction between the frontal, parietal, greater sphenoid and squeamous temporal bone
22
Q
why is the pterion clinically significant (2)
A
is is the weakest point in the skull => easy to fracture which can cause a bleed in the MMA and lead to epidural haemorrhage
also may be an acess point during surgery
23
Q
epidural vs subdural haematoma
A
epi - does not cross suture line, suually associated w pterion skull fracture
sub - crosses suture line, may involve venous blood
24
Q
what 4 type of haemorrhages can arise from traumatic vascular injury
A
- extradural
- subdural
- subarachnoid
- intraparenchymal
25
what are coup and contrecoup injuries
injuries that arise from the head hitting a surface hard causing forces to be trasmitted through the brain (coup) and then for the brain to rebound off the other side of the skull (contrecoup)
26
what injury is commonly seen in motor vehicle accidents
diffuse axonal injury
27
how does diffuse axonal injury occur
cerebrum pivots around the brainstem which causes the axons to stretch
28
what does the stretching of axons in diffuse axonal injury cause
stretched axons causes changes in the axonal cytoskeleton such as compacting microtubules; fast axonal flow is also halted
29
what common injury is a type of diffuse axonal injury
concussion - a mild non permaent axonal injury
30
what do axons release iin response to injury
BAPP
31
what is brain herniation
displacement of the brain due to mass effect
32
what is tonsillar herniation
displacement of the cerebellar tonsils into the foramen magnum compressing the brainstem causing cardio-respiratory arrest
33
what is subfalcine herniation
displacement of the cingulate gyrus compressing the ACA and causing infarction
34
what is uncal herniation and what can it lead to (3)
displacement of the temporal lobe uncus
can lead to:
1. CN III compression
2. PCA compression
3. Paramedian artery rupture (brainstem haemorrhages)
35
what cells myelinate the CNS and PNS
CNS - oligodendrocytes
PNS - schwaann
36
what is the most common demyelinating disorder
multiple sclerosis (see DM)
37
what syndrome is related to MS but occurs in the PNS
Guillain-Barre syndrome
38
what to myelin plaque look like in the brain
irregular, sharply demarcated plaques
39
what is the most severe consquence of measles
subacute sclerosing panencephalitis (long latency period)
40
what is progressive multifocal leukoencephalopathy
rapidly progressing destruction of oligodendrocytes arising from an infection (JC virus) to these cells; the virus is generally harmless unless immunocomprimised
41
what is central pontine myelinolysis
destruction of myeling arising due to the rapid correction of a Na+ defecit (e.g.in severely malnoursished ppl) - this will lead to dehydration of the brain cells
42
what causes leukodystrophies
mutations in the myelin producing enzymes
43
what is an example of a leukodystrophy
adrenoleukodystrophy (ALD)
44
how can ALD be tested for
looking for the presence of long chain fatty acids in the blood
45
what is the most common leukodystrophy
metachromatic leukodystrophy - accumulation of fats in oligodendrocytes due to malfunction of enzyme
46
why are acquired metabolic/toxic brain disorders common
due to the high metabolic demand of the brain
47
what effect can B12 deficiency have on the CNS
subacute combined degeneration of the spinal chord
48
what defines a NDD and what are the 3 main function impacted in these characters of diseases
progressive loss of neurological function characterised by neuronal loss and protein accumulation
1. dementia
2. loss of motor control
3. paralysis
49
what is hydrocephalus ex vacuole
shrinking of brain matter (thinning of gyri and widening of sulci seen)
50
what are the 4 pathological feature seen in AD
1. TAU neurofibrillary tangles
2. senile plaques (β-amyloid)
3. granular vacuole degeneration
4. cerebral amyloidangiopathy (can lead to ICH)
51
what is the normal function of TAU
microtubule association protein that stabilizes neuronal microtubules (this is lost in AD)
52
what is the second most common cause of dementia
vascular dementia
53
what can cause vascular dementia to arise (4)
arises from a multifocal infarction due to:
hypertension
atherosclerosis
vasculitis
54
what is pick's disease
AKA Frontal-temporal dementia ->a tauopathy that results in frontal degeneration (with temporal/parietal sparing)
55
pick's disease presentation
behavioural and language symptoms arising early which eventually progress to dementia
56
what is normal pressure hydrocephalus
ventricular enlargement without increased CSF pressure due to blockage of the normal flow of CSF through the spine and brain
57
3 symptoms of normal pressure hydrocephalus
3Ws:
Wet (incontinence)
Wobbly (gait disturbance)
Wacky (dementia)
58
how is normal pressure hydrocephalus treated
ventriculoperitoneal shunts
59
what are the 4 secondary disease targets that can result in neuronal death
1. gene transcription (TF activation, histone activation etc.)
2. axonal function (fast/slow transport)
3. synaptic transmission (NT storage/release, receptor levels)
4. survivial (apoptosis)
60
4 ways infection can reach the CNS
1. haematological spread
2. infection via local spread (from sinuses, teeth, bone etc.)
3. peripheral nerves (rabies, herpes zoester etc.)
4. direct implantation from trauma
61
what layer of the brain is involved in bacterial meningitis
leptomininges (subarachnoid space)
62
3 types of meningitis
acute pyrogenic (bacterial)
aseptic (viral)
chronic (TB etc.)
63
how does bacterial meningitis usually arise
Haematogenous dissemination of bacteria
64
which bacteria are commonly responsible for bacterial meningitis
(2)
strep. pneumoniae
Neisseria meningitidis
65
what might a brain abcess present as
headache; focal neurological defecit
66
what causes cerebral oedema in a brain abcess
increased vascular permeability
67
what is viral encephalitis accompanied by
viral meningitis (aseptic meningitis can occur alone)
68
what cells become involved in viral encephalitis
neurones and glial cells
69
4 most common primary tumours that spread to the brain
lung
breast
kidney
melanoma
70
where do adult primary brain tumour usually arise
supratentorially
71
what are the 3 most common primary brain tumours in adults
glioblastoma; meningionma; schwannoma
72
what are the 3 most common primary brain tumours in children
pliocytic astrocytoma; ependymoma; medulloblastoma
73
characteristic finding on a scan for glioblastoma
butterfly lesion - arises in the cerebral hemisphere and crosses the corpus callosum
74
what cells surround a glioblastoma
pleomorphic astrocytes surround areas of necrosis with endothelial cell proliferation
75
what is the most common benign brain tumour in adults and where is it derived from
meningioma; derived from arachnoid cells
76
what might a meningioma present with
seizures
77
meningioma pathology
whorled pattern with pasammoma bodies
78
what nerve do schwannomas affect the most and what do they present with
CN VIII (vestibulocochlear), usually at the cerebellopontine angle - presents with deafness and tinnitus
79
what are bilateral schwannomas associated with
neurofibromatosis type 2
80
schwannoma pathology
spindle cell tumour with antoniA and antoni B areas (s100 +ve)
81
how do oligodendrogliomas appear
calcified tumour in the white matter of the frontal lobe
82
how might oligodendrogliomas present
seizures
83
oligodendrogliomas pathology
"fried egg" cells on biopsy with areas of calcification
84
what is the most common primary brain tumour in children
pilocytic astrocytoma (benign tumour)
85
what are the 3 most common areas for a pilocytic astrocytoma to arise
cerebellum; optic nerve/chiasm; hypothalamic region
86
pilocytic astrocytoma presentation
symptoms lasting several months; symptoms relating to the focal defecit depending on where the tumour is
87
pilocytic astrocytoma pathology (2)
1. cystic lesion with a mural nodule;
2. thick eoisinophilic astrocytic processes (rosenthal fibres) with eosinophilic granular bodies
88
what are 2 characteristic cells of pilocytic astrocytoma
1.rosenthal fibres;
2. hair-like projection
89
how is a pilocytic astrocytoma treated
cerebellum - resection + chemo + radiatino
optic/hypothalamic - chemo + radiation
90
what is a medulloblastoma
a malignant tumor derived from the granular cells of the cerebellum
91
why is molecular subtyping important
determines outcome
92
medulloblastoma pathology (2)
1.malignant small round blue cells
2. homer-wright rosettes
93
how does a medulloblastoma spread
Rapid spreading via the CSF
94
what is an ependymoma
malignant tumour of ependymal cells; usually arises in the 4th ventricle and can block the flow of CSF (resulting in hydrocephalus)
95
ependymoma pathology
perivascular (around the bvs) pesuedo-rosettes
96
what is a craniopharyngioma
a benign tumour which arises from the epithelial remnants of rathke's pouche
97
where is a craniopharyngioma found and what structure can it compress
above the piturity; it can compress the optic chiasm
98
what symptom can craniopharyngioma cause due to compression of the optic chiasm
bitemporal hemianopia
