Brain Tumours Flashcards
general presentation of brain tumours
- progressive focal neurological deficit
- motor weakness
- raised ICP features (headache)
- seizures
acute onset of symptoms?
tumour can cause eg if starts bleeding
name 4 supratentorial herniations
what happens in an uncal herniation
the medial part of the temporal lobe (uncus) herniates inferiorly to the tentorium cerebelli
which type of herniation can damage CNIII
uncal - ipsilateral fixed blown pupil
describe ICP headache
- awaken them from sleep
- exacerbated by couging, sneezing,bending
- worse on lying down
raised ICP features
- vomiting without nausea
- ocular palsy
- back pain
- papilloedema - bilateral
- alteredlevel of consciousness
- seizures
cushings triad
Cushing’s triad: increase in systolic and pulse pressure, bradycardia and irregular respiration
- Raised ICP to the point where it exceeds MABP, this causes the arterioles in the brains cerebrum to become compressed. Compression results in cerebral ischaemia
- Activation of sympathetic and parasympathetic nervous system. At this stage sympathetic is activated more and causes hypertension and tachycardia
- Baroreceptors in the aortic arch detect this and trigger a parasympathetic response via CNX, induces bradycardia
- Bradycardia may be caused due to direct mechanical distortion of CNX
- Increased pressure on the brainstem (control of breathing) results in irregular respiratory pattern
presentation of frontal lobe problem
- contralateral weakness due to deficit in M1
- personality changes - disinhibition and cognitive slowing
- urinary incontinence due to disruption of micturition inhibition centre
- gaze abnormalities - frontal eye field involvement
- expressive dysphasia/aphasia if Brocas area on left is involved
- seizures
presentation of temporal lobe problem
- memory deficits
- receptive aphasia/dysphasia for left sided lesions if Wernickes area involved
- contralateral superior quadrantopia
- seizures
presentation of parietal lobe problem
- contralateral weakness and sensory loss due to deficit in S1
- contralateral inferior quadrantopia
parietal lesion on dominant lobe presentation
dyscalculia, dysgraphia, finger agnosia, left right disorientation if dominant lobe affected –> gerstmann syndrome
parietal lesion on non dominant lobe presentation
neglect (not aware of one side of the body), dressing and constructional apraxia
occipital lobe lesion presentation
contralateral homonymous hemianopia, visual hallucinations (V1)
cerebellum lesions presentation
- ipsilateral ataxia
- n and v
- dizzines and vertigo
- slurred speech
- intention tremor
what does toe walking in children indicate
cerebellar problem
very first investigation
fundoscopy to check for papilloedema
imaging
- CT is done first - quickest and widely available
- MRI gives better tissue definition and can be used to grade tumours
what imaging is good for bleeds
CT for acute bleed, MRI for chronic/old bleeds
bleed on left, infarct on right
imaging in children
avoid CTs as they do a lot of harm, MRI is preferred
what should be suspected when an older person presents with possible brain tumour
metastases - always take a cancer history! (haemoptysis, melaena, change in bowel habits, PR bleeding)
what are the characterstics of grade I tumours and who do they occur in
- slow growing, benign
- children and YP
pilocytic (low grade I tumours) - who gets them
children and young adults
pilocytic astrocytoma - pathology
bipolar cells with long hair like projections
management of pilocytic astrocytomas
surgery, high curative rate. have sharply defined edges so are easily removed
where do pilocytic astrocytomas usually arise
cerebellum, brainstem or midline structures, eg thalamus and optic chiasm
which condition are pilocytic astrocytomas in the optic chiasm seen in
NF1
low grade type II tumours prognosis
- are less histologically stable and have the potential to transform to high grade gliomas
what symptom do type II tumours often present with
seizures
common presentation of oligodendrogliomas
seizures and headaches
common age of presentation fo oligodendrogliomas
25-45
what appearance does a oligodendrogliomas often have after invading teh subarachnoid space
toothpaste appearance
prognosis of oligodendrogliomas
best
where do oligodendrogliomas tend to arise
frontal lobe of cerebral hemispheres and can affect white matter and cortex
where do diffuse astrocytomas tend to arise
frontal and temporal lobes
common presentation of diffuse astrocytomas
seizures
which age group gets diffuse astrocytomas
young adults
managment of grade II tumours
surgery and radio and chemo
diffuse astrocytomas are harder to remove as they do not have well defined edges
do grade III tumours arise de novo or do they progress from grade I and II
either
what is the median survival of grade III tumour
2 years
what is the median survival of grade IV tumour
<1 year
what is the most common type of grade IV tumour
glioblastoma
what age group gets GBM
older people
MRI appearance of GBM
butterfly appearance
further tests of GBM after MRI
- histological sample
- tissue molecular analysis to predict response to alklyating agent chemotherapy (temozolamide)
can you cure grade III and IV tumours
no, can improve survival
management of grade III adn IV tumours
chemo radio and surgery -Stupp protocol - improves median survival
what agent is used for chemo
temozolomide - alkylating agent
meningiomas
- usually benign tumours that arise from residual mesenchymal cells in the meninges (arachnoidal cap cells in arachnoid membrane)
- rarely malignant, grow slowly
presentation of meningioma
- most are asynmptomatic
- symptoms of raised ICP
what age group gets meningiomas
elderly females (6 and 7 decade)
what condition is assoicated with multiple meningiomas
NF2 (also bilateral acoustic neuroma)
Foster Kennedy syndrome
can be caused by meningioma in olfactory groove
optic atrophy in the ipsilateral eye (direct pressure on eye) and papilloedema in the contralateral eye (raised ICP)
where do acoustic neuromas most ocmmonly arise from
cerebellopontine angle
where do acoustic neuromas arise from
schwann cells, vestibular portion of CNVIII
how do acoustic neuromas present
- Progressive ipsilateral tinnitus ± unilateral sensorineural deafness (cochlear nerve compression) ± vertigo
- Loss of corneal reflex
- Headache
- Suspect in any patient with unilateral hearing loss
- cause raised ICP when bigger
pathology of acoustic neuromas
Verocay bodies
preferred imaging of meningioma
MRI
which other CN can acoustic neuromas affect
CNVII - facial numbness and tingling
wht should be suspected if patient is young and has bilateral acoustic neuromas
NF2 (multiple meningiomas too)
haemangioblastomas
benign, cystic, highly vascular tumours
where do haemangioblastomas develop
posterior fossa - cerebllar dysfunction and raised ICP
which syndrome are haemangioblastomas associated with
VHL
