Flashcards in Neuro Deck (588)
How common are brain tumours?
16th most common adult cancer, and 2nd most common children cancer
Presentation of a brain tumour?
symptoms of raise ICP: headache, reduced conscious level, nausea and vomiting
progressive neurological deficit and epilepsy
Features of a raised ICP headache?
worst on waking from sleep, increased by coughing, straining and bending forwards, can be relieved by vomiting
What is the cardinal physical sign or a brain tumour?
What causes papilloedema?
obstruction of venous return from the retina
caused by loss of crisp optic nerve head margins, venous engorgement, retinal oedema, haemorrhages, raise ICP, intraneuronal ischemic damagee
What types of focal neurological deficits are there?
motor, sensory, speech, visual, deafness, deteriorating memory, personality change
What type of tumours are focal siezures more common in?
motor, sensory and temporal lobe
Are primary or secondary brain tumours more common?
Treatment of secondary brain tumours?
surgery, radiotherapy, chemotherapy, best supportive care
When would surgery be considered for a brain tumour?
absent or controlled primary disease, younger than 75, good performance status
Where is the main origin for primary brain tumours to occur from?
What is the main type of primary brain tumour?
What is WHOs grading for gliomas?
1 - pilocytic astrocytoma (paediatric tumour)
2 - benign premalignant tumour
3 - anaplastic astrocytoma
4 - glioblastoma multiforme (THE MOST COMMON PHENOTYPE)
If given enough time, what will all gliomas progress to?
glioblastoma multiforme (GBM) with the exception of pilocytic astrocytoma
What is the common pathway to a malignant glioma?
initial genetic error in glucose glycolysis, mutation of isocitrate dehydrogenase 1 (IDH1), resulting in excessive build up of 2-hydroxyglutarate, triggering genetic instability in glial cells and subsequent inappropriate mitosis
What is the less common pathway to a malignant glioma?
no IDH mutation, catastrophic genetic mutation, poor prognosis
Survival of GBM?
20% survive more than 18 months, even with aggressive therapy
Good prognostic factors for a glioblastoma?
under 50, aggressive surgical therapy, good performance post surgery, secondary GBM, MGMT mutatnt (as they means they should respond to chemo)
Bad prognostic factors for a glioblastoma?
over 50, poor neurological function post surgery, non radical surgery treatment, primary GBM, MGMT wild type as means they wont respond to chemo
Traditional vs updated glioblastoma therapy?
debulking surgery, radiotherapy
respective surgery, adjuvant chemo with temozolomide with RT, 6 cycles of teozolomide chemo
How does temozolomide chemo treat brain tumours?
a prodrug, activated by HCl, crosses the blood brain barrier and then methylates guanine in DNA to make replication impossible at the base site
Which tumour is resistant to Temozolomide?
MGMT, by reversing guanine methylation
When does Temozolomide treatment work best?
any age, if debulk first, if performance status if low, no wild type MGMT
What is WHOs performance status for any cancer patient?
1 - capable of light work
2 - self caring >50% of day
3 - limited self care
How does avastin treat brain tumours?
it Is an anti angiogenic agent which shuts down the tumours blood supply
Side effects of avastin?
hypertension, GI haemorrhage, expensive
How does gene therapy treat brain tumours?
inoculation of tumour with replication deficient HSV-1 retrovirus so wild type HSV-1 replicates exponentially and causes encephalitis
modified HSV-1 fails to replicate in normal brain but replicates rapidly in GBM, causing oncolysis and release of progeny virus
tumour cells killed and normal brain cells unaffected
How does dexamethasone treat brain tumours?
powerful synthetic steroid, given orally, improving brain performance, reduces tumour inflammation and oedema
In who is a benign glioma commonly seen?
in the young, rare over 45