Neurosurgery Flashcards
How do brain tumors cause increased ICP?
occupying space
producing cerebral edema
interfering with normal CSF flow
impairing venous drainage
How do pts w brain tumors typically present?
progressive neuro defects dt rising ICP, tumor invasion, or brain compression
headaches
seizures
How are intracranial tumors classified?
Intracerebral
Extracerebral
What are the intracerebral tumors?
glial cell tumors
metastatic tumors
pineal gland tumors
papillomas of the choroid plexus
What are the glial cell tumors?
astrocytomas anaplastic astrocytomas GBM- glioblastoma multiforme oligodendrogliomas ependymomas primitive neuroectodermal tumors
Where do metastatic tumors typically come from?
Lung Breast Melanoma Kidney Colon
What are the extracerebral tumors?
These arise from extracerebral structures: meningiomas (from meninges) acoustic neuromas pituitary adenomas (from pit gland) craniopharyngiomas (from pit gland)
What are the most common CNS tumors seen in adults?
Glial cell tumors and mets tumors (both of which are intracerebral)
Glial cell tumors are 50% of adult CNS tumors!
T/F Children have more posterior fossa tumors
True
What does glioma usually refer to?
Astrocyte tumor.
Can actually refer to any glial tumor, but usu used for astrocytic tumors.
Grades/aggressiveness of astrocytic tumors
Slow-growing astrocytomas are least malignant- grades I and II
In kids, astrocytomas in the post fossa usu have cystic morphology- pilocystic astrocytoma
Anaplastic astrocytomas are more aggressive- grade III
Most common and most malignant is GBM- grade IV
What is a butterfly glioma?
GBM tumor which has tracked through the white matter and crossed the midline via the corpus callosum- looks like a butterfly on CT.
Very poor pgx.
What is an oligodendroglioma?
Slow-growing calcified tumor
Often in frontal lobes
Adults> kids
often a/w seizures
What are ependymomas?
Arise from cells that line the ventricular walls and central canal.
Px w elevated ICP
Mostly in children
Usually arise in 4th ventricle
What kinds of tumors to children usually have?
Infratentoral posterior fossa tumors-
cystic cerebellar astrocytomas
ependymomas
medulloblastomas- highly malignant ones are see in the vermis of young children, but in the cerebellar hemispheres of young adults
Where are most metastatic lesions to the brain located?
Supratentorial, at the cortical-white matter jn
Rx for metastatic braint tumors
If it’s a single, approachable lesion- surgical removal + radiation
If multiple lesions- stereotactic radiosurgery
What is a meningioma?
Slow-growing tumor that arises from meninges lining brain and SC.
Pt px for meningioma
neuro signs and sx from cerebral compression dt expanding tumor mass
seizures
headaches, nausea, vom, mental status chgs- dt elevated ICP
Diffuse headache that is worse in morning after laying down all night
Phys Ex for meningioma
Personality chgs (later to stupor, coma) Speech deficits, confusion Bilateral papilledema (optic disc swelling from increased ICP) Eye deviation (frontal lobe involved) Ataxia if cerebellar Motor or sensory defects if tumor is around central sulcus or deep structures
DD for pt w central neurologic deficits and sx
IC hemorrhage neurodegenerative dz abscess vascular malformation meningitis encephalitis communicating hydrocephalus toxic state (and of course, meningioma)
Dx eval for meningioma
CT or MRI- dx and localize tumor
MRI w gadolinium- visualize high grade gliomas, meningiomas, schwanomas, pit adenomas
T2 MRI for low-grade gliomas
Goal of rx for brain tumors
total tumor removal (when feasible)
but subtotal resection is nec if brain fn will be compromised by full resection
If subtotal resection is performed, what should follow?
post-op radiation therapy
also chemo for some cancer types
Rx for metastatic brain tumors
Whole-brain radiation
sometimes single lesions that are easy to remove are removed first
What kind of drugs are used for perioperative mgmt of increased ICP from cerebral edema?
Corticosteroids- dexamethasone
also may need shunting of CSF if there is hydrocephalus
What is an intracranial aneurysm?
Saccular, berry-shaped aneurysm found at branch points in circle of Willis
What happens when intracranial aneurysms rupture and bleed?
Subarachnoid hemorrhage (SAH) this is rare.
HPE of SAH
sudden onset of worst headache ever
ICP transiently rises w each contraction of the heart–> pulsating headache
Progressive neuro deficits dt blood clot mass effect, vasospasm, or hydrocephalus
Coma and death
How are SAH’s classified?
Hunt-Hess grade 1- (good) to 5 (almost dead)
Dx Eval for SAH
CT
If highly susp but CT is neg, do an LP
If SAH is found, do a four-vessel cerebral angiography to define aneurysm neck and relation w surrounding vessels.
Medical rx for SAH
control of HTN
phenytoin for prophylactic seizure control
mannitol for edema
nimodipine to reduce risk of delayed neuro deficits dt vasospasm