Term
| what is the survival rate for subarachnoid hemorrhage *from aneurysm? |
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Definition
| 50% - 25% of which will die later or be severely disabled by 8 wks |
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Term
| what % of people have a "normal" circle of willis? |
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Definition
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Term
| what is the common presentation of subarachnoid injury? |
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Definition
| abrupt onset of the worst occipital-cervical headache that pt has ever experienced accompanied by n/v and photophobia. if very severe: comatose. |
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Term
| how should a cerebrovascular injury pt be worked up? |
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Definition
| first: non-contrast CT scan to look for blood. second, if blood is seen in an area consistent with aneurysm on CT or a spinal tap is done and see RBCs are visible: do anatomic diagnostic test (transcatheter angiogram, CT angiogram, CTA Reconstruction, or MRA/MRV) |
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Term
| what needs to be done if a if a pt comes into the ER with a complaint of: sudden onset of severe headache with or without photophobia, with or without n/v, with or without meningeal signs, severe headache and negative CT? |
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Definition
| spinal tap to r/o blood in the CSF, b/c mild hemorrhages may not show blood on CT. |
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Term
| what characterizes MRA as a diagnostic test for cerebrovascular injury? |
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Definition
| MRA = MR technology w/intravascular contrast to ID some blood vessels. it is non-invasive and easily available, but it can miss aneurysms under 5 mm. |
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Term
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Definition
| an out-pouching from the arterial wall due to a separation in the muscular layer (medial gap) which allows arterial pressure to force outward stretching and formation of the aneurysm. |
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Term
| what are the 4 kinds of cerebral aneurysms? |
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Definition
| saccular (most common - berry), fusiform (atherosclerotic), mycotic (infectious - peripheral), and dissecting (rare - trauma) |
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Term
| where are most aneurysms located? |
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Definition
| saccular aneurysms are situated in anterior circulation 80% of the time: internal carotid, anterior cerebral/anterior communicating complex, and cerebellar artery - good because easily accessible. |
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Term
| where does aneurysmal rupture hemorrhage into? |
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Definition
| the parenchyma, ventricular system, occasionally subdural and in multiple combinations/locations (20% of the time). |
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Term
| how does risk of aneurysmal rupture correlate w/size? |
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Definition
| risk of aneurysmal rupture increases proportionately with size until get to giant aneurysm (25 mm or bigger). giant aneurysms then bleed less often than smaller aneurysms. |
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Term
| what conditions are associated w/increased intracranial aneurysm risk? |
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Definition
| marfan's syndrome, ehlers-danlos type IV, pseudoxanthoma elasticum, *polycystic kidney disease, and fibromuscular dysplasia |
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Term
| what is the clinical presentation of intracranial aneurysm? |
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Definition
| most pts present w/*subarachnoid hemorrhage (SAH) but some will present w/*cranial neuropathy (mass effect compresses cranial nerves/brain) such as 3rd nerve palsy (= eyelid ptosis, involves either superior cerebellar or posterior communicating artery). 3rd nerve palsy may also present in DM, but only w/muscular and not pupillary involvement (DM only affects the core of the nerve which goes to musculature, but an aneurysm will compress the periphery of the nerve which contains the autonomic pupillary control). intracranial aneurysm pts may also present w/*ischemic stroke (embolizes saccular thrombus distally - rare), *headache, as an *incidental finding on a brain imaging study, or *dead (25-50%) |
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Term
| does clinical presentation of a intracranial aneurysm correlate w/dangerous levels of blood in the brain? |
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Definition
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Term
| what accounts for 60% of spontaneous subarachnoid hemorrhage (SAH)? what is the overall most common cause of SAH? |
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Definition
| aneurysmal rupture. other more rare causes: arteriovenous malformations and hypertensive hemorrhage. the *overall most common cause of SAH: head trauma. |
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Term
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Definition
| abrupt onset of severe headache, unconsciousness, convulsion, vomiting, nuchal rigidity (kernigs/budzinski signs after a few hours), and grossly bloody CSF (60,000 up to 200,000 RBC per CC, several hrs later: xanthochromia, and the sheet sign: 1 WBC/1000 RBC or 1 mg protein per 1000 RBC) |
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Term
| when is the incidence of re-bleeding highest after a SAH? |
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Definition
| in the first 2 days and then over the next 14 days. 50% of pts will re-bleed by 6 months. |
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Term
| what is the hunt-hess clinical grading scale for SAH? |
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Definition
| grade 0: not ruptured. grade 1: asymptomatic or minimal h/a and slight nuchal rigidity. grade 2: moderate-severe h/a, nuchal rigidity, but no neurological deficit other than cranial nerve palsy. grade 3: drowsiness, confusion, or mild focal deficit (big break point). grade 4: stupor, moderate-severe hemiparesis, possible early decerebrate rigidity and vegetative disturbances. grade 5: deep coma, decerebrate rigidity, and moribund appearance. *an apparent grade 4/5 may only be a grade 2/3 w/a clot or hydrocephalus creating the mass effect rather than hemorrhaging blood. |
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Term
| what is the fisher grading scale for SAH? |
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Definition
| a mechanism to discuss the amount of blood seen on a CT scan. 1 - no blood, 2 - diffuse deposition of a thin layer of blood, 3 - localized clots, layer of blood 1 mm+, 4 - intracerebral/intraventricular clots. the higher the fisher grade, the higher the likelihood of vasospasm (very bad complication). |
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Term
| what is unique about an MCA aneurysm rupture? |
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Definition
| MCA aneurysm ruptures are associated w/blood in the parenchyma (temporal lobe) as well as in the subarachnoid space. |
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Term
| what characterizes cavernous carotid aneurysms? |
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Definition
| these tend to not rupture, but if they do, they do not produce a devastating SAH. instead, they rupture into the cavernous sinus which can create a fistula, orbital/retrooribital pain, and CN 3,4,6 paresis. these do not require tx. |
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Term
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Definition
| take hx, stabilize pt, control BP (lower: safer from rupture but can have ischemia), pain meds if needed, control intracranial pressure if elevated, and decrease re-rupture (most effectively done via surgical clipping, but endovascular coiling to induce thrombosis at the site of aneurysm may also be performed). |
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Term
| what does a brain look like grossly which has suffered a ruptured aneurysm? |
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Definition
| swollen, friable and low toleration of surgical manipulation |
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Term
| what is the rationale for waiting 2 wks to operate on SAH? |
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Definition
| vasospasm occurs 4-7 days after SAH, after which the brain is more tolerable to surgery. aneurysms are also more fragile immediately after rupture and extra time allows scarring to take place. |
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Term
| what is the problem w/waiting 2 wks to operate on SAH? |
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Definition
| aneurysms can re-bleed, causing the pt to potentially go into a coma and die (re-bleeds are usually worse). vasospasms (rxn of vasculature to subarachnoid blood) may also occur, causing neurologic deficits. the tx for vasospasm is increased BP/volume, however this then increases the risk of another SAH. |
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Term
| why is operating early (w/in 72 hrs) on SAH pts generally going to provide a better outcome? |
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Definition
| this prevents rebleed and vasospasm can then be treated by increasing BP/volume w/less risk. this is however more difficult. |
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Term
| what are the benefits of endovascular coiling? |
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Definition
| less invasive, less hospital time, fewer complications from sx (will do better for the *first year). |
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Term
| what are the disadvantages of endovascular coiling? |
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Definition
| not always as complete as clipping, may require surgical rescue, difficult to operate on later, associated w/ballooning/stenting, and required annual transcatheter arteriogram. |
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Term
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Definition
| an expensive Ca2+ blocking drug which is thought to reduce ischemia from aneurysmal vasospasm |
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Term
| what is an arteriovascular malformation (AVM)? |
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Definition
| a congenital abnormality where the capillary bed between the arteries and veins is lost |
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Term
| what characterizes the risk of AVM? |
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Definition
| 1/7 incidence of aneurysm, no gender predilection, 70-90% are supratentorial, and most involve the MCA followed by the ACA and finally the PCA. |
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Term
| what is the relationship between AVMs and aneurysms in terms of hemorrhage? |
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Definition
| AVMs are more likely to hemorrhage than aneurysms, but when AVMs do hemorrhage, the consequences are less severe (tissue around AVM is already dead and can accommodate blood). |
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Term
| how can AVMs lead to CHF in kids? |
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Definition
| if enough arterial circulation is shunted back into the veins = heart is overloaded w/fluid |
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Term
| how does an AVM present grossly on the brain surface? |
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Definition
| as a dilated veins w/large contributing arteries |
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Term
| what is the relationship between AVMs and aneurysms in terms of seizure? |
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Definition
| AVMs are more commonly associated w/seizure |
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Term
| what is the spetzler-martin grading scale? |
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Definition
| an AVM grading scale (1-5) which determines surgical tolerability based on the size o the lesion, the eloquence of the tissue and if it drains superficially or deep. |
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Term
| what are tx modalities for AVMs? |
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Definition
| surgery (separates arterial inflow from venous drainage - however need to ensure that venous outflow is still sufficient), embolization, radiation, and combination approaches. |
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Term
| if you can see the AVM, what is there still a risk of? |
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Definition
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Term
| what are the s/s for AVMs? |
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Definition
| h/a, seizures, hemorrhage, fluctuating neurologic deficits, all of which usually appearing before age 40. |
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Term
| what characterizes cavernous angiomas? |
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Definition
| these are seen fairly commonly w/MRI technology. they can cause headaches, but are generally of little concern unless hemosiderin deposits are seen around the base = bleeding has occurred. radiation is commonly used to remove these. |
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