lecture 2: brain aneurysms Flashcards
what is cerebral aneurysm
a bulge like dilation of the wall of a blood vessel within the brain
why do aneurysms develop?
due to weakness in the wall of a vessel, especially at branch points
what are the 3 types of cerebral aneurysms
- saccular
- fusiform
- ruptured
saccular cerebral aneurysm
Saccular aneurysm causes just one side of your artery to bulge
fusiform cerebral aneurysm
Fusiform aneurysm bulges out on all sides of your artery.
ruptured cerebral artery
spills blood into the surrounding tissue (hemorrhage)
CAUSES of aneurysms ?
- idiopathic in majority of cases
- congenital/familial inheritance
- atherosclerosis
- hypertension
- connective tissue disorders
- sickle cell anemia
- infections
- trauma
- smoking
- illicit drug use
- alcohol
pp’s at higher risk of developing aneurysms
- 40-60 year olds
- Females
(very very rare in kids)
symptom associated with cerebral aneurysms and Subarachnoid hemorrhage are:
headaches
“ worst headache of my life”
ACUTE ONSET OF SEVERE HEADACHES
symptom associated with cerebral aneurysms and Subarachnoid hemorrhage are:
facial pain
- occipital pain
- cervical pain
- pain behind eye
- pain in low temple
symptom associated with cerebral aneurysms and Subarachnoid hemorrhage are:
NECK STIFFNESS / PAIN
due to irritation of meningeals
symptom associated with cerebral aneurysms and Subarachnoid hemorrhage are:
alterations in consciousness: confusion or impaired alertness
the sudden increase in intracranial pressure ass. with ruptured aneurysm can lead to a decline is cerebral perfusion pressure, causing syncope.
symptom associated with cerebral aneurysms and Subarachnoid hemorrhage are:
seizures; usually in SAH
mostly within 24 hours of onset
symptom associated with cerebral aneurysms and Subarachnoid hemorrhage are:
autonomic disturbances: fever, nausea, vomiting, sweating, chills, cardiac arrythmias
symptom associated with cerebral aneurysms and Subarachnoid hemorrhage are:
visual symptoms: blurry vision, diplopia, visual field defects
diagnosis of brain aneurysms
- HISTORY
pp will complain of severe onset of headache: worst headache of their life, associated with a stiff/painful neck
diagnosis of brain aneurysms
CT & MRI
- in 90% of cases, this will show a subarachnoid hemorrhage in cases of a ruptured aneurysm
diagnosis of brain aneurysms
lumbar puncture + CSF analysis
- if not recognised by CT
- identification of blood in CSF that runs in subarachnoid space.
diagnosis of brain aneurysms
angiography:
small flexible tube is threaded into one of the brain arteries and is injected with dye whilst pictures of the arteries are being taken
what is vasospasm
A vasospasm is the narrowing of the arteries caused by vasoconstriction. This narrowing can reduce blood flow or even block it.
the two surgical C’s for aneurysm
Clipping
Coiling
what is clipping and what is the benefit of doing it
- neurosurgeron performs this
- cuts skull open
- damaged vessel is identified
- a metal clip id placed across the aneurysm
- this prevents blood from entering the aneurysm causing further growth/damage
what is coiling and what is the benefit of doing it
Coiling involves approaching the aneurysm from inside the blood vessel, so that there is no need to open the skull. Small metal coils are inserted into the aneurysm via a catheter through the arteries that run from the groin to the brain. The coils remain in the aneurysm; they are not removed.
mechanism of formation of aneurysm
- developmental defects in the media and elastica
- focal destruction of internal elastic membrane caused by haemodynamic forces
- enlargement of sac, then rupture
mechanism of formation of aneurysm
- developmental defects in the media and elastica
- focal destruction of internal elastic membrane caused by haemodynamic forces
- enlargement of sac, then rupture
those who survive SAH, are left with neurological deficits, due to
- hemorrhage
- cerebral vasospasm with infarction
- hydrocephalus
three most common locations of saccular/berry aneurysm
- internal carotid artery (terminal)
- middle cerebral artery
- basilar artery (top)
what is sentinal bleeds
aneurysms undergoing small ruptures and leaks of blood into the subarachnoid space
third nerve palsy - ptosis, diplopia, dilation of pupils can indicate aneurysm at what point
junction of post communicating artery and post cerebral arteries
sixth nerve palsy may indicate aneurysm at where
caverous sinus
unilateral blindness can indicate an aneurysm where
circle of willis (anteriormedially)
the side that a ruptured aneurysm is on, can be indicated by what ?
- monocular pain
- unilateral headache
- terson syndrome
ddx of SAH
- migraines (thunderclap headaches)
- stroke
- neurosyphillis
- pheochromocytoma (tumor)
- cerebral venous thrombosis
- pituaritary apoplexis
- ## hypertensive encthalopathy
delayed neurological deficits
delayed neurological deficits is the MAIN preventable cause of SAH
4 major causes of delayed neurological deficits
- rupture/bleed
- hydrocephalus
- vasospam
- hyponatremia
hydrocephalus
this is build up of fluid within brain and can be caused due to sah
hydrocephalus can cause
-stupor
-coma
-progressive drowsiness
- abulia
vasospams can cause the two I’s
- ischemia; signs of ischemia are present 4- 14 days after hemorrhage, mostly 7 days after
- infarction
Hyponatremia; is a complication of sah; what does Hyponatremia mean
decreased sodium level in blood.
- can develop within 2 weeks of developing sah
systemic changes ass. with sah
- ecg changes that may show MI
- increased troponin / MB levels
- decrease in EF = heart failure
- hyponatremia ( decreased ca levels in blood)
- albuminuria ( increased albumin in kidneys = kidney problem )
- glycosuria ( presence of reducing sugars in urine)
- ## leukocytosis
within 72 hrs of developing sah, what scan is effective enough to detect sah
high quality NON CONTRAST CT SCAN
On a CT, the exact offending aneurysm can be concluded by ?
the location of the main clot shown by the CT scan
on a ct, if there’s a collection of blood in the anterior inter-hemispheric fissure (the midline between both hemispheres); this indicates that there’s a rupture where?
rupture at the anterior comminicating
on a ct, if there’s blood in the slyvian fissure ( lateral hemispheric surface of the brain); this indicates that there’s a rupture where?
middle cerebral artery
on a ct, if there’s blood in the anterior perimesencephalic cistern, this indicates there’s a rupture where?
posterior communicating artery or distal basilar artery aneurysm
labs for sah :
moniotr electrolytes once or twice daily. why
because low calcium levels can occur randomly within two weeks of developing sah
what other lab test should we do
troponin levels must be looked at
how to manage raise intracranial pressure
- most times it occurs secondary to other diseases so you must treat the underlying condition
management of vasospasm ( narrowing of arteries)
- calcium channel antogonist nimodipine 60mg every 4 hr
:( = it can cause hypotension worsening the aneurysm
management of hydrocephalus
ventricular shunting - this could be permanent dependent on if its chronic or not
the role of steroids; how do glucocorticoisteroids help sah
reduce head and neck ache caused by irritative effect of the subarachnoid blood
benefit of early aneurysm repair? via clipping or coiling ( INTERVENTIONAL MANAGEMENT)
- prevention of rupture
what scale is helpful in assessing the patient before deciding for interventional management ?
hunt - hess scale
5 grades from mild, severe, somnolent, stupor to coma.
during clipping, craniotomy is required. what is this ?
An operation in which a small hole is made in the skull or a piece of bone from the skull is removed to show part of the brain
when conducting coiling of an aneurysm via a cathether, what artery is it passed from to reach this bulge?
the femoral
clipping is a type of ________ repair
surgical
coiling is a type of ____________ repair
endovascular technique
