27B Hemorrhagic Stroke Flashcards
______ and ______ hemorrhages each account for 50% of cerebral hemorrhages.
Subarachnoid, parenchymal
Subarachnoid aneurysms are MC caused by:
rupture of saccular (berry) aneurysms
What causes berry aneurysms?
developmental defects in the blood vessel wall that tend to enlarge with time
MC locations for berry aneurysms?
Ant cerebral (30%) int carotid (30%) middle cerebral (25%) basilar (10%) post cerebral (5%)
(Ant>post)
Risk factors for subarachnoid hemorrhage?
- tobacco
- ETOH
- HTN
- oral contraceptives
- stimulant drugs
- low cholesterol
- genetics (Marfan, polycystic kidney)
Symptoms of SAH?
- sudden severe HA (“worst”)
- rapid loss of consciousness (some pts)
- neck stiffness, pain
- photophobia and phonophobia
- NV
(focal neurologic signs minimal or absent)
What symptoms follow the rupture of a berry aneurysm within hours?
neck stiffness, pain
photophobia and phonophobia
What causes the symptoms that follow the rupture of a berry aneurysm?
irritation and inflammation of the meninges secondary to the breakdown products of RBC lysis
Signs of SAH?
- abn vitals (HTN, irreg HR)
- subtle or delayed meningeal signs
- retinal hemorrhages
- if present, subtle focal deficits
What causes arrythmia associated with SAH?
RBC breakdown products that irritate brainstem centers regulating heart rate.
CN III paresis resulting in a dilated pupil and ophthalmoparesis is consistent with an aneurysm at:
junction of the internal carotid and posterior communicating arteries
Paraparesis (bilateral leg weakness) suggests an aneurysm of:
anterior cerebral artery
Hemiparesis is consistent with an aneurysm of:
middle meningeal artery
Most helpful noninvasive diagnostic test to identify a subarachnoid hemorrhage
CT
The amount of blood and its location help determine:
- site of the berry aneurysm
- likelihood of a delayed complication called “vasospasm”
CT scan may be negative in a patient with a ruptured berry aneurysm, especially if:
bleeding is slight or if the scan is delayed for a day or more after the rupture
What test should you do if the CT is negative, but you still suspect a SAH?
LP, delayed 3-4h after the onset of HA
(allow time for some of the red blood cells in the subarachnoid space to lyse and release hemoglobin into the spinal fluid, centrifuge to confirm)
Only method to 100% rule out a subarachnoid bleed
LP
What is xanthochromia?
yellow discoloration that results from the break down of hemoglobin; takes a day or more after rupture of the an aneurysm
Imaging performed after SAH confirmed?
gold standard = 4-vessel digital subtraction arteriogram
alternative = MRI (for >5mm)
Trx for SAH?
- coil (through an intra-arterial catheter to cause the aneurysm to clot and seal itself)
- metal clip at the neck of the aneurysm
- combo of both
MC causes for parenchymal hemorrhage?
- head trauma
- HTN
- AV malformations
What are Charcot Bouchard aneurysms?
microaneurysms caused by chronic elevation of the blood pressure –> injury to small cerebral blood vessels
Where do Charcot Bouchard aneurysms develop?
small, penetrating microvessels located in the basal ganglia, thalamus, pons, and cerebellum
(**MC sites of parenchymal hemorrhage)
