15 terms

HD2 Week 3

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Localizing stroke: subcortical
Lenticulostriate arteries off of MCA. Supplies deep subcortical structures, i.e. basal ganglia, internal capsule.
Presents with weakness/sensory loss WITHOUT aphasia, neglect, visual field deficits, gaze preference.
Localizing stroke: lacunar
Small infarct affecting subcortical structures (basal ganglia, internal capsule, thalamus)
PURE motor hemiparesis and/or hemisensory loss, clumsy hand dysarthria syndrome.
- Many due to microatheroma, emboli. Many are clinically silent. Lacunar stroke can be mimicked by large vessel disease.
Anterior vs. Middle cerebral arteries
Anterior: MEDIAL part of parietal, temporal, frontal lobes. LEG weakness. Bilateral stroke-->akinetic mutism (not motivated to speak).
Middle: LATERAL part of parietal, temp, front. ARM and FACE weakness. Visual field deficits, gaze preference, aphasia (if dominant hemisphere), neglect if non-dom hemisphere
Localizing stroke: posterior cerebral artery
(From basilar a., which in turn is from vertebrals, which are from subclavians.)
VISUAL FIELD deficits-->contralateral homonymous hemianopsia!
Localizing stroke: basilar artery
Basilar supplies the Brainstem and Back of Brain!
- Cranial nerve dysfunction
- Cerebellar dysfunction
- Occasionally loss of consciousness, which is otherwise NOT seen with ischemic stroke.
- May show CROSSED/bilateral sensory/motor deficits.
Localizing stroke: vertebral artery
LOWER CN deficit and/or ataxia. CROSSED sensory signs. Wallenberg syndrome.
Wallenberg syndrome
a.k.a. lateral medullary syndrome, posterior inferior cerebellar artery syndrome. Often MISSED by MRI. Vertebral dissection most common cause in YOUNG person.
- CONTRAlateral pain & temp deficits in trunk and extremities, IPSIlateral facial pain & temp sensation loss. Presents with Horner's, dysphagia, diplopia, and facial pain. NO corneal reflex--trigeminal shot.
- Due to damage of spinothalamic tract, cerebellum, trigeminal nucleus. Stroke in VERTEBRAL a. or PICA.
CAREFUL not to confuse this with CAROTID DISSECTION!
What labs are drawn in suspected stroke?
CBC, lytes, coags, cardiac panel, arterial blood gas.
Stat CT scan as well to rule out hemorrhage.
Clinical clues to hemorrhage: headache, nausea/vomiting, very high BP.
Localizing lesions: subarachnoid hemorrhage
"Worst headache of life"
CAN present with focal signs (e.g. 3rd nerve palsy)
CT scan has decent sensitivity, but LP should be performed if CT negative. Positive LP results: CSF xanthochromatic/grossly bloody.
Angiography needed to ID vascular problem (aneurysm vs. vascular malformation).
Most common locations for aneurysm
Anterior communicating (30%)
Posterior communicating (25%)
Middle cerebral a. (20%)
Vertebro-basilar (~10%)
Risk of rupture highest in posterior comm. and vertebro-basilar areas. Risk higher with larger size and hx of previous rupture.
Carotid dissection
CAREFUL--this can also present with crossed signs and Horner's, but is NOT Wallenberg's!
e.g. Right-sided neck pain, RIGHT Horner's, LEFT weakness.
- Notice weakness vs. sensory loss.
Warfarin therapy for stroke prevention
Used in patients with A-fib. ASA not a great choice for a-fib.
OTHERWISE, asa is fine. Similar success rate to warfarin for preventing recurrent stroke.
Atherosclerosis of large vessels: tx options
- Carotid stenosis is most common
- Stenting vs. endarterectomy--generally similar results.
- Favor stenting in cases of high risk for MI, recurrent stenosis after surgery, post-radiation stenosis, etc.
ABCDD scoring for risk of stroke FOLLOWING a TIA
Age >60
BP >140/90
Clinical sx of speech impairment/focal weakness
Diabetes
Duration 10-59 min (1 pt) or over 1 hour (2 pts)
Highest scores correlated with a stroke rate of over 20% within the next 90 days.
Atherosclerotic vs. Embolic strokes: different appearances grossly
- Atherosclerotic strokes are usually large and pale.
- Embolic strokes are usually hemorrhagic