HD2 Week 3
|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%)
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|
Clinical sx of speech impairment/focal weakness
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