Stroke: Localization/Aphasia
What are some non-modifiable risk factors for stroke?
- *Age* #1 non-modifiable risk factor (2X > 55 years old) - Male > Female - Race (AA > White > Asian) - FHx
With a SAH what is the risk of seizure, mortality, re-bleed and vasospasm?
- *All are around 25%* - Seizure 25% overall - Mortality 25% first 24 hours - Risk of rebleed 30% in first month - Vasospasm 25% usually within one week
What are the different aphasias?
- *Fluency -> Comprehension -> Repetition* - Transcortical = repetition intact MCA -> upper -> anterior (Broca) MCA -> lower -> posterior (Wernicke)
What are some modifiable risk factors for stroke?
- *HTN* #1 modifiable risk factor - History of prior TIA/stroke - Heart disease - DM2 - Smoking - Carotid stenosis - EtOH/cocaine abuse - High dose estrogens - Hypercoaguable states - Hyperlipidemia - Migraine headaches - Sleep apnea - PFO
What percentage of TIA patients will develop stroke?
- 5% in one month if untreated, 14% in one year - Highest risk in first month
What are some risk factors for rupture of berry aneurysm?
- > 15 mm - 50-60 years of age - Straining
How does PCA ischemic stroke present?
- Anatomy varies. Usually comes from basilar artery but 20% come from ICA. Supplies CN3 and CN4 nuclei - Visual field cuts and cortical blindness - Prosopagnosia - Palinopsia - Alexia - Transcortical sensory aphasia - Weber syndrome
What is prosopagnosia? What is palinopsia? What is alexia?
- Can not read faces - Abnormal recurring visual images - Can not read words
What is Gerstmann syndrome?
- Dominant MCA stroke at angular gyrus - Agraphia, acalculia, R/L disorientation, Finger agnosia
What is the most common type of stroke?
- Ischemic thrombotic large vessel - Can present like "stuttering" stroke
How does ICA ischemic stroke present?
- Most variable syndrome and usually asymptomatic due to collateral but can affect MCA/ACA distribution - Ocular infarction - Amaurosis fugax
What is paraphasia? What is anomia? What is stereotype speech?
- Similar sounds - Word finding difficulty - Repetition of non-sensical syllables "No No No"
Are smaller or larger AVM more likely to rupture?
- Smaller more likely to hemorrhage - 50% lifetime risk of hemorrhage (2% risk per year) - Usually younger age 20-40
How does MCA ischemic stroke present? Superior vs. inferior division?
- Superior MCA: Embolic to rolandic areas, sensory + motor contralateral face and arms > legs Dominant: Global or Broca's aphasia Non-dominant: Hemi-neglect, spatial perception - Inferior MCA: Lateral temporal and inferior parietal lobe. Superior quadrantanopia or homonymous hemianopsia Dominant: Wernicke's aphasia Non-dominant: Left visual neglect
How does ACA ischemic stroke present?
- Usually has good collateral circulation - Leg weakness, gait apraxia, urinary incontinence, personality dysfunction - Transcortical motor aphasia
What are two types of hemorrhagic stroke?
1. ICH: due to HTN and microaneurysms usually in putamen 2. SAH: due to berry aneurysm usually anterior circle of willis.
What are 6 types of lacunar strokes?
1. Pure motor- internal capsule 2. Pure sensory- thalamus 3. Dysarthria "clumsy hand syndrome"- internal capsule 4. Sensorimotor- internal capsule and thalamus junction 5. Ataxia and leg paralysis 6. Hemichorea-hemiballismus- caudate, STN
What is the size cut off for lacunar strokes?
15 mm
What is the prevalence of TIA in men and women over age 65?
2-4 %
How many strokes are there per year? How many survivors in the US?
780,000 strokes/year 5.8 million survivors
What is definition of stroke?
A cerebrovascular event with clinical signs of focal or global cerebral disturbances >24 hours
What does the lenticulostriate artery supply?
Branch off MCA to supply the internal capsule
How do you grade non-traumatic SAH?
Hunt and Hess Scale (HHS for SAH) 1. Mild HA 2. Severe HA, nuchal rigidity, CN3 3. Drowsiness, focal neurologic deficits 4. Stupor, hemiparesis 5. Coma
What are the types of strokes?
Lacunar stroke would be ischemic small vessel
What medication is useful to prevent vasospasm in SAH?
Nimodipine (CCB)
Melodic intonation therapy (MIT) can help what type of aphasia?
Non-fluent (Broca's) aphasia by using non-dominant right hemisphere
Draw the circle of willis
PICA not labeled
What is the internal capsule?
Subcortical white matter with ascending and descending tracts Anterior limb: Frontal lobe to pons and thalamus Posterior limb: Corticospinal tracts
Is incidence of stroke improving? Why?
Yes, improving due to better control of HTN, smoking