Types of ischemic stroke

1. When during the day do thrombotic strokes usually occur? How do they usually progress? What percentage are preceded by TIA?
2. When do embolic strokes usually occur? What artery is usually affected? What percentage are preceded by TIA?
3. What is the most common cause of an embolic stroke? What are other common causes?
4. What are lacunar infarcts? What is the usual cause?
5. What are the symptoms of lacunar infarct? What percentage are preceded by TIA?

Answers:
1. Thrombotic strokes usually occur during sleep and have slow progression of deficits over 24-48 hrs. 50% are preceded by a TIA.
2. Embolic strokes occur during the day. Deficit is immediate and seizures may occur. The MCA is most often affected. 11% are preceded by TIA.
3. Chronic a-fib is the most common cause. Other causes include MI, cardiac aneurysm, CM, atrial myxoma, valvular heart disease, sick sinus syndrome.
4. Lacunar infarcts are small (<15mm) infarcts seen in the putamen, pons, thalamus, caudate, and internal capsule, due to occlusive arteriolar or small artery disease. They are usually associated with hypertension.
5. Symptoms include relatively pure syndromes (motor, sensory). There is an absence of higher cortical function involvement (language, praxis, non-dom hemisphere syndrome, vision). Onsent may be abrupt or gradual. 23% are preceded by a TIA.