Timing of TIA's preceding stroke, and ABCD score,

Time window for prevention is very short. Neurology 2005; 64:817-820. Study involved 2416 European subjects in trials or a database. 23 % of patients overall gave a history of prior TIA. 17 % occurred on the day of the stroke, 9 % on previous day,and 43 % during the previous week. A risk of 1-2 % at seven days and 2-4 % at one month is usually quoted but omits fact that patients were not recruited until 2 weeks were up. The true early risk may be much higher, even tenfold higher.

Risk of stroke after TIA (cf slide by Brott) average of about 12 studies was about 5 % in first 2 days, 12 % in first 90 days. Kaiser and California studies were cited specifically. 1702 patients presented to California ED's received a diagnosis of TIA and were followed for three months, from record review. ABCD score was derived age > 60 (1 point), bp > 140/90 (1 point), clinical (unilateral weakness 2 points, speech disturbance without weakness one point) and duration (> 60 min, 2 points; 15 m to 60 m, 1 point) Final score 0-6 (Lancet 2005 Rothwell). OR California ABCD score (age> 60 one point, DM 1 pt, duration > 10 min 1 point,any weakness 1 pt, any speech impairment 1 pt, 0-5 score, Johnston JAMA 2000). ABCD (2) score Lancet 2007: age 1 pt, bp 1 pt, weakness/speech impairment 2/1 pts, dur >60 2 pt, 15-60 1 pt, dm 1 pt, 0-7 scale).

ABCD(2) score was validated and is ready for clinical use. 2 day risks for score (0-3) 1 %; score 4-5 (4%), score 6-7 (8%). Pct of patients in low medium and high risk groups were respectively34, 45, 21 respectively.

From Lancet article(2007) 90 day risk appears 0-3 (4 %?), score 4-5 9-13 %, and 6-7, 18-22 % (estimates off chart).

Benign recurrent tia's sensory only may have more tia's but < 3 % risk of stroke.