Outcomes following thrombolysis for posterior circulation stroke
There is relatively less information about indications and outcome for thrombolysis in posterior circulation stroke as compared to anterior circulation stroke. Prior randomized studies either excluded this group of patients (PROACT-II), or used inclusion criteria that made enrollment less likely (NINDS rt-PA, ECASS I & II). Medical records were reviewed for all patients who received intravenous (IV) or intraarterial (IA) thrombolytic therapy for posterior circulation ischemic stroke at the University of California, San Francisco between October 1993 and February 2000. NIHSS was measured at baseline, 1 day, and at discharge, and a Glasgow Coma Scale (GCS) was measured at baseline. A retrospective modified Rankin Scale (mRS) was measured at last follow-up. A mRS≤2 was considered a good outcome. Data were analyzed using the Wilcoxon rank-sum test. 20 patients received thrombolytic therapy: 9 IV rt-PA; 9 IA urokinase; 2 IA rt-PA. Mean age was 57 (range 25–87). 11 of 20 patients were treated within 12 hours (1.5 hours-16 days) of symptom onset. Mean initial NIHSS score was 20 (range 2–39), and GCS was 10 (range 3–15). One day following thrombolytic therapy the mean NIHSS was 13 (range 0–36, p<0. 01), with 16 of the 20 patients having overall improvement (11 of these patients with 5 or more points) despite continued disability. No intracranial hemorrhages were observed. Six patients died of complications between 2 days and 2 weeks, and 3 of these patients were treated >12 hours after stroke onset. At hospital discharge the 8 survivors treated in under 12 hrs had a mean NIHSS of 4 (range 0–13), and the 6 survivors treated beyond 12 hrs had a mean NIHSS of 10 (range 3–20, p<0.10). 7 and 2 patients in the two groups, respectively, had a mRS≤2 (p<0.05, compared to baseline Rankin). Ten patients had an initial GCS of 7 or less, with 9 having motor posturing at the time of presentation. Only 2 of these patients (20%) had a good outcome (ages 25 & 42). Thus, thrombolysis within 12 hours may benefit patients with posterior circulation stroke. Decreased level of consciousness and lack of purposeful movement, as evidenced by a GCS≤7 or motor posturing, respectively, are predictive of poor outcome, even with thrombolytic treatment.