Thrombolysis for mild stroke

Table 2 Studies on thrombolysis in mild stroke

Ref.	Definition of mild stroke	Patients		Favorableoutcome(t-PA vs Placebo)	P	SICH(t-PA vs Placebo)	P
		rt-PA	Placebo
NINDS rt-PA Stroke Study Group[14]	Score ≤ 1 on each NIHSS item and normal consciousness	21	7	100% vs 86%	< 0.02	0% vs 0%	-
	Presumed small-vessel stroke	51	30	69% vs 60%	< 0.02	4% vs 0%	-
	Only motor deficits ± sensory deficits	220	219	61% vs 46%	< 0.02	3% vs 0.5%	-
	NIHSS score ≤ 9, minus all with aphasia, extinction/neglect, or any points on the level of consciousness questions	97	76	81% vs 74%	< 0.02	3% vs 0%	-
	NIHSS ≤ 9	99	78	82% vs 74%	< 0.02	3% vs 0%	-
Köhrmann et al[10]	NIHSS ≤ 4	32	-	94%	-	0%	-
Hassan et al[13]	NIHSS ≤ 6	27	24	92.6% vs 50%	< 0.03	3.7% vs 4.2%	1
Hassan et al[23]	NIHSS ≤ 10	52	98	74% vs 34%	< 0.009	2% vs 3%	-
1Steffenhagen et al[24]	NIHSS ≤ 5	78	16	74.7% vs 81.3%	0.75	2.6% vs -	0.572
2Khatri et al[25]	NIHSS ≤ 5	42	16	78.6% vs 81.3%	-	2.4% vs 0%	-
2Huisa et al[26]	NIHSS ≤ 5	59	74	57.6% vs 68.9%	0.871	5%	-
3Helsinki Stroke Thrombolysis Registry[7]	NIHSS 0-2	58	-	88%	-	0%	-
	NIHSS 3-4	194	-	86%	-	2.6%	-
	NIHSS 5-6	236	-	78%	-	2.1%	-
Greisenegger et al[27]	NIHSS ≤ 5	445	445	41% vs 29%	< 0.001	2.5% vs 0%	-
Urra et al28]	NIHSS ≤ 5	119	84	83% vs 81%	> 0.05	0% vs 0%	-
Logallo et al[29]	NIHSS ≤ 5	158	1633	38% vs 31%	0.07	1.9% vs 0.1%	< 0.001

¹Steffenhagen et al[24] compared the functional outcome of mild stroke patients using the modified Rankin scale (mRS) with severe (NIHSS score > 5) groups. Symptomatic intracerebral hemorrhage was low (2.6% vs 4.7%; P = 0.572). Favorable outcome (mRS score < 2) at 3 mo was more frequent (74.7% vs 34.7%; RR = 2.2, 95%CI: 1.8-2.5, P < 0.001) and mortality rate was lower (8% vs 22.9%; RR = 0.35, 95%CI: 0.16-0.76, P = 0.002). Favorable outcomes were not different (81.3% vs 74.7%, mRS score < 2, P = 0.75) compared to a placebo-treated group with baseline NIHSS scores ≤ 5 (n = 16) from the NINDS t-PA trial;

²In Khatri’s study, 4 of the 58 minor strokes had baseline disability (mRS > 2), and all were in the rt-PA group. In Huisa's study, the NIHSS score at admission was higher in the t-PA treated group compared to that in untreated group (3.4 ± 1.4 vs 1.9 ± 1.3; P < 0001). Thus the selective bias in the two studies might underestimate the effects of thrombolysis;

³In Helsinki Stroke Thrombolysis Registry, they did not give the definition of mid stroke. Fifty-eight mild stroke patients with NIHSS score 0-2 were treated with thrombolysis only when hyperdense cerebral artery sign, artery occlusion on computed tomography (CT) angiography, or perfusion deficit on perfusion CT scan presented. NIHSS: National Institutes of Health Stroke Scale; t-PA: Tissue plasminogen activator; SICH: Symptomatic intracranial hemorrhage.