Intravenous thrombolysis in stroke with admission NIHSS score 0 or 1

Background: Up to 30% of stroke patients initially presenting with non-disabling or mild deficits may experience poor functional outcome. Despite, intravenous thrombolysis remains controversial in this subgroup of stroke patients due to its uncertain risk benefit ratio.

Aim: We aimed to analyze the real-world experience with intravenous thrombolysis in stroke patients presenting with very low NIHSS.

Methods: Data of stroke patients presenting with mild initial stroke severity (NIHSS 0-5) including vascular risk factors, stroke syndrome and etiology, early neurological deterioration, symptomatic intracerebral haemorrhage (sICH), and functional outcome by modified Rankin Scale were extracted from a large nationwide stroke registry and analysed. Patients were categorized and compared according to admission severity NIHSS 0-1 versus NIHSS 2-5 and intravenous thrombolysis use.

Results: Seven hundred and three (2%) of 35,113 patients presenting with NIHSS 0-1 and 6316 (13.9%) of 45,521 of patients presenting with NIHSS 2-5 underwent intravenous thrombolysis. In the NIHSS 0-1 group, intravenous thrombolysis was associated with early neurological deterioration (adjusted OR 8.84, CI 6.61-11.83), sICH (adjusted OR 9.32, CI 4.53-19.15) and lower rate of excellent outcome (mRS 0-1) at three months (adjusted OR 0.67, CI 0.5-0.9). In stroke patients with NIHSS 2-5, intravenous thrombolysis was associated with early neurological deterioration (adjusted OR 1.7, 1.47-1.98), sICH (adjusted OR 5.75, CI 4.45-7.45), and higher rate of excellent outcome (mRS 0-1) at three months (adjusted OR 1.21, CI 1.08-1.34).

Conclusions: Among patients with NIHSS 0-1, intravenous thrombolysis did not increase the likelihood of excellent outcome. Moreover, potential signals of harm were observed. Further research seems to be warranted.