Progression of stroke deficits in patients presenting with mild symptoms: The underlying etiology determines outcome

Background and purpose Patients with acute stroke and mild or rapidly improving symptoms frequently show progression. The role of reperfusion treatment in such patients is not clear. We hypothesized that progression was most likely in patients with cortical localization and such patients may benefit from thrombolysis. Material and methods We interrogated Hamad Stroke Database to evaluate 90-days outcome in patients with acute ischemic stroke admitted within 4 hours and a NIHSS score of <= 6. Evaluation was based on localization (lacunar or cortical), multi-model imaging abnormalities and whether they received rt-PA. The 90-day mRS was used to determine outcome. Results During study period 6381 patients were admitted with acute stroke. Mild stroke within 4 hours was diagnosed in 506 [no thrombolysis: 381(lacunar: 213; cortical: 168), thrombolysis: 125 (lacunar: 45; cortical: 80)]. The rt-PA treated patients had significantly higher NIHSS (2.94 +/- 3.9 versus 1.28 +/- 2.46, p<0.0001), increased rates of complications (16.0% versus 3.9%, p<0.0001) and longer hospital stay (6.05 +/- 8.1 versus 3.78 +/- 3.6 days; p<0.001). In patients with cortical stroke, intracranial arterial occlusions (11.6% vs 3.9%, p<0.0001) and CTP mismatch (22.2% vs 4.4%, p<0.0001) were more frequent in rt-PA treated patients. Discharge mRS (33.6% versus 13.9%, p<0.001) and 90-days mRS (23.2% versus 11.8%, p = 0.002) was significantly worse in patients with cortical stroke (rt-PA-treated and untreated patients). Conclusions The outcome in patients with mild stroke depends on lesion location (lacunar versus cortical) and severity of symptoms. Patients who receive rt-PA have significantly larger deficits, increased imaging abnormalities and higher rates of hospital complication, explaining the poor outcome in such subjects.