Stroke mechanisms and their correlation with functional outcome in medullary infarction.

•Penetrating artery disease (PAD) was the most predominant stroke mechanism of medullary infarction (MI).•Patients with PAD showed more favorable outcome than those with large artery occlusive disease or dissection.•Patients with LAOD and dissection may be predisposed to chronic hypo-perfusion over a long period.•Underlying vascular lesions predicted long term outcome in patients with MI.