Decision for intravenous thrombolysis in a young patient with acute vertical gaze palsy

any vascular risk factors. The neurological examination revealed a skew deviation with complete vertical gaze palsy involving both upward and downward gaze, while horizontal gaze was intact. The calculated National Institute of Health Stroke Scale (NIHSS) was two. Since magnetic resonance imaging (MRI) was not available in this emergency setting, a non-enhanced brain computed tomography (CT) was performed, which did not show any signs of hemorrhage or infarction. Moreover, the CTarteriography was normal. However, dynamic perfusion CT showed a small area of delayed perfusion (abnormally prolonged time to peak, TTP) in the right paramedian thalamus, while cerebral blood volume (CBV) was only slightly reduced, revealing a TTP-CBV mismatch (Fig. 1).