For patients with unknown time of stroke onset, MRI characteristics may be able to discern the timing of the stroke and allow for thrombolytic therapy. Overall, outcomes were better with thrombolysis but at the possible cost of higher mortality and risk of intracranial bleed.
Patients with acute stroke from occluded intracranial internal carotid artery (ICA) or proximal middle cerebral artery (MCA) presenting from 6-24 hours from onset benefitted from endovascular thrombectomy when clinical deficits of stroke were greater than expected based on infarct volume on diffusion-weighted MRI or perfusion CT.
Elderly stroke patients over age 80 who received tPA >3 - 4.5 hours from time of onset were more likely to have symptomatic intracranial hemorrhage (SICH), 10% vs 8% in the <3-hour group, but overall mortality and percentage with good neurological outcome was the same in the delayed group as patients who received it in under 3 hours.
The "upgoing thumb sign" can be used as part of a comprehensive neurological evaluation to help distinguish stroke mimic from actual stroke. It won't replace MRI, but it can be part of the neurological exam, just like we use the Babinski sign. One editorial from 1993 suggested calling it the Hachinski-Babinski, after the discover. Here's how to do it.