J Neurol. 2026 May 13;273(6):310. doi: 10.1007/s00415-026-13845-7.
ABSTRACT
BACKGROUND: Intravenous thrombolysis (IVT) for suspected acute ischemic stroke is initiated before definitive imaging confirmation, resulting in treatment of patients later classified as MRI confirmed infarction (MRI +), MRI negative ischemia (MRI -), or stroke mimics. Characterization of MRI - and mimic presentations may support assessment under uncertainty.
METHODS: We conducted a retrospective cohort study using a prospectively maintained stroke registry at a comprehensive stroke center between (2019-2025). Consecutive patients treated with IVT within 4.5 h of symptom onset who underwent brain MRI within 72 h were included and categorized by diffusion-weighted imaging and final adjudicated diagnosis as MRI + , MRI - ischemia, or stroke mimics.
RESULTS: Among 716 patients treated with IVT, 523 (73.0%) had MRI-confirmed infarction, 119 (16.6%) had MRI-negative ischemia, and 74 (10.3%) were stroke mimics. Compared with MRI + patients, MRI - and mimic groups were younger, more often female, and had a lower vascular risk burden, including atrial fibrillation (P = 0.0002) and hypertension (P = 0.0009). Both groups more frequently presented with minor deficits (NIHSS ≤ 5, P < 0.0001), while moderate-to-severe stroke was less common (P < 0.0001). Stroke mimics had fewer vascular risk factors than MRI - ischemia and were most commonly attributed to migraine, vestibular disorders, seizures, or functional neurologic conditions. Hemorrhagic transformation and in-hospital mortality occurred only in MRI + patients, while MRI - and mimic groups more often discharged home (P < 0.0001).
CONCLUSIONS: MRI negative ischemia and stroke mimics are distinct subgroups among thrombolysed patients, presenting with lower stroke severity and vascular risk. Recognition of these patterns may aid evaluation of mild or atypical presentations while supporting IVT use.
PMID:42128969 | DOI:10.1007/s00415-026-13845-7