Excessive White Matter Hyperintensity Increases Susceptibility to Poor Functional Outcomes After Acute Ischemic...

Area of Science:

• Neurology
• Radiology
• Cardiovascular Research

Background:

• Personalizing post-stroke prognostication requires understanding factors beyond traditional stroke risk profiles.
• White matter hyperintensities (WMH) on MRI are common in stroke patients but their prognostic significance independent of risk factors is unclear.

Purpose of the Study:

• To investigate the association between excessive, unaccounted white matter hyperintensity (uWMH) burden and long-term functional outcomes after ischemic stroke.
• To determine if uWMH burden predicts functional independence (modified Rankin Scale score < 2) post-stroke.

Main Methods:

• Analysis of 890 ischemic stroke survivors from the MRI-Genetics Interface Exploration (MRI-GENIE) study.
• Vascular risk factors (VRFs), acute stroke severity, and MRI-derived WMH and brain volumes were collected.
• Unaccounted WMH (uWMH) burden was modeled based on individual VRF profiles; association with 3-6 month mRS analyzed via linear regression and odds ratios.

Main Results:

• The uWMH burden was significantly associated with long-term functional outcomes (β = 0.104, p < 0.01).
• Excessive uWMH burden significantly reduced the odds of achieving full functional independence (mRS < 2) compared to low and average uWMH groups (OR = 0.4 and OR = 0.61, respectively; p < 0.01).

Conclusions:

• WMH burden exceeding that predicted by traditional vascular risk factors is associated with worse post-stroke functional outcomes.
• uWMH may represent a marker of cumulative brain injury and is a potential indicator of stroke recovery and overall brain health.