Objective: To measure the impact of cerebral white matter hyperintensity (WMH) burden on the outcomes of stroke in general, and stroke subtype specifically.
Methods: A total of 3814 acute ischemic stroke patients were prospectively enrolled from 11 stroke centers. WMH volume on MRI were quantified and categorized into quintiles. First, the impact of WMH on 3-month modified Rankin scale (mRS) in the entire patient population was studied, and in each stroke type that was determined by the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Then, we analyzed inter-group differences by: initial NIH stroke scale at admission, early neurological deterioration during the first 3 weeks after stroke onset, and functional recovery as well as stroke recurrence during the 3-month period following the initial infarct.
Results: Mean age was 67.1 ± 12.9, and 58.7% were men. In large artery atherosclerosis (LAA) stroke, top two WMH quintiles were independently associated with mRS at 3months. However, only the highest quintile was associated with mRS at 3 months in small vessel occlusion (SVO) and cardioembolism (CE). WMHs were independently associated with initial neurological severity in SVO stroke, but not in other subtypes. WMHs were related with early neurological deterioration only in LAA stroke. Regardless of stroke subtypes, WMHs were not associated with stroke recurrence. Higher WMH volume was independently associated with poor functional recovery in LAA stroke but not in CE subtype.
Conclusion: To our knowledge, this is the first study to demonstrate that WMH volume is an independent predictor of outcomes for certain types of stroke subtypes.