DWI Positivity in Mild, Nondisabling Acute Cerebral Ischemia: Data From the PRISMS Trial

Area of Science:

• Neurology
• Radiology
• Stroke Medicine

Background:

• Acute cerebral ischemia (ACI) with mild deficits presents diagnostic challenges for acute infarction detection via diffusion-weighted imaging (DWI).
• The PRISMS trial investigated alteplase versus aspirin for mild stroke.
• This study specifically analyzed DWI-positivity rates and associated factors in mild, nondisabling stroke patients.

Purpose of the Study:

• To determine the detection rate of acute infarction (DWI-positivity) in patients with mild, nondisabling stroke.
• To assess the association between baseline clinical and imaging characteristics (including white matter hyperintensity [WMH]) and DWI-positivity.
• To explore the potential impact of alteplase treatment on DWI-positivity in this patient group.

Main Methods:

• Analysis of data from the phase 3b, randomized, double-blinded PRISMS trial.
• Central, blinded assessment of day 2 magnetic resonance imaging (MRI) for DWI-positivity, prior infarct, and WMH burden (Fazekas grade and volume).
• Regression modeling adjusted for alteplase treatment, demographics, and clinical covariates.

Main Results:

• Of 212 patients with MRI, 51% showed DWI-positivity (median lesion volume 1.20 cc).
• Higher Fazekas grade and prior infarct were univariately associated with DWI-positivity.
• White matter hyperintensity (WMH) was not independently associated with DWI-positivity (aOR: 1.01), but alteplase treatment was inversely associated (aOR: 0.48).

Conclusions:

• White matter hyperintensity (WMH) does not predict DWI-positivity in mild, nondisabling acute cerebral ischemia (ACI).
• Alteplase treatment may be associated with a reduced likelihood of DWI-positivity in mild ACI.
• Further research is warranted to confirm the hypothesis that alteplase reduces DWI positivity in mild stroke.