Diffusion-weighted imaging identifies a subset of lacunar infarction associated with embolic source

Area of Science:

• Neurology
• Vascular Neurology
• Neuroimaging

Background:

• Lacunar infarcts, small lesions in penetrator artery territories, cause distinct clinical syndromes.
• Determining the vascular pathophysiology of lacunar infarcts often requires detailed pathological examination.
• Multiple, small infarcts occurring close in time but spread across the brain suggest an embolic origin.

Purpose of the Study:

• To determine the frequency of multiple acute lesions in patients with lacunar syndromes.
• To characterize the clinical features of patients with lacunar syndromes and diffusion-weighted imaging (DWI) evidence of multiple acute lesions.
• To investigate the potential embolic mechanism underlying lacunar syndromes.

Main Methods:

• Sixty-two consecutive patients presenting with a well-defined lacunar syndrome were enrolled.
• Diffusion-weighted imaging (DWI) was performed within 3 days of emergency room admission.
• Patients were evaluated for the presence of multiple acute lesions on DWI.

Main Results:

• Diffusion-weighted imaging (DWI) revealed multiple acute lesions in 10 patients (16%).
• An "index lesion" in a penetrator territory explaining the clinical syndrome was present in all patients.
• Subsidiary infarcts were typically punctate and located within leptomeningeal artery territories.

Conclusions:

• Approximately 16% of patients with classic lacunar syndromes exhibit multiple infarcts on DWI.
• The presence of subsidiary infarcts is associated with a higher frequency of identifiable stroke causes.
• This finding may guide investigations and treatment strategies for secondary stroke prevention.