Unilateral watershed cerebral infarcts

Area of Science:

• Neurology
• Radiology
• Vascular Medicine

Background:

• Watershed (WS) cerebral infarcts occur in border zones between major cerebral arteries.
• Understanding the specific locations and causes of WS infarcts is crucial for diagnosis and treatment.
• Previous studies have not fully characterized the clinical and etiological spectrum of unilateral WS infarcts.

Purpose of the Study:

• To analyze the clinical presentation and etiology of symptomatic unilateral watershed (WS) cerebral infarcts.
• To correlate specific WS infarct locations with characteristic neurological deficits.
• To identify underlying causes, such as hemodynamic compromise or embolism, in patients with WS infarcts.

Main Methods:

• Retrospective analysis of 51 patients with symptomatic unilateral WS cerebral infarcts identified on CT scans.
• Categorization of infarcts based on location: anterior/middle cerebral artery (ACA/MCA) border, MCA/posterior cerebral artery (PCA) border, and superficial/deep MCA border.
• Clinical data review, including neurological examination findings, onset symptoms, and vascular risk factors.

Main Results:

• Infarcts were located between superficial ACA/MCA territories (22 patients), superficial MCA/PCA territories (20 patients), and superficial/deep MCA territories (9 patients).
• Characteristic neurological pictures were associated with each infarct location.
• Syncope (37%) and focal limb shaking (12%) were common presenting symptoms.
• Internal carotid artery occlusion or stenosis was present in 75% of patients, often associated with hemodynamic compromise (cardiopathy, hypotension) or elevated hematocrit.
• Embolic infarction was unlikely, identified in only 4% of patients with atrial fibrillation.

Conclusions:

• Symptomatic unilateral watershed cerebral infarcts have distinct clinical and etiological profiles based on their location.
• Hemodynamic factors, particularly internal carotid artery stenosis/occlusion coupled with conditions causing reduced cerebral perfusion pressure, are the primary cause.
• Embolic causes are less common in this specific patient cohort.