Isolated Upper Limb Weakness From Ischemic Stroke: Mechanisms and Outcome

Area of Science:

• Neurology
• Stroke Medicine
• Vascular Neurology

Background:

• Isolated upper extremity (UE) weakness is an uncommon stroke presentation.
• Characterizing the stroke mechanisms and outcomes in these patients is crucial for effective management.

Purpose of the Study:

• To investigate the clinical and imaging features, etiologies, management, and outcomes of patients with isolated UE weakness due to stroke.
• To differentiate stroke characteristics based on infarct location, specifically motor strip versus non-motor strip infarcts.

Main Methods:

• Analysis of the Get with the Guidelines-Stroke dataset (n=7643) to identify patients (n=87) with isolated UE weakness.
• Detailed stroke evaluation including diffusion-weighted magnetic resonance imaging and arterial imaging.
• Classification of patients into Group-A (motor strip infarct) and Group-B (non-motor strip infarct) for comparative analysis.

Main Results:

• Patients with motor strip infarcts (Group-A) more frequently had carotid artery stenosis or irregular plaque (84.5%) and large-artery atherosclerosis mechanisms (46%) compared to Group-B.
• Cardioembolic mechanisms were more common in Group-B (44%) than Group-A (13%).
• Recurrent strokes occurred in 11.5% of patients, with a higher incidence in those with mild-moderate carotid stenosis and plaque ulceration/thrombus.

Conclusions:

• The stroke mechanism in acute isolated UE weakness is diverse.
• Motor strip infarcts are associated with carotid stenosis, often with vulnerable plaques, while other infarct locations suggest cardioembolism.
• A significant risk of recurrent stroke exists, especially in the presence of mild-moderate carotid stenosis with plaque ulceration/thrombus.