Unique Clinicopathologic Subclassifiers of Cryptogenic Cerebral Emboli.

Area of Science:

• Neurology
• Cardiology
• Vascular Medicine

Background:

• Embolic stroke of undetermined source (ESUS) is a significant clinical challenge.
• Ipsilateral nonstenotic internal carotid artery (ICA) plaque (<50% stenosis), cardiac atriopathy (specifically left atrial enlargement - LAE), and patent foramen ovale (PFO) are potential contributors to ESUS.
• Identifying the specific etiology of ESUS is crucial for targeted prevention strategies.

Purpose of the Study:

• To investigate the prevalence and clinical characteristics of different etiologies of unilateral, anterior circulation ESUS.
• To identify predictors for nonstenotic ipsilateral ICA plaque (NSP), LAE, and PFO in ESUS patients.
• To evaluate the utility of clinical and radiographic features in predicting the proximal source of cerebral emboli.

Main Methods:

• A retrospective analysis of consecutive ESUS patients with unilateral, anterior circulation stroke from 2019-2021.
• Patients were categorized into mutually exclusive groups: NSP (plaque ≥3mm), LAE (sex-adjusted moderate-to-severe), PFO, or "occult ESUS" (no identified cause).
• Descriptive statistics and multivariable logistic regression were used to analyze group characteristics and identify independent predictors.

Main Results:

• Of 132 patients, 16% had NSP, 13% had LAE, and 7% had PFO; 64% had "occult ESUS".
• LAE was associated with older age and more frequent intracranial occlusions.
• Patients with LAE showed a higher prevalence of paroxysmal atrial fibrillation (56%) compared to those with PFO or NSP. Tobacco use was linked to NSP, while older age and tobacco use were inversely associated with PFO.

Conclusions:

• Clinical and radiographic features can help predict the specific proximal source of cerebral emboli in ESUS.
• Identifying these features can guide more cost-effective outpatient diagnostic testing for stroke etiology.
• This approach may improve the etiological diagnosis and management of ESUS patients.