Cryptogenic Stroke Diagnosis and Evaluation

Patient Characteristics and Risk Factors

Cryptogenic stroke accounts for approximately 25-40% of all ischemic strokes, representing a diagnosis of exclusion that should only be made after systematically ruling out all identifiable causes of stroke, as noted by the American Heart Association 1
Patients with cryptogenic stroke are less likely to have classic risk factors for atheroembolic stroke, such as hypertension, hyperlipidemia, and diabetes, according to the European Society of Cardiology 2
There is a higher likelihood of having a patent foramen ovale (PFO) in patients with cryptogenic stroke compared to the general population, as stated by the American College of Cardiology 2
Cryptogenic stroke is characterized by being a diagnosis of exclusion, presenting more frequently in young patients, and having a heterogeneous nature, possibly including multiple undetected mechanisms 3, 4

The following diagnostic tests are recommended for patients with suspected cryptogenic stroke:
To classify a stroke as cryptogenic, the following criteria must be met after a complete diagnostic evaluation: absence of large artery atherosclerosis, absence of major cardioembolic sources, absence of small vessel disease, and absence of other identifiable causes 7
ESUS is a subgroup of cryptogenic strokes, representing approximately 1 in 6 ischemic strokes, characterized by a non-lacunar infarct pattern, and presumed to be of embolic origin but without an identifiable source after standard evaluation 7

Complete obliteration of arteriovenous malformations (AVM) is recommended due to the high cumulative bleeding risk over a lifetime 5
The decision to close a PFO should be made jointly by the patient, cardiologist, and neurologist, considering the likelihood of a causal role of the PFO 6
Antiplatelet therapy remains the recommended treatment for most patients with cryptogenic stroke, but anticoagulation should be considered in patients with detected atrial fibrillation 7
In young patients (≤60 years) with patent foramen ovale, careful evaluation is necessary to determine if they may benefit from closure of the foramen ovale 7
Prolonged cardiac monitoring significantly increases the detection of atrial fibrillation in patients with cryptogenic stroke, with detection rates of up to 23.7% with sequential multifase monitoring 7