Patent foramen ovale : Deep vein thrombosis may result in paradoxical embolism in patients with PFO. About 40% of patients with cryptogenic stroke have PFO compared with 25% of the general population. However, the actual embolic source can often not be identified.
Non-stenotic arterial plaques: Complicatedplaques with signs indicative of intra-plaque haemorrhage in an ipsilateralcarotid artery are detected in 1 in 4 of patients with cryptogenic stroke. Aortic arch atherosclerosis is believed to be a specific cause of ESUS, particularly with plaques >4 mm diameter.
ESUS is a diagnosis of exclusion based on radiological and cardiologicalexaminations. For exclusion of haemorrhagic or lacunar strokes CT or MRI imaging is needed. Both procedures also allow detection of embolic pattern of ischemic lesions. 12-lead ECG and cardiac monitoring for at least 24 h with automated rhythm detection are mandated to exclude atrial fibrillation; echocardiography is used to detect other major-risk cardioembolic sources. For imaging of both the extracranial and intracranial arteries supplying the area of brain ischaemia, examination methods like catheter, MR/CT angiography or cervical duplex plus transcranial Doppler ultrasonography are required. They allow an exclusion of large vessel stenosis.
Cryptogenic stroke vs ESUS
Cryptogenic stroke is also an ischemic stroke with more than one probable cause or strokes with incomplete diagnostic workup. ESUS has a clearer definition, with an established minimum diagnostic requirements; this is not required in defining a cryptogenic stroke. ESUS is an embolic stroke for which no probable cause can be identified after a standard diagnostic evaluation.
Management
Due to the lack of data, there are no specific treatment guidelines for ESUS. Current guidelines recommend antiplatelet therapy for patients with non-cardioembolic ischemic stroke. However, it is widely believed that there is a substantial overlap between ESUS and cardioembolic stroke so there may be a rationale for anticoagulation. This approach is currently tested in clinical trials.
Epidemiology
On average, ESUS accounts for about 1 in 6 ischemic strokes according to a systematic literature review of 9 studies. Patients with ESUS tend to be relatively young and experience mild strokes. However, ESUS is associated with high recurrence rates. Of 2045 ESUS patients
The stroke recurrence rate was 29.0% over 5 years in patients with ESUS, which is similar to patients with cardioembolic stroke, but significantly higher than all types of non-cardioembolic stroke. However, mortality was significantly lower in patients with ESUS than cardioembolic stroke.
