Embolic stroke of undetermined source

Embolic stroke of undetermined source (ESUS) is an

• Stroke detected by
  CT or MRI that is not lacunar
• No major-risk cardioembolic source of embolism
• Absence of extracranial or intracranial
  ischaemia
• No other specific cause of stroke identified (e.g.,
  drug misuse
  )

Signs and symptoms

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Causes

The following factors are suggested as pathogenesis of ESUS:^[4]

• Subclinical atrial fibrillation: Detectable in ~2.7-30% of ESUS patients, depending on duration and modality of ECG monitoring
  .
• Patent foramen ovale (PFO): 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
  ipsilateral carotid artery are detected in 1 in 4 of patients with cryptogenic stroke.^[5][6] Aortic arch atherosclerosis is believed to be a specific cause of ESUS, particularly with plaques >4 mm diameter.^[4][7]
• Further
  cardiac ultrasound
  .
• Other causes:
  Arterial dissections, infection-related vasculopathies (esp. Varicella zoster virus), thrombophilia, cancer-related thrombosis, migraine, Fabry disease and other genetic, autoimmune or rheumatic
  causes.

ESUS is a diagnosis of exclusion based on radiological and cardiological examinations. 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 (TTE and/or TEE) is used to detect other major-risk cardioembolic sources (e.g., intracardiac thrombi, or ejection fraction <30%). 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 (≥ 50%).^[2]

Cryptogenic stroke vs ESUS

Cryptogenic stroke is also an ischemic stroke with more than one probable cause or strokes with incomplete diagnostic workup.^[3] 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.^{[citation needed]}

Management

Due to the lack of data, there are no specific

On average, ESUS accounts for about 1 in 6 ischemic strokes (17% (range 9 – 25%)) according to a systematic literature review of 9 studies.[13] Patients with ESUS tend to be relatively young and experience mild strokes. However, ESUS is associated with high recurrence rates. Of 2045 ESUS patients (identified by 8 studies)

• 58% were male,
• the mean age was 65 years,
• the average annualized rate of stroke recurrence was 4.5%
• mean
  NIHSS
  at stroke onset was 5.

The stroke recurrence rate was 29.0% over 5 years in patients with ESUS, which is similar to patients with cardioembolic stroke (26.8%), but significantly higher than all types of non-cardioembolic stroke. However, mortality was significantly lower in patients with ESUS than cardioembolic stroke.^[14][15]

References