Patent foramen ovale-associated stroke repeatedly misdiagnosed as cerebral small vessel disease: A case report.

Background: Transthoracic echocardiography (TTE) is the most commonly used screening method for cardiac structural abnormalities. However, it may lead to a missed diagnosis of partial patent foramen ovale (PFO)-associated stroke.

Case Presentation: A 60-year-old male was admitted to the hospital for recurrent left limb weakness with or without slurred speech for 14 months. No stroke-related cardiac structural abnormality was detected during repeated TTE, and the patient was diagnosed with cerebral small vessel disease. Finally, right-to-left shunt was detected by contrast-enhanced transcranial Doppler. Subsequently, the patient was diagnosed with PFO-associated stroke by transesophageal echocardiography and contrast transesophageal echocardiography.

Conclusions: TTE has a low detection rate of PFO, such that it is easily missed. Contrast-enhanced transcranial Doppler is easy to operate and should be promoted as a supplementary measure to stroke etiological investigation and primary PFO screening.