Cryptogenic Stroke with Isolated Cranial Nerve Deficits Attributable to a Small PFO: Successful Management with Cocoon Occluder

Abstract

Patent foramen ovale (PFO) is present in approximately 20–25% of the general population but is implicated in only a small subset of ischemic strokes, particularly in young adults with cryptogenic events. Stroke in individuals under 45 years accounts for only 10–15% of all ischemic strokes, and PFO-related presentations with isolated cranial nerve involvement are exceptionally rare. We report a 40-year-old male who presented with acute slurring of speech and deviation of the mouth to the left. Neurological examination revealed dysarthria and tongue deviation without motor weakness. A thorough work-up for young-onset stroke was performed: bilateral carotid and vertebral Doppler were normal, chest radiograph was normal, antinuclear antibody (ANA) and antiphospholipid antibody (APLA) profiles were negative, homocysteine was borderline elevated, and fundus examination showed no papilledema. CT venous angiography of the lower limbs ruled out deep venous thrombosis. Magnetic resonance imaging demonstrated acute non-hemorrhagic infarcts in the right inferior frontal gyrus and right post-central gyrus. Transthoracic echocardiography with bubble contrast revealed right-to-left shunting during Valsalva, and transesophageal echocardiography (TEE) confirmed a 4-mm PFO. Given the patient’s young age and isolated cranial nerve presentation, TEE-guided PFO closure was performed with a Cocoon 30/30 occluder device under fluoroscopic guidance, with no residual shunt post-procedure. The patient remained hemodynamically stable, developed no arrhythmia, and demonstrated marked improvement in speech function during follow-up. This case underscores the clinical relevance of small but hemodynamically significant PFOs in young patients with cryptogenic stroke and highlights the importance of systematic etiological evaluation and timely intervention.