Recurrent Transient Ischemic Attacks and Migraine Headaches: What Is the Etiology?

Abstract

INTRODUCTION: Many harbor the diagnosis of asymptomatic patent foramen ovale(PFO). The annual incidence is close to 27%(1). Clinical syndromes including paradoxical embolism, gas embolism in decompression sickness, platypnea-orthodeoxia syndrome, and recurrent migraine headaches can result. We report a case of PFO with recurrent transient ischemic attacks and migraine headaches. CASE PRESENTATION: A 68 year old male with emphysema, CAD, multiple TIAs, and chronic migraines presented with confusion and expressive aphasia suspicious for CVA. He was intubated for airway protection. After intubation, he developed hypoxemia with use of high positive airway pressures. He had no prior cardiopulmonary symptoms. His history includes smoking and alcoholism. Vitals were T 36.6C, BP 106/61, HR 76, RR 30, and SpO2 89% at 100% FiO2. He had decreased breath sounds at lung bases. Heart sounds were distant without murmur, S3 or S4. No jugular venous distension or peripheral edema was present. Laboratory values were WBC of 13.2, normal troponin, BNP 345. Arterial blood gas showed pH 7.48, PaO2 54 mmHg, PaCO2 36 mmHg, HCO3 of 35. ECG was normal. Imaging showed bibasilar opacities, small pleural effusions, emphysema, and no pulmonary embolism. Evaluation by transthoracic echocardiogram(TTE) with bubble study showed an EF of 55% without systolic dysfunction. There was right-to-left intracardiac shunt. Transesophageal echocardiogram (TEE) confirmed the diagnosis of PFO with passage of contrast from the right to left atrium. Right heart catheterization showed pulmonary hypertension with AVO2 difference elevated at 5.28 vol%. Neurologic work up was negative for CVA. In addition to reducing PEEP on the ventilator, he received systemic corticosteroids for underlying chronic lung disease and vancomycin for suspected pneumonia. He received anticoagulation, antiplatelet therapy, and IV fluids were filtered to prevent air embolism. No surgical intervention was considered. He was successfully extubated. DISCUSSION: The diagnosis of PFO is common in adults, but it can remain asymptomatic for many years. Stroke, TIA, recurrent migraines, and vascular headaches are linked with PFO. It is hyothesized that vasoactive substances that trigger migraines are inactivated in the lungs. Via a PFO with right-to-left shunt the lungs are bypassed and vasoactive substances like emboli can enter the cranial circulation(2). Recurrent headaches are the result. TTE, TEE, and transcranial doppler with saline contrast are diagnostic. Antiplatelet agents and anticoagulation are recommended therapy. Closure can be considered in certain situations. CONCLUSIONS: We demonstrated a case of PFO with recurrent TIAs and chronic migraines. This patient developed hypoxemia with increased airway pressures. We feel these phenomena are consistent with right-to-left shunt associated with our patient's PFO.