BACKGROUND: Internal carotid artery fenestration is a rare vascular anomaly that may present with transient ischemic attack symptoms due to localized flow disturbances. It is important to report such cases, as they present unique diagnostic challenges and clinical implications, particularly when associated with systemic vascular risk factors such as diabetes and hypertension. Differentiating internal carotid artery fenestration from other conditions, such as internal carotid artery dissection, is crucial for appropriate management and patient outcomes. CASE PRESENTATION: A 78-year-old Iranian female patient with a medical history of uncontrolled diabetes mellitus and hypertension presented to the emergency department with sudden-onset double vision, dizziness, and weakness in her left limbs. Symptoms lasted for 15 minutes and fully resolved. Neurological examination revealed mild weakness in the left upper and lower limbs but no sensory deficits. A bruit was detected over the left carotid artery, raising suspicion for carotid artery disease. Blood tests showed elevated blood glucose, and imaging studies, including carotid Doppler ultrasound, revealed irregularities and increased intima-media thickness, suggesting early vascular changes. Brain computed tomography scan was normal, and computed tomographic angiography of the head and neck revealed an incidental finding of internal carotid artery fenestration at the cervical segment. The fenestration appeared as a mild fusiform dilation of internal carotid artery with no signs of dissection or thrombosis. The patient was started on dual antiplatelet therapy (aspirin and clopidogrel) and optimized for blood pressure and lipid control. She was discharged with no residual neurological deficits, and follow-up was arranged for continued management of her cardiovascular risk factors. CONCLUSION: This case highlights the diagnostic challenges and clinical relevance of internal carotid artery fenestration, particularly in patients with systemic vascular risk factors. Although internal carotid artery fenestration is often asymptomatic, it can be associated with cerebrovascular complications, such as ischemic events. In this case, the transient symptoms likely resulted from localized hemodynamic disturbances due to the fenestrated artery. While there is no established consensus on the management of asymptomatic internal carotid artery fenestration, dual antiplatelet therapy and risk factor optimization remain key strategies. Further research is needed to better understand the implications of internal carotid artery fenestration and to refine diagnostic and management protocols for these rare vascular anomalies.
Aalinezhad et al. (Mon,) studied this question.