From the Research
Introduction to Internal Carotid Artery (ICA) Syndrome
The syndrome of the internal carotid artery (ICA) encompasses a range of clinical manifestations resulting from occlusion or significant stenosis of the ICA. This condition is characterized by its variability in presentation, which is influenced by several factors including collateral circulation, cerebral vasoreactivity, and the characteristics of the occlusion itself 1.
Clinical Manifestations
The clinical features of ICA occlusion can vary widely, ranging from asymptomatic cases to recurrent transient ischemic attacks (TIAs) or major strokes. The development of symptoms is influenced by preexisting risk factors, previous stroke, chronic hypoperfusion, and vascular risk factors 1. In some cases, patients may present with pulsatile tinnitus, ischemic stroke, migraine, Horner's syndrome, or subarachnoid hemorrhage, as seen in cases of ICA agenesis 2.
Diagnostic Considerations
Diagnosis of ICA syndrome involves imaging studies such as computed tomography (CT), magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) to assess the degree of occlusion and the presence of collateral circulation. The absence of the bony carotid canal on CT can indicate ICA agenesis 2.
Treatment Options
Treatment of ICA syndrome depends on the underlying cause and the patient's clinical presentation. Medical management includes antithrombotic and anticoagulant agents, as well as control of vascular risk factors 1, 3. Surgical options may include carotid endarterectomy, especially in cases of significant stenosis or occlusion 4, 5. In some cases, endovascular repair may be considered, particularly for patients with carotid stump syndrome 3. Ipsilateral external carotid endarterectomy has also been reported as a successful treatment for chronic complete occlusion of the ICA 5.
Surgical Interventions
Surgical interventions aim to restore blood flow to the affected area or to prevent further ischemic events. Carotid endarterectomy with end-to-end anastomosis may be performed, and in some cases, resection of the styloid process may be necessary, as in the treatment of Eagle syndrome 4.
Medical Management
Medical management focuses on reducing the risk of further ischemic events through the use of statins and dual anti-platelet therapy. This approach is particularly important in the management of carotid stump syndrome 3.
Differential Diagnoses and Caveats
Differential diagnoses for ICA syndrome include other causes of cerebrovascular disease, such as atherosclerosis, vasculitis, and moyamoya disease. It is essential to consider these alternatives when evaluating patients with suspected ICA syndrome. Additionally, the presence of associated anomalies, such as cerebral aneurysms, should be investigated, as these may represent a potential life-threatening condition 2.