Dolichoectasia describes an artery that has become abnormally long, wide, and often twisted. This condition results from a deterioration of the vessel wall, causing it to distend and elongate. When this occurs in the basilar artery, located at the base of the brain, it is termed basilar artery dolichoectasia. The basilar artery is a singular blood vessel formed by the joining of the two vertebral arteries. It supplies oxygenated blood to the brainstem and cerebellum, structures that control many fundamental bodily functions.
Causes and Risk Factors
Basilar artery dolichoectasia (BDA) develops from acquired and, less commonly, congenital factors that weaken the arterial wall. Prolonged high blood pressure (hypertension) is a frequent acquired cause. Continuous stress on artery walls damages the collagen and elastin within the vessel’s structure, allowing it to stretch and become tortuous. Atherosclerosis, where plaque builds up inside arteries, also contributes to arterial wall weakening. High cholesterol levels can similarly damage the vessel wall, leading to dolichoectasia.
Genetic predispositions and connective tissue disorders increase susceptibility to BDA. Marfan syndrome and Ehlers-Danlos syndrome, for example, can lead to weaknesses in blood vessel walls. Autosomal dominant polycystic kidney disease is another genetic condition associated with an increased risk. Advanced age is a general risk factor, with the condition more common in individuals over 50. Males also exhibit a higher incidence of intracranial dolichoectasia compared to females.
Associated Symptoms and Complications
The enlarged and elongated basilar artery can cause symptoms primarily through two mechanisms: compression of nearby neurological structures or disruption of blood flow within the vessel. Compression can lead to symptoms such as vertigo, hearing loss, or tinnitus. Facial pain (trigeminal neuralgia) or involuntary facial muscle contractions (hemifacial spasm) can also occur. More extensive brainstem compression might manifest as difficulties with speech (dysarthria), involuntary eye movements (nystagmus), or swallowing problems (dysphagia).
Beyond direct compression, BDA can lead to serious vascular complications impacting brain blood supply. Ischemic stroke, a common risk, occurs when blood flow is blocked, often due to blood clots within the widened artery. Slow blood flow within the dilated vessel can facilitate clot formation, depriving brain tissue of oxygen. Less frequently, the weakened artery wall may rupture, leading to a hemorrhagic stroke, though this is less common than ischemic complications. Many individuals with basilar artery dolichoectasia remain without symptoms, often discovered incidentally during imaging for other reasons.
Diagnosis and Monitoring
Diagnosis of basilar artery dolichoectasia relies on neuroimaging techniques that provide detailed views of the brain’s blood vessels. Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA) are standard methods. These modalities allow visualization of the basilar artery’s size and its relationship with surrounding brain structures. Specific criteria for diagnosis include a basilar artery diameter exceeding 4.5 millimeters, a lateral deviation greater than 10 millimeters from its expected straight path, or a length exceeding 29.5 millimeters.
Computed Tomography (CT) and CT Angiography (CTA) can also detect and assess BDA. Once diagnosed, regular follow-up imaging is recommended. This monitoring helps track changes in the artery’s dimensions or its potential impact on adjacent brain tissue over time, allowing for intervention if progression occurs.
Medical Management and Treatment
Medical approaches for basilar artery dolichoectasia focus on reducing the risk of complications, particularly stroke, rather than reversing the artery’s abnormal shape. Management involves controlling risk factors that contribute to arterial wall weakening. Managing high blood pressure is a primary strategy, as it addresses a major contributor to the condition’s progression. Controlling cholesterol levels and diabetes also forms part of this risk factor control.
To mitigate ischemic stroke risk, antiplatelet drugs (e.g., aspirin) or anticoagulants (e.g., warfarin) may be prescribed to prevent blood clots within the dilated artery. Medication choice depends on the patient’s risk profile for clotting and bleeding. Surgical or endovascular interventions are high-risk for the basilar artery due to its delicate location and potential for severe complications. These invasive procedures are reserved for severe cases where symptoms are debilitating or life-threatening, and conservative medical management has proven insufficient.