Cerebral vessels

The prevalence of undiagnosed cerebral aneurysms in the general population is 2 %. Aneurysms are often discovered as incidental findings during a magnetic resonance imaging (MRI) scan of the head that was performed for other reasons—usually to investigate headaches or dizziness.

Whether an incidentally discovered aneurysm should be treated is always a case-by-case decision. This involves weighing the risk of rupture against the risks of treatment. The most important factors are the size, location, and shape of the aneurysm, a family history of the condition, and modifiable risk factors such as smoking or hypertension.

The risk of complications from treating unruptured aneurysms is approximately 1.5% at large centers specializing in aneurysm treatment—for both surgery and endovascular therapy.

The decision to proceed with treatment or to opt for active surveillance should be discussed and made during a personal consultation with a specialist at an aneurysm center.

The question of the hereditary nature of aneurysms is often raised. Fortunately, only a small proportion of patients have a genetic predisposition and therefore a family history of aneurysms. If there is no familial cluster, regular screening of relatives of a patient with an aneurysmal subarachnoid hemorrhage is not necessary.

The most common and, at the same time, most serious complication of an aneurysm is rupture, which leads to a subarachnoid hemorrhage. In this condition, blood at arterial pressure leaks into the space between the brain and the base of the skull. The typical sign of an aneurysm rupture is a sudden, excruciating headache of an intensity that the affected person has never experienced before.

Following a rupture, the aneurysm should be treated within one to two days using endovascular aneurysm occlusion (coiling) or microsurgical clipping. The optimal treatment of aneurysms is one of the major research focuses at Inselspital.

Arteriovenous malformations (AVMs) are abnormalities of the blood vessels and consist of a network of shunts between cerebral arteries and veins. AVMs can vary greatly depending on their size, blood flow pattern, and location in the brain, and can cause a wide range of symptoms. The most common symptoms include headaches, epileptic seizures, and intracerebral hemorrhages. Whether and how an AVM should be treated always involves a balancing of the risk of rupture against the risks of treatment. AVMs are a key area of focus at Inselspital, both scientifically and clinically.

Cavernomas, also known as cavernous malformations, are vascular malformations consisting of small, irregular vascular chambers surrounded by brain or spinal cord tissue. They contain no brain tissue and no major arteries or veins inside. The risk of hemorrhage is relatively low—except for cavernomas in the brainstem. Nevertheless, a cavernoma can cause epilepsy, headaches, or neurological deficits. However, most of these vascular clusters do not cause any symptoms and are discovered incidentally during imaging (MRI). Whether and how a cavernoma should be treated must be decided on an individual basis for each patient.

A hemangioblastoma, or angioblastoma for short, is a rare, benign (WHO Grade I), and highly vascular tumor that often contains cystic components in addition to a solid mass. Hemangioblastomas are most commonly located in the cerebellum, brainstem, or spinal cord. Hemangioblastomas frequently occur in association with von Hippel-Lindau syndrome (VHL), but can also arise sporadically. Microsurgical removal of a hemangioblastoma is the treatment of choice. The difficulty of the surgery varies depending on the size, location, and extent of the tumor cyst.

Dural arteriovenous malformations, also known as dural fistulas, are acquired abnormal connections between arterial vessels and venous blood vessels in the brain. Too much blood flows through these connections, which can cause ringing in the ears in milder cases. In severe cases, blood backing up into the brain can cause cerebral hemorrhages, epileptic seizures, or brain swelling with tissue necrosis.

Carotid stenosis refers to the narrowing of the carotid artery caused by atherosclerosis. Carotid stenosis is common and is one of the leading causes of a stroke.

The goal of treatment is to prevent further strokes and the associated neurological deficits. There are two treatment options available: surgical removal of the atherosclerotic plaque or endovascular therapy. The decision on which treatment is appropriate is made on an interdisciplinary basis by the neurovascular board and tailored to each individual patient. Treatment requires an experienced team of neurosurgeons, neurologists, and neuroradiologists.

A cerebral circulatory disorder occurs when the brain is no longer supplied with sufficient blood. A stroke is an acute cerebral circulatory disorder. The causes of such circulatory disorders are varied.

Treatment typically involves managing risk factors or endovascular therapy. For circulatory disorders that originate within the skull and cannot be treated endovascularly, bypass surgery may be considered.

Moyamoya disease is a rare condition affecting the brain’s blood vessels, characterized by a slowly progressive narrowing of the intracranial carotid artery and its main branches. Patients with this condition are at significant risk of stroke, as blood flow to the brain is typically insufficient or may lead to intracerebral hemorrhage.

Neurosurgical treatment is the only effective therapy for reducing the risk of recurrent strokes and the associated neurological deficits. The success of the treatment depends crucially on an experienced team of neurosurgeons, neuroanesthesiologists, neurointensivists, and neurologists.