Vascular lesions are rare problems that affect the blood vessels in the brains and spinal cords of newborns, infants and growing children. While some vascular lesions can be frightening and potentially life-threatening, many of these conditions can be successfully treated.
Some of the more common of these rare conditions include aneurysms, arteriovenous malformations (AVM), angiomas and moyamoya disease. While these vascular lesions are all different, they have some similarities since they each involve the blood supply to the brain. In most instances, the symptoms do not appear gradually but rather abruptly. Some signs of problems are headaches, seizures … and occasionally even coma. In those lesions where the symptoms are gradual, parents often notice a slow change in a child’s function over weeks to months.
The following is an overview of the different vascular lesions in children:
- Aneurysms – Aneurysms are rare pediatric lesions that can affect blood vessels throughout the body. In the young brain, these bubble-like protrusions of an artery tend to occur where a major artery branches into smaller arteries in the deep crevices between the various lobes of the brain. Most aneurysms are discovered when they rupture, usually causing an intense headache. Ruptured aneurysms are also associated with vomiting, a stiff neck, and light bothering the eye. Other neurologic symptoms include weakness, eye movement problems, stupor, seizures and even coma and death.
- Arteriovenous malformations (AVMs) -- AVMs are composed of arteries that communicate directly with veins rather than feeding into progressively smaller blood vessels that would then supply the brain with nutrients. This results in veins that contain blood under abnormally high pressure. The veins may rupture, leading to bleeding within the brain. Additionally, because the blood that should be supplying the brain with nutrients cannot function properly, some parts of the brain near an AVM may not receive appropriate amounts of blood flow. Symptoms of AVMs include bleeding in the brain, seizures, headache and neurological problems involving speech, vision, strength, coordination or sensation.
- Angiomas – The most common neurovascular lesions in children are cavernous angiomas of the brain. These lesions, which are much less dangerous than AVMs, are small tangles of blood vessels that do not have any intervening brain substance. These lesions rarely cause life-threatening bleeding in the brain, but they tend to be located in more critical areas where their complete removal may be associated with high risk. Since the lesions are not under high pressure, when they bleed, it is more of a leak than a rupture. This leaking of blood can irritate the brain around it and cause seizures.
- Moyamoya disease – First described in children of Japanese descent, this condition involves the carotid arteries, which are two of the large “feeding vessels” to the brain. They may occur in families and may be multiple in nature. With moyamoya disease, the carotid arteries undergo an unexplained but spontaneous narrowing, resulting in a stroke or evidence of insufficient blood flow to the brain. The brain responds by developing many small collateral vessels, which on X-ray images can appear to resemble a “puff of smoke,” and thus the Japanese name, moyamoya. Moyamoya has been found in the United States, Europe, Australia and Africa, primarily affecting children, adolescents and young adults. Females are more frequently affected than males. Untreated patients develop headaches, spontaneous bleeds and strokes with progressive neurologic decline unless surgically revascularized, with the blood supply being reinstated.
Diagnosis of Vascular Lesions
The accurate diagnosis of vascular lesions is crucial in tailoring an optimal treatment plan. Once a vascular event is suspected, an emergency evaluation is required to provide the child with the best chance of a successful outcome.
A diagnosis may be confirmed by a series of tests, which may include:
- A CT scan and MRI/MRA (magnetic resonance angiogram) of the head, which help doctors look for blood or a stroke in the brain.
- Angiogram or arteriogram, which provide images of the brain’s blood vessels
Treatment of Vascular Lesions
There are three treatment options for children with vascular lesions. They include:
- Endovascular embolization -- This procedure, which is performed by an interventional radiologist, involves treating the problem by injecting different materials in the blood vessels to help stop the source of bleeding. This may be a permanent cure, or it may make it easier for the surgeon to then treat the problem by decreasing the risks of bleeding or stroke during surgery.
- Surgery – Microsurgery may be appropriate for lesions that cause symptoms and are accessible. For instance, removal of a cavernous angioma through surgery eliminates the risk of bleeding. And surgery is the treatment of choice with this condition since cavernous angiomas are not visible on an angiogram and consequently, endovascular embolization is not possible. In this approach, the surgeon treats the vascular lesion by removing it surgically.
- Focused X-rays -- Some vascular lesions can be treated using a type of focused X-rays such as the gamma knife or a LINAC. These X-ray treatments use radiation to selectively occlude the lesion, but unlike surgery, the treatments may require upwards of two years to take maximum effect.