Treatment of Cavernous Malformation
What Are Cavernous Malformations?
An abnormality in the blood vessels of the brain is known as a vascular malformation. One type is called a cavernous malformation (also known as a cavernoma or cavernous angioma), identifiable by an unusual cluster of blood vessels that resembles a raspberry. The walls of these blood vessels are abnormally porous, making them prone to bleed periodically.
Cavernous malformations are relatively uncommon, with a prevalence of 0.3% to 0.5% in the general population (approximately 1 in 200 to 250 people have this condition). Cavernous malformations can be sporadic or familial/hereditary. Those with sporadic cavernous malformations usually have a solitary lesion, while those with familial cavernous malformations generally have multiple lesions throughout their central nervous system.
Treatment Guidelines for Cavernous Malformations
Cavernous malformations will not shrink or go away on their own. Treatment options are different for every person and depend on several factors, such as the size, location, symptoms, and bleeding status of the cavernous malformation, as well as your overall health. The various options available are observation, medical management, and/or surgery.
Each of these treatment methods has its own pros and cons, and each has a specific situation in which it is preferred. Your neurosurgeon will walk you through these choices and explain the risks and benefits of each option so that you can make an informed decision. The experience of the neurosurgeon is important regarding the surgical outcome.
Watchful waiting is a treatment strategy for those who have few or no symptoms and is especially useful for a cavernous malformation that has not bled or is in a deeper part of the brain that is difficult to reach safely surgically. It is also a reasonable strategy for those who are not healthy enough for surgery. By using observation only, potential complications associated with surgery and medications can be avoided; taking additional time off from work for recovery is also unnecessary.
However, the risk of the cavernous malformation bleeding persists at a rate of 1% per year. A key part of watchful waiting is undergoing regular magnetic resonance imaging (MRI) scans. These scans are done to assess the size and bleeding of the cavernous malformation. You will likely be asked to have an MRI scan once per year for the first couple of years. If you start to develop symptoms (seizures), you might be advised to begin taking a medication or to undergo surgery if medications are not controlling the seizures.
The most common medications prescribed for cavernous malformations are antiepileptic drugs (AEDs). These medications prevent seizures by changing chemicals in the brain. There are many types, and each has its own way of working and different benefits and risks.
- Levetiracetam—works by sticking to a protein in the brain called SV2A. It can stop many types of seizures, but it can also make you feel fatigued or irritable or cause behavioral changes.
- Carbamazepine—helps stabilize the electrical activity in the brain and stop seizures by blocking channels of sodium. It works for many types of seizures but can cause dizziness, sleepiness, or nausea.
- Valproic acid—stops seizures by increasing the level of a chemical called gamma-aminobutyric acid (GABA) in the brain. It helps calm overactive neurons and prevent seizures and works for a wide range of seizures, but it can also make you gain weight or lose hair and can cause liver damage. Women who are pregnant should not use this medicine.
- Phenytoin—stops seizures by blocking sodium channels in the brain. It works like carbamazepine but blocks different types of channels. It is effective at treating many types of seizures, but it can also cause gum overgrowth, tremors, rashes, or liver damage. It is not safe for pregnant women.
- Lamotrigine—stops seizures by blocking sodium and calcium channels in the brain. It works well for many types of seizures, but it can also cause dizziness, nausea, or headaches.
It is essential to work closely with your doctor/neurologist and follow his or her instructions carefully to get the most benefit from the medication while minimizing any potential side effects.
Note that these medications cannot cure a cavernous malformation; they only prevent seizures from occurring. Medical management is especially useful for a cavernous malformation that is seated deep within the brain, making it very difficult to remove surgically. Medical management is also useful for those with a cavernous malformation that has not bled or bled just once and is not causing any other symptoms.
If you develop drug-resistant seizures, you might need to increase the number of AEDs that you take. Drug-resistant seizures can also be a reason to move forward and undergo surgery to remove the cavernous malformation (the cause of the seizures).
Pain relief may be needed for patients with a cavernous malformation, and the choice of painkiller will depend on the severity and type of pain experienced. Commonly used painkillers for people with cavernous malformations include the following:
- Nonsteroidal anti-inflammatory drugs (NSAIDs)—can help relieve mild to moderate pain and reduce inflammation (examples are ibuprofen and naproxen).
- Acetaminophen—another option for pain relief, particularly for those who cannot take NSAIDs (an example is Tylenol).
- Opioids—prescribed for severe pain but should be used with caution because of the risk of addiction and other side effects.
- AEDs—medications that are sometimes also used to relieve nerve pain caused by a cavernous malformation (examples are gabapentin and pregabalin).
Be sure to talk to your doctor before taking any painkillers, because they might have side effects and can interact with other medications that are prescribed for your treatment.
Surgery for a cavernous malformation is usually advised when it is located in an easily accessible part of the brain and is causing significant symptoms such as medically non-responsive seizures or neurological problems.
The surgery is done under general anesthesia; you will be asleep during surgery and won’t feel a thing. You will be attached to a ventilator to help you breathe during the operation. You will be constantly monitored throughout the surgery by your anesthesiologist to ensure that you are safe.
An incision in the scalp is made, and a part of the skull is opened (craniotomy) so that the neurosurgeon can access the cavernous malformation. The lesion is then carefully removed with specialized instruments; normal brain tissue and normal blood vessels are protected as much as possible. After the cavernous malformation is removed, the skull bone is put back in place, and stitches are used to close the incision.
You will be asked to stay in the hospital for a few days after surgery so that you can be monitored in the event of any complications. The entire recovery process will take around 6 weeks. After surgery, more than 80% of patients say that they feel better and experience a reduction in symptoms and often complete freedom from seizures. In general, the sooner you undergo surgery after seizures start happening, the better the outcome.
However, certain risks are involved with surgery. Along with the risk of bleeding, infection, and a leak of cerebrospinal fluid from the operative site, around 5% of patients develop new neurological problems such as weakness of a limb(s) or difficulty speaking. The risk of death after surgery to remove a cavernous malformation is approximately 1% to 2%.
Discuss the risks and benefits of surgery with your neurosurgeon. Choosing a neurosurgeon who is experienced in handling a surgery as technically difficult as cavernous malformation removal is very important.
Stereotactic radiosurgery (SRS) is a technique used to direct radiation beams to a desired part of the brain with high levels of accuracy and precision. SRS is a noninvasive method of treatment, so you will not have any incisions or be left with visible scars. It is important to note that this mode of therapy is rarely used for cavernous malformations.
Different SRS systems such as Gamma Knife, Linear Accelerator–based systems (such as CyberKnife), and proton beam therapy are commonly used for treatment, and each has differences in accuracy, precision, availability, and cost. Consult with your neurosurgeon to determine the best system for your treatment.
SRS treatment usually requires only one session, and you should be able to return home on the same day. The process begins by attaching a frame over your head. Some systems require you to wear a custom-made mask. An MRI scan is then done to determine the exact location of the cavernous malformation and the precise location to be targeted. Then, you will be asked to lie down in a radiotherapy bunker while the machine targets the cavernous malformation with precise beams of radiation; this process takes about 1 hour. Once the SRS is done, the head frame is removed, and you will be sent home if no issues arise.
Temporary side effects, such as pain where the head frame was attached and headaches, are expected. A serious possible side effect after SRS treatment is bleeding from the cavernous malformation.
SRS treatment is a noninvasive and relatively quick option and is particularly suitable for people who are not able to undergo general anesthesia. It is also useful for cavernous malformations that are deep within the brain (such as the brainstem). However, the long-term relief from symptoms may not be as effective as with conventional surgery, and the cavernous malformation might take longer to shrink. SRS systems are available only in specialized centers, and the cost of this sophisticated treatment modality should be considered.
Being diagnosed with a cavernous malformation can be overwhelming. Various treatment options are available, each of which has its advantages and disadvantages. Be sure to discuss personalized treatment strategies with your neurosurgeon.
- Cavernous malformations can be observed, treated with medication, or removed surgically.
- Observation includes having regular MRI scans to check the size of and bleeding from the cavernous malformation.
- Medical management usually includes AEDs, which prevent seizures.
- Surgery is usually advised for those with a cavernous malformation that is easily accessible and is causing significant symptoms.