A brain aneurysm is a bulge in a blood vessel of the brain. It is created by a weakened spot in the vessel wall, which can enlarge over time, posing serious health risks. If left untreated, aneurysms can rupture, leading to a hemorrhagic stroke, brain damage and death.
“Statistically speaking about 6 percent of the population in the United States has an unruptured brain aneurysm or a bubble that has burps. That’s about 1 in 50 people”, said Dr. Ryan Dahlgren, medical director of Neuro Endovascular Surgery at Cleveland Clinic Indian River Hospital.
“The problem with these brain aneurysms isn’t so much that they’re there in the brain, but in the space around the brain – should the bubble ever explode and release blood into and around the brain. That’s really where a devastating event can occur.
“Most of the time, people don’t have symptoms and only find out about that bubble in their brain when the explosion occurs,” he continued. “Some people do get lucky. A small percentage of people get some warning-sign headaches. We interpret those headaches as the blood vessels stretching or the bubble stretching and those blood vessels are very, very sensitive. They’re telling you that this is about to blow up.
“People who come in with those type symptoms and we can catch it before it does blow up, are very lucky and we consider them huge saves. The problem is that so many things can cause headaches that it’s difficult to decipher. If the headaches are unusual in nature and can’t be attributed to anything, they should be assessed by a primary care physician and get some imagining done. Imaging these days is very sophisticated and can detect an aneurysm early on.”
Several factors can contribute to the development of a brain aneurysm. One of the primary causes is the weakening of blood vessel walls. Over time, high blood pressure or atherosclerosis (the buildup of fatty deposits) can erode the integrity of these walls, increasing the risk of an aneurysm.
Genetic factors also play a role, and individuals with a family history of brain aneurysms are at greater risk. According to Mayo Clinic, genetic predisposition and certain inherited disorders, such as polycystic kidney disease or connective tissue disorders, increase the likelihood of aneurysm formation.
Lifestyle factors are equally important. Smoking is a significant risk factor, as the chemicals in tobacco can damage blood vessels. Chronic high blood pressure or hypertension also places extra strain on the vessel walls, making them more likely to weaken and bulge. Age and gender are additional risk factors; women and individuals over 40 are more likely to develop aneurysms.
“There are things you can control and things you can’t control and then there’s a big percentage of just bad luck,” Dr. Dahlgren said. “Genetics is something you can’t control and if your family is prone to forming these aneurysms then you are more likely to get them too. For these people we recommend a screening with a CT scan or an MRI.
“Then there are environmental things that you can control like regulating your blood pressure to reduce the strain on the blood vessels and not smoking, which is known to cause damage to your blood vessels.
“If a bubble is detected in an MRI or CT scan, the next step would be to do a cerebral angiogram, which is a catheter-based imaging exam where we can look at the aneurysm, get extremely precise measurements of the aneurysm and see exactly how the blood is flowing into that aneurysm. The difference between the non-invasive imaging of the CT and MRI and cerebral angiogram is like comparing a 1980s TV to a 2024 super high-definition LCD TV where you can now see every blemish on a newscaster’s face, and they aren’t as pretty as they used to be.”
Treatment for brain aneurysms depends on their size, location and whether they have ruptured.
For unruptured aneurysms, treatment is aimed at preventing rupture in the future. In some cases, aneurysms are monitored through imaging scans like MRIs or CT scans and intervention is only recommended if the aneurysm grows.
One common treatment is surgical clipping. In this procedure, a surgeon places a metal clip at the base of the aneurysm to stop blood flow to the area, effectively preventing the aneurysm from growing or rupturing.
“The upside to surgical clipping is that it’s a definitive treatment,” said Dr. Dahlgren. “The downside is that it requires removing a portion of the skull, dissecting into the brain, and placing that clip.”
A less invasive approach is endovascular coiling which involves inserting a catheter through the arteries and placing soft platinum coils into the aneurysm to promote clotting and reduce the risk of rupture.
“With endovascular surgery, instead of clipping from the outside in, we treat that aneurysm by filling that bubble with a series of detachable coils that essentially forms a bird’s nest in that bubble and seals it off,” Dr. Dahlgren explained. “We have technology that holds those coils in place and reconstructs the blood vessel wall so that the aneurysm is excluded from the circulation. Over time the whole wall of the blood vessel is remodeled.
“Endovascular surgery doesn’t require any removal of the skull or manipulation of the brain. It’s all done through a small incision in the leg and moving the catheter through the arteries and into the vessels of the cerebrovascular vessels.”
Determining which procedure is best for the patient depends on the positioning of the aneurysm and the individual patient’s health and age.
“We look at the risks verses benefit,” Dr. Dahlgren explained. “If the aneurysm appears to have a low risk of rupturing and the patient has presented no symptoms, we may choose to just monitor it. If it’s in a position where it’s at high risk of rupturing, then we consider doing one of the procedures.
“Age is also a determining factor. A 50-year-old with decades of life ahead of them may choose to have a procedure to prolong their life, while a 90-year-old may choose to take their chances on it never rupturing and if it does accept is as their way to go.
“It’s always a difficult conversation to have with a patient. At Cleveland Clinic we have a multidisciplinary approach with highly skilled endovascular and open neurosurgeons on staff, so it’s always a joint discussion on which procedure is best for each individual.”
If an aneurysm does rupture, immediate emergency care is required, but the odds are not good, according to Dr. Dahlgren.
“If it ruptures, most people don’t survive the ambulance ride to the hospital,” he said. “And about two thirds of those who do survive suffer a permanent neurological deficit.”
Dr. Ryan Dahlgren received his medical degree and served an internship in Internal Medicine at the University of Oklahoma College of Medicine and did his residency at the University of Oklahoma Health Sciences Center. He completed a fellowship in Neuro Radiology at Jackson Memorial Hospital at the University of Miami School of Medicine and a fellowship in Neuro Endovascular Surgery at Cleveland Clinic. He is accepting new patients at Cleveland Clinic Indian River Hospital’s Medical Office Building, 1155 35th Lane in Vero Beach. You can call 772-563-4741 for an appointment.