Found a Brain Aneurysm by Accident? A Neurosurgeon Explains Your Next Steps

Many brain aneurysms are found by accident, on a scan done for an unrelated reason such as headaches or a minor injury. For patients, the news can be frightening. According to Stanislav Naydin, M.D., PharmBS, director of neurocritical care and endovascular neurosurgery at Neurosurgeons of New Jersey, it’s often better news than it sounds.

“The first thing I want people to know is to take a breath,” Naydin told The Educated Patient. “Finding an aneurysm this way is, in a real sense, good news.”

Without the scan, the aneurysm would have stayed a hidden risk, he explained. Once it’s found, doctors can measure it and build a care plan.

More common, and less dangerous, than most people think

About 3 in 100 adults have a brain aneurysm, and most never rupture or cause symptoms, Naydin said. On average, the yearly risk of rupture is about 1%, and it’s much lower for many small aneurysms.

He believes public perception is skewed because the only aneurysm stories most people hear are the dramatic ones. Ruptures are true emergencies, and they make the news, especially when a well-known person is affected. The far more common story, someone living with a small, stable aneurysm for decades, rarely gets told.

“An aneurysm is not a death sentence,” Naydin said.

Weighing the risk of waiting against the risk of treatment

Choosing between monitoring and treatment comes down to comparing two risks: the risk the aneurysm poses if left alone and the risk of treating it. Neither is zero, Naydin said.

To estimate an aneurysm’s natural risk, specialists rely on large, long-term studies such as the International Study of Unruptured Intracranial Aneurysms (ISUIA), along with tools like the PHASES score, which combines key factors into an individual estimate.

Those factors include:

• Size: Larger aneurysms generally carry more risk.
• Location: Aneurysms in certain arteries tend to behave more aggressively.
• Shape: An irregular aneurysm, or one with a small bulge called a bleb on its wall, raises more concern than a smooth, round one.
• Growth: Growth on follow-up scans is one of the strongest warning signals.
• Personal history: Age, blood pressure, smoking, prior brain bleeding and family history also shift the balance.

That’s why an aneurysm that sounds alarming on paper may only need watching. A small, smooth aneurysm in a lower-risk location, in a patient whose other risk factors are well controlled, may have a very low chance of ever causing a problem.

Naydin also considers how the patient feels. For some people, living with an untreated aneurysm causes ongoing anxiety that affects their quality of life, and that’s a legitimate factor in deciding whether treatment makes sense.

What monitoring involves

“Monitoring is an active plan, not simply ‘wait and see,’” Naydin said.

Follow-up imaging is usually noninvasive, such as an MRA or CTA. The first follow-up scan often comes around six months, and if the aneurysm stays stable, scans can be spaced further apart. Doctors watch mainly for growth or changes in shape.

When the first scan leaves questions open, Naydin may recommend a diagnostic cerebral angiogram. In this minimally invasive test, a thin catheter is threaded through an artery to image the brain’s blood vessels directly. It sometimes shows there’s no aneurysm at all, since a normal branch point in a vessel can look like a small aneurysm on routine imaging.

Between scans, patients can lower their risk by controlling blood pressure and not smoking. Naydin also makes sure every patient knows the warning signs. A sudden, severe headache unlike any they’ve had before needs emergency care right away.

Treatment without opening the skull

Many people still assume aneurysm treatment means open brain surgery. Today, many aneurysms can be treated endovascularly, from inside the blood vessels. Doctors guide a thin catheter from an artery in the wrist or groin up to the brain and seal off the aneurysm with devices such as coils or flow diverters. There’s no incision on the head, and many patients go home within a day or two.

Questions worth asking at the first appointment

Naydin hopes every patient will ask:

• Does my family history matter? A parent, sibling or child with a brain aneurysm or subarachnoid hemorrhage raises a patient’s risk and may mean other relatives should consider screening.
• Could I have an underlying condition that affects my blood vessels? Some inherited conditions, including certain connective tissue disorders, are linked to aneurysms.
• What is my actual risk, and what can I do to lower it? Quitting smoking is the single most powerful change a patient can make, Naydin said. Controlling blood pressure and eating a healthy diet also help.

Above all, he wants patients to leave understanding that an incidental aneurysm is a manageable condition with a clear plan.

“An incidental aneurysm is a reason for informed attention, not fear,” he said.

For more from Naydin, read Brain Aneurysm Found on MRI on the Neurosurgeons of New Jersey blog.