Division of Neurointerventional Radiology

What is it?

An acute ischemic stroke occurs when a blood clot blocks an artery supplying blood to the brain. When the "pipe" is blocked, the brain cells beyond that point are starved of oxygen and nutrients. Without immediate help, these brain cells can begin to die within minutes. 

How did I get it?

Most ischemic strokes are caused by one of two things: a blood clot that forms inside a narrowed brain artery (thrombosis), or a clot that forms elsewhere in the body—often the heart—and travels up to the brain (embolism). Common risk factors include high blood pressure, high cholesterol, smoking, diabetes, or heart conditions like atrial fibrillation (AFib).

How is it diagnosed?

Diagnosis happens very quickly in the emergency room. Doctors use rapid imaging, such as a CT scan or MRI, to look at the brain and its blood vessels. These scans help the team confirm if there is a blockage and exactly where it is located.

Does it need to be treated?

Yes. This is a medical emergency. “Time is brain,” meaning every minute the artery stays blocked, more brain cells are lost. Immediate treatment is the best way to prevent permanent disability, such as paralysis or loss of speech, and to save the patient's life.

How can it be treated?

There are two primary ways our team clears the blockage: 

• Clot-Busting Medication (tPA/TNK): A powerful "liquid" medication given through an IV to dissolve the clot.
• Mechanical Thrombectomy: This is where our Neurointerventional team springs into action. We thread a tiny catheter through your blood vessels directly to the site of the clot in the brain. Using a specialized retriever or suction device, we physically "grab" and remove the clot to instantly restore blood flow.

What is it?

In order to prevent stroke we can treat one of the most common causes: arterial narrowing or stenosis, the most common of which afflicts the carotid arteries.

Carotid artery stenosis (also called carotid artery disease) is a narrowing of the two large arteries on either side of your neck. These vital vessels carry oxygen-rich blood from your heart to your brain. The narrowing is typically caused by a buildup of plaque—a sticky substance made of fat, cholesterol, and calcium—on the inner walls of the artery.

How did I get it?

Plaque buildup, or atherosclerosis, develops slowly over many years. While it is a natural part of aging, certain factors can speed up the process.

Common risk factors include:

• High blood pressure and high cholesterol
• Smoking or tobacco use
• Diabetes
• A family history of heart disease or stroke

How is it diagnosed?

Since this condition often has no symptoms in its early stages, it is frequently discovered during a routine checkup if a doctor hears a "whooshing" sound (called a bruit) through a stethoscope. To confirm the diagnosis and measure the narrowing, we use advanced imaging such as:

• Carotid Ultrasound: Using sound waves to visualize blood flow and plaque
• CT Angiography (CTA) or MRA: Detailed 3D scans that provide a clear “map” of the neck arteries

Does it need to be treated?

Yes, if the narrowing is significant. Carotid stenosis is a major cause of stroke. A stroke can happen if the artery becomes completely blocked or if a small piece of plaque breaks off and travels into the brain. Treatment is recommended to "clean" or "open" the artery to prevent a future stroke, especially if you have already experienced “warning signs” like a TIA (mini-stroke).

How can it be treated?

At Lahey, our team offers several ways to restore healthy blood flow:

• Medical Management: For mild cases, we use medications like aspirin or statins, along with lifestyle changes (quitting smoking, healthy diet), to prevent the plaque from growing.
• Carotid Artery Stenting: This is our core neurointerventional specialty. It is a minimally invasive procedure where we thread a catheter to the neck and place a small mesh tube (a stent) to hold the artery open. We use specialized "filters" during the procedure to catch any debris and protect the brain.
• Carotid Endarterectomy (CEA): A traditional surgical procedure where a vascular surgeon makes an incision in the neck to physically remove the plaque.
• TCAR (TransCarotid Artery Revascularization): A "hybrid" approach that combines surgery and stenting for certain patients.

What is it?

A brain aneurysm (also called a cerebral or intracranial aneurysm) is a weak or thin spot on a blood vessel in the brain that balloons out and fills with blood. While many aneurysms go unnoticed, the danger is that they can leak or rupture, causing life-threatening bleeding into the space around the brain (a subarachnoid hemorrhage).

How did I get it?

Aneurysms usually develop over time rather than being present at birth. They often form at “forks” in the arteries where the blood flow is strongest. Risk factors that can weaken artery walls include: 

• Smoking and high blood pressure
• Family history (genetics)
• Age (most common in adults over 40)
• Certain medical conditions like polycystic kidney disease

How is it diagnosed?

Many aneurysms are found incidentally when a patient is getting a scan for an unrelated reason, like a headache or an injury. At Lahey, we use high-resolution imaging to find and measure them: such MRA or CTA Scans: which provide non-invasive 3D pictures of the blood vessels.

Does it need to be treated?

Not every aneurysm requires immediate management. If an aneurysm is very small and hasn't ruptured, we may simply “watch and wait” with regular imaging. However, if the aneurysm is large, growing, or has a shape that suggests a high risk of bursting, treatment is necessary to prevent a devastating stroke. If an aneurysm has already ruptured, it is a medical emergency that requires instant treatment.

How can it be treated?

Our team specializes in the most advanced, minimally invasive endovascular treatments:

• Coiling: We thread a catheter to the aneurysm and pack it with tiny, soft platinum wires (coils). these stop the blood from entering the bulge, causing it to safely clot off. 
• Flow Diversion (Stenting): We place a high-tech mesh tube (stent) across the opening of the aneurysm. This reroutes the blood flow past the weak spot, allowing the aneurysm to shrink and heal over time. 
• Surgical Clipping: A traditional neurosurgical approach where a small metal clip is placed at the “neck” of the aneurysm to pinch it shut.

What is it?

An Arteriovenous Malformation (AVM) is a tangle of abnormal blood vessels that connects arteries and veins in the brain or spine. Normally, arteries carry oxygen-rich blood to the brain through tiny capillaries, which then transition into veins to carry blood back to the heart. In an AVM, the blood bypasses the capillaries and flows directly from arteries to veins at high pressure. This can cause the vessels to rupture or “steal” blood away from healthy brain tissue.

How did I get it?

There is no single cause of an AVM. They cannot spread, and there is nothing you can do or change that will prevent one from occurring. There are some genetic causes. Some rare types of AVMs run in families. These are associated with a condition called Hereditary Haemorrhagic Telangiectasia, or Osler-Weber-Rendu Syndrome.

How is it diagnosed?

AVMs are often discovered after a person experiences a seizure, a sudden severe headache, or symptoms similar to a stroke. To see the tangle clearly, we use noninvasive imaging followed by a cerebral angiogram which is the most important test for planning treatment. Our specialists thread a catheter to the brain to map exactly how the blood enters and leaves the AVM.

Does it need to be treated?

The main goal of treatment is to prevent a brain hemorrhage (bleeding). Because AVMs involve high-pressure blood flowing through weak vessels, they have a risk of rupturing over time. If an AVM is in a very deep or “eloquent” part of the brain (responsible for speech or movement), our team carefully weighs the risks of treatment versus the risk of leaving it alone. If it has already bled, it almost always requires treatment to prevent a second, more dangerous bleed.

How can it be treated?

Because AVMs are complex, the Lahey team often uses a multimodal approach (more than one type of treatment):

• Endovascular Embolization: Our neurointerventional team threads a tiny catheter into the AVM and injects a medical “glue” or liquid buffering agent (like Onyx) to plug the abnormal vessels and reduce blood flow. 
• Surgical Resection: A neurosurgeon performs a traditional operation to carefully remove the AVM from the surrounding brain tissue. 
• Stereotactic Radiosurgery (LINAC): A non-invasive treatment that uses focused radiation beams to cause the AVM vessels to slowly wither and close up over 1–3 years.

To learn more, you can watch videos on spinal AVMs and brain AVMs.

What is it?

A dural arteriovenous fistula (dAVF) is an abnormal connection between an artery and a vein in the tough, protective covering of the brain or spinal cord (the dura mater). Normally, high-pressure blood from arteries passes through tiny capillaries before entering low-pressure veins. In a dAVF, the artery connects directly to the vein. This creates a high-pressure "short circuit" that can cause the veins to swell, leak, or back up, potentially leading to brain or spinal cord injury.

How did I get it?

dAVFs are usually acquired later in life. They often develop after a blood clot forms in one of the brain’s large drainage veins (venous sinus thrombosis). The body tries to bypass the blockage by growing new, abnormal vessel connections. Other triggers can include head trauma, previous brain surgery, or chronic ear infections, though sometimes the cause remains unknown.

How is it diagnosed?

The symptoms of a dAVF can be unique. Patients often hear a rhythmic "whooshing" or "pulsing" sound in one ear that matches their heartbeat (called pulsatile tinnitus). Others may experience vision changes or headaches. To diagnose it, we use MR and CT as well as a diagnostic angiogram which is the most critical test. Our specialists thread a catheter to the site to precisely map the "fistula" (the connection point) and determine how the blood is draining.

Does it need to be treated?

It depends on the "drainage pattern." If the blood is draining into the large veins of the skull, it may be low-risk and only require monitoring. However, if the blood is backing up into the smaller, fragile veins on the surface of the brain (cortical venous reflux), the risk of brain hemorrhage or stroke is much higher. In these cases, treatment is necessary to prevent permanent damage.

How can it be treated? 

Our team specializes in closing these abnormal connections from the inside: 

• Endovascular Embolization: This is the primary treatment at Lahey. We thread a microcatheter through the blood vessels to the exact spot where the artery and vein meet. We then inject a medical "glue" or liquid polymer (like Onyx) or use tiny platinum coils to plug the connection and stop the high-pressure flow. 
• Surgical Disconnection: If the fistula is in a location that is difficult to reach with a catheter, a neurosurgeon may perform a small procedure to physically "clip" or tie off the abnormal connection. 
• Stereotactic Radiosurgery: In rare cases, focused radiation is used to gradually close the fistula over several months. 

To learn more, watch a video on dural arteriovenous fistulas.

What is it?

Intracranial hypotension is a condition where the pressure of the fluid surrounding your brain and spinal cord—called Cerebrospinal Fluid (CSF)—is too low. Usually, this happens because of a "leak" in the tough outer membrane (the dura) of the spine. A specific, newly discovered type of leak is the CSF-Venous Fistula, where the fluid doesn't just leak into the body; it drains directly and abnormally into a nearby vein, like a sink left running with the drain open.

How did I get it?

Most cases occur spontaneously, meaning they happen without a clear injury. It can be caused by a tiny bone spur on the spine that pokes a hole in the dura, or by a weakness in the dural membrane itself (sometimes associated with connective tissue disorders). In the case of a CSF-Venous Fistula, it is an abnormal connection that develops over time, though the exact reason why these connections form is still being studied by specialists.

How is it diagnosed?

The hallmark symptom is a positional headache—a headache that feels much worse when you are standing up and significantly improves or disappears when you lie flat. Because these leaks can be microscopic, they are often missed on standard scans. At Lahey, we use highly specialized imaging to find them: including Brain and Spine MRI: To look for signs that the brain is "sagging" due to low pressure and Ultra-High-Resolution CT Myelogram as the most advanced way to pinpoint a tiny fistula or leak point.

Does it need to be treated?

Yes, if the symptoms are affecting your quality of life. While not usually life-threatening, the chronic, severe headaches can be disabling. In some cases, long-term low pressure can lead to complications like collections of fluid or blood around the brain (subdural hematomas) or extreme lethargy.

How can it be treated?

Our neurointerventional team offers targeted, minimally invasive solutions:

• Epidural Blood Patch: We inject a small amount of your own blood near the leak site. The blood clots and acts as a natural bandage to seal the hole.
• Fibrin Glue Injection: For more stubborn leaks, we use a specialized medical "glue" to precisely plug the opening.
• Endovascular Embolization (for Fistulas): If a CSF-Venous Fistula is found, we can often thread a tiny catheter through the veins to the exact spot of the leak and close the abnormal connection from the inside using tiny coils or glue.
• Surgical Repair: If the leak is caused by a large bone spur or a significant tear, a spine surgeon may be brought in to physically repair the dura.

Hear about one patient’s experience with SIH.

To learn more, watch a video on CSF leaks and intracranial hypotension.

What is it?

Idiopathic Intracranial Hypertension (IIH), previously known as pseudotumor cerebri, is a condition where the pressure of the fluid around your brain (cerebrospinal fluid or CSF) becomes too high. The name "pseudotumor" comes from the fact that it causes symptoms similar to a brain tumor—such as severe headaches and vision changes—even though no tumor is present.

How did I get it?

"Idiopathic" means the exact cause is unknown. However, it is most common in women of childbearing age and is strongly linked to being overweight or recent weight gain. Experts believe it happens when your body either produces too much CSF or, more commonly, doesn't reabsorb it back into the bloodstream properly. Certain medications, such as some antibiotics or steroids, can also increase the risk.

How is it diagnosed?

Because IIH mimics other conditions, diagnosis involves several steps to rule out other causes:

• Eye Exam: An ophthalmologist checks for papilledema, which is swelling of the optic nerve at the back of the eye caused by high pressure.
• Brain Imaging: CT or MRI scans are used to ensure there are no tumors or blood clots.
• Spinal Tap (Lumbar Puncture): This is the definitive test to measure the exact pressure of your spinal fluid and confirm it is higher than normal.

Does it need to be treated?

Yes. While not life-threatening, untreated IIH can lead to permanent vision loss or even blindness because the constant pressure damages the optic nerves. It also causes chronic, disabling headaches that significantly impact quality of life.

How can it be treated?

The goal is to lower the pressure and protect your sight. At Lahey, our team uses a tiered approach:

• Weight Management & Medication: Often the first step, losing even 5–10% of body weight can significantly reduce pressure. Medications like acetazolamide (Diamox) are also used to help your body produce less fluid. 
• Venous Sinus Stenting: This is a specialized, minimally invasive procedure performed by our neurointerventional team. In many IIH patients, the large veins in the brain (venous sinuses) are narrowed. We place a tiny mesh tube (a stent) to open these veins, which allows the fluid to drain properly and often provides immediate relief from headaches and whooshing sounds in the ears.
• Shunt Surgery: In some cases, a surgeon may place a thin tube (shunt) to drain excess fluid from the brain or spine to another part of the body.

What is it?

Pulsatile tinnitus is a rhythmic thumping, swooshing, or whooshing sound in your ear that beats in time with your heartbeat. Unlike common tinnitus, which is often a constant ringing, this version is usually a physical sound caused by turbulent blood flow in the vessels near your ear. It can be soft and intermittent or loud enough to disrupt sleep and daily concentration.

How did I get it?

Pulsatile tinnitus is not a disease itself but a symptom of an underlying vascular or structural issue. It occurs when blood flow changes from a smooth, quiet stream to a noisy, turbulent one. Common causes include:

• Narrowed Arteries or Veins
• Abnormal Connections: such as dural arteriovenous fistulas or  AVMs
• High Pressure: such as Idiopathic Intracranial Hypertension (IIH)
• Anatomical Variants: a blood vessel positioned unusually close to the ear structures

How is it diagnosed?

Because the cause can be complex, our team uses a systematic map of your blood vessels: We check if the sound changes when you turn your head or if it can be heard by a doctor using a stethoscope (objective tinnitus). MRI/MRA or CT/CTA/CTV scans provide high-resolution images of the brain’s anatomy and blood flow.

Does it need to be treated?

It depends on the cause. For some, it is a benign but annoying sound. However, in other cases, it can be a warning sign of more serious conditions. If the sound is debilitating or linked to a dangerous vascular issue, treatment is recommended.

How can it be treated?

Our goal is to silence the sound by fixing the underlying blood flow problem:

• Venous Sinus Stenting: If a narrowed vein is causing high-pressure noise, we place a tiny mesh stent to open the vessel and smooth out the flow.
• Embolization: For fistulas (dAVF) or AVMs, we use catheters to deliver tiny coils or medical glue to close off the abnormal "noisy" connection.
• Medical Management: If the cause is high blood pressure or IIH, medications may be used to reduce pressure and quiet the symptoms.

To learn more, watch a video on tinnitus.

Note: This is an experimental treatment option, and we maintain very strict inclusion criteria for candidates.

What is it?

A migraine is a complex neurological condition characterized by intense, throbbing headaches often accompanied by nausea and sensitivity to light or sound. While traditional treatments focus on brain chemistry, our team is exploring an innovative approach called Middle Meningeal Artery (MMA) Embolization. This procedure targets the blood vessels in the lining of the brain (the dura) that may play a role in triggering or worsening chronic migraine pain.

How did I get it?

The exact cause of migraines is still being researched, but they are believed to result from a combination of genetic factors and environmental triggers. These triggers can cause the nervous system to overreact, leading to inflammation and the dilation of blood vessels in the brain’s protective covering, which sends intense pain signals to the brain.

How is it diagnosed?

Migraines are typically diagnosed by a neurologist based on your medical history, symptoms, and the frequency of your attacks. To determine if you are a candidate for our experimental embolization procedure, we perform imaging to rule out other causes of headaches.

Does it need to be treated?

Treatment is considered when migraines become chronic (occurring 15 or more days per month) and significantly interfere with your work, family life, and overall well-being. Because this specific procedure is experimental, it is reserved for patients who have not found relief through standard therapies.

How can it be treated? 

Most migraines are managed with lifestyle changes, oral medications, or Botox injections. However, for a very specific group of patients, our neurointerventional team offers MMA Embolization (Experimental).

Using a minimally invasive catheter-based approach, we navigate to the Middle Meningeal Artery and use medication or liquid agents to reduce the blood flow to the dural lining. The goal is to "calm" the overactive pain signals originating from these vessels.

Strict Inclusion Criteria: Because this is an emerging therapy, candidates must have failed multiple conventional treatments and undergo a rigorous screening process by both our neurointerventionalists and headache specialists to ensure the highest level of safety and appropriateness.

What is it?

A vertebral compression fracture (VCF) occurs when one of the bones in your spine (a vertebra) collapses or cracks. This most often happens in the mid-to-lower back. Unlike a clean break in an arm or leg bone, a compression fracture causes the bone to lose its height and take on a wedge shape, which can lead to a hunched posture and significant back pain.

How did I get it?

The most common cause is osteoporosis, a condition that thins and weakens bones as we age. When bones are very fragile, even everyday activities like reaching, coughing, or a minor trip can cause a fracture. Other causes include:

• Trauma: a fall or a car accident
• Tumors: certain cancers that spread to the bone can weaken the vertebrae

How is it diagnosed?

If you have sudden, severe back pain—especially if it gets worse when standing or walking and feels better when lying down—we use imaging (CT, MR, x-Ray) to look for a fracture.

Does it need to be treated?

While some fractures heal on their own with rest, bracing, and pain medication, many do not. If left untreated, a VCF can lead to chronic pain, decreased mobility, and a stooped posture (kyphosis). If the pain is severe enough to keep you from walking or performing daily tasks, a minimally invasive procedure is often recommended to stabilize the bone.

How can it be treated? 

Our team specializes in "cementing" the bone to stop the pain and restore stability:

• Vertebroplasty: Using image guidance, we thread a small needle into the fractured bone and inject a medical-grade bone cement. The cement hardens quickly, acting like an internal cast to stabilize the fracture. 
• Kyphoplasty: Similar to vertebroplasty, but we first use a small balloon to create space and try to restore some of the bone's lost height before injecting the cement. 
• Medical Management: We work closely with your primary doctor or bone health specialist to ensure you are treated for the underlying osteoporosis to prevent future.

What is it?

Basivertebral Nerve (BVN) Ablation is a minimally invasive, outpatient procedure designed to treat chronic vertebrogenic low back pain. While many back pains come from discs or muscles, vertebrogenic pain actually comes from the vertebral bones themselves. This procedure uses radiofrequency energy (heat) to “turn off” the basivertebral nerve, preventing it from carrying pain signals from the spine to the brain.

How did I get it?

Vertebrogenic pain is caused by the wear and tear of the “endplates” — the areas where your spinal discs connect to the vertebral bones. Over time, these endplates can become inflamed or damaged due to aging, heavy lifting, or repetitive stress. This inflammation irritates the basivertebral nerve, leading to chronic, deep, aching pain in the lower back.

How is it diagnosed?

We identify candidates using very specific criteria on an MRI. We look for “Modic changes” — distinctive signs of inflammation or swelling in the vertebral bone marrow near the endplates. If you have chronic low back pain for at least six months that hasn't responded to conservative treatments (like physical therapy or injections), and your MRI shows these specific changes, you may be a candidate.

Does it need to be treated?

This condition is not life-threatening, but the pain can be debilitating. If your back pain limits your ability to work, exercise, or enjoy daily life, and you want a long-term solution that does not involve major spinal fusion surgery or long-term pain medication, BVN ablation is a highly effective option.

How can it be treated?

At Lahey, our neurointerventional specialists perform this procedure using the Intracept System:

• The Procedure: Under image guidance (X-ray), we insert a specialized probe through a tiny incision into the vertebrae. 
• The Ablation: We apply radiofrequency heat to the basivertebral nerve for a few minutes. This cauterizes the nerve so it can no longer transmit pain. 
• The Result: Because the nerve is deactivated, the pain relief is often long-lasting. Unlike some injections that wear off, this is a one-time procedure that does not require an implant or permanent hardware in your back.