Middle Meningeal Artery Embolization for Headache: Uses and Evidence

Middle meningeal artery embolization for headache is an interventional treatment method applied particularly in cases of chronic subdural hematoma or recurrent intracranial pain. In this procedure, a microcatheter is advanced into the middle meningeal artery, an embolic material is injected, and abnormal vascular flow is terminated.

The treatment is preferred to prevent recurrent hematoma development after surgical drainage or to provide pain control in patients who are not suitable for surgery. Due to its minimally invasive nature, the procedure shortens recovery time and reduces complication rates. Clinical selection must be performed meticulously.

In the embolization technique, branches of the middle meningeal artery are visualized using digital subtraction angiography, and an embolic agent (particles, coils, or liquid material) is applied to the target area. The aim of the procedure is to eliminate pathological vascular leakage and reduce the risk of hematoma recurrence.

In the post-procedural period, a marked reduction in headache, a decrease in hematoma volume, and neurological improvement are observed. When performed by experienced interventional neuroradiologists, middle meningeal artery embolization is a safe, effective, and modern treatment approach that provides long-term pain control.

What Is Treatment-Resistant Chronic Migraine and How Does It Affect Life?

When we talk about headache, we are referring to a condition that goes far beyond a simple discomfort for some people, bringing life almost to a standstill. Chronic migraine is an extremely debilitating disease characterized by headache occurring on 15 or more days per month, with a significant portion of these headaches having migraine features. This is not just a number; it means spending half or more of a month in pain, with sensitivity to light and sound, nausea, and being unable to perform daily activities.

For a person in this situation, going to work, taking care of children, participating in social life, or even performing the simplest household chores can be as challenging as climbing a mountain. This constant state of pain gradually consumes a person’s hope and traps them in a vicious cycle.

A migraine being described as “treatment-resistant” or “refractory” in medical terms means that despite stopping at many points along a long and exhausting journey to get rid of this condition, the patient can never quite reach the destination. These patients have tried many known and evidence-based preventive treatment methods at the correct doses and for sufficient durations, but either received no benefit or were unable to continue treatment due to side effects. This never-ending search exhausts both the patient and their family physically and emotionally.

These patients’ typically unsuccessful treatment attempts include the following:

• Beta-blockers
• Anticonvulsant (antiepileptic) medications
• Tricyclic antidepressants
• Calcitonin Gene-Related Peptide (CGRP) antibodies
• OnabotulinumtoxinA (Botox) injections

It is precisely at this point, in this “therapeutic gap” where standard treatments are exhausted, that the need for innovative therapies operating through entirely different mechanisms—such as middle meningeal artery embolization—becomes apparent.

How Was This New Embolization Treatment Discovered?

Like many revolutionary discoveries in the history of medicine, the story of this treatment began with an unexpected observation—almost by chance. Everything was noticed during the treatment of a completely different condition than headache: chronic subdural hematoma (cSDH).

cSDH is a condition that usually occurs in elderly individuals after minor head trauma, characterized by the slow accumulation of blood between the outermost membrane of the brain and the skull. This accumulation can exert pressure on the brain, leading to serious neurological problems. The most important feature of this condition is the formation of an inflamed, highly vascular membrane (neomembrane) around the accumulated blood, which continuously produces small bleedings. This membrane creates a vicious cycle, causing the hematoma to grow. Although the traditional treatment is surgery, recurrence rates have been quite high. To prevent these recurrences, interventional radiologists developed middle meningeal artery embolization as a non-surgical solution.

The goal of this method was to occlude the middle meningeal artery, the main blood supply of the inflamed and bleeding membrane. By cutting off the membrane’s blood supply, the inflammatory cycle is broken, and the accumulated blood is gradually resorbed by the body. The method proved to be extremely successful and safe in the treatment of cSDH. However, the real surprise occurred during this process.

Physicians noticed that some of the patients who underwent this embolization for cSDH also suffered from long-standing, refractory chronic headaches prior to the procedure. When these patients returned for follow-up after the intervention, they reported with great surprise and relief that not only had the bleeding in their brains improved, but the stubborn headaches that had turned their lives into a prison for years had either significantly improved or completely disappeared.

This “incidental discovery” sparked a moment of realization in the scientific community. It became clear that this procedure was not only eliminating a structural problem—the blood accumulation—but was also intervening in a pain-generating mechanism underlying headache. This observation gave rise to the idea that the treatment should be investigated independently of cSDH, directly for the treatment of primary headache syndromes. It was like a living, real-world proof—outside the laboratory—of one of the most fundamental theories we know about headache mechanisms: the trigeminovascular theory.

What Is the Mechanism Behind Headache? Why Does This Embolization Target This Vessel?

The answer to this question lies in the complex anatomy of our brain and the membranes that surround it like armor. Contrary to what most people believe, brain tissue itself does not feel pain. However, when you touch the outermost layer of the membranes protecting the brain—the dura mater—severe pain is felt. This membrane is richly supplied with pain-sensitive nerve endings and a dense vascular network. This is the stage on which headaches such as migraine are played out. The main actors on this stage are the nerve and vascular network known as the trigeminovascular system.

The most important vessel of this system is the middle meningeal artery (MMA), the main artery supplying the dura mater. This artery and its branches are intertwined with fibers of the trigeminal nerve that carry pain signals, almost like ivy. In other words, there is direct physical proximity and interaction between pain nerves and blood vessels.

When a migraine attack begins, a chain of events is triggered within this system:

• Nerve Activation: Various triggers (stress, sleep deprivation, hormonal fluctuations) activate pain nerves.
• Release of Inflammatory Mediators: Activated nerve endings release powerful chemicals into the surrounding tissue and vessel walls. The most well-known of these is Calcitonin Gene-Related Peptide (CGRP), frequently mentioned in migraine treatment.
• Vessel Dilation and the Pain Cycle: These released chemicals cause abnormal dilation (vasodilation) of the middle meningeal artery and increase the permeability of the vessel wall. This makes the surrounding nerve endings even more sensitive, creating the characteristic throbbing, severe pain of migraine. This is truly a “vicious cycle”: nerve activation dilates the vessel, and the dilated vessel further stimulates the nerve, intensifying and perpetuating the pain.

The goal of middle meningeal artery embolization is precisely to break this vicious cycle that fuels the fire. This procedure does far more than simply occluding a vessel; it essentially cuts off the “fuel” of the inflammatory reaction that produces pain. By permanently occluding the middle meningeal artery, we effectively shut down the engine of the pain mechanism.

While conventional medications temporarily suppress symptoms or block a chemical pathway, embolization eliminates the physical structure that sustains the disease cycle. This logically explains why the treatment can provide long-lasting relief for months or even longer.

Is There Evidence That This Embolization Treatment Is Effective?

This innovative treatment approach is not based solely on logical reasoning; it is also supported by a growing body of scientific evidence. Clinical studies evaluate the effectiveness of the treatment using standardized and reliable measurement tools, and the results are quite promising.

• Initial Strong Signals From Chronic Subdural Hematoma (cSDH) Studies:

As mentioned earlier, the first and most striking data came from patients who underwent embolization for cSDH. In a study conducted by Catapano and colleagues, it was reported that 89% of patients with chronic headache prior to cSDH treatment experienced significant improvement after the procedure, and 78% reported complete resolution of their headaches. On the HIT-6 (Headache Impact Test-6) scale, which measures the impact of headache on daily life, the patients’ average score decreased from 64—indicating “very severe impact”—to 40, meaning “little or no impact.” This concretely demonstrated the magnitude of improvement in these patients’ quality of life.

• Studies Conducted Directly in Chronic Migraine Patients:

Following these initial observations, researchers began testing this treatment directly in patients with treatment-resistant chronic migraine. In a pioneering study by Vanzin and colleagues, 10 patients selected from the most challenging migraine cases were treated. The patients’ baseline mean HIT-6 score was 69.1, indicating a life-paralyzing level of disability. Just 30 days after the procedure, this score dropped to an average of 38.6. Most impressively, this remarkable improvement was maintained at 3- and 6-month follow-ups. This demonstrated that the effect of the treatment was not a temporary enthusiasm but provided sustainable and lasting relief.

Some standard metrics used to evaluate treatment success include:

• HIT-6 (Headache Impact Test): Measures the overall impact of headache on work, social life, and daily activities.
• MIDAS (Migraine Disability Assessment): Quantifies the number of days work, school, or household activities were missed due to migraine over the past three months.
• Pain Scale (VAS): Asks the patient to rate pain severity on a scale from 0 to 10.

When all this evidence is considered together, it becomes clear that middle meningeal artery embolization has strong potential to offer a powerful, effective, and long-lasting solution for chronic headache in properly selected patients.

Who Is a Suitable Candidate for This Embolization Treatment?

Middle meningeal artery embolization is not a magic wand for everyone suffering from headache. To achieve the greatest benefit and maintain maximum safety, careful and meticulous patient selection is of critical importance. These criteria are derived from both ongoing scientific study protocols and accumulated clinical experience in this field.

There are fundamental characteristics that an ideal candidate for this treatment should possess.

• Definitive Diagnosis: The patient must have been diagnosed with “chronic migraine” by a neurologist according to the International Classification of Headache Disorders.
• Treatment Resistance: The most important criterion is that the disease is “refractory” or treatment-resistant. This means the patient has tried preventive medications from at least two or three different classes (including Botox and newer-generation CGRP antibodies) at adequate doses and durations without success.
• Age Range: Generally, patients between 18 and 65 years of age are considered candidates, although this range may be flexible depending on overall health status.
• Absence of Structural Problems: Brain MRI or CT scans performed prior to treatment should not reveal any other structural cause of headache (such as a tumor or vascular malformation).

Lidocaine Suppression Test (LST): A “Rehearsal” to Predict Treatment Response

This test is a highly valuable tool that helps us predict who will benefit most from permanent embolization. It serves as a kind of “rehearsal” to determine whether the treatment is likely to work.

• How Is It Performed?: In the angiography suite, access is obtained through the groin or wrist, and a very thin catheter is advanced into the middle meningeal artery.
• Drug Administration: While the patient is experiencing their typical headache, a very small amount of local anesthetic (lidocaine) is injected into the vessel through the catheter.
• Evaluation of the Result: If the patient experiences a marked reduction in headache severity shortly after the injection, the test is considered “positive.”

A positive LST indicates that the patient’s pain mechanism is strongly associated with the middle meningeal artery and surrounding nerve network, suggesting a high likelihood of benefiting from permanent embolization. This is one of the most powerful tools we have for selecting the right patient.

How Is the Embolization Procedure Performed, and What Are the Steps?

Middle meningeal artery embolization is a minimally invasive intravascular procedure that does not require large surgical incisions. It is performed by interventional radiologists, typically in a specially equipped room known as an angiography suite. The procedure progresses through careful steps, prioritizing patient comfort and safety.

The main steps of the procedure are as follows.

• Preparation and Access: A mild sedative is administered to help the patient relax. Then, under local anesthesia, a thin sheath is placed into an artery—usually at the wrist or groin. This serves as the entry point for the entire procedure.
• Catheter Navigation: Through this sheath, a longer and flexible tube called a guiding catheter is advanced under fluoroscopic guidance to the main carotid artery in the neck.
• Reaching the Target: Through the guiding catheter, a microcatheter as thin as a strand of hair is carefully advanced to the target vessel—the main trunk of the middle meningeal artery. This is the most delicate and experience-demanding part of the procedure.
• Safety Check and Mapping: Once the microcatheter is in position, contrast material is injected to create a detailed “road map” (angiogram) of the vessel. This map is vital for identifying any dangerous connections between the target vessel and critical arteries supplying the eye or brain. This step is the cornerstone of procedural safety.
• Embolization (Occlusion): After all safety checks are completed, special occlusive materials (very small particles or liquid embolic agents) are slowly and carefully injected through the microcatheter to permanently occlude the vessel.
• Completion of the Procedure: Once complete cessation of blood flow in the target vessel is confirmed, the catheters are withdrawn, and the access site is closed with a small bandage.

Depending on the distribution of the headache, this procedure can be performed on one side (unilateral) or both sides (bilateral) in the same session. Especially in headaches involving the entire head, bilateral treatment often yields more durable and satisfactory results.

Are There Risks Associated With This Embolization Procedure? Is It Considered Safe?

As with any medical intervention, middle meningeal artery embolization carries potential risks. However, when performed by an experienced interventional radiologist using modern technology and strict safety protocols, these risks are extremely low. Safety is not an inherent property of the procedure itself, but rather a result actively created through the operator’s meticulousness and expertise.

The most concerning and closely monitored risk is unintended vessel occlusion (non-target embolization). This can occur if embolic material escapes from the target vessel and travels to arteries supplying the eye, brain, or facial nerve, potentially causing serious outcomes such as permanent vision loss, stroke, or facial paralysis. However, very strict precautions are taken to prevent this risk.

The main safety strategies used to prevent these serious risks include:

• Detailed Anatomical Mapping: High-resolution angiograms obtained before and during the procedure are used to identify all risky vascular connections.
• Safe Catheter Positioning: Embolization is never initiated until the microcatheter tip is positioned beyond identified dangerous connections, in a completely safe zone.
• Controlled and Slow Injection: The embolic material is injected very slowly under continuous fluoroscopic monitoring. The procedure is immediately halted if any reflux or suspicious flow is observed.
• Appropriate Material Selection: In high-risk anatomies, larger particles that cannot pass through dangerous connections are selected to enhance safety.

Other potential complications are rarer and generally milder.

• Facial Paralysis: This may occur due to involvement of a branch supplying the facial nerve. In the vast majority of reported cases, this condition is temporary and resolves completely over time.
• Access Site Issues: Bruising, mild bleeding, or swelling may occur at the wrist or groin where the catheter was inserted.

Studies involving thousands of patients treated for chronic subdural hematoma show that the overall complication rate of this procedure is as low as 1–3%. These data provide the clearest evidence of how safe the procedure can be when strict safety rules are followed.

Frequently Asked Questions

Prof. Dr. Özgür KILIÇKESMEZ

Prof. Dr. Özgür Kılıçkesmez is one of Türkiye’s leading interventional radiology and neuroradiology specialists, focusing on minimally invasive endovascular treatments. His primary areas of expertise include aneurysm and stroke treatments, embolization procedures, non-surgical treatments of thyroid and parathyroid diseases, interventional oncology, and peripheral vascular interventions. He currently serves as the Head of the Interventional Radiology and Neuroradiology Department at Istanbul Memorial Göztepe Hospital.
Graduating from Istanbul University Cerrahpaşa Faculty of Medicine in 1997, Prof. Dr. Kılıçkesmez received advanced training in interventional radiology and oncology as a Clinical Fellow at London Guy’s & St Thomas’ and King’s College Hospital between 2012 and 2013. He earned the title of Professor in 2020 and, in the same year, became the Founding Interventional Radiologist at SBÜ Çam and Sakura City Hospital. He also holds the EBIR (European Board of Interventional Radiology) certification.
Prof. Dr. Kılıçkesmez has 94 international and 40 national publications and over 2500 citations. He serves as a reviewer for prestigious journals such as the American Journal of Roentgenology (AJR) and Diagnostic & Interventional Radiology. With his clinical and academic expertise, he is a nationally and internationally recognized authority in stroke treatment, brain aneurysm, embolization, tumor ablation, and minimally invasive treatments of thyroid/parathyroid diseases.