What Is an SPG Block and How Does It Treat Migraines?

Why Migraines and Head Pain Are So Difficult to Treat

Chronic migraines affect more than 39 million Americans, and for many, conventional treatments — prescription medications, lifestyle modifications, even Botox injections — provide incomplete or temporary relief. Migraines are not simply "bad headaches." They are complex neurological events involving abnormal brain activity, blood vessel changes, and nerve pathway sensitization that can be extraordinarily difficult to control.

For patients with chronic migraines, trigeminal neuralgia, cluster headaches, or atypical facial pain, one of the most promising and underutilized treatments available is the sphenopalatine ganglion (SPG) block — a minimally invasive procedure that targets one of the brain's most critical pain relay stations.

At Physicians Ketamine Institute of Destin, FL, we use sphenopalatine ganglion blocks to treat patients suffering from chronic migraines, trigeminal neuralgia, and atypical head and neck pain — and we're frequently asked: what exactly is an SPG block and how does it work?

In this article, Dr. Megan Barnett, a board-certified anesthesiologist with over 15 years of clinical experience, explains the anatomy behind the SPG block, what the procedure involves, which conditions it treats, and what you can realistically expect from treatment.

What Is the Sphenopalatine Ganglion?

To understand how an SPG block works, you first need to understand what the sphenopalatine ganglion is and why it matters for pain.

The sphenopalatine ganglion (also called the pterygopalatine ganglion) is a small but extraordinarily important cluster of nerve cells located deep behind the nose, roughly at the level of the back of your eye socket. It sits in a bony space called the pterygopalatine fossa — a natural cavity in the skull that sits at a critical crossroads of several major nerve pathways.

Why This Tiny Structure Matters So Much

The SPG is essentially a neural relay station that connects three different branches of the nervous system:

• The trigeminal nerve (cranial nerve V): This is the largest cranial nerve and the primary sensory nerve of the face. It carries pain signals from the face, teeth, sinuses, and meninges (the membranes surrounding the brain). The trigeminal nerve is directly implicated in migraines, trigeminal neuralgia, and cluster headaches.
• The parasympathetic nervous system: The SPG contains parasympathetic nerve fibers that control blood vessel dilation in the brain and nasal membranes. During a migraine, abnormal parasympathetic activation through the SPG contributes to the throbbing, pulsating pain and the nasal congestion and tearing that many migraine sufferers experience.
• The sympathetic nervous system: Sympathetic fibers also pass through the SPG, connecting to blood vessel regulation and pain modulation pathways.

Because the SPG sits at this three-way intersection, it acts as a central hub for head and facial pain signals. When the SPG is overactive or sensitized — as it often is in chronic migraine patients — it amplifies pain signals, promotes inflammation, and maintains the neurological "feedback loop" that keeps migraines recurring.

What Is an SPG Block?

An SPG block is a procedure that delivers a local anesthetic (numbing medication) directly to the sphenopalatine ganglion, temporarily interrupting its ability to transmit pain signals. By "blocking" this neural relay station, the procedure can:

• Break the pain cycle: Interrupting the SPG's pain signaling can break the self-reinforcing cycle of migraine activation, giving the nervous system a chance to "reset."
• Reduce parasympathetic overactivity: By calming the parasympathetic fibers in the SPG, the block can reduce the blood vessel dilation and inflammation that contribute to migraine pain.
• Desensitize the trigeminal pathway: Repeated SPG blocks can reduce the overall sensitivity of the trigeminal pain pathway, making future migraine attacks less frequent and less severe.

The Mechanism in Simple Terms

Think of the SPG as a circuit breaker in your home's electrical panel. When there's an electrical overload (a migraine), the circuit keeps firing and sending excessive pain signals through the wiring (nerve pathways). An SPG block temporarily flips that circuit breaker off, stopping the overload and allowing the system to stabilize. Over time, with repeated treatments, the circuit becomes less prone to overloading in the first place.

What Does the SPG Block Procedure Involve?

One of the most remarkable things about the SPG block is how simple and well-tolerated the procedure is, despite targeting a deep neurological structure. Here's what you can expect at Physicians Ketamine Institute:

Step 1: Preparation

You'll be seated comfortably in a reclined position. Dr. Barnett will review your symptoms, confirm the treatment plan, and answer any last-minute questions. No sedation is required — you'll be fully awake and alert throughout the procedure.

Step 2: Nasal Anesthetic Application

The most common approach at our clinic is the transnasal method, which is the least invasive technique available. Dr. Barnett inserts a thin, flexible catheter (a small, soft tube) through the nostril. The catheter is advanced along the top of the nasal passage until it reaches the area adjacent to the sphenopalatine ganglion.

This is not painful — the sensation is similar to having a swab placed in your nose for a COVID test, though slightly deeper. Most patients describe it as "mildly uncomfortable" rather than painful.

Step 3: Anesthetic Delivery

Once the catheter is in position, a local anesthetic (typically lidocaine or bupivacaine) is delivered through the catheter. The anesthetic bathes the mucous membrane overlying the SPG, which is thin enough to allow the medication to diffuse through and reach the ganglion below.

You'll remain in the reclined position for approximately 15–20 minutes to allow the anesthetic to fully absorb and take effect.

Step 4: Recovery

After the procedure, you may notice:

• A mild numbness in the back of the throat (temporary, resolves within 30–60 minutes)
• A slightly bitter taste from the anesthetic dripping down the back of the throat
• Occasional mild nosebleed (rare)

Most patients can leave the office within 30 minutes of the procedure and return to normal activities the same day. No driver is needed.

Total Procedure Time

From start to finish, the entire SPG block procedure takes approximately 20–30 minutes, including preparation and the post-procedure observation period. The actual anesthetic application takes only a few minutes.

What Conditions Does an SPG Block Treat?

The SPG block is effective for a range of head and facial pain conditions because of the ganglion's central role in pain transmission. Here are the primary conditions treated:

Chronic Migraines

Chronic migraines — defined as 15 or more headache days per month, with at least 8 meeting migraine criteria — are the most common indication for SPG blocks. The procedure can reduce both the frequency and severity of migraine attacks. Multiple studies have shown that serial SPG blocks (a series of treatments over several weeks) can produce cumulative benefits, with some patients experiencing a 50% or greater reduction in monthly migraine days.

Trigeminal Neuralgia

Trigeminal neuralgia causes sudden, severe, electric shock–like facial pain, often triggered by mundane activities like chewing, talking, or touching the face. Because the trigeminal nerve connects directly to the SPG, blocking the ganglion can interrupt the pain signals and provide significant relief. SPG blocks are particularly valuable for trigeminal neuralgia patients who can't tolerate or haven't responded to anticonvulsant medications.

Cluster Headaches

Cluster headaches are sometimes called "suicide headaches" because of their extraordinary severity. They involve intense, unilateral (one-sided) pain around the eye, often with tearing, nasal congestion, and restlessness. The parasympathetic activation through the SPG is a key component of cluster headache pathophysiology, making SPG blocks a targeted and effective treatment for these attacks.

Atypical Facial Pain

Atypical facial pain is a catch-all term for chronic facial pain that doesn't fit neatly into another diagnosis. These patients often suffer for years without a clear diagnosis or effective treatment. Because the SPG is involved in so many facial pain pathways, an SPG block can help determine whether the ganglion is contributing to the pain — and if the block provides relief, it confirms the SPG's involvement and justifies further treatment.

Cancer-Related Head and Neck Pain

Patients with head and neck cancers, or those experiencing pain from cancer treatment (radiation, surgery), may benefit from SPG blocks as part of a multimodal pain management approach. The block can reduce pain intensity and potentially decrease the need for opioid medications.

Post-Dural Puncture Headache

SPG blocks have also shown efficacy for post-dural puncture headaches (headaches that occur after spinal taps or epidural procedures), offering a less invasive alternative to an epidural blood patch in some cases.

How Quickly Does an SPG Block Work?

One of the most appealing aspects of the SPG block is the speed of onset:

• Acute relief: Many patients notice a reduction in pain intensity within 15–30 minutes of the procedure. For patients who receive an SPG block during an active migraine, the headache may resolve or significantly diminish within the time it takes for the anesthetic to absorb.
• Preventive effects: The preventive benefits — reduced frequency and severity of future attacks — typically develop over the course of a series of blocks. Most protocols involve 2 blocks per week for 6 weeks (12 total), with cumulative improvement building throughout the series.

How Long Does Relief Last? How Many Blocks Do You Need?

This is one of the most important questions patients ask, and the answer varies based on the condition being treated and the individual's response:

Single Block

A single SPG block may provide relief lasting hours to days. For an acute migraine, this may be sufficient to break the current attack. However, for chronic conditions, a single block rarely produces long-term benefits on its own.

Serial Block Protocol

The most effective approach for chronic migraines and other persistent conditions is a series of SPG blocks. A typical protocol involves:

• 2 blocks per week for 6 weeks (12 total)
• Each session takes approximately 20–30 minutes
• Cumulative benefits build with each successive block

After completing a full series, many patients experience months of sustained improvement in headache frequency and severity. Periodic maintenance blocks (monthly or as needed) can help sustain the benefits long-term.

Long-Term Outlook

SPG blocks work best as part of a comprehensive treatment plan. At Physicians Ketamine Institute, Dr. Barnett may combine SPG blocks with other treatments — such as ketamine infusions for chronic pain — for patients with severe or refractory migraines.

How Does an SPG Block Compare to Medication for Migraines?

Many migraine patients arrive at Physicians Ketamine Institute after trying multiple medications — triptans, beta-blockers, anticonvulsants, antidepressants, CGRP inhibitors, and even Botox — with insufficient results. Here's how SPG blocks compare to these conventional approaches:

Factor	Medications	SPG Block
Mechanism	Systemic (affects whole body)	Targeted (acts on specific nerve cluster)
Side Effects	Often significant (fatigue, weight gain, cognitive effects, rebound headaches)	Minimal (temporary throat numbness, rare mild nosebleed)
Onset	Preventives take weeks to months; triptans work in 30–60 min for acute attacks	15–30 minutes for acute relief; cumulative preventive effect over series
Drug Interactions	Multiple potential interactions	None — local anesthetic only
Rebound Risk	Medication overuse headache is common with frequent acute med use	No rebound risk
Invasiveness	Oral or injectable medications	Transnasal (through the nose), no needles in most cases

SPG blocks are not a replacement for all migraine medications, but they can be an excellent addition to a treatment plan — and for some patients, they may reduce or eliminate the need for daily preventive medications.

Is the SPG Block Painful?

This is understandably a top concern for patients. The short answer is: the SPG block is well-tolerated by the vast majority of patients.

The transnasal approach used at Physicians Ketamine Institute does not involve needles. The thin, flexible catheter is guided gently through the nasal passage. Most patients describe the sensation as:

• "Like a cotton swab in the nose but a little deeper"
• "Mildly uncomfortable but not painful"
• "Way easier than I expected"

Some patients experience a brief stinging or burning sensation as the anesthetic is applied, which resolves quickly. On a 0–10 discomfort scale, most patients rate the procedure between 2 and 4.

For patients who are anxious about the procedure, Dr. Barnett's anesthesiology background ensures a gentle, expert approach with a focus on patient comfort.

Who Is a Good Candidate for an SPG Block?

You may be a good candidate for an SPG block if you have:

• Chronic migraines (15+ headache days per month) that haven't responded adequately to 2 or more preventive medications
• Trigeminal neuralgia that is difficult to control with medication
• Cluster headaches, particularly during an active cluster period
• Atypical facial pain without a clear diagnosis
• Medication overuse headaches (the SPG block can help break the rebound cycle without adding another medication)
• Sensitivity to or intolerance of migraine medications
• A desire for a non-pharmacological treatment approach

SPG blocks are generally safe for most patients. Contraindications are minimal and include active nasal infections, known allergy to local anesthetics, and certain bleeding disorders. Dr. Barnett evaluates each patient individually during the consultation.

Frequently Asked Questions

What is a sphenopalatine ganglion block?

A sphenopalatine ganglion (SPG) block is a minimally invasive procedure that delivers a local anesthetic to a cluster of nerve cells (the SPG) located behind the nose. The SPG is a major relay station for pain signals in the head and face. By temporarily numbing this ganglion, the procedure interrupts pain transmission and can provide relief for migraines, trigeminal neuralgia, cluster headaches, and other head and facial pain conditions.

How long does an SPG block take?

The entire procedure takes approximately 20–30 minutes, including preparation and a brief observation period afterward. The actual anesthetic application takes only a few minutes. Most patients leave the office within 30 minutes and can return to normal activities the same day.

Does the SPG block hurt?

The transnasal SPG block is well-tolerated by most patients. It does not involve needles. A thin, flexible catheter is guided through the nasal passage to deliver the anesthetic. Most patients rate the discomfort between 2 and 4 on a 0–10 scale. Some experience a brief stinging sensation when the anesthetic is applied, which resolves quickly.

How many SPG blocks do I need for migraines?

For chronic migraines, the most effective protocol is a series of approximately 12 blocks (2 per week for 6 weeks). Single blocks can provide acute relief for an active migraine, but the cumulative, preventive benefits require a full series. After the initial series, periodic maintenance blocks (monthly or as needed) can help sustain improvement.

How quickly does an SPG block work?

Many patients notice pain relief within 15–30 minutes of the procedure. For patients receiving an SPG block during an active migraine, the headache may significantly improve or resolve within this timeframe. The preventive effects (reduced frequency and severity of future attacks) build cumulatively over the course of a treatment series.

How long does relief from an SPG block last?

A single block may provide relief lasting hours to days. A full series of 12 blocks can produce sustained improvement lasting weeks to months. The duration varies by patient and condition. Maintenance blocks can extend the benefits long-term. At Physicians Ketamine Institute, Dr. Barnett tailors the maintenance schedule to each patient's response pattern.

Can an SPG block cure migraines permanently?

SPG blocks do not "cure" migraines in the sense of permanently eliminating them, but they can significantly reduce the frequency, severity, and duration of migraine attacks. For some patients, the improvement is dramatic enough that migraines become a minor, manageable issue rather than a debilitating condition. Periodic maintenance treatments help sustain the benefits.

Are there side effects from an SPG block?

Side effects are minimal. The most common include temporary numbness in the back of the throat (resolves in 30–60 minutes), a bitter taste from the anesthetic, and occasional mild nosebleed. Serious complications are extremely rare. Because the procedure uses only a local anesthetic delivered through the nose, there are no systemic side effects or drug interactions.

Can SPG blocks help with trigeminal neuralgia?

Yes. Because the trigeminal nerve is directly connected to the sphenopalatine ganglion, SPG blocks can interrupt the pain signals that cause the sudden, severe facial pain characteristic of trigeminal neuralgia. SPG blocks are particularly helpful for patients who can't tolerate anticonvulsant medications or who need additional pain relief beyond what medications provide.

Do I need a referral for an SPG block?

You do not need a referral to schedule a consultation at Physicians Ketamine Institute of Destin. Dr. Barnett will evaluate your condition, review your headache history and previous treatments, and determine whether SPG blocks are appropriate for you. If you've been dealing with chronic migraines, trigeminal neuralgia, or atypical facial pain, an SPG block may offer the targeted relief you've been looking for.

Take the Next Step Toward Relief

If chronic migraines, trigeminal neuralgia, or facial pain have been controlling your life, the sphenopalatine ganglion block may be the treatment you've been missing. At Physicians Ketamine Institute of Destin, FL, Dr. Megan Barnett combines expert anesthesiology training with a compassionate, patient-centered approach to deliver targeted pain relief.

Schedule your SPG block consultation today, or call us at (850) 598-0099.