A sphenopalatine ganglion block is a procedure that delivers a numbing agent to a small cluster of nerve cells tucked deep behind the nose, temporarily interrupting pain signals and autonomic nerve activity involved in headaches, facial pain, and several other conditions. The procedure has been used for decades and can be performed in a doctor’s office in minutes, often with nothing more than a thin catheter slid into the nostril. It has gained attention as an option for migraines, cluster headaches, and post-procedure headaches, though the strength of evidence varies depending on the condition being treated.
What the Sphenopalatine Ganglion Actually Does
The sphenopalatine ganglion (SPG) sits beneath the maxillary nerve, deep in the face behind the nasal passages. It is one of the largest collections of nerve cells outside the brain, and it acts as a relay station where sensory fibers, parasympathetic fibers, and sympathetic fibers all converge. That makes it involved in regulating blood flow to the brain, tear production, nasal congestion, and pain signaling across much of the face and head.1World Journal of Acupuncture – Moxibustion. Sphenopalatine ganglion stimulation: Clinical applications and innovative development Because so many different nerve pathways pass through this single structure, blocking it can affect a surprisingly wide range of symptoms.
The scientific rationale is straightforward: sensory fibers running through the SPG carry pain information from the head and face, while autonomic fibers control things like blood vessel dilation and glandular secretion. When those fibers are disrupted by a local anesthetic, both the pain transmission and the autonomic symptoms that often accompany headaches (tearing, nasal stuffiness, facial flushing) can quiet down.2PubMed. Sphenopalatine Ganglion Block in the Management of Chronic Headaches The block works by disrupting nociceptive transmission and autonomic activation, essentially hitting the pause button on a nerve hub that is amplifying the problem.3PubMed Central. Sphenopalatine Ganglion Blocks in Headache Management: A Review
How the Procedure Is Done
The simplest and most common version is the transnasal approach. A clinician inserts a thin, flexible catheter or cotton-tipped applicator into the nostril and advances it along the top of the nasal passage until it rests near the SPG. A local anesthetic, usually lidocaine or bupivacaine, is then dripped or sprayed onto the mucous membrane overlying the ganglion. The anesthetic soaks through the thin tissue and reaches the nerve cluster beneath. No needles are required, and the whole thing typically takes a few minutes.
Two purpose-built catheter devices dominate practice in the United States. A survey of American Headache Society members found that the SphenoCath and the Tx360 were the two most commonly used delivery methods, each accounting for roughly 42% of applications.4PubMed Central. Sphenopalatine ganglion block in primary headaches: An American Headache Society member survey Both are designed to guide the anesthetic to the right spot without imaging or sedation. Some clinicians also use a simple atomizer to spray the anesthetic into the nasal cavity, which is even less invasive though potentially less precise.
For cases that need a more targeted or longer-lasting effect, there are needle-based approaches. The infrazygomatic technique involves inserting a needle through the cheek under fluoroscopic or CT guidance to reach the SPG directly. This allows injection of larger volumes of anesthetic or the use of radiofrequency energy for ablation.5PubMed Central. Sphenopalatine Ganglion Block and Radiofrequency Ablation: Technical Notes and Efficacy These needle-guided procedures are reserved for more severe or refractory cases and carry more risk than the transnasal route.
Migraine Treatment
Migraine is probably the condition where SPG blocks have attracted the most clinical interest. In one study of acute migraine treatment, about 71% of patients were completely headache-free 15 minutes after the procedure, and nearly 78% were headache-free at 2 hours. Pain scores dropped from an average of about 7 out of 10 down to under 1. Almost all patients rated their improvement as “good” or “very good.”6PubMed Central. Sphenopalatine Ganglion Block for the Treatment of Acute Migraine Headache Those numbers are striking, though it is worth noting this was not a placebo-controlled trial, which means some of the benefit could reflect placebo response or natural resolution of the attack.
A broader look at the evidence found that roughly 87% of SPG block administrations for acute migraine resulted in pain relief, with minimal side effects.7PubMed Central. Sphenopalatine ganglion (SPG) blocks: Evidence and implementation for acute migraine treatment in the primary care setting The fact that the block can be performed in a primary care office rather than requiring a specialist or emergency department visit makes it appealing as a first-line option for patients who do not respond well to oral medications or who cannot take triptans.
One practical question is whether the block works as a preventive measure or only as an acute treatment. Some clinicians perform repeated blocks at regular intervals in patients with chronic migraine, operating on the theory that repeatedly interrupting SPG signaling may reduce attack frequency over time. A retrospective review of patients using a self-administered nasal spray targeting the SPG found that physicians judged the treatment useful as a preventive in about 79% of chronic migraine patients at three months and as an acute treatment in about 75%.8Journal of Anesthesia and Anesthetic Drugs. Retrospective Chart Review: The Feasibility of a Self-Administered Nasal Spray Targeting the Sphenopalatine Ganglion (SPG) in Treatment of Chronic Migraine That is encouraging, but the evidence for prevention is far thinner than for acute relief.
Cluster Headaches
Cluster headache is one of the most painful conditions known, and the SPG’s role in it is especially well-studied. The autonomic symptoms that define cluster attacks, such as tearing, nasal congestion, and eyelid drooping on the affected side, all run through the parasympathetic pathways of the SPG. That makes it a logical target.
In a placebo-controlled pilot study of patients with refractory chronic cluster headache, SPG stimulation (using an implanted device rather than a simple block) relieved pain in about 67% of treated attacks, compared to just 7% with sham stimulation. Long-term follow-up at 24 months confirmed that the treatment continued to work as an acute rescue for attacks. Beyond stopping individual attacks, roughly 35% of patients saw their attack frequency drop by more than half, suggesting a preventive effect from repeated stimulation. Overall, about 61% of patients responded either acutely, in terms of frequency, or both.9PubMed Central. Managing cluster headache with sphenopalatine ganglion stimulation: a review A systematic review concluded that the SPG is a promising target for treating cluster headache across all three modalities: blocks, radiofrequency ablation, and neurostimulation.10PubMed Central. Sphenopalatine ganglion: block, radiofrequency ablation and neurostimulation – a systematic review
Post-Dural Puncture Headache
A post-dural puncture headache (PDPH) can develop after a spinal tap or epidural, when cerebrospinal fluid leaks through the puncture site and causes an intense positional headache that worsens when you sit up or stand. The traditional treatment is an epidural blood patch, which is effective but invasive, requiring another needle in the spine. Clinicians have been interested in whether an SPG block could serve as a simpler first step.
The evidence here is genuinely mixed. Case reports and small series are enthusiastic. One report described a woman with a refractory PDPH after a cesarean section who got immediate relief from an SPG block.11PubMed Central. Efficacy and potency of sphenopalatine ganglion block for the management of postdural puncture headaches in post-cesarean section: A case report and literature review A narrative review noted that researchers have explored the SPG block as a simpler alternative to the epidural blood patch, but acknowledged that existing evidence is scarce and the block cannot yet be recommended for all patients.12PubMed Central. Sphenopalatine ganglion block for relieving postdural puncture headache: technique and mechanism of action of block with a narrative review of efficacy
The most rigorous study on this question paints a less optimistic picture. A randomized, blinded trial compared SPG blocks using local anesthetic versus placebo and found no meaningful difference: pain scores at 30 minutes were similar between the two groups, and about half of the patients in both the active and placebo arms still needed an epidural blood patch afterward.13British Journal of Anaesthesia. Sphenopalatine ganglion block for the treatment of postdural puncture headache: a randomised, blinded, clinical trial That trial is important because it introduces a control for placebo effect, something the case reports and series lack. A meta-analysis of randomized trials concluded there is insufficient evidence on both the efficacy and safety of SPG blocks for PDPH, rating the overall quality of evidence as low to very low.14Brazilian Journal of Anesthesiology (English Edition). Trans-nasal sphenopalatine ganglion block for post-dural puncture headache management: a meta-analysis of randomized trials The block might help some individuals, but the current data do not support it as a reliable substitute for the epidural blood patch.
Facial Pain and Other Conditions
Because the SPG sits at a crossroads of facial sensation and autonomic control, clinicians have tried blocking it for a range of conditions beyond primary headaches. Trigeminal neuralgia is one example. A case report described a young woman with both migraine and trigeminal neuralgia related to multiple sclerosis whose pain did not respond to standard medications. She experienced immediate symptom relief after an SPG block.15PubMed Central. Sphenopalatine Ganglion Block: Treatment of Migraine and Trigineminal Neuralgia Associated With Multiple Sclerosis These off-label uses are mostly documented in case reports and small series rather than controlled trials, so the evidence base is thin even if individual results can be impressive.
Chronic vasomotor rhinitis, the type of persistent nasal stuffiness and runny nose that is not caused by allergies, is another condition where SPG blocks have shown promise. A study of 30 patients found that about two-thirds achieved complete relief of their rhinitis symptoms after an average of three weekly blocks, with no recurrence over a follow-up period of 12 to 20 months.16PubMed. Vasomotor rhinitis and sphenopalatine ganglion block The connection makes anatomical sense because the parasympathetic fibers that drive nasal gland secretion and blood vessel dilation in the nose pass directly through the SPG.
Post-Operative Pain After Sinus and Nose Surgery
Endoscopic sinus surgery and rhinoplasty are known for producing significant postoperative discomfort, partly because the SPG’s territory overlaps so heavily with the surgical field. Several studies have tested whether performing an SPG block during or immediately after these procedures reduces recovery pain.
In patients undergoing endoscopic sinus surgery, an SPG block with bupivacaine reduced pain scores for the first 24 hours compared to a control group, and patients in the block group needed less rescue pain medication.17PubMed Central. Effect of Sphenopalatine Ganglion Block With Bupivacaine on Postoperative Pain in Patients Undergoing Endoscopic Sinus Surgery The benefit faded after 24 hours, with no significant difference at 48 hours or beyond. A similar pattern appeared in septorhinoplasty patients: the block provided better analgesia in the early postoperative window and reduced the number of patients who needed additional pain medication in the first two hours.18PubMed Central. Postoperative effects of bilateral sphenopalatine ganglion blockade in septorhinoplasty operations; double-blind randomized clinical trial
Not every trial has found a clear-cut benefit. One study of preemptive SPG blocks before sinus surgery found a limited trend toward reduced pain with bupivacaine compared to saline, but the results did not reach statistical significance, and the authors called for larger studies.19PubMed. The effectiveness of preemptive sphenopalatine ganglion block on postoperative pain and functional outcomes after functional endoscopic sinus surgery The overall picture is that the block can help with early recovery pain, but it is not a replacement for standard postoperative pain management.
Lidocaine Versus Bupivacaine and Dosing Questions
The two local anesthetics used most often for SPG blocks are lidocaine and bupivacaine. Lidocaine acts faster but wears off sooner; bupivacaine takes longer to kick in but lasts longer. A study comparing the two in transnasal SPG blocks for headache found that about 89% of lidocaine treatments and 94% of bupivacaine treatments resulted in pain improvement, with an average pain reduction of about 3 points on a 10-point scale for both. The difference between the two was not statistically significant.20PubMed. Lidocaine Versus Bupivacaine in the Treatment of Headache with Intranasal Sphenopalatine Nerve Block In practice, clinicians choose between them based on availability, patient history with local anesthetics, and whether they want a faster onset or a longer duration.
Dosing is another area where the evidence is still developing. A randomized dose-finding study in an emergency department tested different volumes and approaches (1 mL versus 3 mL, one nostril versus both) for bupivacaine SPG blocks in headache patients. Sustained headache relief rates ranged from about 19% to 35% across the groups, and none of the higher-dose or bilateral groups showed a statistically significant improvement over the lowest dose group.21Annals of Emergency Medicine. A Randomized, Dose-Finding Study of Sphenopalatine Ganglion Block With Bupivacaine for Emergency Department Patients With Headache That suggests more anesthetic is not necessarily better, though the relatively modest overall response rates in that study may also reflect the fact that ER headache populations are diverse and not all headaches involve SPG-mediated pathways.
Safety and Side Effects
The transnasal approach has a favorable safety profile. A meta-analysis of randomized trials found no life-threatening adverse events across the included studies. The most common side effects are local and short-lived: mild discomfort during catheter insertion, a bitter taste from the anesthetic dripping down the throat, brief nosebleeds, nasal congestion, and transient numbness in the palate or face.22Brazilian Journal of Anesthesiology (English Edition). Trans-nasal sphenopalatine ganglion block for post-dural puncture headache management: a meta-analysis of randomized trials Occasional tearing or a change in face temperature can occur when the sympathetic fibers are affected, and these are actually considered signs that the block reached the right spot.
A prospective double-blind trial in post-cesarean patients found no significant changes in blood pressure or heart rate after the block, reinforcing that transnasal SPG blocks do not meaningfully affect cardiovascular stability. The only side effect that showed a statistically significant difference from placebo was the bitter taste.23International Journal of Pain. Trans-Nasal Sphenopalatine Ganglion Block for Post-Dural Puncture Headache after Caesarean Delivery: A Prospective, Double-Blind Clinical Trial Needle-based approaches through the cheek carry more risk, including potential for local infection, nerve injury, or bleeding, but serious complications are rare in experienced hands.
Radiofrequency Ablation and Neurostimulation
When repeated SPG blocks provide temporary relief but the pain keeps returning, clinicians sometimes escalate to longer-lasting interventions targeting the same structure. Radiofrequency ablation (RFA) uses a needle placed under imaging guidance to deliver heat energy to the ganglion, creating a controlled lesion that disrupts its signaling for months or longer. In a study of 15 patients with intractable chronic cluster headache who had responded to temporary SPG blocks, percutaneous RFA reduced the average number of weekly attacks from 17 down to about 5 at one month, with the benefit persisting though gradually diminishing over 18 months of follow-up. Pain disability scores also improved substantially in the first year.24PubMed. Sphenopalatine ganglion radiofrequency ablation for the management of chronic cluster headache
Neurostimulation takes yet another approach: rather than destroying nerve tissue, a small device is surgically implanted near the SPG and delivers electrical pulses on demand. This is the technology tested in the cluster headache study mentioned earlier, where stimulation aborted attacks in about two-thirds of cases and reduced attack frequency in a third of patients.25PubMed Central. Managing cluster headache with sphenopalatine ganglion stimulation: a review The appeal of neurostimulation is that it is reversible and adjustable, unlike ablation. The downside is that it requires a surgical implant in the face, which carries its own risks and costs. Both RFA and neurostimulation are reserved for patients who have not responded to less invasive options.
Children and Pregnancy
Headache treatment in children and pregnant women is complicated by the fact that many standard medications are either unapproved or potentially unsafe for these groups. The SPG block is appealing in both populations because it delivers medication locally rather than systemically.
A study of SPG blocks in children with refractory headaches reported 100% technical success, statistically significant pain reduction, and no complications.26PubMed. Sphenopalatine Ganglion Nerve Block for the Treatment of Migraine Headaches in the Pediatric Population The procedure was well tolerated, which matters when treating a population that tends to be anxious about medical interventions. The evidence base in pediatrics is still small, but the early results are promising enough that some headache centers have incorporated it into their practice for children who do not respond to first-line treatments.
In pregnancy, a case report described a patient who received repeated SPG blocks every two weeks through the remainder of her pregnancy for migraine, with immediate pain reduction after each procedure and sustained relief between treatments. She remained largely migraine-free during that period.27Neurology. Sphenopalatine Ganglion (SPG) Block as Short-Term Migraine Prophylaxis During Pregnancy: A Case Report A single case report is far from definitive evidence, but it illustrates the clinical logic: for a pregnant woman whose migraines are disabling and who cannot safely take most preventive medications, a local nerve block that avoids systemic drug exposure has obvious appeal.
Self-Administration at Home
One of the more interesting recent developments is the idea that patients could perform SPG blocks on themselves at home using simple devices. A case series of four patients with post-dural puncture headache described a technique using a needleless syringe to drip local anesthetic into the nostril while the patient lies on their back with their head extended. The authors argued that the approach is feasible, easy, and safe enough for ambulatory or home use, and that it could help patients avoid the need for an epidural blood patch.28Brazilian Journal of Anesthesiology (English Edition). Self-applied sphenopalatine ganglion block for postdural puncture headache: four case reports
For chronic migraine, a retrospective review of patients using a self-administered nasal spray found that most patients judged it useful both as an acute and preventive treatment at three months, with no significant adverse effects beyond transient numbness near the application site.29Journal of Anesthesia and Anesthetic Drugs. Retrospective Chart Review: The Feasibility of a Self-Administered Nasal Spray Targeting the Sphenopalatine Ganglion (SPG) in Treatment of Chronic Migraine Two patients did experience temporary migraine worsening after use and stopped treatment, a reminder that even a low-risk procedure can occasionally backfire. Self-administration is not yet mainstream, and questions remain about whether patients can consistently get the anesthetic to the right spot without a clinician’s guidance, but it represents a shift toward giving patients more control over a treatment that is inherently simple in its mechanics.
Where the Evidence Stands Overall
The research landscape on SPG blocks is wide but uneven. A systematic review that gathered 83 publications on SPG interventions found that only 23 had evidence levels above case series, and the vast majority of those higher-quality studies focused on the block itself rather than ablation or neurostimulation.30PubMed Central. Sphenopalatine ganglion: block, radiofrequency ablation and neurostimulation – a systematic review That means for many of the conditions where SPG blocks are used, clinicians are relying on case reports and small uncontrolled series rather than rigorous randomized trials. The acute migraine data are the strongest, cluster headache neurostimulation has at least one placebo-controlled trial, and the PDPH evidence has been notably weakened by a blinded trial that failed to separate the block from placebo.
None of this means the block does not work. The anatomy and physiology make a compelling case for why it should work, patient satisfaction in clinical practice tends to be high, and the safety profile of the transnasal approach is genuinely excellent. But a procedure’s popularity can outpace its evidence, and SPG blocks are a case where clinicians and patients should be honest about what we know confidently versus what we are still figuring out. For someone considering the procedure, the most useful framing is probably this: the block is low-risk and often effective, especially for acute migraine and cluster headache, but it is not guaranteed to work for every headache type, and the duration of relief varies widely from person to person.