A Novel Method of Noninvasive Sphenopalatine Ganglion Stimulation in Craniofacial Pain: Case Series and Literature Review
Year: 2026
Type: article
Abstract: BACKGROUND: Implanted sphenopalatine ganglion (SPG) stimulation is a well-established treatment for cluster headaches, but its use in other headache disorders remains limited. The development of noninvasive, transmucosal SPG stimulation offers a potential alternative to implanted SPG stimulation devices that eliminates the need for an invasive implantation procedure, which could expand its indications beyond cluster headaches. With this proof-of-concept study including a case series and a literature review, we aimed to determine the safety and clinical effectiveness of noninvasive SPG stimulation in patients with craniofacial pain and especially refractory facial pain. MATERIALS AND METHODS: The MEDLINE (PubMed) data base was queried using predefined search terms and inclusion/exclusion criteria for studies of SPG for headache and facial pain. The search period was not limited. Furthermore, a retrospective, single-center, single-arm study was performed. Patient recruitment was conducted in April 2024. Patients with chronic facial pain, with pain duration >12 months and refractory to pharmacologic, interventional, and neurosurgical treatment, were eligible. Noninvasive, transmucosal SPG stimulation was performed using a flexible nasal electrode, guided under fluoroscopy during the first session, and for eight to 12 months repeated at individual intervals based on clinical response. Safety was assessed by collecting data on adverse events and complications. For the assessment of clinical effectiveness, pain intensity was measured on the numeric rating scale (NRS) at baseline, after every stimulation session for one month and after an individual follow-up. Further outcome measures assessed at baseline, at one month after the first stimulation session, and after the individual follow-up included the visual analog scale (VAS), McGill Pain Questionnaire (MPQ), and the Short-Form MPQ. Quality of life was assessed with the 36-Item Short Form Survey (SF-36) quality of life questionnaire. RESULTS: A thorough review of the available literature identified a total of 13 relevant results. The included studies were randomized controlled trials (RCTs), individual cohort studies, case series, and case reports, using implantable and nonimplantable SPG stimulation in patients with primary headaches including cluster headache and intractable migraine and facial pain including PIFP. Implanted SPG stimulation in chronic cluster headache achieved pain relief in 62% of attacks within 15 minutes and complete pain freedom in 40% of patients, whereas 35% to 45% of patients experienced ≥50% reduction in attack frequency over long-term follow-up. Alleviation in headache disability and improvement in quality of life were sustained up to 24 months. Therapy efficacy critically depends on accurate electrode placement. Noninvasive intranasal SPG stimulation also showed durable benefits in refractory primary headaches. Four patients with refractory facial pain were included in the case series. All four cases indicated improvement after SPG stimulation. Pain intensity decreased in all cases, with reductions in NRS from 9.0 ± 1.2 at baseline to 5.8 ± 1.3 after one month and 4.0 ± 2.6 at individual follow-up (eight-12 months), VAS (80 ± 14 → 40 ± 16 → 40 ± 26) and present pain index on MPQ (4.5 ± 0.6 → 2.3 ± 1.0 → 2.8 ± 1.1). In one patient, complete pain resolution was achieved whereas others experienced sustained partial relief. Quality of life, measured on the SF-36 questionnaire, also improved, with physical functioning increasing from 28.8 ± 6.3 to 70 ± 7.1 after one month and 87.5 ± 11.9 at follow-up, pain scores from 23.8 ± 2.5 to 72.5 ± 8.7 and 55 ± 27, and vitality from 21.3 ± 4.8 to 55 ± 8.2 and 60.3 ± 6.8. The improvements in pain relief and quality of life regarding physical functioning and vitality remained evident even after eight to 12 months in all four cases, whereas the required frequency of stimulation sessions decreased. CONCLUSION: The findings of this study, which are based on data from four patients and in accordance with the literature reviewed, appear to show that noninvasive, transmucosal SPG stimulation is an effective and safe therapeutic option for patients experiencing refractory facial pain. This method may offer an alternative for individuals requiring infrequent stimulation and can serve as a test or bridging therapy for those who may eventually require permanent SPG stimulation. The noninvasive and nonpermanent nature of the treatment under discussion suggests that it also may be used for exploratory purposes in other craniofacial pain disorders, such as migraine and tension-type headache. The most significant and evident limitation of the study is the small sample size; therefore, the results should be considered preliminary and not generalized. Further studies are required to confirm these findings. Such studies should include RCTs in larger patient populations with longer follow-ups.
Institutions: St George's Hospital, Medical University of Warsaw
Language: English
Subfield: Anesthesiology and Pain Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,110
OpenAlex ID: W7119917965