Pulsed radiofrequency of the SPG: indications and pathway
Targeted neuromodulation, not an automatic procedure
Pulsed radiofrequency of the sphenopalatine ganglion (SPG) applies intermittent electrical pulses to modulate neural activity, maintaining the working temperature around 42 °C. It is distinct from thermal or lesional radiofrequency, which uses higher temperatures to produce a controlled lesion.
It is an interventional procedure reserved for selected cases, after a definitive diagnosis and optimisation of therapies indicated for the specific headache or pain syndrome.
Learn more about the principles of therapeutic radiofrequency (in Italian)
When it may be considered
The assessment concerns selected patients with refractory headache or craniofacial pain:
- after specialist diagnosis, with particular attention to trigeminal autonomic cephalalgias
- when first-line therapies are ineffective, not tolerated or insufficient
- after reviewing available imaging, considering CT when needed for access planning and a transmucosal block when clinically appropriate
- after individual assessment of the balance between expected benefits, limitations and risks
The diagnostic block may guide the pathway, but a positive response does not guarantee the outcome of radiofrequency.
How the procedure is performed
- in a controlled environment, with clinical monitoring
- under sterile conditions and with local anaesthesia or calibrated sedation
- under fluoroscopic guidance, to verify the trajectory and position with precision
- with Cosman G4 generator and pulsed radiofrequency parameters defined for the individual case
The procedure is followed by clinical observation and scheduled follow-up.
Possible outcomes, limitations and evidence
The response is assessed over time and may include:
- reduction in pain intensity or attacks
- reduction in episode frequency and, when possible, medication burden
- improvement in function and quality of life
The extent and duration of benefit are variable. The available evidence on SPG radiofrequency procedures is still limited and derives largely from small studies and clinical series: there are no guaranteed results.
This page is part of the PONOS pathway dedicated to craniofacial pain, refractory headaches and the sphenopalatine ganglion.
PONOS experience and method
Dr Evangelos Panagiotakos performs sphenopalatine ganglion neuromodulation within a rigorous clinical pathway: diagnosis, patient selection, radiological planning, informed consent and follow-up over time.
The SPG clinical pathway
- Specialist diagnosis
- Imaging and selection
- Transmucosal test, if appropriate
- Indicated procedure
- Follow-up
The transmucosal test: value and limitations
The SPG transmucosal test, performed with local anaesthetic — in the PONOS protocol 2% lidocaine — may provide screening information on the possible involvement of the ganglion in the pain condition.
The result must be interpreted with caution:
- the block may provide temporary relief and clinical information; it does not independently establish a diagnosis or replace the headache treatment plan
- a positive response does not guarantee the success of pulsed radiofrequency
- a negative response does not automatically exclude SPG involvement
The clinical decision integrates diagnosis, symptom progression, treatments already performed, imaging and test response.
→ dedicated page: “Sphenopalatine Ganglion Transmucosal Test”
Safety, risks and follow-up
Access to the SPG requires accurate anatomical planning and fluoroscopic guidance. Pulsed radiofrequency is designed as a neuromodulatory technique, but remains an invasive procedure and not without risks.
Before treatment, the following are assessed:
- current therapies, coagulation, allergies and comorbidities
- individual anatomy, side to be treated and radiological findings
- informed consent, monitoring and post-procedure instructions
Possible adverse events include transient pain, bleeding, infection, haematoma or sensory changes; the risks relevant to the proposed access route and technique must be discussed before treatment.
After the procedure
Follow-up considers multiple dimensions, not only the pain score:
- intensity, frequency and duration of attacks
- medication use, functional recovery and quality of life
- time to onset of benefit, duration and possible recurrences
Results are individual: a benefit may appear rapidly or gradually, be partial or not occur.
Further information on the sphenopalatine ganglion
Scientific references
Selected references for further reading on the diagnoses and treatments discussed on this page.
- Ho KWD, Przkora R, Kumar S. Sphenopalatine ganglion: block, radiofrequency ablation and neurostimulation – a systematic review. J Headache Pain. 2017;18:118. (Systematic review)
- Tolba R, Weiss AL, Denis DJ. Sphenopalatine Ganglion Block and Radiofrequency Ablation: Technical Notes and Efficacy. Ochsner J. 2019;19:32–37. (Technical review)
- May A et al. European Academy of Neurology guidelines on the treatment of cluster headache. Eur J Neurol. 2023;30:2955–2979. (Guidelines)
These sources distinguish nerve blocks, radiofrequency and neurostimulation: results from one technique cannot automatically be applied to another.