PONOS CLINIC · SPECIALIST PAIN CARE
Transmucosal SPG test
How it works, what it tells us and its limitations.
A local anaesthetic block via the nasal route, interpreted within the specialist pathway for craniofacial pain.
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What is the transmucosal sphenopalatine ganglion test
The transmucosal sphenopalatine ganglion (SPG) test, also called a transnasal block, involves the application of local anaesthetic to the nasal mucosa. Access is through the nostril, without percutaneous puncture. In the pathway dedicated to the sphenopalatine ganglion, any potential relief and its duration are observed.
Purpose of the test
The test aims to:
- explore the possible role of the SPG in maintaining pain
- provide additional information in the diagnostic process
- guide (not decide) subsequent clinical choices
The block may provide temporary relief and be used to observe the clinical response. It is not an examination that, on its own, confirms a diagnosis or proves that pain originates exclusively from the SPG.
How the evaluation is performed
- Before: symptoms, therapies, and conditions that may affect the procedure are reconstructed. Report allergies to local anaesthetics, medications taken, and nasal problems; do not modify therapy independently.
- During: the physician applies the anaesthetic nasally using the technique chosen for the case. Medication, quantity, and timing are defined clinically.
- After: the pain is compared with the initial level, and any relief, duration, and side effects are noted.
What to note after the test
Record the time, pain intensity before and after, changes in associated symptoms, the return of pain, and any rescue medication. If pain is not present at the time of the procedure, report it: this data changes the interpretation of the result.
Possible discomforts
Nasal irritation, a bitter taste, tearing, or a temporary sensation of numbness in the palate or throat may occur. Post-test instructions are provided by the physician based on the individual response.
Studies describe benefits primarily in the short term for certain conditions; methods and results are heterogeneous. Scientific insight: systematic review of SPG treatments.
Clinical interpretation: the critical point
- Positive response: data to be integrated into the evaluation
- Negative response: does not alone exclude SPG involvement
- Intensity and duration of relief: to be recorded, without considering them a guarantee for radiofrequency
The response is interpreted alongside the diagnosis, the technique used, the spontaneous course of the attacks, and other therapies. A transient improvement does not automatically select the patient for a percutaneous procedure.
Limitations of the test
- it is not a decisive test
- it does not replace clinical diagnosis
- it does not automatically select for RF
The interpretative risk is attributing a greater significance to the result than what can be demonstrated. Especially in episodic headaches, it is necessary to distinguish the observed relief from the natural conclusion of the attack.
PONOS clinical experience
At PONOS Clinic, the test is considered after clinical evaluation. Bring reports, available examinations, and a list of therapies already tried, including benefits and side effects. The goal is to gather useful elements to decide the next step, which may also consist of re-evaluating the diagnosis or pharmacological therapy.
A different procedure: pulsed radiofrequency of the SPG
- Procedure performed under fluoroscopic guidance
- Selective targeting of the ganglion
- Percutaneous procedure distinct from the transmucosal test
- To be evaluated individually: a positive test is not enough to indicate it
Links to SPG pages
Continue the SPG pathway
- Sphenopalatine ganglion: main page
- Cluster headache: diagnosis and treatments
- Pulsed radiofrequency: indications, technique, and risks
Request a specialist assessment
Dr Evangelos Panagiotakos MD
Anaesthesiologist – Interventional Pain Specialist
Frequently asked questions
Does a positive block guarantee later treatment success?
No. The response is interpreted alongside the diagnosis and other clinical findings.
Does every patient need a procedure?
No. Each step is considered only when it answers a clinical question or offers an appropriate balance of potential benefit and risk.