Ultrasound-guided pulsed radiofrequency for chronic facial pain

In patients whose pain can be attributed to a branch of the trigeminal nerve, ultrasound-guided pulsed radiofrequency (PRF) may be considered when conservative care provides insufficient benefit or is not tolerated. At PONOS Clinic, assessment considers both peripheral branches and, where appropriate, the maxillary (V2) and mandibular (V3) divisions.

PRF delivers pulses of radiofrequency energy through an electrode positioned near the nerve, with the aim of modulating pain signalling. Unlike thermal radiofrequency, it does not aim to create a thermal lesion in the nerve. This does not mean it is risk-free or that the outcome is guaranteed.

Peripheral branches and sensory territories

Target selection depends on the distribution of pain, sensory examination and diagnosis. The territories listed are approximate and may overlap: the location of pain alone is not enough to select a nerve for treatment.

For some targets, including the zygomatic nerve, specific clinical evidence for PRF is particularly limited. This list describes possible anatomical targets to assess, not equivalent indications or proven outcomes for every nerve.

Ultrasound-guided PRF of V2 and V3

When symptoms affect a broader territory, treatment of the maxillary division V2 or mandibular division V3 at an extracranial site may be considered. These targets are more proximal than the individual cutaneous branches and are distinct from the Gasserian ganglion.

Ultrasound allows anatomical landmarks to be identified, vessels to be assessed with Doppler and needle placement to be guided. Direct visualisation of the nerve depends on the target and individual anatomy. The motor component of V3 must also be considered.

Further information: V2 treatments and V3 treatments.

Chronic pain, neuropathic mechanisms and patient selection

Different mechanisms and sensitisation may coexist in persistent pain. Burning, electric shocks, pain on light touch or sensory changes help guide assessment, but pain duration does not automatically establish a neuropathy. Neuropathic pain is associated with a lesion or disease of the somatosensory system; sensitisation alone is not synonymous with nerve damage.

PRF is therefore assessed for a consistent clinical diagnosis and target. A selective local anaesthetic block, when indicated, may help assess the territory involved; temporary relief does not guarantee subsequent PRF effectiveness. In PIFP itself, without a demonstrable peripheral target, neuromodulation of trigeminal branches is not routine treatment.

What outcomes can be expected?

Studies on V2/V3 and clinical reports on certain peripheral branches describe possible pain reduction in selected patients. However, evidence differs by diagnosis, target, guidance technique and protocol: outcomes in trigeminal neuralgia do not establish general effectiveness for persistent idiopathic facial pain. Evidence for the auriculotemporal nerve also includes individual case reports, which cannot provide a reliable estimate of the probability of success.

Benefit may be partial or temporary and is also assessed through sleep, eating and daily activities. Alternatives and risks are discussed before the procedure, including bleeding or haematoma, infection, a flare-up of pain, sensory changes and injury to nearby structures. Ultrasound guidance supports procedural control but does not eliminate these risks.

References: Can et al.: retrospective study of ultrasound-guided maxillary and mandibular PRF; Lim et al.: ultrasound-guided infraorbital nerve PRF; Tereshko et al.: PRF for auriculotemporal neuralgia, a case report; IASP: definition of neuropathic pain.

Frequently asked questions about chronic persistent facial pain

Are persistent facial pain and trigeminal neuralgia the same?

No. Persistence describes how long pain lasts. Trigeminal neuralgia and PIFP are different diagnoses, although neuralgia may include continuous pain between attacks. Clinical assessment helps distinguish them.

If tests are normal, is the pain imaginary?

No. A normal test does not invalidate the pain reported. Results must be interpreted alongside the history and examination, avoiding both premature conclusions and repeated investigations without an indication.

Is pain after dental treatment always PIFP?

No. Dental causes and possible post-traumatic neuropathies must be assessed. A temporal association with a procedure alone does not identify the mechanism of pain.

Is radiofrequency indicated in every case?

No. Chronic facial pain alone is not an indication. Invasive procedures are not routine treatment for PIFP; any intervention requires an appropriate diagnosis and target, with discussion of expected benefits, limitations and risks.

When is urgent assessment needed?

New pain with loss of vision, a painful red eye, facial weakness or other neurological deficits requires urgent assessment. Fever with facial swelling or difficulty swallowing needs prompt medical attention; call 112 if you have difficulty breathing.

What should I bring to the first consultation?

Available reports and images, dental records and a list of medicines and procedures already tried. A short diary of the location, duration, triggers and course of the pain may help the assessment.

Further reading: ICHD-3 criteria for PIFP and the scientific references below.

This information helps explain the care pathway and does not replace individual clinical assessment.