Radiofrequency lesioning (also known as thermocoagulation) uses heat from an electric current to create a lesion (an area of damage) on the offending trigeminal nerve branch so that pain is no longer triggered.
The procedure
This is usually an hour-long procedure carried out under a short general anaesthetic or deep sedation. As with the other percutaneous procedures, a hollow needle is inserted through the cheek and into the foramen ovale to reach the trigeminal (Gasserian) ganglion.
The traditional procedure is to insert an electrode down the needle once it is in place and you are then awakened. The surgeon passes a low current through the electrode so that you can report exactly which area of the face you feel has been stimulated.
You are then re-sedated and the area targeted with a higher electric current to produce a heat (radiofrequency) lesion to damage the trigeminal nerve. Some practitioners now carry out the whole procedure with the patient asleep, relying on placement of the needle by X-ray, as for other methods.
The temperature and time can be varied, with the goal being to damage the nerve enough to interfere with its ability to transmit pain signals to the brain, whilst preserving touch sensations in the face, although some mild numbness is highly likely.
After the surgery, your cheek may be a bit sore, but you should be able to touch the former trigger zones without causing pain and be able to resume normal activities right away.
Advantages
- A very high initial success rate: over 90%. · Pain relief is usually immediate and the procedure can be repeated if the pain returns.
Disadvantages At least some mild numbness is highly likely. While the amount of damage (and hence numbness) can be adjusted, less numbness usually results in earlier return of pain. Numbness of the eye and temporary jaw muscle weakness are both possible.
Around 2% of patients suffer from severe numbness or Anaesthesia Dolorosa following the procedure.
The procedure is less effective when there is already loss of sensation or where there are multiple trigger zones in different nerve branches.
