Several disorders that cause facial pain can be successfully treated by neurosurgical procedures. It is important to accurately diagnose the disorder and identify the best treatment for each disorder. In the absence of randomized prospective studies, standardized methods of reporting, and standardized outcome criteria, it is difficult to compare the results of various surgical procedures and the different reported series of the same surgical procedure. Nevertheless, several important observations emerge from reviews of the literature and personal experience.
General Observations on Facial Pain
- Accurate diagnosis is required.
- The diagnosis of typical Trigeminal Neuralgia (TGN) is seldom difficult.
- In general, the length of the list of the patients symptoms is directly proportional to the likelihood of treatment failure.
- Medical treatment should be explored before surgery is contemplated.
- There is no successful surgical procedure for treatment of atypical facial pain.
- It is more difficult to treat neuropathic than neuralgic pain.
- Patients with dysesthetic pain seldom respond to ablative surgery.
- There is no single superior treatment for facial pain. The treatment should be individualized. Patients should have access to a broad spectrum of treatment options.
- The results of surgical treatment diminish as facial pain becomes more chronic.
Results for Recurrent Trigeminal Neuralgia
Controversy exists regarding the treatment of persistent or recurrent TGN. All procedures that currently treat initial TGN can effectively treat recurrent pain. To help select the best treatment, the authors review the following facts and observations:
TGN frequently recurs in other trigeminal divisions
TGN frequently recurs in trigeminal divisions previously free of pain. This observation, which can follow all surgical procedures, may represent progression of the underlying disorder rather than recurrence.
Repeat MVD is frequently unsuccessful
A second MVD is performed in less than one-third of all posterior fossa explorations for pain recurring after a prior MVD; therefore, most patients undergoing a second posterior fossa surgery require or undergo trigeminal rhizotomy (28-30). Repeat MVD is associated with increased risk of cranial nerve palsy, perioperative morbidity, and dysesthesia (28-30). In the series of Barker et al., the risk of disturbing facial numbness increased to 8% after repeat MVD (6). In our experience, better results can be achieved by using percutaneous techniques (1). In less than 1% of cases, patients with intractable TGN require complete section of the sensory and motor root to achieve pain relief.
Repeat glycerol rhizotomy is frequently unsuccessful
Repeat glycerol rhizotomy is associated with a higher risk of technical failure because the trigeminal cistern becomes less accessible after repeated glycerol injections (21,31). There is no documentation that PSR rhizotomy and balloon compression are associated with greater technical failure when these procedures repeated. All percutaneous procedures do have a higher risk of sensory complications following repeated procedures.
Percutaneous destructive procedures are not indicated in patients
All percutaneous destructive procedures fail to relieve recurrent trigeminal pain in patients who are analgesic in the painful division. Such patients may require posterior fossa exploration for MVD or intracranial trigeminal rhizotomy, radiosurgery, dorsal root entry zone (DREZ) surgery, or motor cortex stimulation.
Posterior fossa exploration for recurrent trigeminal pain following MVD is not suitable to the majority of patients because of a low success rate. Superior results can be achieved by percutaneous destructive procedures, especially PSR rhizotomy, with less risk of perioperative complications. Otherwise healthy patients with pain recurring after a prior percutaneous destructive procedure are best treated by MVD. A repeat percutaneous procedure or radiosurgery is considered for patients who are medically unhealthy. Patients who have recurrent TGN in an analgesic area rarely benefit from repeat destructive surgery, but may be relieved by decompression or complete section of the sensory and motor root.
Through the Trigeminal Neuralgia Association (TNA), local support groups are available. The support group provides an opportunity for patients and their families to share experiences, receive support, and learn about advances in treatments, pain control, and medications. Additional information is available on the web at www.tna-support.org or facial-neuralgia.org
If you would like information about the Greater Cincinnati Trigeminal Neuralgia Support Group, please call the Mayfield Clinic at (513)569-5290. For support outside Greater Cincinnati, please contact the Trigeminal Neuralgia Association at 800-923-3608.
The following journal articles and books formed the basis of our observations along with our own personal experience. Bibliography listing.