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Summary of the evidence
- There is low quality evidence that trigeminal glycerol rhizotomy is effective for the treatment of adults with trigeminal neuralgia.
- The procedure may provide some benefit for trigeminal neuralgia patients in cases where less invasive medical interventions or appropriate psychosocial measures have failed.
- The evidence was provided by one systematic review, one comparative study and four observational studies, covering a total of 934 patients. Pain relief was reported in a range of studies beyond one year.
Clinical practice recommendations | |
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Trigeminal glycerol rhizotomy may be considered for the treatment of adults with trigeminal neuralgia for whom medical (and, where appropriate, psychosocial) management has failed (C). |
What is trigeminal glycerol rhizotomy?
Trigeminal glycerol rhizotomy is a technique that causes a chemical lesion to the trigeminal nerve in order to change the way it transmits pain. The trigeminal nerve carries sensation and pain fibres from the face to the brain.
What conditions is trigeminal glycerol rhizotomy used for in the studies appraised?
- Idiopathic trigeminal neuralgia that is inadequately controlled by medical management.
- Multiple sclerosis-related trigeminal neuralgia that is inadequately controlled by medical management.
How is trigeminal glycerol rhizotomy done?
The procedure is usually carried out under local anaesthetic and sedation. A needle is passed under X-ray control to the hole where the trigeminal nerve travels into the skull. Glycerol is injected through this needle to just inside the skull, adjacent to where the nerve ganglion is located. The patient is then repositioned to allow the glycerol to come into contact with different parts of the ganglion depending on where their pain is felt.
Where is trigeminal glycerol rhizotomy done?
The procedure is carried out in a hospital operating room or radiology department with access to an operating room.
Who does trigeminal glycerol rhizotomy?
A neurosurgeon usually performs this procedure.
How effective is trigeminal glycerol rhizotomy?
One systematic review, one comparative study and four observational studies provided information on the effectiveness of trigeminal glycerol rhizotomy for the treatment of adults with trigeminal neuralgia.
The systematic review included two relevant uncontrolled studies (n=85, n=60) that reported complete pain relief in patients with trigeminal neuralgia after one year in 68% and 86% of patients respectively (Lopez et al. 2004). At three year follow-up, 54% and 53% of patients were pain-free. The authors conclude that the available evidence is limited, particularly in the longer term.
In the comparative study, the outcomes of trigeminal glycerol rhizotomy operations were compared to the results of two other treatments for idiopathic trigeminal neuralgia (n=44) and trigeminal neuralgia related to multiple sclerosis (n=18). However, it was not clear how the patients were selected for each intervention and it was therefore not appropriate to compare the results directly. A single trigeminal glycerol rhizotomy treatment was successful for up to two years in 81% of people with idiopathic trigeminal neuralgia and in 44% of those whose trigeminal neuralgia was related to multiple sclerosis. (Braun et al. 1996).
The four observational studies reported that among patients who received trigeminal glycerol rhizotomy:
- 76% had excellent or good pain relief at 12 months (Bergenheim et al. 1995, n=99). The rate of success was higher in people who had not undergone previous treatment such as radiofrequency neurotomy or ethanol injections;
- Median time to resumption of medical treatment was 726 days (North et al. 1990, n=85);
- 72% had no recurrence of symptoms at one year, 32% at three years and 8% at six years (Saini 1987, n=469 at one year follow-up);
- 81% were pain free at 2 to 48 month follow-up (Hakanson 1981, n=74).
How safe is trigeminal glycerol rhizotomy?
Adverse effects following trigeminal glycerol rhizotomy were reported in the above-mentioned studies and in 18 additional poorer quality studies not included in the evaluation of effectiveness. Those commonly reported included corneal disturbance (occurring in 5-24% of patients), dysaesthesia (3-24%), hypoaesthesia (3-33%), anaesthesia dolorosa (0-5%) and herpes (3-50%). Other effects were reported less frequently and included major sensory disturbance, swelling or bruising at injection site, periodic itching, tear flow disturbance, paralysis of motor component of trigeminal nerve branch, diplopia and meningitis.