What is trigeminal neuralgia?
Trigeminal neuralgia consists of a pain with very particular characteristics. Patients describe it as if it were an electric shock, a cramp, which is located on one side of the face and specifically in one of the territories corresponding to the trigeminal nerve, which picks up the sensitivity of the face.
This nerve has three branches and the pain can be located in the forehead and the orbit, or in the cheek, extending towards the wing of the nose or the region in front of the auricle; or, finally, in the jaw, extending towards the base of the tongue and the chin.
These pains are of short duration and are repeated, i.e., they appear in bouts. They appear in relation to friction, or coinciding with chewing or speech and are very disabling for the patient.
What are the causes and what are the symptoms?
Trigeminal neuralgia is characterized because the pain in the form of electrical discharges or cramps is very specific. And it also has, as I have already mentioned, a characteristic anatomical radiation.
Sometimes there are tumors that are compressing and irritating the trigeminal nerve and removal of the tumor relieves this problem. On other occasions, we do not find a clear cause on diagnostic imaging and we are faced with the so-called typical or essential trigeminal neuralgia.
The initial response to medication is usually very good and is also an aspect that helps us to confirm the diagnosis. Specifically, the first line drug to treat these patients is carbomazepine or tegretol.
Initially, these patients improve with this drug, but later the crises reappear and we have to take other measures. Also characteristically the pain respects sleep and these patients, who in many occasions can hardly eat or shave in the case of men, can sleep several hours, and very restfully, at night.
How can we treat it?
With regard to the treatment of trigeminal neuralgia, except when there is a cause such as the tumor that I have mentioned, which can be operated with good results, when it is an essential neuralgia the first thing to try is medication. Subsequently, the second line of treatment is radiosurgery. Radiosurgery has the advantage that it is not an invasive treatment and it is effective in 80% of patients suffering from trigeminal neuralgia, although it takes between three and nine months to take effect.
The side effects that this treatment can produce is that in 30% of patients there is a decrease in sensitivity on the affected side of the face, which in most patients is something completely bearable.
Another possibility is the realization of a thermocoagulation in Gasser’s ganglion, which produces a decrease in sensitivity and pain relief in 70% of patients who are treated. Or compression of Gasser’s ganglion, by introducing a small balloon, the so-called Mullan technique, which is inflated with physiological saline and compresses the fibers of this nerve located in Gasser’s ganglion, also relieving pain.
Finally, in young patients, the so-called microvascular decompression can be attempted, which consists of a surgical intervention in which the trigeminal nerve is dissected and freed from the arteries or veins that are compressing it. This is a procedure especially indicated in those patients with low surgical risk and with a possibility of improvement between 80% and 85% of the patients treated.