Trigeminal neuralgia, causes and neurosurgical treatment
Trigeminal neuralgia is a disease that generates a great decrease in the quality of life of patients. Clinically, it manifests as an intense pain in the form of discharges through one or more territories of the hemiface. The pain is triggered by low intensity stimuli, such as chewing, shaving or brushing your teeth. When the symptomatology is very pronounced, it greatly complicates the daily activities of the patient, who even have difficulties to eat correctly.
This pathology can appear in different stages of life, especially after the 5th decade of life. The pain is frequently located in the second and third branches of the trigeminal nerve (V2-V3), that is, in the posterioronasal area, cheekbone and jaw.
The trigeminal nerve, also called V cranial nerve, is responsible for collecting the sensitivity of the face. It is also responsible for controlling the musculature of chewing. In its path from the brainstem to the face can be compromised by several structures, usually vascular and meninges.
The cause of trigeminal neuralgia is due to compression of the nerve in its exit from the brainstem (cisternal portion) by an artery or vein (Fig. 1). It is usually the superior cerebellar artery, which intimately contacts the nerve.
The treatment of these patients begins with medical treatment after a general evaluation. It must always be complemented with an image study (magnetic resonance) that discards, for example, a tumor origin of neuralgia. The medical treatment consists of a combination of different drugs that the neurologist regulates to monitor the evolution of the patient.
The failure rate of medical treatment is very high, up to 75%. Therefore, most of these patients will require an alternative treatment.
Trigeminal neuralgia: neurosurgical treatment
The most effective neurosurgical treatment, which directly treats the cause of pain (microvascular trigeminal involvement), is microvascular decompression. Through this technique of brain surgery, the neurosurgeon can access the trigeminal nerve that is compromised. For this an incision is made behind the ear and a small window in the cranial bone. The neurosurgical approach allows us to explore, liberate and isolate the trigeminal from the commitments that affect it. In all the patients that intervene in trigeminal neuralgia, some type of compression of the nerve is observed, either by an artery, vein or by combinations of both together with adhesions of the meningeal layers.
From our extensive experience in the management of patients with this type of neuralgia, we consider microvascular trigeminal decompression as a safe treatment option with a very low rate of complications, which should be offered to all patients with trigeminal neuralgia in which the medical treatment have failed. It is an intervention that can be performed in patients with a wide range of age, since the postoperative recovery is quick and comfortable for the patient.
Other treatment options are treatment by percutaneous puncture of the trigeminal ganglion (Gasser’s ganglion). From this ganglion originate the three branches of the nerve that innervate the face) and consists on application of radiofrequency energy on it. The third option is radiotherapy on said ganglion in order to alleviate the painful symptomatology. In our opinion, these last two techniques are not reversible, and can cause complications such as the dreaded painful anesthesia, in which the patient maintains pain and associates a loss of sensitivity in the corresponding hemiface.
Dr. Javier Sendra Tello