The trigeminal nerve is the fifth of the twelve cranial nerves, so also called cranial nerve V. It is divided into three branches:
- - Ophthalmic (V1)
- - Maxillary (V2)
- - Mandibular (V3)
Ophthalmic and maxillary branch have sensory component, while the mandibular also has a motor function (innervate the masseter muscle). The three branches have a common origin Gasser ganglion, located at the base of the skull.
When the trigeminal nerve suffers a disorder, it occurs what is called trigeminal neuralgia, which mainly affects people between 60 and 70 years, especially women, although it can also occur in younger people.
Symptoms of trigeminal neuralgia
This condition is presented as a very acute facial pain that lasts a few seconds or a few minutes in some cases. In fact, in the world of Pain Unit , it is considered one of the most intense colors, in addition to greatly affect the daily life of those who suffer failure , causing high degrees of disability.
Typically, the pain on the right side of the face and in some cases triggered by friction or from actions such as swallowing, speaking or shaving. The branches usually affected are the 2nd and 3rd.
Since this symptom can also mean a tumor or vascular intracranial pathology, or multiple sclerosis, usually you need an MRI to discard.
Treatment of trigeminal neuralgia
Once diagnosed the disorder, the first option is antiepileptic drug therapy, antidepressants or neuromodulators and even opioids. The first-line drug is carbamazepine or oxcarbazepine. However, this treatment is ineffective in some patients, so we must resort to interventionist approach.
In this field, conventional radio frequency thermocoagulation of Gasser ganglion is treatment that is usually recommended. It is to access the node by the oval hole (at the base of the skull) percutaneously, always in the operating room and full monitoring.
The patient is placed face up, under light sedation and local anesthesia, and a needle 2 cm of the oral commissure is inserted. Always under fluoroscopic guidance, the needle tunnel-vision towards the oval hole is placed, controlling the depth with a side view.
Once the foramen ovale is a motor and sensory stimulation is done to know where to place definitively the tip of the needle. Having secured the area in the ganglion of Gasser, the patient is anesthetized and takes between two and four thermal injury on nerve fibers.
After surgery, the patient wakes up and is entered under observation to check that no short-term complications. Although the technique is safe, you can always some risk, among which are:
- - Bleeding from puncture of the carotid artery (0.2-2% probability)
- - Weakness of the masseter muscle (10-24% chance)
- - Paresthesias (5-26% probability)
- - Painful anesthesia (0.3-4% probability)
- - Cranial nerve palsies (0.2 to 6.5% probability)
- - Ocular palsy (0.5% probability)
Other complications that may have are training retrobulbar hematomas, facial hematoma, keratitis, corneal reflex impaired, hard of hearing or vasomotor rhinorrhea.
Moreover, the rate is above immediate improvement of 95% and total pain relief is accomplished in about 80% of cases, even in some cases to completely remove the medication. Although 25% of cases may reoccur pain, the patient can repeat the treatment.