WHAT IS TRIGEMINAL NEURALGIA?Trigeminal neuralgia (facial pain) is a condition that usually occurs in older age. The pain typically occurs in one cheek or lower jaw, and can extend to the nostril or upper lip. Less frequently, pain can also occur around an eye. The pain usually comes in short, intense attacks, often triggered by touching the nose while washing or shaving, eating, or talking. The pain occurs in the area of the trigeminal nerve. This fifth cranial nerve runs forward from an area between the spinal cord, cerebrum, and cerebrum and forms a kind of relay station, nerve ganglion, or ganglion (Gasserian ganglion) at the base of the skull. Here, the nerve divides into three branches: the first branch supplies sensation to the skin above the eye and cornea; the second branch supplies sensation to the skin on the cheek and nostril; and the third branch supplies sensation to the skin on the lower jaw and controls the jaw muscles.WHAT CAUSES TRIGEMINAL NEURALGIA?The cause of trigeminal neuralgia is unclear. Some consider it a kind of epilepsy ("seizure") of the nerve, given the pain that occurs in attacks. A relatively modern theory proposes that a small blood vessel at the back of the head, where the nerve originates, presses against the nerve, triggering the pain. With age, a kind of elongation of the blood vessels occurs, and the bends become more pronounced, making this less common at a younger age. While the theory isn't entirely conclusive, it is useful in daily practice. Furthermore, trigeminal neuralgia occasionally occurs in patients with multiple sclerosis, possibly due to damage at the base of the nerve (in the trigeminal nucleus).TREATMENTTrigeminal neuralgia can almost always be treated in one way or another. Several treatment options are available:
Medication:
This treatment is based on the "epilepsy concept" and therefore consists of administering medications that are also used in epilepsy to prevent or suppress seizures. Carbamazepine and phenytoin (both generic names) are the most commonly used. In young patients, the drawback is that if medication is chosen, it may require lifelong use.
Severing a nerve branch:
This option is almost exclusively used for pain in the first branch, i.e., above the eye. One drawback is the development of complete numbness in the forehead area after the procedure.
Disabling the ganglion: The
ganglion can be punctured using a needle from a point just to the side of the mouth through a hole in the base of the skull. This is usually done under X-ray guidance and can be performed under general or local anesthesia. Several methods can be used to treat the ganglion: creating an injury with heat, electrical current, injecting medication, or applying pressure with an inflatable balloon. The goal is to preserve nerve function as much as possible, but this isn't always successful.
Surgery at the base of the nerve itself, at the back of the head.
This is a more extensive procedure in terms of approach and therefore less suitable for older patients or those with an increased surgical risk. In this procedure, the nerve is located, after which the blood vessel, which in almost all cases is pressing against the nerve, is removed. A sponge-like structure is placed between the nerve and the blood vessel to prevent recurrence. The nerve is completely spared in this procedure.
As a last resort, especially when previous procedures have failed, the nerve at the back of the head can also be severed. This is usually not done completely, as pain usually occurs in the second and third branches, while the goal is to preserve sensation in the cornea.RISKS AND COMPLICATIONSDuring procedures in which nerve branches are deliberately disabled, facial numbness occurs in the area served by those nerve branches. This is different from a crooked face, which is often confused with it. The muscles for facial movement (expression) are supplied by the facial nerve, the seventh cranial nerve. The numbness is comparable to the numb cheek one might get at the dentist after an anesthetic injection, but then it is permanent.
Because accessing the trigeminal nerve requires working along the contiguous seventh and eighth cranial nerves (for expression and hearing, respectively), these nerves do carry a small risk of loss. Fortunately, this is rare and almost always temporary.
During procedures on the ganglion cyst, attempts are made to disable only the second and third branches, but this is not always successful. Sometimes, loss of the first branch occurs, meaning loss of sensation in the cornea. This makes it impossible to notice when a speck of dirt enters the eye, posing a risk of inflammation.
Facial tic:
Facial tic, or "twitch," is caused by sudden activity of the seventh cranial nerve, or facial nerve. The situation is similar to trigeminal neuralgia. However, the facial nerve is primarily a motor nerve, so no pain or other sensory sensations occur, but rather uncontrolled movements in the muscles it serves. These tics occur primarily in stressful situations and can be extremely disruptive in social interactions.
The cause is similar to that of trigeminal neuralgia, so the treatment follows a parallel path. A blood vessel at the back of the head can be severed from the nerve, which almost always leads to the disappearance of the tic. The risk here is loss of function of the seventh or eighth (auditory) cranial nerve.RESULTSThe treatments mentioned almost always lead to the disappearance of the pain or twitching, provided the risk is acceptable. The treatment chosen depends on the location of the pain, the patient's age, the effect of the medication, and the preferences of the patient and the treating physician. In a small percentage of cases, the pain or tic may return. In such cases, the preferred treatment is reassessed. Most treatments can be repeated without many problems. |
