Trigeminal neuralgia is a common clinical cranial nerve disease, mostly occurring in middle-aged and elderly people, characterized by recurrent, transient, electric shock-like pain in the face, known as the “world’s first pain. It seriously endangers the physical and mental health of patients and directly affects their normal work and life, and in serious cases, it can lead to depression and even suicide. With the continuous development of medicine and the in-depth research of many neurologists in this area, the treatment method for primary trigeminal neuralgia has been matured, and trigeminal nerve microvascular decompression is the best and most effective treatment plan for primary trigeminal neuralgia, which can cure the painful attacks on the basis of preserving the nerve function of patients, and make patients return to smile is no longer a dream.
What is trigeminal nerve
The trigeminal nerve is the fifth of twelve pairs of cranial nerves in the head, and is a mixed sensory and motor nerve that governs the face and mouth. It starts from the brain cadre and divides into thicker sensory nerve roots and thinner motor nerve roots. The sensory fibers of the trigeminal nerve originate from neurons in the semilunar ganglion, and its central protrusions are clustered into the trigeminal sensory roots, which are about 19.6 MM long, 4.7 MM wide, and 2 MM thick, and divide into three trunk branches after exiting the skull: the ophthalmic, maxillary, and mandibular branches (hence the name trigeminal nerve), which are distributed in the frontal (forehead), maxillary (cheek), and mandibular (jaw) regions, respectively, and manage pain, temperature, touch, and mastication sensations in these three parts. The trigeminal nerve is located in the frontal region (forehead), the maxillary region (cheek) and the mandibular region (jaw).
What is trigeminal neuralgia?
Trigeminal neuralgia, commonly known as “facial pain”, is a severe and recurrent electric shock-like pain in the distribution area of the trigeminal nerve in the face, starting from a point in the face, mouth or jaw and spreading to one or more branches of the trigeminal nerve, with the second and third branches being the most common. The pain does not extend beyond the midline of the face or the trigeminal nerve distribution area. Occasionally, bilateral trigeminal neuralgia occurs, accounting for about 3% of cases.
The prevalence and nature of pain in trigeminal neuralgia
Trigeminal neuralgia is most common in middle-aged and elderly people, with about 182 cases per 100,000 people, the majority of cases occurring over the age of 40, slightly more in women than in men, mostly on the right side of the face, and rare bilaterally. The pain is mostly caused by the maxillary or mandibular branch on one side and gradually extends to both branches or even all three branches.
Trigeminal neuralgia symptoms
Patients have painful episodes like cutting, stabbing, tearing, burning or electric shock-like severe and unbearable pain, and even painful. The attacks are often unpredictable, with trigger points, also known as “trigger points”, often located on the upper lip, nose, gums, corners of the mouth, tongue, eyebrows and other places. Light touch or stimulation of the trigger point can trigger an attack of pain; each pain attack lasts from a few seconds to 1 to 2 minutes and stops abruptly. At the beginning of the disease, the number of attacks is small and the interval is long, ranging from several minutes to several hours; as the disease develops, the attacks become more frequent, the interval is gradually shortened, and the pain gradually increases and becomes more intense. The pain attacks decrease at night. There is no discomfort during the interval; talking, eating, washing, shaving, brushing teeth and wind blowing can trigger the pain attack, so that the patient is depressed, careful and cautious in action, even afraid to wash face, brush teeth, eat and speak carefully for fear of causing an attack. During the attack, the patient often suddenly stops talking, eating and other activities, and the painful side can show spasms, i.e. “painful spasms”, frowning and clenching teeth, opening the mouth to cover the eyes, or rubbing the face with the palm of the hand, resulting in local skin roughness, thickening, loss of eyebrows, conjunctival congestion, lacrimation and salivation. The patient’s expression is tense and anxious. Some patients mistakenly think that they have toothache and go to the stomatology department, and some of them still have pain even after removing several teeth.
Classification of trigeminal neuralgia
Trigeminal neuralgia can be divided into two categories: primary trigeminal neuralgia and secondary trigeminal neuralgia, among which primary trigeminal neuralgia is more common.
1. Primary trigeminal neuralgia: It refers to trigeminal neuralgia in which no clear organic lesion is found through imaging examination and other means. It may be caused by compression of nerve roots by neighboring blood vessels, or it may be caused by compression due to thickening of the arachnoid membrane and narrowing of the bone foramen through which the nerve passes.
2. Secondary trigeminal neuralgia: It refers to trigeminal neuralgia caused by organic lesions such as tumor, inflammation and vascular malformation that stimulate the trigeminal nerve. This type is different from the primary one in that the pain is often persistent and positive signs of trigeminal nerve can be detected.
Etiology of primary trigeminal neuralgia
There are different theories about the etiology of trigeminal neuralgia, mainly the central lesion theory (about 1%) and the peripheral lesion theory (99%). Among the peripheral lesions, vascular compression, arachnoid thickening, and calcification account for more than 95% of the causes. In addition, demyelinating diseases, viral infections, the “short circuit” theory, genetics, and metabolic reactions account for about 4% of the causes.
Treatment methods
I. Drug treatment
Carbamazepine: It is effective in 70% of patients for pain relief, but about 1/3 of patients cannot tolerate its side effects such as drowsiness, dizziness and gastrointestinal discomfort. It is started twice a day and can be used three times a day later. 0.2~0.6g per day, divided into 2~3 doses, with an extreme dose of 1.2g per day.
2.Oxcarbazepine: The starting dose is 150mg bid and can be increased by 300mg every 3-4d, up to 2400 mg/d. The minimum effective dose for maintenance treatment is generally 300-600mg bid. oxcarbazepine has an earlier onset of action than carbamazepine and less incidence of adverse reactions.
3, gabapentin: the starting dose of 300mg / d, can be increased by 300mg every 2-3 days until the relief of symptoms, the maximum dosage of domestic literature is more than 2000-2400mg / d; foreign literature reports available up to 3600mg / d. Adverse effects are: drowsiness, ataxia, weakness, vertigo. The incidence has been reported to be about 22%. The efficacy is similar to that of carbamazepine, but with reduced side effects.
3.Chinese herbal medicine and acupuncture and other treatments: have certain efficacy.
Second, surgical treatment
1.Trigeminal nerve and semilunar ganglion closure
The trigeminal nerve is denatured and blocked by injecting drugs directly to relieve pain. The commonly used drugs for closure are anhydrous alcohol and glycerin. Peripheral branch closure is simple to perform, but the effect is not long-lasting, usually lasting 3-8 months, rarely more than 1 year. The operation of meniscal ganglion closure is relatively complicated, which can cause facial sensory numbness, neurokeratitis and other complications, and is prone to recurrence.
2.Percutaneous radiofrequency thermal coagulation treatment of meniscal ganglion
Is a safe, simple, patient-friendly treatment method, the efficacy of up to 90%, but also easy to relapse. The rationale is that the nociceptive fibers of the trigeminal nerve can be selectively destroyed, while preserving the tactile fibers. This method is suitable for patients who cannot tolerate open surgery due to their advanced age.
3.Microvascular decompression
This procedure is currently the preferred surgical treatment for primary trigeminal neuralgia. Indications for surgery include: patients with frequent pain episodes that affect life and work, patients with poor or ineffective treatment such as medication, and patients who cannot tolerate long-term medication. Patients whose trigeminal nerve is confirmed to be compressed by blood vessels by MRTA imaging; patients who are willing to undergo surgery due to poor results of other treatments; and patients whose blood vessels compressing the trigeminal nerve and producing pain are called “responsible blood vessels”.
The responsible vessels are: ① superior cerebellar artery (75%) ② anterior inferior cerebellar artery (10%) ③ basilar artery ④ other rare responsible vessels include posterior inferior cerebellar artery, variant vessels, transverse cerebral pontine veins, lateral veins and basilar plexus. The responsible vessel can be one or multiple, and can be either an artery or a vein.
Microvascular decompression treatment for trigeminal neuralgia.
Microvascular decompression is currently a widely used surgical treatment technique. The treatment principle of microvascular decompression is to microscopically dissect and isolate the blood vessels compressing the nerve roots at the brainstem so that the pulsation of the vessels no longer knocks on the nerve roots. The procedure involves making a 3-4 cm long incision behind the patient’s ear, making a small bone window, and the surgeon seeing the patient’s brain structure through a microscope, locating the root of the trigeminal nerve into the brainstem, then locating the “offending” blood vessel that is compressing the nerve, separating it from the corresponding nerve, and relieving the compression. A small spacer (a shock-absorbing material) is used to separate the nerve from the blood vessel to prevent it from compressing the trigeminal nerve. This spacer is a special material that is, first, very histocompatible, i.e., it does not cause rejection between it and normal brain tissue; second, very insulating, i.e., it insulates the blood vessel from the nerve; and third, it is not absorbed and has no adverse effects.
With the improvement of microsurgery technology, the operation is simple, with high efficiency, low mortality, few complications and high safety.
In summary, various treatment methods for trigeminal neuralgia have their advantages and disadvantages. In general, for those who do not have good results or cannot tolerate medication, if they are in good health and have no contraindications such as serious organic diseases, microvascular decompression can be considered first, but for patients who are elderly, in poor health, cannot tolerate or are unwilling to undergo microvascular decompression surgery, other treatment such as radiofrequency disruption and Gamma knife can be used as appropriate However, for patients of advanced age, poor physical condition, or those who are unable or unwilling to undergo microvascular decompression surgery, other treatments such as radiofrequency disruption and Gamma knife can be used as appropriate.
Prevention of trigeminal neuralgia
It is advisable to choose soft and easy-to-chew food. Patients with pain induced by chewing should eat a liquid diet, do not eat fried things, should not eat irritating, too acidic and too sweet food and cold food; diet should be nutritious, usually should eat more vitamin-rich and detoxifying food; eat more fresh fruits, vegetables and beans, less fatty meat and more lean meat, food to light is appropriate.
2, eat gargle, talk, brush teeth, wash face action should be gentle. In order not to induce plate machine point and cause trigeminal neuralgia. Do not eat irritating foods such as onions.
3, pay attention to head and face warmth, avoid local freezing, moisture, do not use too cold, too hot water to wash the face; usually should maintain emotional stability, should not be excited, should not be fatigued and stay up late, often listen to soft music, calm mood, maintain adequate sleep.
4, keep a happy spirit, avoid mental stimulation; try to avoid touching the “trigger point”; regular living, indoor environment should be quiet, neat, fresh air. At the same time, the bedroom should not be attacked by wind and cold. Appropriate participation in sports, exercise, enhance physical fitness.