Trigeminal neuralgia is the most common neurological disease of the brain, mainly manifested by recurrent paroxysmal severe pain in the distribution area of the trigeminal nerve on one side of the face, with an incidence rate of 52.2/100,000 in China, slightly more in women than in men, and the incidence rate can increase with age. Trigeminal neuralgia mostly occurs in middle-aged and elderly people, with more right-sided than left-sided. The disease is characterized by sudden onset, sudden stop, lightning-like, knife-like, burning-like, intractable and severe pain in the trigeminal nerve distribution area of the head and face. The pain can be severe when speaking, washing the face, brushing the teeth or breezing, or even when walking. The pain lasts for a few seconds or minutes, and it comes in periodic episodes with intervals as normal.
Etiology and pathogenesis.
There is no definite conclusion on the etiology and pathogenesis of trigeminal neuralgia, and none of the theories can explain its clinical symptoms. At present, the trigeminal nerve microvascular compression leading to nerve demyelination and epileptiform neuralgia are the most supported theories.
Clinical presentation:
The age is mostly above 40 years old, with the middle-aged and elderly people being the most common. The pain is more on the right side than on the left side, and the pain starts from a point on the face, mouth or jaw and spreads to one or more branches of the trigeminal nerve, with the second and third branches being the most common, and the first branch being rare. The pain does not extend beyond the midline of the face and does not exceed the distribution area of the trigeminal nerve. Occasionally, there is bilateral trigeminal neuralgia, accounting for 3%; the nature of the pain is such as inverted cutting, needling, tearing, burning or electric shock-like intense pain, or even painful; the pattern of pain: the onset of trigeminal neuralgia is often without warning, while the pain attacks are generally regular. Each pain attack lasts from only 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, but with the development of the disease, the attacks are gradually more frequent, the interval is gradually shortened, and the pain is gradually aggravated and intense. The pain attacks decrease at night. There is no discomfort during the interval; triggering factors: talking, eating, washing face, shaving, brushing teeth and wind blowing can trigger painful attacks, so that patients are depressed, act cautiously, and even dare not wash face, brush teeth, eat, and speak carefully for fear of causing attacks; trigger point: trigger point is also called “trigger point”, often located in the upper lip The trigger point is often located on the upper lip, nose, gums, corners of the mouth, tongue, eyebrows and so on. Light touch or stimulation of trigger points can stimulate painful episodes; expression and facial changes; seizures often suddenly stop talking, eating and other activities, the painful side can show spasms, that is, “painful spasms”, frowning and clenching teeth, opening the mouth to cover the eyes, or using the palm of the hand to rub the face so that the local skin roughness, thickening, eyebrow hair loss, conjunctival congestion, tearing and Salivation. The patient’s expression is nervous and anxious; neurological examination: no abnormal signs, a few have facial hypesthesia.
Such patients should have further medical history, especially if they have a history of hypertension, and a comprehensive neurological examination, including lumbar puncture, skull base and internal auditory tract radiography, cranial CT, MRI, etc., if necessary, to help differentiate from secondary trigeminal neuralgia. Classification: Trigeminal neuralgia can be divided into two categories: primary (symptomatic) trigeminal neuralgia and secondary trigeminal neuralgia, with primary trigeminal neuralgia being more common. Primary trigeminal neuralgia is defined as having clinical symptoms, but no organic lesion related to the onset of the disease is found by applying various examinations. Secondary trigeminal neuralgia has clinical symptoms, while clinical and imaging examinations can reveal organic diseases such as tumor, inflammation, vascular malformation, etc. Secondary trigeminal neuralgia is mostly seen in middle-aged and young adults under 40 years old, usually without trigger points, with no obvious triggering factors, and the pain is often persistent, and some patients can be found with other manifestations of the primary disease. CT, MRI, and nasopharyngeal biopsy of the brain are helpful for diagnosis.
Differential diagnosis
1, toothache: trigeminal neuralgia is often misdiagnosed as toothache, and often the healthy teeth are extracted, or even all the teeth are extracted but still ineffective, before attention is drawn to it. The pain caused by dental disease is persistent, mostly confined to the gum area, with local caries or other lesions, and the diagnosis can be confirmed by X-ray and dental examination.
2, paranasal sinusitis: such as frontal sinusitis, maxillary sinusitis, etc., for limited persistent pain, may have fever, nasal congestion, thick runny nose and local pressure pain.
3, glaucoma: acute attack of unilateral glaucoma is misdiagnosed as trigeminal nerve branch 1 pain, glaucoma is persistent pain, does not radiate, may have vomiting, accompanied by congestion of the conjunctiva, shallow anterior chamber and increased intraocular pressure, etc.
4.Temporomandibular arthritis: pain is limited to the temporomandibular joint cavity, it is persistent, there is pressure pain at the joint site, joint movement disorder, pain is closely related to jaw movement, X-ray and specialist examination are feasible to assist the diagnosis.
5.Migraine: The pain area is beyond the range of trigeminal nerve, and there are mostly visual aura before the attack, such as blurred vision, dark spots, etc., which may be accompanied by vomiting. The pain is persistent and long, often half a day to 1-2 days.
6, trigeminal neuritis: short history, persistent pain, sensory hypersensitivity or hyperalgesia in the trigeminal nerve distribution area, may be accompanied by motor impairment. The neuritis mostly develops after a cold or paranasal sinusitis, etc.
7, cerebellar pontine horn tumor: pain attack may be the same as trigeminal neuralgia or atypical, but mostly seen in young people under 30 years old, mostly with hyperalgesia in the trigeminal distribution area, and may gradually produce other symptoms and signs of cerebellar pontine horn. X ray, CT intracranial scan and MRI can help to confirm the diagnosis.
8.Tumor invasion of skull base: most common is nasopharyngeal carcinoma, often accompanied by epistaxis and nasal congestion, which can invade most cerebral nerves and enlarged cervical lymph nodes, and the diagnosis can be confirmed by nasopharyngeal examination, biopsy, skull base X-ray, CT and MRI.
9.Glottopharyngeal neuralgia: it is easily confused with trigeminal nerve branch 3 pain, and the sites of glottopharyngeal neuralgia are different, such as soft palate, tonsils, pharyngeal tongue wall, tongue root and external auditory canal. The pain is induced by swallowing action. The pain can disappear after spraying the pharyngeal area with 1% cocaine.
10.Trigeminal nerve hemianopsia tumor: ganglion cell tumor, chordoma, meningioma of the fossa mai, etc., may have persistent pain, and the patient has obvious trigeminal nerve sensory and motor disorders. There may be bone destruction and other changes on skull base X-ray.
11.Facial neuralgia: Mostly seen in young people, the pain is beyond the trigeminal nerve and can extend to the back of the ear, the top of the head, the occipital neck, and even the shoulder. The pain can be persistent, up to several hours, not related to the movement, not afraid of touch, can be bilateral pain, and can be heavier at night.
Treatment methods
Drug treatment
1.Carbamazepine: It is effective for 70% of patients, but about 1/3 of patients cannot tolerate its side effects such as drowsiness, dizziness and gastrointestinal discomfort. It can be given twice daily at first, and later three times daily. 0.2~0.6g per day, divided into 2~3 doses, with an extreme dose of 1.2g per day.
2.Phenytoin sodium (sodium phenytoin): less effective than carbamazepine.
3.Chinese herbal medicine treatment: has certain efficacy.
4.Buried intestinal thread treatment: buried intestinal thread treatment is a kind of tissue therapy, which uses chrome-made sheep intestinal thread buried in or near the nerve hole to block nerve conduction, so as to achieve the purpose of paroxysmal pain.
Surgical treatment
1.Trigeminal nerve and semilunar ganglion closure
In 1903, Schosser was the first to apply trigeminal nerve peripheral branch closure to treat trigeminal neuralgia. The procedure is performed by injecting drugs directly on the trigeminal nerve to denature it and cause conduction block, thus relieving pain. The commonly used closure drugs 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 complex and can cause complications such as neurokeratitis, with an overall efficiency of 72-99%, an early recurrence rate of 20%, and a recurrence rate of 50% in 5-10 years.
2, hemianopia percutaneous radiofrequency thermal coagulation treatment
It is a safe, simple and patient-friendly treatment method with efficacy up to 90%. The rationale is that it can selectively destroy the nociceptive fibers in the trigeminal nerve while preserving the tactile fibers. It is performed by inserting a radiofrequency needle electrode into the semilunar ganglion under X-ray or CT guidance, energizing it and gradually heating it to 65-75 degrees to destroy the target point for a duration of 60 seconds. This method is suitable for patients who cannot or refuse craniotomy due to their advanced age.
3.Microvascular decompression (micorvascular decompression, MVD)
MVD surgery is currently the preferred surgical treatment for primary trigeminal neuralgia, first proposed by Professor Jannetta in 1967. The blood vessels that compress the trigeminal nerve and produce pain are called “responsible vessels”.
The common responsible vessels are
The superior cerebellar artery (75%), which can form a vascular loop extending caudally, is in contact with the trigeminal nerve at the brainstem and mainly compresses the nerve root above or above the medial side.
(ii) Anterior inferior cerebellar artery (10%), generally the anterior inferior cerebellar artery compresses the trigeminal nerve from below, and may also form a clamping compression on the trigeminal nerve together with the superior cerebellar artery.
③Basilar artery, with age and hemodynamic effects, the basilar artery may bend to both sides and compress the trigeminal nerve root, generally more bent to the side of the thinner vertebral artery.
④Other rare responsible vessels include posterior inferior cerebellar artery, variant vessels (such as permanent trigeminal artery), transverse cerebral pontine vein, lateral veins and basilar plexus. The responsible vessel can be one or multiple, and can be either an artery or a vein.
Microvascular decompression is performed by making a 4 cm longitudinal incision behind the affected ear and within the hairline under general anesthesia, making a cranial opening of approximately 2 cm in diameter, entering the pontocerebellar horn region under a microscope, exploring the trigeminal nerve pathway, “loosening” all possible compressive vessels and arachnoid cords, and isolating these vessels with Once the responsible vessels are isolated, the source of irritation disappears and the hyperexcitability of the trigeminal nucleus disappears and returns to normal. The vast majority of patients experience immediate postoperative pain disappearance and retain normal facial sensation and function without compromising quality of life.
Prevention and daily maintenance
1. Diet should be regular. 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 to avoid inducing 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 is not attacked by wind and cold. Appropriate to participate in sports, exercise, enhance physical fitness.