Trigeminal neuralgia is the most common neurological disease of the brain, mainly manifested by recurrent episodes of severe pain in the distribution area of the trigeminal nerve on one side of the face. Trigeminal neuralgia mostly occurs in middle-aged and elderly people, with the right side more than the left side. The disease is characterized by sudden onset, stoppage, lightning-like, slash-and-burn, 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 walking in the breeze, or even when walking. The pain lasts for a few seconds or minutes and is periodic, with the same intervals as in normal people.
Etiology and pathogenesis
The etiology and pathogenesis of trigeminal neuralgia have not yet been clearly established, and none of the theories can explain the clinical symptoms. At present, the trigeminal nerve demyelination theory and the epileptiform neuralgia theory are the most supported ones.
Gender and age of clinical presentation
Age is mostly above 40 years old, with the middle-aged and elderly people being the most common. There are more women than men, about 3:2;
Pain site
The pain spreads from a point on the face, mouth or jaw 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 area of distribution of the trigeminal nerve. Occasionally, bilateral trigeminal neuralgia occurs in 3% of cases;
Nature of pain
The nature of the pain is such as backward cutting, stabbing, tearing, burning or electric shock-like pain, or even unbearable pain;
Pain pattern
The onset of trigeminal neuralgia is often unpredictable, and pain attacks are usually regular. 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, but as the disease develops, the attacks become more frequent, the interval is shortened, and the pain becomes more intense. The pain episodes decrease at night. There is no discomfort during the interval; 5. Triggering factors: talking, eating, washing, shaving, brushing teeth and wind blowing can trigger painful attacks, resulting in patients being depressed, acting cautiously, not even daring to wash their faces, brush their teeth, eat, and speak carefully for fear of causing attacks;
Trigger point
Trigger points, also known as “trigger points”, are 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 a painful attack;
Expression and facial changes
The painful side may show spasm, i.e. “painful spasm”, frowning and clenching teeth, opening mouth to cover eyes, or rubbing the face with palms, resulting in local skin roughness, thickening, loss of eyebrows, conjunctival congestion, lacrimation and salivation. The expression is tense and anxious;
Neurological examination
No abnormal signs, a few have facial hyperalgesia. In such patients, further history should be taken, especially if there is a history of hypertension, and a comprehensive neurological examination should be performed, 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 and organic diseases such as tumor, inflammation and vascular malformation can be detected by clinical and imaging examinations. Secondary trigeminal neuralgia is usually seen in middle-aged and young adults under 40 years of age, 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 it is often brought to attention when healthy teeth are extracted, or even when all the teeth are removed but still ineffective. 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, etc.
3.Glaucoma
Unilateral glaucoma acute attack misdiagnosed as trigeminal nerve branch 1 pain, glaucoma is persistent pain, does not radiate, may have vomiting, accompanied by ball conjunctival congestion, anterior chamber shallowing and increased intraocular pressure, etc.
4.Temporomandibular arthritis
The pain is limited to the temporomandibular joint cavity and is persistent, with pressure pain at the joint site and joint movement disorder, and the pain is closely related to jaw movement.
5.Migraine
The pain area is beyond the range of trigeminal nerve. Before the attack, there are mostly visual aura, 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, pain is persistent, sensory hypersensitivity or hypoesthesia in the trigeminal nerve distribution area, may be accompanied by motor impairment. The neuritis mostly develops after 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, with hyperalgesia in the trigeminal nerve distribution area, and may gradually produce other symptoms and signs in the cerebellopontine angle. X ray, CT intracranial scan and MRI can help to confirm the diagnosis.
8.Tumor invading skull base
Nasopharyngeal carcinoma is most common, often accompanied by epistaxis and nasal congestion. It can invade most of the 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 can be easily confused with trigeminal nerve branch 3 pain, and the sites of hyohypopharyngeal neuralgia are different, such as soft palate, tonsils, pharyngeal 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.Tumor of trigeminal nerve hemianopsia
It can be seen as ganglioneuroma, chordoma, meningioma of McDonald’s fossa, etc. It may have persistent pain and the patient has obvious sensory and motor disorder of trigeminal nerve. There may be bone destruction and other changes on skull base X-ray.
11.Facial neuralgia
The pain can extend beyond the trigeminal nerve 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 is started twice daily and later may be given 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 medicine treatment: has certain efficacy.
Surgical treatment
1.Trigeminal nerve and semilunar ganglion closure
In 1903, Schosser pioneered the use of trigeminal nerve peripheral branch closure to treat trigeminal neuralgia. The procedure is performed by injecting a drug directly on the trigeminal nerve to denature it and cause a conduction block, thus relieving pain. The commonly used drugs for closure are anhydrous alcohol and glycerin. Peripheral branch closure is simple, 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 an efficacy of up to 90%. The rationale is that it can selectively destroy the nociceptive fibers in the trigeminal nerve, while preserving the tactile fibers. The method involves inserting a radiofrequency needle electrode into the meningeal ganglion under X-ray or CT guidance and gradually heating it to 65-75 degrees to destroy the target site for 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 vessel that compresses the trigeminal nerve and produces pain is called the “responsible vessel”.
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.
③The basilar artery, with age and hemodynamic influence, 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.
Under general anesthesia, a 4-cm longitudinal incision is made behind the affected ear, within the hairline, and a cranial opening of approximately 2 cm in diameter is made to access the pontocerebellar angle under the microscope. Once the responsible vessels are isolated, the source of irritation disappears and the hyperexcitability of the trigeminal nucleus disappears and returns to normal. In the vast majority of patients, the pain disappears immediately after surgery and normal facial sensation and function are preserved without compromising quality of life.
Prevention and daily maintenance
It is advisable to choose soft, easy-to-chew foods. Patients with pain induced by chewing should eat a liquid diet, do not eat fried food, should not eat stimulating, too acidic and sweet food and cold food; diet should be nutritious, usually should eat more vitamin-rich and detoxifying food; eat more fresh fruits, vegetables and legumes, less fatty meat and more lean meat, food should be light.
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 food such as onion.
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.