Since the etiology and pathology of trigeminal neuralgia are still unclear, the aim of treatment should be long-term analgesia. The methods of analgesia are still varied. They can be roughly divided into non-invasive and invasive treatment methods. Non-invasive treatment methods include medication, Chinese herbal acupuncture therapy and physiotherapy. They are suitable for patients with short duration of illness and mild pain. It can also be used as a complementary treatment to invasive treatment methods. Invasive treatment methods include surgery, injection therapy and radiofrequency thermal coagulation therapy.
I. General therapy
(i) Drug therapy
1.Carbamazepine 2 times a day at first, later 3 times a day. 0.2~0.6g per day, divided into 2~3 times, the extreme amount is 1.2g per day. 24~48h after taking the drug, there is analgesic effect.
2.Phenytoin sodium (alias Dalendin, a white powder, odorless, slightly bitter taste. Easily soluble in water, almost insoluble in ether or chloroform, easily deliquescent in air.
(II) Chinese medicine treatment
According to Chinese medicine, trigeminal neuralgia belongs to the category of “headache”, “migraine” and “facial pain”. In ancient medical books, there are records of the names of “first wind”, “brain wind” and “head wind”, such as “Suwen. Wind theory: “the first wind of the symptoms, head and face sweating evil wind, when the first wind 1 day is very sick, headache can not be out inside.” Some patients with trigeminal neuralgia can receive certain therapeutic effects after taking traditional Chinese medicine, which can stop or reduce the pain attacks. Some clinicians have used internal Chinese medicine to treat trigeminal neuralgia and have achieved certain results. Traditional Chinese medicine advocates the treatment of this disease by identifying the evidence and giving targeted treatment according to different types. For the type of wind attack, it is recommended to activate blood circulation, remove blood stasis, dispel wind and relieve pain.
We can use Wu Zhu Yu Tang (25g each of Dang Shen and Chuan Xiong, 18g each of Wu Zhu Yu, Bai Zhi and Tian Ma, 12g each of Ginger, Peppermint and Fang Feng, 20g each of Danshen and Xiang Shen, 15g of Red Peony, 30g of Hooked Vine and 3g of Hossein), or we can use 10g of White Fructus, 10g of Sclerotium, 10g of Tian Ma, 10g of Fang Feng, 10g of Angelica dahurica, 10g of Hossein, 10g of Bile Nan Xing, 10g of Di Long, 10g of Chuan Xiong and 3g of Scorpion. Rhizoma Chuanxiong 10g, Radix Scorpion 3g. For the type of inflammation of liver fire, it is used to nourish Yin and submerge Yang, lower fire and quench wind. We can use 5g of whole scorpion, 2 centipedes, 15g of each of Sclerotinia sinensis, Di Long, Chuanxiong, Niubizi, Shengdi, Bai Shao, Bai Zhu, 10g of each of Chuan Wu, 10g of each of Angelica dahurica, Tian Ma, and Semen Parviflora, 4g of Hessian, 20g of Hooked vine, and 30g of Shijiazhuang (first decoction). It can also be used with 9g each of white silkworm, bramble, fried myrrh, gentian grass and tribulus terrestris, 12g each of dahurica, 15g each of white peony and raw groundnut, 30g of stone cassia (decoction first), 6g of whole scorpion and 3g of licorice.
(C) Acupuncture treatment
1, general acupuncture therapy Acupuncture treatment is clinically convenient, safe and quick, with few side effects. Main acupoints: Fengchi, Catarrh, Shimonoseki, Hand Sanli, Hegu. Supporting points: Sun, Yangbai, Laozhu, and Touwei for the first branch of pain. For the 2nd and 3rd branch pain, add Sun, Sibai, Shimonoseki, Aural Hui, Dicang, Chengjue, Yingxiang. The needle can also be used for electro-acupuncture treatment by electro-stimulation machine.
2.Acupuncture of the peripheral branches of the trigeminal nerve Acupuncture of the supraorbital foramen, infraorbital foramen, posterior superior alveolar foramen and chin foramen, direct acupuncture of the peripheral branches of the trigeminal nerve, waiting for pain and numbness in the distribution area of the ipsilateral branches, and obtain rapid analgesic effect. The acupuncture technique held is a strong stimulation by lifting and twisting, regardless of yin and yang supplementation and diarrhea, and the patient is placed in the prone position for the first time, and the technique should be light so as not to cause dizziness or fear of needles.
Second, the trigeminal nerve peripheral branch closure therapy
Trigeminal nerve peripheral branch closure is a common method for clinical treatment of trigeminal neuralgia. The injection sites are mainly the bone holes through which the trigeminal nerve branches pass, such as the supraorbital hole, infraorbital hole, inferior alveolar hole, chin hole and pterygopalatine hole. The drugs used include anhydrous ethanol, phenol solution, doxorubicin, streptomycin, etc. The range of pain relief with trigeminal peripheral branch closure treatment is limited, and its effectiveness is also closely related to the operator’s skill level and the extent of the patient’s condition; therefore, most patients relapse within six months to two years.
The peri-trigeminal nerve branch block is divided into: supraorbital nerve block, infraorbital nerve block, posterior superior alveolar nerve block, maxillary nerve block, chin nerve block, inferior alveolar nerve block and mandibular nerve block according to the injection site.
III. Semilunar ganglion block therapy
The treatment of trigeminal neuralgia with semilunar ganglion block has been widely used both at home and abroad, and this injection therapy has been proved to be effective for many years. However, because the injection technique is difficult to master, mainly because the accuracy of the puncture operation is difficult to grasp, the treatment effect varies greatly with each person’s technique.
The semilunar ganglion in the cranial cavity is punctured through the oval hole, and nerve-destroying drugs such as glycerin, anhydrous ethanol, phenol solution, doxorubicin, and adriamycin are injected to block the 2nd, 3rd, or even all three branches of the trigeminal nerve, and a prolonged blocking effect can be obtained. It is used for the treatment of intractable trigeminal neuralgia, maxillofacial cancer pain and postherpetic pain.
Treatment indications
1.This injection therapy is suitable for all patients with more serious and stubborn trigeminal neuralgia, especially for old, weak and chronically ill patients with contraindications to open surgery.
2.Trigeminal neuralgia involving both the 2nd and 3rd branches, the 1st and 2nd branches or all the 3 branches, and the peripheral branch block is ineffective.
3, Intractable trigeminal neuralgia after facial herpes zoster.
Complications
Some complications that may be caused by semilunar ganglion block are mostly due to damage to nearby blood vessels, cerebral nerves and tissues caused by inappropriate direction of puncture (unarmed puncture without instrument positioning) or too deep needle entry, or damage caused by a large dose of ethanol (a highly safe drug used in our hospital – medical high purity glycerol) and flowing into the subarachnoid space. The incidence of complications is very low.
Most of the complications of the semilunar ganglion block can be avoided with effort. The main complications are: loss or abnormal sensation in the area of the block; vertigo syndrome; difficulty in mastication; cerebral nerve damage;. ipsilateral keratitis, corneal ulcers, etc. The relationship between injection therapy and craniotomy is complementary to each other. Surgical treatment of trigeminal neuralgia has been rare in recent years. Patients who are suitable for craniotomy should be treated with injection therapy first. For those who have failed to perform craniotomy, or those who have poor surgical results, or those who have relapsed after surgery, injection therapy can also receive very good results.
Radiofrequency thermal coagulation therapy
Overview Radiofrequency thermal coagulation therapy is the use of high temperature on the ganglion, nerve trunk and nerve roots and other parts, so that the protein coagulation denaturation, thereby blocking the transmission of nerve impulses. Currently, radiofrequency thermal coagulation therapy is more widely used in the clinic, and the therapeutic effect of thermal coagulation is good, but there are more complications, and there are no reported cases of death. Although the recurrence rate is high, due to the ease of operation, it can be repeatedly performed for the ultimate purpose of analgesia.
Adverse reactions and complications
1. Pain during operation This method needs to obtain the cooperation of the patient. It should be made clear before treatment that such treatment under local anesthesia is painful, and the patient’s understanding and cooperation must be obtained, and attention should be paid to slow heating from 60°C, which can reduce the pain caused by sudden high temperature.
2.Intracranial hemorrhage The medial aspect of the semilunar ganglion is adjacent to the cavernous sinus and the internal carotid artery, so inadvertent puncture or entering the foramen ovale too deeply can easily damage and bleed, and in serious cases, intracranial hematoma can be formed. (Instrument positioning puncture can be completely avoided)
3, cerebral nerve damage such as facial light paralysis, etc.
4, intracranial infection Strict aseptic operation can prevent secondary intracranial infection. Special attention should be paid to prevent repeated punctures of the buccal mucosa by the puncture needle to bring bacteria from the oral cavity into the skull.
Herpes zoster can appear in the affected area several days after surgery, and its mechanism is not clear. Local nail violet or cortisone ointment can be applied, and it will heal in a few days.
6, keratitis a more serious complication of hemianoplasty is the loss of corneal reflexes, serious cases can cause paralytic keratitis, which can eventually lead to blindness. It is important to control the heating temperature and time during the procedure and to check the change of corneal reflex at any time. In cases where loss of corneal reflex has occurred, patients should be instructed to wear glasses and use eye ointment to protect the cornea and prevent keratitis. In some cases, it takes several months for the corneal reflex to gradually recover after it disappears.
7. Facial sensory disorders Most patients can have varying degrees of facial sensory disorders after treatment. In the 315 cases summarized by Menzel, about 93.1% of patients had different degrees of numbness or burning sensation in the face after treatment. Therefore, before treatment, patients and their families have the right to inform the treating physician about the possible side effects of treatment.
V. Peripheral nerve avulsion
Some experts believe that the arteries supplying the trigeminal nerve become sclerotic and ischemic, resulting in degeneration of nerve fibers due to disturbance of nutrient metabolism. The compression of blood vessels by the proliferation of peripheral nerve tissue at the distal end of the nerve further reduces the blood supply and aggravates the degeneration of the nerve, resulting in the demyelination of nerve fibers and the phenomenon of “short-circuiting and crosstalk”. For this reason, peripheral nerve avulsion surgery has emerged in clinical practice. When performing this surgery, as much of the nerve should be avulsed proximally as possible to prevent recurrence of trigeminal neuralgia after surgery. Since this method is stretched and ineffective in the treatment of multi-branch pain or deep pain trigeminal neuralgia, it is not used much.
VI. Balloon compression method of the semilunar ganglion
The balloon compression method is an international technique that has been used for the treatment of trigeminal neuralgia since the eighties. The patient is under general anesthesia, tracheal intubation and controlled breathing. The duration of anesthesia varies from 20 to 160 minutes, depending on the proficiency of the puncture operator. Therefore, it is required that the anesthesia be terminated at any time and the patient be awake as soon as possible. Semilunar ganglion puncture is performed under an x-ray screen. A 14-gauge puncture needle with a needle core is punctured through the facial skin.
The puncture needle is stopped at the foramen ovale and the core is withdrawn, and the Fogarty balloon is placed into the semilunar ganglion via the puncture needle. The catheter connector outside the balloon was connected with a syringe and 1 to 2 ml of fluid was injected to distend the balloon to form a pear-shaped capsule of approximately 1 × 1.5 cm (as seen on the X-ray screen) and maintained for several minutes. At the end of compression the fluid is withdrawn and the distended balloon is recovered. The balloon is withdrawn with the puncture needle and the puncture site is compressed to stop bleeding. The entire operation is performed under an x-ray screen. The success rate of the operation is about 90%, but the recurrence after six months is effective to be treated again, and the long-term effect is to be observed.
VII. Trigeminal nerve root microvascular decompression
Since Dandy first put forward the argument that vascular compression of the trigeminal nerve root can cause trigeminal neuralgia in 1934, some clinical data also showed that vascular compression of the trigeminal nerve is one of the causes of trigeminal neuralgia. Many scholars have therefore used neurovascular decompression to treat trigeminal neuralgia.
(I) Common methods Currently, the following craniotomies are commonly used in the treatment of trigeminal neuralgia: transcranial middle fossa trigeminal sensory root dissection, trigeminal spinal bundle dissection, trigeminal root decompression and posterior cranial fossa trigeminal root microvascular decompression.
(B) Surgical operation technique After routine disinfection, 2% lidocaine is used for infiltration anesthesia or general anesthesia in the postauricular marker line. An incision is made along the marker line, and a bone window of approximately 2 cm in diameter is drilled with a cranial drill immediately behind the posterior border of the sigmoid sinus (the bone debris is collected and set aside). The cerebellum was gently retracted posteriorly and superiorly under the operating microscope, and a miniature cerebral pressure plate with a 2- to 3-mm wide band suction tube was placed to reach the root of the trigeminal nerve, and the vascular compression and other lesions were explored distally from the nerve out of the cerebral bridge. A small autologous muscle piece is placed between the nerve and the vessel. The nerve that is compressed by the vessel is wrapped around and separated from the vessel. At this point, the patient is asked to hit the trigger point with his own hand and perform certain movements that normally trigger pain, and if there is no pain, decompression is achieved. The incision is closed with layer-by-layer sutures.
(C) Factors affecting the subjective satisfaction of the surgical outcome Trigeminal neuralgia is treated with apparent microvascular decompression, and although the long-term efficacy has been reported differently, it can still be applied as a feasible method. In the past, long-term outcome follow-ups have mostly focused on objective factors, but lacked understanding of patients’ subjective satisfaction with the treatment outcome, which is also important for judging the overall effect of trigeminal nerve decompression. Some factors that affect subjective satisfaction include.
1. trigeminal neuralgia is a disorder that causes great pain to patients, and various treatment methods do not have very satisfactory results. Thus, it was found during the follow-up that although objectively the pain did not disappear completely after the surgery, leaving mild pain or pain recurrence, but the pain level was mild, and the condition that the pain could not be controlled by drugs before the surgery was changed, or accompanied by mild complications, subjectively the patients were still satisfied with the results of this surgery. For this objective and subjective inconsistency, it is understandable that patients self-compared the kind of unbearable pain before surgery with the situation after surgery to arrive at the right choice, which also enhanced confidence in the use of manifest microvascular decompression for trigeminal neuralgia. The high satisfaction rate of patients in the follow-up indicates that this procedure is still not a better method for trigeminal neuralgia treatment.
2. The early cure rate after surgery is not reliable. During the follow-up, it was found that most of those who did not have pain relief or complete relief after surgery expressed dissatisfaction. These patients were all cases in the early stage of carrying out apparent microvascular decompression surgery. In recent years, due to the emphasis on the identification of the involved vessels, especially those cases where the small unnamed artery crosses the trigeminal nerve or contacts at the brainstem, or where multiple invading vessels exist or the arterial ring is hidden, the vein is cut by compression electrocoagulation, and the thickened arachnoid membrane around the nerve is also completely cut to straighten the trigeminal nerve root, and satisfactory results are obtained.
3. After microvascular decompression surgery, patients will not be satisfied if complications such as facial sensory impairment or hearing impairment remain despite pain relief. Performing vascular decompression not only to relieve pain, but also must pay attention to the preservation of nerve function, which is an important point different from other surgical methods for trigeminal neuralgia.
Eight, gamma knife treatment of trigeminal neuralgia
Gamma knife was introduced more than 30 years ago, has become the most important tool in the field of stereotactic radiosurgery. The principle of gamma knife analgesia is to focus gamma rays on the pre-selected pain-related brain nuclei or nociceptive conduction pathways, a high-dose irradiation to destroy the nociceptive conduction pathways, blocking the conduction of nociception and achieve the analgesic effect. Gamma knife treatment of trigeminal neuralgia has also achieved certain efficacy.
Gamma knife treatment is to calculate the three-dimensional coordinates of the trigeminal nerve root through imaging positioning, and then focus the gamma rays on the target point, the treatment physician can block the nociceptive conduction through the control of the dose size. The treatment process is simple, less painful and easily accepted by patients. However, a treatment is expensive, around $20,000. According to the industry experts engaged in gamma knife work, the success rate of gamma knife treatment of trigeminal neuralgia is about 60%, and there is a possibility of recurrence.
According to the current experience, the conditions suitable for gamma knife treatment are
① persistent post-herpetic trigeminal neuralgia for which other treatments have failed.
② diagnosed as secondary trigeminal neuralgia, there is a smaller tumor or vascular malformation in the cranium by imaging, and gamma knife can be applied to treat its primary lesion. Usually the pain will be relieved with the improvement of the primary lesion.