1.Introduction of trigeminal neuralgia: Trigeminal neuralgia refers to the recurrent paroxysmal severe neuralgia in the distribution area of the facial trigeminal nerve, also known as painful convulsions, which is one of the common clinical diseases and one of the most difficult diseases recognized at home and abroad. Most trigeminal neuralgia starts at the age of 40, especially in women. The attack is like a lightning-like, knife-cutting sensation, which is unbearable. Patients with trigeminal neuralgia often do not dare to wipe their faces, eat, or even swallow saliva, thus seriously affecting their normal life and work.
2, trigeminal nerve knowledge: trigeminal nerve is the 5th pair of brain nerves, is the thickest pair of brain nerves in the cranium, as a mixed nerve. The trigeminal nerve emanates from the pontocerebral center and is divided into motor and sensory roots. The motor root governs the movement of the temporalis and masticatory muscles; the sensory root manages the sensation of pain, temperature and touch in the face. The sensory roots are thicker than the motor roots and are divided into three branches within the trigeminal hemimelia. The peripheral protrusions of neurons in the anterior medial part of the trigeminal hemimelia form the first branch, the ophthalmic branch; the middle part forms the second branch, the maxillary nerve; and the posterior lateral part forms the third branch, the mandibular nerve. These three nerves exit the skull via the supraorbital fissure, foramen ovale and foramen ovale respectively.
3.Classification and etiology of trigeminal neuralgia.
(1) Primary trigeminal neuralgia: It refers to the recurrent severe facial neuralgia without organic damage. Most trigeminal neuralgia is primary, presumably related to demyelination of the trigeminal nerve and vascular compression.
(2) Neuralgia caused by intracranial cholesteatoma, nerve sheath tumor, meningioma, hemangioma and other skull base tumors causing compression of the trigeminal nerve is called secondary trigeminal neuralgia, accounting for about 5% of trigeminal neuralgia.
4.Treatment of trigeminal neuralgia.
(1) Drug treatment, patients with initial onset of symptoms are often mild, so they can try drug treatment to control the pain, such as oral carbamazepine or Dexedrine. If medication is ineffective, or the dose of medication is high and directly affects liver and kidney function, the following methods can be chosen for treatment
(2) Trigeminal nerve hemimelia radiofrequency thermocoagulation
The trigeminal meningeal ganglion is located at the base of the middle cranial fossa and is surrounded by important structures such as the internal carotid artery, cavernous sinus and multiple pairs of cranial nerves. The depth of puncture can be up to 7.5cm from the skin. Due to the deep location of the foramen ovale and the large anatomical variation, it is difficult to ensure the accuracy of the puncture by hand and experience, and it is difficult to ensure the efficacy if the puncture is not in place.
(3) Transcranial trigeminal nerve vascular decompression and other procedures, the advantage is that the technology is mature and the efficacy is good, the disadvantage is that the cost is higher and the patient has to bear the risk of general anesthesia craniotomy. For patients with secondary trigeminal neuralgia or young patients with primary trigeminal neuralgia, craniotomy, microvascular decompression surgery or nerve root amputation can be considered for complete treatment.
5.Applications of radiofrequency thermal coagulation of the semilunar ganglion
(1) Primary trigeminal neuralgia, those with unsatisfactory effect by taking medication.
(2) Obvious adverse drug reactions to painkillers such as carbamazepine.
(3) Patients with trigeminal neuralgia who are too old and frail to tolerate open surgical treatment.
(4) Reluctance to undergo cranial trigeminal neurovascular decompression.
(5) Patients who have relapsed after open trigeminal nerve vascular decompression.
(6) Patients with recurrence after controlled radiofrequency thermocoagulation therapy, which may be followed by recoagulation.
(7) Patients with unsatisfactory results of gamma knife treatment and whose pain has not been eliminated or reduced.
(8) Trigeminal neuralgia caused by tumor, and the pain is not improved by gamma knife or surgical treatment.
6.Advantages of radiofrequency thermal coagulation of the semilunar ganglion
Safe and efficient, the operation time is generally 30-60 minutes, immediate pain relief during the operation, the patient is awake, receiving temperature-controlled treatment plan, the effect is immediate, immediately relieving the long-term pain and the trouble of taking painkillers. It also has a low recurrence rate and low cost, and is gladly accepted by the majority of patients. The use of 64-row spiral CT foramen ovale three-dimensional reconstruction technology ensures accurate puncture of the foramen ovale and trigeminal hemimelia, which significantly improves the treatment effect.
After the puncture is in place, the trigeminal meniscus can be stimulated with a weak current to verify whether the proposed target area of destruction matches the patient’s pain-onset area, making the destruction more delicate and safe. Temperature-controlled thermocoagulation is to gradually increase the temperature in the target area of destruction, taking advantage of the different heat tolerance of nociceptive and tactile nerve fibers to selectively destroy nociceptive nerve fibers, and the treatment process is accurately adjustable, avoiding the blindness of anhydrous alcohol or glycerin injection and eliminating the side injury of injecting irritating drugs. It avoids the risk of general anesthesia, pain and trauma of surgery, and fatal and disabling craniotomy.
7.The process of radiofrequency thermal coagulation therapy for trigeminal neuralgia
(1) Outpatient registration or telephone appointment to visit the hospital, and outpatient examination for admission.
(2) Pre-operative examination, check the examination results the next day to confirm the diagnosis of primary trigeminal neuralgia and exclude other conditions such as skull base tumor.
(3) CT-guided radiofrequency thermocoagulation of the semilunar ganglion at the appointed time, postoperatively sent to the ward for prophylactic antimicrobial application for 3 days, and discharged.