Neuralgia is damage to the nerves in peripheral part nervous system, which is located outside the spinal cord and brain, but connects them with all organs. This problem occurs quite often and is quite treatable, especially if the damage is small. One of the most common ailments is neuralgia trigeminal nerve, responsible for the sensitivity of the oral cavity and the entire face as a whole. It is the largest nerve branch emerging from the cranium. The pain with this type of neuralgia is quite severe, so even anti-inflammatory and analgesic medications are unable to drown it out. A trigeminal nerve block can help in such a situation.
The procedure for blocking impulses emanating from the trigeminal nerve branch is performed by a neurologist in a hospital setting using special drugs. The entire process takes place under local anesthesia and neurotope drugs, ganglion blockers, corticosteroids, anticholinergics and other drugs are usually used for blockade.
Such blocking is not always performed with the aim of eliminating pain. Sometimes it is performed for diagnostic purposes before surgery due to severe damage to the nerve branch of the trigeminal nerve or one of the peripheral nodes. A procedure is performed to correctly determine the source of painful pulsation. You can check whether the location is correct by injecting an anesthetic into the area where the blockade is planned. If the discomfort disappears, the procedure will be effective.
Blocking pain performed on a specific area that has been damaged. The central blockade includes the following nodes:
- Gasserov. It is quite difficult to block it, because this node is located in cranium. Doctors perform this procedure for diagnostic purposes before surgery or if the neuralgia is of central origin. Due to the fact that the injection will be too painful for the patient, the entire process takes place under intravenous sedation (superficial drug sleep). An injection is made through the skin of the cheek in the area of the 2nd molar of the upper jaw. The needle should enter the cranial cavity through the pterygopalatine fossa, and an ultrasound machine can be used to ensure that there are no malfunctions. The painful throbbing usually goes away immediately after the drug is injected, but such an injection usually leaves an unpleasant side effect. Half of a person’s face becomes numb for 8-10 hours;
- Pterygopalatine. Blockade of innervation in this area is carried out only if the pain is localized in the 2nd and 3rd branches of the trigeminal nerve. Typically, the patient exhibits autonomic disturbances, for example, increased salivation, redness on the skin, and excessive lacrimation. Invasion (implementation) in this case is not as deep as when blocking the gasserian node, so the injection is performed without intravenous sedation. Before the procedure, the doctor asks the patient to lie on his side so that the damaged area remains on top. The injection is also given through the cheek 3 cm diagonally from auricle and the depth of needle insertion is approximately 4 cm. The pain goes away almost immediately after the injection.
Anesthetizing large nodes such as the trigeminal nerve requires precision and care on the part of the physician performing the procedure. If the execution technique is not ideal or even the slightest mistake is made, then there can be serious consequences, including paralysis of the facial muscles.
Blocking remote branches
Neuralgia may manifest itself as a secondary form and the pain will not be so pronounced. In this case, the neurologist will only numb the pinched nerves:
- Mandibular. You can stop the painful pulsation in this area with an injection of an anesthetic drug, which will be given inside the mouth. The needle must pass through the pterygomaxillary fold, which is localized between the 7th and 8th teeth on lower jaw;
- Infraorbital. Due to its pinching, pain occurs in the area upper lip and nose (lateral part). You can stop the discomfort by making an injection at the level of the canine (canine) fossa. The injection is performed through the skin in the area of the nasolabial fold. The infraorbital nerve is located approximately 1 cm below the edge of the eye;
- Chin. When it is damaged, pain occurs in the chin area and discomfort radiates to the lower lip. An anesthetic injection is performed between the 4th and 5th teeth in the area of the chin;
- Supraorbital. In patients with pinching of this particular nerve, throbbing pain radiates to the forehead and the base of the nose. The injection to block the nerve signal should be performed near the edge of the brow ridge on its inner side. You can understand exactly where the injection should be performed by palpation. After all, the place where pain is felt most strongly is the entry point of the nerve branch.
Nerve branches are usually anesthetized quite simply and if the injections are performed correctly there are no side effects does not arise.
You can understand the location of the branches and nodes of the trigeminal nerve based on this picture:
Medicines used to perform the procedure
Medications to perform the blockade are usually selected in a standard manner. The exception is the situation when the patient is intolerant to the composition of a certain drug. The basis of treatment is local anesthetics, which prevent the nerves from sending signals, due to which pain relief occurs in a certain area. In addition to them, neurologists use special medications designed to block impulses in the nodes of the autonomic nervous system. In addition to drugs that affect pain pulsation, drugs with anti-inflammatory, anticonvulsant and wound-healing effects are used. They serve to improve the regeneration of the damaged trigeminal nerve.
The most commonly used drugs are:
- Pachycarpine and anticholinergics. Such drugs perform the function of blocking at the level of nerve nodes. After their use, the spasm subsides and nerve conduction in the damaged areas improves. Adding them to the solution for the pain blocking procedure is also recommended if the patient has pronounced vegetative symptoms;
- Corsticosteroids. Among this group, hydrocortisone is most often used, which serves to reduce inflammatory process in nerve tissues. Due to this effect, pain relief will last much longer, and the regeneration of damaged areas of the nerve will accelerate;
- B vitamins. They are extremely important for the normal functioning of the nervous system. When added to a blockade solution, such vitamins will help normalize the functions of damaged nerves.
In the old days, alcohol-novocaine blockades were used with particular popularity. This method is based on an injection of novocaine diluted in alcohol. The injection was carried out in the tissue that surrounds the damaged nerve, due to which it was partially destroyed and the pain stopped. This method is no longer used nowadays, since scars form in the nerve fiber due to the damage received and relapses of neuralgia are possible.
Carbamazepine for trigeminal neuralgia
A course of treatment for trigeminal neuralgia is prescribed by a neurologist after a long examination. The patient will have to undergo them to find out whether the disease manifests itself or whether it is only a secondary manifestation of a more serious pathological process. If, after performing all the necessary examinations, which include a blood test, ultrasound, MRI, CT and x-ray, the doctor diagnoses neuralgia, then Carbamazepine can help with it. This drug is an anticonvulsant and forms the basis for the treatment of damaged nerves, regardless of their location.
In the territory Russian Federation Carbamazepine is produced by many pharmaceutical companies, so purchasing it is not difficult. Its effect consists of 2 parts:
- Reducing the duration of pain attacks;
- Increased time between attacks.
Many people think that Carbamazepine reduces pain, but this is a misconception. This drug, like other drugs with anticonvulsant effect do not eliminate pain, but only reduce its attacks and their frequency of occurrence.
Many experts recommend this medication as a preventive measure, because it does not remove discomfort, but can warn them. If an attack does begin, the drug must be combined with anesthetics so as not to feel severe discomfort.
Carbamazepine also has other forms of release, for example, Finlepsin Retard, which is its extended-release analogue. The main active ingredient of the drug exerts its effect on nerve fibers, including the trigeminal nerve, much longer than expected due to its slow release. This form of medication is suitable for people who do not like to take medications often or are afraid of missing their next dose. A long-acting drug will have its effect constantly, which means the chances of an attack occurring will be minimal.
Often people switch from carbamazepine to its long-acting analogue in order to reduce the concentration of the drug in the body and reduce the chance of developing complications from taking the medication. After all, experts have repeatedly noted that slow-release drugs are much less likely to cause side effects.
Method of taking the medication
One tablet contains 200 mg of Carbamazepine active substance and per day you are allowed to take no more than the dosage indicated in the instructions. According to experts, if you increase the dosage of the medication even more, the positive effect will not be achieved and side effects will begin to appear instead. An overdose can be recognized by the following symptoms:
- General weakness in the body;
- Allergic manifestations (itching, urticaria, allergic rhinitis);
- Drowsiness;
- Changes in taste perception.
Carbamazepine not only prevents the impulse that causes pain from passing from the damaged nerve to the central nervous system, but also slows down useful signals. Because of this, the reaction slows down when performing a muscle contraction. This nuance should be taken into account when choosing medications for the course of treatment of trigeminal neuralgia.
The dose must be selected strictly individually to avoid side effects. Initially, you should start with a minimum amount, and then gradually increase it until the result is visible, but not higher than the permissible maximum. The neurologist usually prescribes 1 tablet (200 mg) at a time, 3 times a day, and then increases it to 2 to enhance the effect.
When the desired result is achieved, namely a decrease in the frequency and duration of painful attacks, the doctor will reduce the dosage. For preventive purposes and to maintain the effect, you should use the medication on the recommendation of a doctor.
When combining the anticonvulsant drug Carbamazepine with other drugs, the maximum dose should be reduced. This should be done by a doctor, and it is not recommended to change the dosage on your own or take any medications without the knowledge of a specialist.
The trigeminal nerve is mixed, it has four nuclei, of which two sensory and one motor are located in the hindbrain, and one sensitive (proprioceptive) is in the midbrain. The processes of cells embedded in the motor nucleus (nucleus motorius) emerge from the pons on the line separating the pons from the middle cerebellar peduncle and connecting the exit site nn. trigemini et facialis (linea trigeminofacialis), forming the motor nerve root, radix motoria. Next to it, a sensory root, radix sensoria, enters the substance of the brain. Both roots form the trunk of the trigeminal nerve, which, upon exiting the brain, penetrates under the hard shell of the bottom of the middle cranial fossa and lies on the upper surface of the pyramid temporal bone at its top, where the impressio trigemini is located. Here the hard shell, bifurcating, forms a small cavity for it, cavum trigeminale. In this cavity, the sensitive root has a large trigeminal ganglion, ganglion trigeminale. The central processes of the cells of this node make up the radix sensoria and go to the sensitive nuclei: nucleus pontinus n. trigemini, nucleus spinalis n. trigemini and nucleus mesencephalicus n. trigemini, and the peripheral ones are part of the three main branches of the trigeminal nerve, extending from the convex edge of the ganglion.
Branches of the trigeminal nerve: first, or ophthalmic, n. ophthalmicus, second, or maxillary, n. maxillaris, and the third, or mandibular, n. mandibularis. The motor root of the trigeminal nerve, which does not participate in the formation of the node, passes freely under the latter and then joins the third branch.
Block of the mandibular nerve (trunk anesthesia according to Weisblatt)
Anesthesia of the mandibular nerve is carried out at the foramen ovale. The needle is injected with iodine in the middle of the zygomatic arch (trago-orbital line), immersed to a depth of 4-5 cm to the lateral plate of the pterygoid process of the sphenoid bone. Then remove the needle until subcutaneous tissue and, turning it 1 cm posteriorly, immerse it to the same depth.
Anesthesia zone: all tissues and organs receiving innervation from the third branch of the trigeminal nerve.
Complications:
diplopia;
Maxillary nerve block (trunk anesthesia)
O Subzygomatic pterygoid tract in the pterygopalatine fossa according to S. N. Weisblat. The projection of the outer plate of the pterygoid process is located in the middle of the tragus-orbital (trago-orbital) line drawn from the tragus of the auricle to the middle of the plumb line that connects the outer edge of the orbit with the infero-external canthus of the eye. Making shots! in the middle of the trago-orbigal line, moving the needle perpendicular to the skin until it stops at the outer plate of the pterygoid process of the sphenoid bone. The depth of immersion of the needle is noted (4-6 cm), then it is withdrawn more than halfway, turned anteriorly at an angle of 15-20° and again immersed into the tissue to the marked depth.
b) Subzygomatic tract (according to Matas-Brown-Hurtl). The injection is carried out in the
ku under the bottom edge zygomatic bone, at the level of the zygomaticalveolar
ridge and move it along the soft tissues of the cheek up, back and inward.
Between the tubercle of the upper jaw and the pterygoid process wedge-shaped
bone, at a depth of about 5 cm, the needle enters the pterygopalatine fossa.
c) Orbital path (according to Voino-Yasnetsky). The injection is done at the lower late-
ral edge of the orbit, moving the needle along it lateral wall By
towards the inferior orbital fissure by 4-5 cm.
c) Palatal tract (intraoral). The needle is inserted through the greater palatine foramen and advanced along the palatine canal 3-4 cm to the pterygopalatine fossa.
Anesthesia zone: all tissues and organs receiving innervation from the second branch of the trigeminal nerve.
Complications:
getting a needle into the nasal cavity or auditory tube with infection to the base of the skull;
diplopia;
temporary loss of vision due to impregnation of the optic nerve with an anesthetic.
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Blockade of the motor branches of the trigeminal nerve according to Egorov
Among the numerous methods of blocking the branches of the mandibular nerve, subzygomatic methods have become widespread.This approach is relatively shorter and more accessible for advancing the needle to the branches of the trigeminal nerve.
When studying anatomical preparations and histotopographic sections, the author found that under the lower edge of the zygomatic arch there are layers of skin, subcutaneous fatty tissue, sometimes parotid salivary gland, masticatory and temporal muscles.
Correspondingly, the posterior half of the mandibular notch between the inner surface of the temporal muscle and outer surface In the lower part of the bone of the same name there is a narrow layer of fiber, which gradually expands downward and, at the level of the mandibular notch, separates the medial surface of the masticatory and temporal muscles from the lateral pterygoid muscle.
The width of the layer of fiber in the pterygotemporal space in adult specimens ranges from 2 to 8 mm. On preparations of newborns it is presented in the form of a narrow layer 1-2 mm wide. The strip of this fiber below merges with the fiber of the pterygomaxillary space, the latter reaching the lower edge of the mandibular foramen.
On top, a thin layer of fiber is sometimes located between the base of the skull and the lateral pterygoid muscle, as well as between the upper and lower heads of this muscle. The motor branches of the mandibular nerve are located in the described layers of fiber.
It should be noted that the distance from the outer surface of the lower edge of the zygomatic arch to the fiber of the upper part of the pterygotemporal space in adults is subject to very significant individual fluctuations (15-35 mm) (P. M. Egorov).
Existing subzygomatic methods of blocking the branches of the mandibular nerve (Bersche et al.) do not take into account the wide range of variability in spatial relationships between organs and tissues located along the path of needle advancement. The research conducted by the author makes it possible to introduce a certain precision into the technique of blocking the motor branches of the mandibular nerve from the lower edge of the zygomatic arch and to individualize the depth of needle insertion for each patient and deposit the anesthetic solution only in the tissue of the pterygotemporal space.
The author found that as a guide for turning off the motor branches of the mandibular nerve from the lower edge of the zygomatic arch, it is advisable to use the lateral surface of the squama of the temporal bone, located almost in the same vertical plane with the tissue of the pterygotemporal space.
The essence of this method is as follows: the patient is in the dental chair. His head is turned in the opposite direction. Using the thumb of the left hand, the doctor determines the location of the head of the lower jaw and the anterior slope of the articular tubercle. To do this, he asks the patient to open and close his mouth, move his lower jaw from side to side.
Having determined the location of the articular tubercle, the doctor asks the patient to close his mouth, then, without removing his finger from the articular tubercle, treats the skin with alcohol or tincture of iodine. Under the lower edge of the zygomatic arch, he inserts a needle directly anterior to the base of the articular tubercle and moves it slightly upward (at an angle to the skin of 65-75°) until it comes into contact with the outer surface of the scales. (Fig. 27.1), marks the depth of immersion of the needle in soft fabrics and pulls it up to the zygomatic arch towards himself. Then he places the needle perpendicular to the skin or slightly downward and again immerses it in the soft tissue at the marked distance (Fig. 27.2; 28).
Rice. 27. The path traversed by the needle during blockade of the motor branches of the trigeminal nerve according to Egorov. Scheme of a section drawn in the frontal plane through the right half of the head of an adult in front of the articular tubercle.
1 - determining the depth of immersion of the needle (until it stops at the scales of the temporal bone); 2 - position of the needle when injecting an anesthetic solution at the infratemporal crest; 3 - chewing muscle; 4 - branch of the lower jaw; 5 - zygomatic arch; 6 - temporal muscle; 7 - medial pterygoid muscle; 8 - lateral pterygoid muscle; 8 - pterygomaxillary space; 9 - pterygomaxillary space; 10 - parapharyngeal space; 11 - submandibular salivary gland.
Rice. 28. Position of the syringe when administering an anesthetic solution (according to Egorov).
The end of the needle is at the top of the infratemporal crest, in the pterygotemporal cellular space. The nerves pass here, in the pterygotemporal cellular space. The nerves innervating the temporalis and masticatory muscles pass through here. Along the slit-like gap separating the upper head of the lateral pterygoid muscle from the base of the skull, there is a direct connection with the tissue of the infratemporal fossa, in which other motor and sensory branches of the mandibular nerve are located.
To turn off the motor branches of the mandibular nerve in order to relieve spasm and pain in masticatory muscles Ah, it is quite enough to introduce 1-1.5 ml of a 0.5% anesthetic solution without vasoconstrictors. The anesthetic is administered slowly over 2-3 minutes.
By the end of the anesthetic administration, patients often note a significant improvement in mouth opening, a decrease or cessation of pain at rest and during movements of the lower jaw. Favorable results that occurred after blockade of the motor branches of the trigeminal nerve confirm the diagnosis of temporomandibular joint pain dysfunction syndrome.
At the same time, this blockade is good medical procedure, relieving pain for 1.5-2 hours, sometimes more a long period time. However, more often a less intense dull pain appears again. Carrying out 4-6 blockades with an interval of 2-3 days along with other methods of treatment ( physiotherapy, autogenic training, etc.) leads to the cessation of pain and restoration of the full range of movements of the lower jaw.
An anesthetic depot is created in the area where the neurovascular bundles of the masticatory, temporal, and lateral pterygoid muscles are located. This circumstance is of no small importance, since in the area of injection of the anesthetic solution there is a local temperature increase of 1-2°C within 48-72 hours.
The simplicity of the technique and the absence of complications during more than 5 thousand blockades convinced us of the high effectiveness of this diagnostic and therapeutic method. After a course of treatment with blockades, in 32% of patients with severe pain syndrome, we observed the cessation of pain and normalization of the functions of the temporomandibular joint for a long period of time.
In patients with weak severe symptoms syndrome of painful dysfunction of the temporomandibular joint (slight pain or clicking in the joint, etc.), we noted favorable results from drug therapy, medicinal physical culture and other treatment methods without blocking the motor branches of the trigeminal nerve with weak anesthetic solutions.
P.M. Egorov, I.S. Karapetyan
Since trigeminal neuralgia may cause changes in the innermost fiber, taking classical painkillers may not have the desired effect. In this case, a method called a trigeminal nerve block can help. She represents medical procedure aimed at eliminating pain syndrome caused by an inflammatory process.
At the first signs of inflammation of the trigeminal nerve, treatment first begins with taking anticonvulsant, anti-inflammatory, and antispasmodic drugs.
The blockade procedure is prescribed in the following cases:
- Dilated blood vessels;
- Severe sweating;
- Reddened skin.
The most common reason is expressed in severe pain, which interferes with the patient’s normal functioning. For example, pain can occur during the most mundane processes, such as chewing food, brushing teeth, or during a conversation. In this case, blocking the branches of the trigeminal nerve becomes the only solution to quickly return to normal life. The causes of such severe pain can be various infectious diseases, migraines, and inflammation of the maxillary sinuses.
Also, the reasons for the blockade are diagnosed neuritis or neuroma. The latter is a tumor formation of the trigeminal nerve. As a rule, despite its benign nature in most cases, it provokes pronounced pain, the elimination of which is difficult to eliminate with medication.
During the procedure, the doctor injects an anesthetic drug using a syringe. But in order for the drug to really work, it is necessary to correctly identify the affected branch of the trigeminal nerve. Each of them has its own injection zone.
An interesting fact is that the blockade is carried out not only to relieve the patient of severe pain, but also for diagnostic purposes. They resort to the procedure before surgery on the damaged trigeminal nerve.
In order to determine whether the affected area in which surgical intervention is intended has been correctly identified, an injection with an anesthetic is given to it. If after this the patient feels relief and the pain becomes less severe or disappears altogether, then the area has been identified correctly. This method allows you to prevent medical errors.
Central blockade
Central trigeminal nerve block is performed for the following nodes:
- Gasser knot. The procedure for this area is complicated by the fact that the gasserian node is located directly in the cranium. Injections are administered through the cheek in the area of the second molar. The needle should go around the jaw and pass into the cranial cavity through an opening located in the area of the pterygopalatine fossa. The procedure is carried out using intravenous sedation, as it involves significant pain, and an ultrasound machine to control the insertion of the needle. A side effect of pain relief may be temporary numbness of half the face, which goes away after about 8-12 hours;
- Pterygopalatine node. The technique of blocking this node is carried out in case of damage to the second or third branch of the trigeminal nerve. As a rule, this condition is accompanied by redness skin, increased salivation and lacrimation. To implement the blockade, the patient is placed on his side on a horizontal surface. The syringe needle is inserted through the cheek approximately 3 cm from the auricle diagonally. The depth of needle insertion varies from 3.5 to 4 cm. Sedation is not required in this case.
The trigeminal nerve block technique requires high professionalism and absolute precision. If the technique is performed incorrectly, the result can be paralysis. facial muscles.
If distant branches of the trigeminal nerve are affected, pain is usually less pronounced.
In this case, the blockade is performed for one of the following nerves:
- Mandibular. The anesthetic is administered through oral cavity, namely through the mucous membrane in the area of the pterygomaxillary fold. This area located between the 7th and 8th molars of the lower jaw;
- Infraorbital. This nerve is located approximately 1 cm below the lower edge of the eye. Pain when it is pinched is felt in the area of the upper lip and wings of the nose. The needle is inserted into the nasolabial fold at the level of the canine fossa;
- Chin. The pain in this case covers the area of the chin and lower lip. The blockade is carried out by administering an injection in the area of the mental foramen, approximately between the 1st and 2nd molars of the lower jaw;
- Supraorbital. This nerve is directly responsible for sensation in the forehead and base of the nose. An anesthetic injection is given to the area inside brow ridge. In order to determine the exact location of needle insertion, it is necessary to perform small taps with your fingertips. Where the pain is felt most pronounced is the right place.
When the anesthetic is administered, the pain disappears almost immediately. If the doctor follows correct technique procedure, the risk of side effects is reduced to zero.
Intraosseous blockade
Trigeminal bone block is performed using local anesthesia. During the procedure, a special intraosseous needle is inserted into the periosteum, and then into the cancellous bone tissue the anesthetic gets in. Under the influence of the injection, the pressure in the bone canal where the affected nerve is located decreases. Vascular microcirculation is also stimulated.
Contraindications to this procedure are:
- Ongoing infectious diseases in the acute stage;
- Presence of diseases of the cardiovascular system;
- Disorders of the blood clotting process.
Average term therapeutic effect is 2 months. Only in 5% of patients the procedure does not have a positive result.
Side effects are quite rare. They can be expressed in the following phenomena:
- Allergic reaction to the drugs used;
- Irritation of the maxillary sinus;
- Complications in the form infectious diseases. As a rule, they are not serious and can be treated quickly without the use of antibiotics.
For the blockade procedure for trigeminal neuralgia, local anesthetics are used. They are the main component, as they are able to relieve pain. Additionally, anti-inflammatory, anticonvulsants, as well as medications aimed at regenerating nerves and eliminating painful impulses that arise in the vegetative nodes.
A standard drug complex for carrying out a blockade can be a combination of Novocaine 1-2%, the anti-inflammatory hormone Hydrocortisone and vitamin B12 that nourishes the nerve, for example, in the form of Cyanocobalamin.
Novocaine 1-2% is a standard drug for blocking the ternary nerve Used for the procedure medical supplies have a very wide variety.
Therefore, they are divided into the following groups:
- Pahikarpin. Used in case of damage to nerve nodes. Its use helps eliminate spasmodic pain in the area of the vascular wall, as well as improve nerve conduction. If the patient has obvious autonomic disorders, then this drug is also appropriate to use for blockade;
- Anticholinergics. They have an effect similar to Pahikarpin;
- Corticosteroid hormones. They are aimed at eliminating the existing inflammatory process in the tissues of the body. As a rule, when taking hormones of this group, pain relief takes time. But regeneration of damaged nerves occurs much faster. The most popular drugs in this group are Hydrocortisone and Kenalog;
- B vitamins. They are also often included in the injection solution. Vitamins not only act on the very cause of neuralgia, but also have a positive effect on the condition of the body as a whole, for example, strengthen the immune system.
The blockade procedure can be done in most medical centers. Today, it is a fairly accessible method of eliminating pain due to neuralgia.
A. Indications. The two main indications are trigeminal neuralgia and intractable pain due to malignant tumors of the facial region. Depending on the location of the pain, blockade of the Gasserian ganglion, or one of the main branches of the trigeminal nerve (ophthalmic, maxillary or mandibular nerve), or small branches is indicated.
B. Anatomy. The trigeminal nerve (cranial V) leaves the brain stem with two roots, motor and sensory. Next, the nerve enters the so-called trigeminal (Meckel's) cavity, where it expands, forming a thickening - the trigeminal (lunate, gasserian) node, which is an analogue of the sensitive spinal node. Most of the gasserian ganglion is enclosed in a duplicative hard meninges. The three main branches of the trigeminal nerve depart from the Gasserian ganglion and leave the cranial cavity separately. The optic nerve enters the orbit through the superior orbital fissure. The maxillary nerve leaves the cranial cavity through the foramen rotundum and penetrates the pterygopalatine fossa, where it divides into a number of branches. The mandibular nerve exits the cranial cavity through the foramen ovale and then divides into an anterior trunk, which sends motor branches mainly to the muscles of mastication, and a posterior trunk, which gives off a number of small sensory branches (Fig. 18-4A).
B. Method of performing the blockade.
1. Blockade of the gasserian node. To perform this blockade (see Fig. 18-4B), it is necessary to be guided by the results of radiography. The most common is the anterolateral approach. A 22 G needle 8-10 cm long is inserted approximately 3 cm lateral to the corner of the mouth at the level of the upper second molar; the needle is directed medially, upward and dorsally. The tip of the needle is oriented towards the pupil (when viewed from the front) and the middle of the zygomatic arch (when viewed from the side). The needle should pass outward from the oral cavity between the branch of the lower jaw and upper jaw, then lateral to the pterygoid process and penetrate into the cranial cavity through the foramen ovale. If cerebrospinal fluid or blood is not obtained during the aspiration test, then inject 2 ml local anesthetic.
2. Blockade of the optic nerve and its branches. Due to the risk of keratitis, actually optic nerve do not block, limiting themselves to blocking its branch - the supraorbital nerve (see Fig. 18-4B). This nerve is easily identified in the supraorbital notch and blocked with 2 ml of local anesthetic. The supraorbital notch is located on the supraorbital edge of the frontal bone, above the pupil. The supratrochlear nerve is blocked in the superomedial corner of the orbit, and 1 ml of anesthetic is used.
3. Blockade of the maxillary nerve and its branches. The patient's mouth should be slightly open. A 22 G needle with a length of 8-10 cm is inserted between the zygomatic arch and the mandibular notch (see Fig. 18-4D). After contact with the lateral plate of the pterygoid process (approximately at a depth of 4 cm), the needle is removed a certain distance and directed slightly higher and anteriorly, after which it penetrates the pterygopalatine fossa. 4-6 ml of anesthetic is injected, and paresthesia should occur. The described technique allows you to block the maxillary nerve and pterygopalatine ganglion. Blockade of the pterygopalatine ganglion and the anterior ethmoidal nerve can be carried out through the mucous membrane of the
Rice. 18-4. Block of the trigeminal nerve and its branches
Rice. 18-4. Block of the trigeminal nerve and its branches (continued)
Nasal cavity: swabs soaked in a solution of local anesthetic (cocaine or lidocaine) are inserted along the medial wall of the nasal cavity into the area of the sphenopalatine foramen.
The infraorbital nerve passes through the infraorbital foramen, where it is blocked by injecting 2 ml of anesthetic. This hole is located approximately 1 cm below the edge of the orbit; it can be reached by inserting a needle 2 cm lateral to the wing of the nose and directing it upward, dorsally and somewhat laterally.
4. Block of the mandibular nerve and its branches. The patient's mouth should be slightly open (see Fig. 18-4D). A 22 G needle 8-10 cm long is inserted between the zygomatic arch and the mandibular notch. After contact with the lateral plate of the pterygoid process (approximately at a depth of 4 cm), the needle is removed a certain distance and directed slightly higher and dorsally towards the ear. 4-6 ml of anesthetic is injected, and paresthesia should occur. The lingual and inferior alveolar nerves are blocked from inside the mouth using a 22 G needle 8-10 cm long (see Fig. 18-4E). The patient is asked to open his mouth as wide as possible. With the index finger of his free hand, the doctor palpates the coronoid notch. The needle is inserted at the indicated level (approximately 1 cm above the surface of the last molar), medial to the examiner's finger and lateral to the sphenomandibular ligament. Then the needle is advanced along the medial surface of the mandibular ramus 1.5-2 cm in the dorsal direction until it contacts the bone. An injection of 2-3 ml of local anesthetic blocks both nerves.
The terminal portion of the inferior alveolar nerve is blocked at its exit from the mental foramen, which is located at the angle of the mouth at the level of the second premolar. 2 ml of anesthetic is injected. The criterion for correct needle position is the appearance of paresthesia or the needle entering the hole.
D. Complications. Complications of Gasserian ganglion block include unintentional injection of anesthetic into blood vessel or subarachnoid space, Horner's syndrome, blockade of the masticatory muscles. With a maxillary nerve block, there is a high risk of massive bleeding, and with a mandibular nerve block, there is a high risk of inadvertent block of the facial nerve.
Facial nerve block
A. Indications. Blockade of the facial nerve is indicated for spasms of the facial muscles, as well as for herpetic lesions of the nerve. In addition, it is used in some ophthalmological operations (see Chapter 38).
B. Anatomy. The facial nerve leaves the cranial cavity through the stylomastoid foramen, where it is blocked. The facial nerve provides taste sensation to the anterior two-thirds of the tongue, as well as general sensation to the eardrum, external auditory canal, soft palate, and part of the pharynx.
B. Method of performing the blockade. The needle insertion point is immediately anterior mastoid process, below the external auditory canal and at the level of the middle of the ramus of the lower jaw (see Chapter 38).
The nerve is located at a depth of 1-2 cm and is blocked by injecting 2-3 ml of local anesthetic into the area of the stylomastoid foramen.
D. Complications. If the needle is inserted too deeply, there is a risk of blocking the glossopharyngeal and vagus nerve. A careful aspiration test is necessary because facial nerve located in close proximity to the carotid artery and internal jugular vein.
A. Indications. Blockade of the glossopharyngeal nerve is indicated for pain caused by the spread of malignant tumor on the base of the tongue, epiglottis, palatine tonsils. In addition, the blockade makes it possible to differentiate neuralgia of the glossopharyngeal nerve from trigeminal neuralgia and neuralgia caused by damage to the knee ganglion.
B. Anatomy. The glossopharyngeal nerve exits the cranial cavity through the jugular foramen medial to the styloid process and then passes in an anteromedial direction, innervating the posterior third of the tongue, muscles and mucous membrane of the pharynx. The vagus nerve and accessory nerve also leave the cranial cavity through the jugular foramen, passing next to the glossopharyngeal nerve; close to them carotid artery and internal jugular vein.
B. Method of performing the blockade. A 22 G, 5 cm long needle is used and inserted just posterior to the angle of the mandible (Fig. 18-5).
Rice. 18-5. Glossopharyngeal nerve block
The nerve is located at a depth of 3-4 cm, stimulation of the nerve allows you to more accurately orient the needle. Inject 2 ml of anesthetic solution. An alternative approach is made from a point located midway between the mastoid process and the angle of the mandible, above the styloid process; the nerve is located immediately anterior to the styloid process.
D. Complications. Complications include dysphagia and vagal block, leading to ipsilateral vocal cord paralysis and tachycardia, respectively. Blockade of the accessory and hypoglossal nerves causes ipsilateral paralysis of the trapezius muscle and tongue, respectively. Performing an aspiration test helps prevent intravascular injection of anesthetic.
A. Indications. Occipital nerve blocks are indicated for the diagnosis and treatment of occipital headaches and occipital neuralgia.
Rice. 18-6. Occipital nerve block
B. Anatomy. The greater occipital nerve is formed from the posterior rami of the cervical spinal nerves C2 and C3, while the lesser occipital nerve is formed from the anterior rami of these same nerves.
B. Method of performing the blockade. The greater occipital nerve is blocked by injecting 5 ml of anesthetic solution approximately 3 cm lateral to the occipital protuberance at the level of the superior nuchal line (Fig. 18-6). The nerve is located medial to the occipital artery, which can often be palpated. The lesser occipital nerve is blocked by injecting 2-3 ml of anesthetic further lateral along the superior nuchal line.
D. Complications. There is a negligible risk of intravascular injection.
Phrenic nerve block
A. Indications. Blocking the phrenic nerve can sometimes eliminate pain caused by damage to the central parts of the diaphragm. In addition, it can be used for intractable hiccups.
B. Anatomy. The phrenic nerve is formed from the roots of the spinal nerves C3-C5 and descends along the lateral edge of the anterior scalene muscle.
B. Method of performing the blockade. The nerve is blocked from a point located 3 cm above the clavicle, just lateral to the posterior edge of the sternocleidomastoid muscle and above the anterior scalene muscle. 5-10 ml of anesthetic solution is injected.
D. Complications. In addition to intravascular injection for concomitant disease or lung injury may worsen respiratory function. It is impossible to block both phrenic nerves at the same time.
A. Indications. The blockade is indicated for pain in the shoulder (arthritis, bursitis).
B. Anatomy. The suprascapular nerve is the main sensory nerve that innervates shoulder joint. He is a branch brachial plexus(C4-C6), passes through the superior edge of the scapula in the scapular notch and then penetrates the supraspinatus and infraspinatus fossa.
B. Method of performing the blockade. The nerve is blocked by injecting 5 ml of anesthetic solution into the notch of the scapula, located on the border of the lateral and middle third of its upper edge (Fig. 18-7). Correct location needles is confirmed by the appearance of paresthesia or muscle contractions during electrical stimulation.
D. Complications. If the needle moves forward too much, pneumothorax is possible. There is a risk of supraspinatus and infraspinatus paralysis.
A. Indications. Selective paravertebral blockade in the cervical spine is indicated for the diagnosis and treatment of pain caused by the spread of a malignant tumor to cervical region spine and spinal cord or shoulder girdle.
Rice. 18-7. Suprascapular nerve block
B. Anatomy. The cervical spinal nerves are located in the grooves of the transverse processes of the corresponding vertebrae. In most cases, the transverse processes can be palpated. It should be noted that, unlike the thoracic and lumbar spinal nerves, the cervical spinal nerves exit through the intervertebral foramina of the vertebrae at the level of the corresponding segments of the spinal cord (see Chapter 16).
B. Method of performing the blockade. For nerve blockade at the CII-CVII level, the lateral approach is most common (Fig. 18-8). The patient is seated and asked to turn his head in the direction opposite to the puncture. Draw a line between the mastoid process and the tubercle of Chassignac (the so-called tubercle of the transverse process of the sixth cervical vertebra). Draw a second line parallel to the first and 0.5 cm dorsally. Using a 22 G needle 5 cm long, inject 2 ml of anesthetic solution at each level along the second line. Since the transverse process of CII can be difficult to palpate, the anesthetic solution at this level is injected 1.5 cm below the mastoid process. The remaining transverse processes are usually 1.5 cm apart from each other and located at a depth of 2.5-3 cm. It is advisable to carry out a diagnostic blockade under X-ray control.
D. Complications. Unintentional subarachnoid, subdural or epidural injection of anesthetic at the neck level quickly causes respiratory arrest and arterial hypotension. The entry of even a small amount of anesthetic into the vertebral artery leads to loss of consciousness and convulsions. Other complications are represented by Horner's syndrome, as well as blockade of the recurrent laryngeal and phrenic nerves.
Paravertebral blockade in thoracic region
A. Indications. Unlike intercostal blockade, paravertebral blockade in the thoracic region
Rice. 18-8. Paravertebral blockade in the cervical region
Interrupts the transmission of impulses along both the posterior and anterior branches of the spinal nerves (see Chapter 17). Therefore, this blockade is indicated for pain caused by lesions of the thoracic spine, chest or front abdominal wall, including vertebral compression fractures, posterior rib fractures and acute herpes zoster. This technique is indicated when it is necessary to block the upper thoracic segments, where the scapula makes it difficult to perform a classic intercostal block.
B. Anatomy. Each root of the thoracic spinal nerve emerges from the intervertebral foramen under the transverse process of the corresponding vertebra.
B. Method of performing the blockade. The patient lies on his stomach or side (see Fig. 17-30). Use a needle to spinal tap Size 22, 5-8 cm long, equipped with a movable stopper (bead or rubber stopper). According to the classical technique, the needle is inserted 4-5 cm lateral to the midline of the back at the level of the spinous process of the overlying vertebra. The needle is directed anteriorly and medially at an angle of 45° to the midsagittal plane and advanced until it contacts the transverse process. The needle is then partially withdrawn and directed directly under the transverse process. A movable limiter on the needle marks the depth of the transverse process; When the needle is partially withdrawn and reinserted, it should not be advanced more than 2 cm beyond the stopper. At the level of each segment, 5 ml of anesthetic solution is injected.
According to another technique, in which the risk of pneumothorax is lower, the injection point is located much more medially, and the “loss of resistance” technique used is reminiscent of an epidural puncture (see Chapter 17). The needle is inserted in the sagittal direction 1.5 cm lateral to the midline at the level of the spinous process of the superior vertebra and advanced until it contacts the lateral edge of the vertebral plate. Then the needle is removed to the subcutaneous tissue and reinserted, but the tip of the needle is directed 0.5 cm laterally, maintaining the sagittal direction; As the needle advances, it perforates the superior costotransverse ligament lateral to the vertebral plate and below the transverse process. The correct position of the needle is confirmed by the loss of resistance with a constant supply of saline solution at the moment of penetration through the costotransverse ligament.
D. Complications. The most common complication of paravertebral block in the thoracic region is pneumothorax; Other complications include unintentional subarachnoid, subdural, epidural and intravascular injection of anesthetic solution. With multi-level blockade or the introduction of a large volume of anesthetic, even at one level, there is a risk of sympathetic blockade and arterial hypotension. To exclude pneumothorax after paravertebral blockade in the thoracic region, radiography must be performed.
Paravertebral somatic blockade in the lumbar region
A. Indications. Paravertebral somatic blockade in the lumbar region is indicated for the diagnosis and treatment of pain associated with damage to the spine, spinal cord and spinal nerves at the lumbar level.
B. Anatomy. The lumbar spinal nerves enter the fascial sheath of the psoas major muscle almost immediately upon exiting the intervertebral foramina. The fascial sheath is delimited anteriorly by the fascia of the psoas major muscle, posteriorly by the fascia of the quadratus lumborum muscle, and medially by the vertebral bodies.
B. Method of performing the blockade. Access to the lumbar spinal nerves is the same as described for paravertebral blockade at the thoracic level (Fig. 18-9). A needle with a size of 22 G and a length of 8 cm is used. It is advisable to radiologically confirm the correct choice of level for the blockade. During diagnostic blockade, only 2 ml of anesthetic is injected at each level, since a larger volume blocks an area larger than the corresponding dermatome. For therapeutic purposes, 5 ml of anesthetic solution is administered, and from level LIII, larger amounts (up to 25 ml) can be used to achieve complete somatic and sympathetic blockade of the lumbar nerves.
Rice. 18-9. Paravertebral blockade in the lumbar region
D. Complications. Complications include unintentional subarachnoid, subdural and epidural injection of anesthetic solution.
Blockade of the medial branches of the lumbar nerves and anesthesia of the facet (intervertebral) joints
A. Indications. This blockade allows us to assess the role of damage to the facet joints in the genesis of back pain. For intra-articular injections, corticosteroids are administered along with local anesthetics.
B. Anatomy. Each facet joint is innervated by the medial branches of the primary posterior rami of the spinal nerves, which arise above and below the joint. Thus, each joint receives innervation from at least two adjacent spinal nerves. Each medial branch bends around the superior edge of the underlying transverse process, passing in the groove between the base of the transverse process and the superior articular process.
B. Method of performing the blockade. This blockade should be performed under x-ray control with the patient in the prone position (Fig. 18-10). A 22 G needle with a length of 6-8 cm is inserted 5-6 cm lateral to the spinous process and directed medially to top edge base of the transverse process. For blockade of the medial branch of the primary posterior branch 1-1.5 ml of anesthetic solution is injected into the spinal nerve.
An alternative technique involves injecting a local anesthetic (with or without corticoids) directly into the joint. The patient lies on his stomach with a slight rotation (a pillow is placed under the anterior iliac crest on the blockade side), which facilitates the identification of the facet joints during fluoroscopy. Before administering the anesthetic correct position needles should be confirmed by injecting 0.5 ml of radiopaque contrast agent. D. Complications. When an anesthetic is injected into the dura mater, a subarachnoid block develops, and when an anesthetic solution is injected too close to the spinal nerve root, there is a risk of segmental sensory and motor blockade.
