Sciatic nerve arises from the ventral branches of the L4-L5 spinal nerves, which merge with the S1-S3 branches of the nerves on the way from the lumbosacral trunk. Passing along the inner wall of the pelvis, it leaves through the sciatic notch and passes under the pear-shaped muscle, where it lies between the sciatic tubercle and the greater trochanter of the femur. Staying at this depth, it descends into the thigh and proximal to the knee and is divided into peroneal and tibial nerves. The sciatic nerve itself is clearly divided into two trunks: the medial, which includes the branches L4-S3 and which gives rise to the tibial nerve, and the lateral, formed by L4-S2 and giving rise to the common peroneal nerve. The sciatic nerve itself has no sensitive branches. The lateral trunk provides the innervation of the short head of the biceps of the thigh, the medial trunk innervates the semitendinosus, the semimembranosus and the long head of the biceps of the thigh, and with the help of the obturator nerve, the large adductor is innervated.
Etiology. Most of the neuropathies of the sciatic nerve, regardless of whether the buttocks or the thigh are affected, develop as a result of injury. Neuropathies of the sciatic nerve, associated with trauma, are inferior in frequency of occurrence, probably only to the neuropathy of the peroneal nerve, caused by the same cause. These include neuropathy caused by damage to the pelvic bones, fractures of the femur, or gunshot wounds. Injection injuries are no longer such a common cause of neuropathy as in the past, and the frequency of compression injuries is increasing, and they often occur with prolonged immobilization, which is observed during various surgical interventions (for example, aorto-coronary shunting). For mixed reasons is the infringement of the nerve by compressing fibrous cords, local hematomas or tumors.
It is necessary to mention the so-called piriformis syndrome. To date, there are few cases that accurately confirm the proposed pathogenesis of this syndrome - compression of the sciatic nerve lying above the piriformis muscle, although this syndrome remains a frequent clinical diagnosis. Point pain of the sciatic nerve at the level of the piriformis muscle can also be observed in patients suffering from plexopathy or lumbosacral radiculopathy, and does not necessarily confirm the pathological compression of the sciatic nerve with the piriformis muscle.
91. Neuropathy of the sciatic nerve (sciatica).
Etiology: infection or intoxication, diseases of the pelvic organs, fracture of the spine and pelvic bones.
Clinic: characterized by pain in the buttocks, the back of the thigh, the lateral surface of the leg and back of the foot, pain of the sciatic nerve on palpation (midway between the greater trochanter and sciatic bulge) and tension, Lesag's symptom, decrease or absence of the Achilles reflex, flabbiness of the gluteus and triceps of the lower leg , disorders of sensitivity in the lateral region of the leg and on the back of the foot, lumbar scoliosis, with severe damage to the sciatic nerve - pronounced paresis and paralysis of the muscles of the leg, are affected by either unbig whether the feet and fingers (patients cannot stand on their heels, the foot hangs down - “horse” foot) or flexors of the foot and fingers (bending of the foot and fingers is impossible, standing on the toes - “heel” foot), in some muscles of the lower legs are affected (patients they cannot stand on their toes or on their heels - a “dangling” foot; the muscles of the lower leg and trophic disorders (hypertrichosis, skin atrophy or hyperkeratosis, trophic ulcers on the plantar surface of the first finger and heel) atrophy.
Treatment: see question 90.
Clinical picture of sciatic nerve neuropathy
Anamnesis. Lesions of the entire nerve, which, fortunately, occur infrequently, are associated with paralysis of the popliteal muscles and all muscles below the knee. A decrease in sensitivity is observed in the innervation zones of the tibial and peroneal nerves. Partial lesions, especially the lateral trunk, are often manifested by the overhanging of the foot.
92. Neuropathy of the femoral nerve.
Etiology: compression in the area of the inguinal ligament with hernias, neoplasms, inflammatory processes in the pelvic cavity.
Clinic: pain in the anterior surface of the thigh and lower leg, femoral nerve painful with pressure or tension, Mackiewicz's positive symptoms (pain on the anterior surface of the thigh or in the inguinal crease when the leg is bent at the knee joint of a patient lying on his stomach), Wasserman (pain on the anterior surface thighs when straightening an elongated leg of a patient lying on the abdomen), paresis or paralysis of the quadriceps, iliopsoas and sartorius muscles - flexion of the hip at the hip joint, extension of the tibia or rotation is limited or impossible of hip outwards, knee reflex reduced or absent, on the front surface of the femur and tibia upset sensitivity, atrophy of the affected muscles.
Treatment: see question 90.
93. Neuritis of the peroneal and tibial nerves.
Etiology: injuries, infections.
Clinic of neuritis of the tibial nerve: paresis or paralysis of the triceps muscle of the calf and the posterior tibial muscle, the long flexor of the foot, the plantar flexions of the foot and toes are upset, walking and standing on the toes - the "heel" of the foot, the clawed position of the fingers, atrophy of the triceps, the Achilles reflex is reduced or absent, sensitivity is disturbed on the back of the leg, on the lateral and plantar surface of the foot, sometimes pain, vegetative-trophic disorders
Clinic of neuritis of the peroneal nerve: paresis and paralysis of the peroneal muscle group (long and short peroneal) and muscles of the anterior surface of the tibia (anterior tibial, long and short extensor of the toes), inability to raise the outer edge of the foot, unbend and extend the foot outwards, unbend the main phalanges of the fingers , the anterior muscles of the tibia, the "horse" foot atrophy, the sensitivity decreases or is lost on the lateral surface of the tibia and the back of the foot.
Clinical examination for sciatic nerve neuropathy
- Neurological. Although there may be varying degrees of severity of muscle paralysis innervated by both the medial and lateral trunks, the most frequent clinical manifestations are changes in the muscles innervated by the lateral trunk. Changes in sensitivity are different, but limited to the zone of spread of the sensory branches of the peroneal and tibial nerves. The stretch reflexes of the hamstring muscles and the Achilles tendon may be reduced or absent.
- General. Palpation along the sciatic nerve can reveal volume lesions or local pain and sensitivity points, which, as mentioned earlier, does not completely exclude the presence of proximal lesions.
Differential diagnosis. It is necessary to carefully check whether radiculopathy (especially L5-S1 segments) is masked under the neuropathy of the sciatic nerve. The straightened leg lift test (a symptom of Lasegue), often positive with radiculopathy, can also be positive in cases of plexopathy of the lumbosacral plexus, as well as with neuropathy of the sciatic nerve. However, if the sciatic nerve is suspected of neuropathy, a thorough examination of the rectum and pelvic organs is indicated, since it is impossible to determine by other means that the sacral plexus is involved in the pathological process due to massive formations of the pelvic organs. Finally, it must be remembered that the presence of isolated neuropathies of the common peroneal and tibial nerves is possible.
Examination for sciatic nerve neuropathy
Electrodiagnosis. Both the nerve stimulation test (NSS) and EMG help distinguish the sciatic nerve mononeuropathy from L5-S2 radiculopathy or plexopathy, but careful screening of the paraspinal and gluteus muscles is required. However, since the lateral trunk of the sciatic nerve is most frequently involved in the pathological process, EMG data may demonstrate similar results. In some mononeuropathies of the sciatic nerve, anomalous results of the study of the motor and sensitive functions of the peroneal nerve are often encountered with normal results of the study of the tibial nerve.
Visualization methods. In cases where radiculopathy and plexopathy cannot be ruled out, valuable information can be obtained through further neurological research. In addition, in cases where only the sciatic nerve is detected, an MRI with gadolinium makes it possible to effectively trace the course of this nerve and determine focal anomalies.
Neuropathy of the sciatic nerve is one of the most common mononeuropathies; in its frequency it is inferior only to the neuropathy of the peroneal nerve. In most cases, is one-sided. It is observed mainly in middle-aged people. The incidence among the age group of 40-60 years is 25 cases per 100 thousand population. Equally common in females and males. There are cases when sciatic neuropathy seriously and permanently reduces the patient's ability to work and even leads to disability. In this regard, the pathology of the sciatic nerve is a socially significant issue, the resolution of the medical aspects of which is under the jurisdiction of practical neurology and vertebrology.
Anatomy of the sciatic nerve
The sciatic nerve (n. Ischiadicus) is the largest human peripheral nerve trunk, its diameter reaches 1 cm. It is formed by ventral branches of the lumbar L4-L5 and sacral S1-S3 spinal nerves. Having passed the pelvis along its inner wall, the sciatic nerve, through the same cut, goes to the back surface of the pelvis. Then it goes between the greater trochanter of the femur and the sciatic tubercle under the piriformis muscle, goes to the thigh, and above the popliteal fossa is divided into the fibular and tibial nerves. The sciatic nerve does not give sensory branches. It innervates the biceps, half-membranous and semitendinosus thigh muscles responsible for flexion in the knee joint.
According to anatomy n. ischiadicus secrete several topical levels of its lesion: in the small pelvis, in the area of the piriformis muscle (so-called piriformis syndrome) and on the thigh. The pathology of the terminal branches of the sciatic nerve is described in detail in the articles “Neuropathy of the peroneal nerve” and “Neuropathy of the tibial nerve” and will not be discussed in this review.
Causes of Sciatic Nerve Neuropathy
A large number of sciatic neuropathies are associated with nerve damage. Injury n. ischiadicus is possible in case of fracture of the pelvic bones, dislocation and fracture of the hip, gunshot, ragged or incised wounds of the thigh. There is a tendency to an increase in the number of compression neuropathies of the sciatic nerve. Compression can be caused by a tumor, aneurysm of the right arterial artery, hematoma, prolonged immobilization, but most often it is caused by a compression of the nerve in the sub-like space. The latter is usually associated with vertebral changes occurring in the pear-shaped muscle by reflex muscular-tonic mechanism in various spinal pathologies, such as: scoliosis, lumbar hyperlordosis, spinal osteochondrosis, lumbar spondyloarthrosis, herniated intervertebral disk, etc.
According to some data, approximately 50% of patients with discogenic lumbar radiculitis have a clinic of pear muscle syndrome. However, it should be noted that the neuropathy of the sciatic nerve of vertebrogenic origin can be associated with direct compression of nerve fibers as they exit the spinal column as part of the spinal roots. In some cases, the pathology of the sciatic nerve at the level of the piriformis muscle can be triggered by an unsuccessful injection into the buttock.
Inflammation (neuritis) n. ischiadicus can be observed in infectious diseases (herpes infection, measles, tuberculosis, scarlet fever, HIV infection). Toxic damage is possible as with exogenous intoxications (arsenic poisoning, drug addiction, alcoholism), and with the accumulation of toxins due to dismetabolic processes in the body (diabetes, gout, dysproteinemia, etc.).
Symptoms of sciatic nerve neuropathy
Pathognomonic symptom of neuropathy n. ischiadicus is a pain along the affected nerve trunk called sciatica. It can be localized in the area of the buttocks, spread from top to bottom along the back of the thigh and radiate along the back-outer surface of the lower leg and foot, reaching to the very tips of the fingers. Often patients characterize sciatica as “burning”, “shooting through” or “piercing like a dagger blow”. Pain syndrome can be so intense that it does not allow the patient to move independently. In addition, patients note a feeling of numbness or paresthesia on the posterior-lateral surface of the lower leg and some areas of the foot.
Objectively, paresis (decrease in muscle strength) of the biceps, semimembranosus and semitendinosus muscles, leading to difficulty in bending the knee, is detected. At the same time, the prevalence of antagonist muscle tone, in the role of which the quadriceps muscle of the thigh acts, leads to the position of the leg in the state of the bent knee joint. Walking with a straight leg is typical - when moving the leg forward for the next step, it does not bend at the knee. There is also paresis of the foot and toes, a decrease or absence of the plantar and Achilles tendon reflexes. With a sufficiently long course of the disease, atrophy of the paretic muscle groups is observed.
Disorders of pain sensitivity cover the lateral and posterior surface of the lower leg and almost the entire foot. In the area of the lateral ankle, loss of vibration sensitivity is noted, in the interphalangeal joints of the foot and the ankle - weakening of the musculo-articular feeling. Typical soreness when pressing the sacrum gluteal point - exit points n. ischiadicus on the thigh, as well as other trigger points of Valle and Gar. The characteristic symptom of ischial neuropathy is positive symptoms of Bonnet's tension (shooting pain in a patient lying on his back with passive abduction of the leg bent at the hip joint and knee) and Lassegue (pain when trying to lift a straight leg from the supine position).
In some cases, neuropathy of the sciatic nerve is accompanied by trophic and vasomotor changes. The most pronounced trophic disorders are localized on the lateral side of the foot, the heel and the back of the fingers. On the sole, hyperkeratosis, anhidrosis or hyperhidrosis is possible. On the posterior-lateral surface of the leg revealed hypotrichosis. Due to vasomotor disturbances, cyanosis and cooling of the foot occur.
Diagnosis of sciatic nerve neuropathy
Diagnostic search is carried out mainly in the framework of the neurological examination of the patient. The neurologist pays special attention to the nature of the pain syndrome, areas of hypoesthesia, reduction of muscle strength and loss of reflexes. Analysis of these data allows you to set the topic of the lesion. Its confirmation is carried out using electroneurography and electromyography, which allow to differentiate sciatic mononeuropathy from lumbosacral plexopathy and L5-S2 level radiculopathy.
Recently, to assess the state of the trunk of the nerve and the anatomical structures surrounding it, an ultrasound technique is used that can give information about the presence of a nerve tumor, its compression, degenerative changes, etc. The determination of the genesis of neuropathy can be performed using X-ray MRI of the spine), pelvic radiography, pelvic ultrasound, ultrasound and radiography of the hip joint, CT scan of the joint, analysis of blood sugar, etc.
Treatment of sciatic nerve neuropathy
The priority is the elimination of causal factors. For injuries and wounds, a plastic or nerve suture, reposition of bone fragments and immobilization, removal of hematomas are performed. In case of volumetric formations, the question of their removal is solved, in the presence of a herniated disc - of discectomy. Concurrent therapy is conducted in parallel, aimed at stopping inflammation and pain response, improving blood supply and metabolism of the affected nerve.
As a rule, pharmacotherapy includes nonsteroidal anti-inflammatory (ibuprofen, lornoxicam, nimesulide, diclofenac), drugs that improve blood circulation (pentoxifylline, nicotinic acid, benciclan), metabolites (hydralized from the blood of calves, thioctic acid, vitamin B). Perhaps the use of medical blockades - the local injection of drugs in the trigger points along the sciatic nerve.
Of the methods of non-pharmacological effects, physiotherapy (SMT, UHF, diadynamic therapy, local UFO), massage, post-isometric relaxation, and physical therapy in the recovery period are successfully applied.
Physiotherapy and other methods
Neuropathy of the right sciatic nerve or the left is well treatable with physiotherapeutic procedures designed to consolidate success.
- UHF - increases the permeability of the walls of blood vessels, heats the site of the lesion, promotes the regeneration of damaged tissues.
- Magnetotherapy - eliminates swelling, inflammation of the sciatic nerve, surrounding tissues. Promotes cell regeneration.
- Laser therapy - stimulates microcirculation of blood in tissues, capillaries, reduces pain, reduces swelling.
- Electrophoresis - reduces swelling, improves blood supply to tissues. The procedure is carried out with the use of drugs.
Physiotherapy manipulations are contraindicated for people with oncological, dermatological, infectious pathologies. You can not carry out the procedure for patients suffering from epilepsy, hypertension.
To eliminate the symptoms of inflammation of the sciatic nerve, treatment is prescribed not only during the exacerbation. It is recommended during remission. To avoid the return of the disease or its complications, patients need to undergo preventive treatment, which includes:
- Massage - to get the effect you need to go about 10 sessions. The procedure is prescribed to improve blood flow, lymph drainage, reduce puffiness, relieve muscle spasm.
- Manual therapy (according to indications) - eliminates the pinching of the sciatic nerve, improves mobility in the lumbosacral region, relieves muscle tone.
- Exercise therapy - physiotherapy exercises are prescribed on the recommendation of the attending physician, a set of exercises is developed individually. The goal of physical education is to strengthen the muscular system, maintaining the elasticity of the ligaments.
Restorative events are held in the period of stable remission. Exercise should gradually become more complex, and as the muscles strengthen, the number of repetitions increases.
Post-injection neuropathy of the sciatic nerve occurs under the influence of toxic, allergic or mechanical factors. The most commonly diagnosed is damage to the trunk of a nerve with an injection needle, when the injection is not done in the upper outer quadrant of the buttock, but closer to the middle or bottom of the gluteus muscle. Symptoms of a lesion may appear gradually or immediately after an unsuccessful manipulation.
As the disease worsens, motor disturbances are observed, and pain occurs. With a complete lesion of the sciatic nerve, the foot loses the ability to move, swelling, ulcers, bluish color of the skin may appear, and the patient is painful to step on the foot.
Phased treatment is aimed at restoring nerve tissue, preventing possible complications of the joints, muscles, tendons, and with a shallow lesion takes no more than 4 weeks. The complex of therapeutic measures includes therapeutic exercises, hydrokinesitherapy, electrophoresis with drugs (iodine, lidaza), ultrasound treatment, peloidotherapy, electrical stimulation, Dibazol.
Post-injection neuropathy, the consequences of deep injuries and injuries of the lower extremities are attributed to the post-traumatic neuropathy of the sciatic nerve.
The causes of the appearance of pathology are:
- Wounds, injuries (including after injections).
- Blows, bruises, long clamping of the nerve.
- Dislocation of joints, bone fractures.
Symptoms of damage in most cases are as follows:
- Movement disorders, functionality.
- Paralysis is complete or partial.
- Change in sensitivity, change in temperature of a damaged limb.
- Decreased muscle tone.
- Possible neuralgia, burdened with pain of varying severity.
Treatment of neuropathy of the sciatic nerve of mechanical origin is carried out by conservative methods and is developed individually. Therapy includes the following activities:
- Apparatus and drug stimulation of nerves and muscles.
- Passive forms of physical therapy.
- Reception (intramuscularly, intravenously) of vitamins of group B, and also C and E.
- In some cases, surgical treatment is indicated.
Damage to the sciatic nerve rarely disables it completely, most often a certain segment of nervous tissue suffers.
Complications after arthroplasty
Neuropathy of the sciatic nerve after arthroplasty occurs in less than 1% of operated patients. Pathology is the result of an incorrectly chosen endoprosthesis, the surgeon's mistakes.
Defeat is divided into two types depending on the mechanism of development:
- Ischemic - a consequence of squeezing the nerve trunk injured during the operation of tissues. Manifested in persons with underdeveloped muscles and subcutaneous fat.
- Traction. When setting the head of the prosthesis into the joint, the surgeon performs a hip extension (traction). Excessive tensile stresses lead to nerve damage.
If neuropathy occurs immediately after surgery, this indicates traction damage. The appearance of the symptoms of neuropathy of the sciatic nerve in a few days after the operation indicates the ischemic nature of the disease.
Patients complain of a sensitivity disorder, sometimes a burning pain appears in the foot, the gait changes. The patient can not stand on the heel, when lifting the foot of the foot sags to carry out the step, the patient raises his leg high. After the visual symptoms are detected, diagnosis - radiography, electromyography is appointed.
For the treatment of this type of neuropathy of the sciatic nerve, it is recommended to take groups of anesthetics, antispasmodic, antihypoxic drugs, membrane protectors, antiplatelet agents, biostimulants and antioxidants are also needed. Drug therapy is complemented by therapeutic massage, prescribed a course of hyperbaric oxygenation and electroneuromyostimulation.
Recipes of traditional medicine are aimed at eliminating the main symptoms of neuropathy of the sciatic nerve - pain and inflammation.
Effective outdoor products:
- Honey massage - heat the honey (300 g) in a water bath until foam appears, remove from the heat, pour medical alcohol (50 g) into the hot honey, mix thoroughly. Apply to the rubbing of the affected areas, hold massage clapping movements.
- Beeswax soften, roll out into a cake of such size that it completely covers the sore spot, and apply. Fasten the compress, top with a woolen cloth, leave overnight.
- Cut the leaves of agave lengthwise and apply a soft part to the site of pain, fix it with a wet bandage.
- Baths with coniferous decoction - young shoots of pine, fir, spruce (about 1 kg) pour boiling water (3 l) and boil, infuse for 4 hours, drain. The resulting infusion pour into a warm bath, take about 15 minutes before bedtime.
Receiving infusions and decoctions helps to quickly eliminate the symptoms of neuropathy of the sciatic nerve. Treatment with folk remedies complements drug and physiotherapy
- Pour a large tablespoon of dried aspen leaves with one cup of boiling water and boil for 30 minutes on low heat. After straining and cooling, consume 30 ml / 3 times a day.
- Boil the crushed deviacil root in 200 ml of water over low heat for 5 minutes. After cooling and filtering, drink in the morning and evening, dividing the broth into two equal parts.
- Diuretic compositions normalize metabolism, contribute to the restoration of nerve fibers (decoctions of rose hips, parsley, calendula, chamomile, etc.).
Any active person can get sciatic nerve neuropathy. The case history for everyone begins in the same way - acute pain, treatment, remission. Further actions for full recovery involve preventive measures designed to prevent the recurrence of the disease and improve the health of the patient as a whole.
What will benefit:
- Sanatorium treatment in specialized health centers, where you can undergo a course of procedures.
- Dosed sports - swimming, nordic walking, yoga, etc.
- Balanced diet.
- Compliance with wakefulness and sleep.
- It is necessary to avoid hypothermia, stress, etc.
- Normalize body weight.