Sensory neuropathy of the median nerve. Median nerve neuropathy (carpal tunnel syndrome, carpal tunnel syndrome)

Neuritis median nerve is an inflammatory disease of the peripheral nerve that can cause different kind pain all over the nerve. In a person, sensitivity can be disturbed and muscle weakness is manifested in the area that this nerve innervates.

Affecting several nerves at once, the disease is called polyneuritis. This disease is diagnosed by a neurologist. In order for neuritis to be correctly and accurately diagnosed, the specialist must conduct a general examination and make all kinds of specific functional tests. In addition to the general examination, the doctor should perform electromyography, electroneurography, and a specially designed study of the EAP.

A disease such as neuritis can be caused by many reasons. This can be ordinary hypothermia, and various infections that have entered the human body in the process of various injuries, as well as with some vascular disorders, with hypovitaminosis.

Moreover, such intoxications as exogenous and endogenous can lead to the development of neuritis. Most often, peripheral nerves can affect the musculoskeletal canals. It should be noted that the anatomical narrowness of this canal can lead to such unpleasant disease like neuritis, and develop the so-called tunnel syndrome.

Often, such a disease can appear as a result of compression of the peripheral nerve trunk itself. This can happen at any time, during surgery and even in your sleep. Take, for example, a person who long time walks exclusively with the help of crutches. During this time, he may develop neuritis of the axillary nerve.

If a person squats for a very long time, then he may develop. If a person's profession is associated with constant flexion and extension of the hand, then he can develop neuritis of the median nerve (this most often applies to people who play the piano and cello).

Causes of neuritis of the median nerve

There are many reasons for the occurrence of such a disease. All kinds of injuries can provoke the appearance of this disease. upper limbs, nerve damage in the process of violating the necessary technique during an internal injection into the cubital vein, various wounds that are on the surface of the forearm, overexertion of the hand, which are of a professional nature.

The functionality of the median nerve allows you to define it as mixed. Due to the fact that he is able to conduct innervation a large number groups of muscles, as a result of their contraction, such types of movement are produced as extension and flexion of two wrist fingers, namely the second and third. There are also such types of movements that are produced by some muscles of the median nerve along with the ulnar ones. Its general composition includes all kinds of sensory fibers that are capable of innervating the skin on the radial carpal surface, the palmar surface, starting from the first and ending with the fourth finger of the hand, as well as the back surface of all available distal phalanges of the above fingers.

Symptoms and diagnosis of neuritis of the median nerve

If a patient has median nerve neuritis, symptoms such as weakness in flexion of the hand, weakness in flexion of the first and second fingers, especially the terminal phalanges, appear. The sensitivity of the palmar surface of the first and second fingers is significantly reduced.

the most successful and successful treatment neuritis of the median nerve lies in the fact that all kinds of therapeutic effects occurred precisely at the point of damage to the nerve itself. In order to simplify and improve treatment somewhat, the attending physician should know the following:

in order to carry out targeted treatment, the specialist will take an interest in which specific point is affected;
what reasons led to such an ailment (it can be all kinds of injuries, scars and compression in the area of a particular nerve);
it is important to determine the degree and level of damage to a particular nerve.

About all kinds of diagnostic methods have already been mentioned above. Now in more detail about some of them.

Electroneuromyography. Thanks to this examination, you can easily determine the speed and volume of impulses along the existing nerve. Moreover, thanks to this examination, you can easily detect the damaged area and determine the time for the restoration of the existing nerve. In addition, electroneuromyography allows you to accurately assess the effect of any type of treatment, so you can choose the most appropriate and effective method.

When conducting radiography and computed tomography, you can get the full necessary information about the deformation of a particular joint and all available bone canals of a given nerve. Moreover, it is possible to determine the causes and points of defeat with greater certainty.

Treatment of the disease

After the specialist managed to find out the reason for which the compression of this nerve occurs, all kinds of treatments become more effective and correct. In the process of treatment, the specialist should resort to etiotropic therapy.

This therapy includes treatment with antibiotics, various antiviral and vascular drugs.

Moreover, the treatment of this difficult disease should include various anti-edematous and anti-inflammatory drugs. It is necessary to carry out various physiotherapy, specially designed massage and exercise therapy.

If the nerve is compressed, the main objectives of treatment are:

Elimination of compression of the median nerve. To do this, it is necessary to carry out a sufficiently powerful resolving therapy. In order to this therapy was produced, you need to start with the use of various enzymes, as well as take various agents and preparations that absorb and soften scar tissue, and much more. There are also such cases that for a complete cure, only manual therapy and massage at the site of damage are sufficient.
Acceleration of healing and, of course, restoration of the nerve itself. To do this, it is necessary to resort to the use of some modern medicines who are able to restore the liberated from all harmful factors nerve.
Restoration of muscle function and muscle volume. In order for the treatment to positive result, it is necessary to perform all kinds of restorative procedures. In this matter, each patient can be helped by a rehabilitation doctor.

When injuring the median nerve, first of all, it is necessary to decide on conservative or surgical treatment. Each doctor will be able to resolve this issue only when a needle myography is performed, thanks to which it will be possible to determine the degree of damage.

After the doctor diagnoses and finds out all his questions, only then he will choose the most suitable method of treatment for each patient.

Defeat n. medianus in any part of it, leading to pain and swelling of the hand, a disorder in the sensitivity of its palmar surface and the first 3.5 fingers, a violation of the flexion of these fingers and opposition thumb. Diagnosis is carried out by a neurologist based on the results of a neurological examination and electroneuromyography; additionally, with the help of radiography, ultrasound and tomography, musculoskeletal structures are examined. The treatment includes painkillers, anti-inflammatory, neurometabolic, vascular pharmaceuticals, exercise therapy, physiotherapy, massage. Surgical interventions are performed according to indications.

General information

Neuropathy of the median nerve is quite common. The main contingent of patients is young and middle-aged people. The most common sites of damage to the median nerve correspond to the zones of its greatest vulnerability - anatomical tunnels, in which compression (compression) of the nerve trunk is possible with the development of the so-called. tunnel syndrome. The most common tunnel syndrome n. medianus is carpal tunnel syndrome - compression of the nerve when it passes to the hand. The average incidence in the population is 2-3%.

The second most common site of damage to the median nerve is its area in the upper part of the forearm, which runs between the muscle bundles of the round pronator. This neuropathy is called pronator teres syndrome. In the lower third of the shoulder n. medianus may be compressed by an abnormal process of the humerus or Struser's ligament. Its defeat in this place is called Struser's tape syndrome, or the syndrome of the supracondylar process of the shoulder. In the literature, you can also find a synonymous name - the Coulomb-Lord-Bedossier syndrome, which includes the names of the co-authors who first described this syndrome in 1963.

Anatomy of the median nerve

N. medianus is formed by joining bundles brachial plexus, which, in turn, start from the spinal roots C5-Th1. After passing axillary zone runs next to the brachial artery along the medial edge of the humerus. In the lower third of the shoulder, it goes deeper than the artery and passes under the ligament of Struzer, when it enters the forearm, it goes in the thickness of the round pronator. Then it passes between the flexor muscles of the fingers. On the shoulder, the median nerve does not give branches, sensory branches depart from it to the elbow joint. On the forearm n. medianus innervates almost all the muscles of the anterior group.

From forearm to hand n. medianus passes through the carpal tunnel. On the hand, it innervates the muscles that oppose and abduct the thumb, partially the muscle that flexes the thumb, and the worm-like muscles. Sensory branches n. medianus innervate the wrist joint, the skin of the palmar surface of the radial half of the hand and the first 3.5 fingers.

Causes of median nerve neuropathy

Neuropathy of the median nerve can develop as a result of nerve injury: its contusion, partial break fibers in cut, torn, stab, gunshot wounds or damage by bone fragments in case of fractures of the shoulder and forearm, intra-articular fractures in the elbow or wrist joints. The reason for the defeat of n. medianus may be dislocations or inflammatory changes (arthrosis, arthritis, bursitis) of these joints. Compression of the median nerve in any of its segments is possible with the development of tumors (lipomas, osteomas, hygromas, hemangiomas) or the formation of post-traumatic hematomas. Neuropathy can develop as a result of endocrine dysfunction (with diabetes mellitus, acromegaly, hypothyroidism), with diseases that entail changes in ligaments, tendons and bone tissue(gout, rheumatism).

The development of tunnel syndrome is due to compression of the median nerve trunk in the anatomical tunnel and a violation of its blood supply due to concomitant compression of the vessels supplying the nerve. In this regard, the tunnel syndrome is also called compression-ischemic. Most often, median nerve neuropathy of this genesis develops in connection with professional activity. For example, painters, plasterers, carpenters, packers suffer from carpal tunnel syndrome; round pronator syndrome is observed in guitarists, flutists, pianists, in nursing women who hold a sleeping child on their arm for a long time in a position where his head is on the mother's forearm. The cause of the tunnel syndrome may be a change in the anatomical structures that form the tunnel, which is noted with subluxations, tendon damage, deforming osteoarthritis, rheumatic disease of the periarticular tissues. In rare cases (less than 1% in the general population), compression is due to the presence of an abnormal process of the humerus.

Symptoms of median nerve neuropathy

Neuropathy of the median nerve is characterized by severe pain syndrome. The pain captures the medial surface of the forearm, hand and fingers 1-3. Often it has a burning causalgic character. As a rule, pain is accompanied by intense vegetative-trophic disorders, which is manifested by swelling, heat and redness or coldness and pallor of the wrist, the radial half of the palm and 1-3 fingers.

The most noticeable symptoms of movement disorders are the inability to make a fist, oppose the thumb, bend the 1st and 2nd fingers of the hand. Difficulty bending the 3rd finger. When the hand is bent, its deviation to the ulnar side is observed. Tenor muscle atrophy is a pathognomonic symptom. The thumb is not opposed, but placed on a par with the rest, and the hand becomes similar to a monkey's paw.

Sensory disturbances are manifested by numbness and hypesthesia in the zone of innervation of the median nerve, i.e., the skin of the radial half of the palm, the palmar surface and the rear of the terminal phalanges of 3.5 fingers. If the nerve is affected above the carpal tunnel, then the sensitivity of the palm is usually preserved, since its innervation is carried out by a branch extending from the median nerve to its entrance to the canal.

Diagnosis of neuropathy of the median nerve

AT classic version median nerve neuropathy can be diagnosed by a neurologist during a thorough neurological examination. To identify motor insufficiency, the patient is asked to perform a series of tests: clench all fingers into a fist (1st and 2nd fingers do not bend); scrape on the surface of the table with the nail of the index finger; stretch a sheet of paper, taking it only with the first two fingers of each hand; rotate with your thumbs; connect the tips of the thumb and little finger.

With tunnel syndromes, Tinel's symptom is determined - soreness along the nerve when tapping at the site of compression. It can be used to diagnose the location of the lesion n. medianus. In pronator teres syndrome, Tinnel's symptom is determined by tapping in the region of the pronator's snuffbox (upper third of the inner surface of the forearm), with carpal tunnel syndrome - by tapping on the radial edge of the inner surface of the wrist. In supracondylar process syndrome, pain occurs when the patient simultaneously extends and pronates the forearm while flexing the fingers.

Clarify the topic of the lesion and differentiate neuropathy n. medianus from shoulder plexitis, vertebrogenic syndromes (sciatica, disc herniation, spondylarthrosis, osteochondrosis, cervical spondylosis), polyneuropathy helps electroneuromyography. In order to assess the condition of bone structures and joints, bone radiography, MRI, ultrasound or CT of the joints are performed. In supracondylar process syndrome, an x-ray of the humerus reveals a “spur”, or bone process. Depending on the etiology of neuropathy, the following are involved in the diagnosis:

Successful treatment depends on both the type and age of the injury.

Treatment of post-traumatic neuropathies

Post-traumatic neuropathies associated with damage to any nerve trunk on the forearm (ulnar, radial and median nerves) are treated in a fresh time by restoring the anatomical integrity.

In this case, execution is shown neurolysis - surgical operation, aimed at releasing the nerve from squeezing by scar tissue. Thus, the sooner you turn to a specialist with post-traumatic neuropathy, the better the treatment process will be and the less postoperative complications will occur.

If, after the onset of the development of the lesion, a sufficiently long time has already passed (from 2-3 months), then the surgical intervention will be much more voluminous. In this case, you will either have to sew in the nerves in an uncomfortable position of the upper limb (to reduce the tension, the arm is specially bent and unbent in certain joints), or plastic surgery (transplant) should be performed.

The more time passes after the injury, the more likely the development of neurogenic contracture of the hand - the affected nerve ceases to innervate certain muscles and there are irreversible changes in the form of muscle contracture. These contractures can only be eliminated with the help of various orthopedic operations, during which the transposition of the tendons and muscles is performed.

Also one of the relatively new, but very popular methods surgical correction or prevention of neurogenic contractures of the limb at a high level of damage is neuroticism- restoration of lost muscle innervation.

Treatment of compression neuropathies

With early treatment of a patient with initial manifestations of compressive neuropathy, treatment with conservative therapy methods is possible:

produced splinting(fixation with a splint or orthosis) limbs in a physiological position
appointed NSAIDs(non-steroidal anti-inflammatory drugs), drugs that improve trophism and regeneration nervous tissue(such as Trental, Neuromidin, B vitamins, Prozerin)
physiotherapy.

A separate problem in the treatment is the introduction of hormonal drugs into the intended area of nerve compression. Such injections are appropriate only for an idiopathic cause of the disease, because they do not eliminate volumetric formations that are the cause of the disease.

In addition, at the injection site hormonal drug a site of dystrophy and degeneration of surrounding tissues with altered vascularization is always found, and the drug can get into the region of the nerve or nearby tendons. All this can lead to the development of persistent contractures of the hand, neurological disorders expressed pain syndrome. In our practice, we try to avoid the use of methods that can lead to such complications.

Treatment of carpal tunnel syndrome

The most common type of lesion is ischemic tunnel neuropathy (tunnel syndrome). This is a carpal tunnel syndrome, in which the median nerve, located in the carpal tunnel, is compressed either by a thickened wall of this channel, or by some volumetric formations (tumor). It can also be compressed due to the modified sheaths of the flexor tendons.

If compression occurs at the level of the carpal tunnel, the most common treatment for ulnar ischemic neuropathy is dissection of the wall of the carpal tunnel.

The incision is performed either in an open way (open release) or with the help of endoscopic techniques. The difference between these surgical methods of treatment is only in the size of the surgical access. The use of endoscopy allows operations to be performed through small incisions, but with an open release, it is possible to visualize the entire canal, which gives best review and allows you to make sure that there are no volumetric formations.

Treatment of cubital tunnel syndrome

The second most common ischemic neuropathy syndrome is cubital duct syndrome. This is an ischemic neuropathy of the ulnar nerve, which runs at the level of the elbow joint in the cubital canal formed by the ulna and the connective tissue "bridge".

Depending on the alteration of the canal walls, various treatment options are possible - from simple dissection of the canal wall connective tissue bridge to nerve transposition into intact tissues. For example, if there is a deformity in the area of the bone walls of this canal, there is a need to move the ulnar nerve to the palmar side relative to the elbow joint.

Another type of compression neuropathy is ischemic neuropathy of the ulnar nerve at the level of Guyon's canal. This canal is located on the hand (as well as the carpal one) and is formed by the bones of the wrist and the connective tissue bridge. This pathology occurs quite rarely and is treated by decompressing the canal (dissecting one of its walls).

The choice of anesthetic aid depends on the type and volume of the operation - if this is a simple option for dissecting the canal wall, then conduction anesthesia is sufficient. For longer and more serious operations, general anesthesia is preferred.

Additional Treatment

In the postoperative period, it is obligatory to immobilize the operated limb in a physiological position (with compression neuropathies or nerve plasty). When stitching with a slight tension, it is advisable to fix in a forced position, in which the tension of the nerve will be the least.

In the process of treating neuropathy, regardless of the cause of the lesion, drug therapy should also be used:

be sure to prescribe vitamins of group B, drugs "Trental", "Prozerin", which improves neuromuscular transmission, "Neuromidin", "Dibazol" in minimal doses
treatment should be accompanied by immobilization of the operated limb (up to 3 weeks) to minimize scarring in the surgical area. In addition, immobilization is necessary to reduce the risk of suture rupture in the postoperative period.
it is also necessary to carry out adequate physiotherapy exercises, the purpose of which is to prevent the development of contractures in the operated limb and the use of physiotherapy, which will be aimed at reducing the formation of scar tissue in the area of operation

To assess the dynamics of recovery of the damaged nerve after surgery, it is necessary to periodically perform electroneuromyography.

MEDIAN NERVE [n. medianus(PNA, JNA, BNA)] - a long branch of the brachial plexus that innervates the muscles of the forearm and hand, the skin of the palm and palmar surface of the I - III fingers and the radial surface of the IV finger, as well as the skin of their back surface in the region of the distal phalanges.

S.'s anatomy of N, zones and objects of its innervation were studied in detail in 18-19 centuries. V. L. Gruber, F. Henle, Krause (K. F. T. Krause). In the 20th century Borchardt and Vyasmensky (M. Borchardt, Wjasmenski), A. V. Triumfov, A. H. Maksimenkov presented data on the bundle structure of the nerve, its connections with neighboring nerves, the number and ratio of the components of S. n. nerve fibers.

Anatomy

S. n. is formed by the medial (radix med.) and lateral (radix lat.) roots, respectively, from the medial and lateral bundles of the subclavian part of the brachial plexus (see). The specified roots cover a brachial artery and connect, forming S.'s trunk of n. The connection of the roots of S. n. can occur at various levels - from the axillary fossa, where the bundles cover the axillary artery, to the lower third of the shoulder, where the bundles surround the brachial artery, and in 25% of cases, the loop ("fork") S. n. it can also be double (see color table to Art. Ulnar nerve, Radial nerve, Fig. 1, 2, 4). In 80% of cases, the nerve fibers of S. n. belong to C5 - Th1, in 20% of cases - C6 - Th1. At the level of the upper third of the shoulder S. n. contains from 1 to 24 bundles of nerve fibers (on average 12) and up to 38 at the level of the cubital fossa, where the formation of muscle branches takes place - up to 38 bundles. The number of nerve fibers in S. n. fluctuates within considerable limits (see. Nerves). So, in the middle of the shoulder, there are 19-32 thousand myelin and 18-25 thousand non-myelin fibers. The number of myelin fibers of various diameters in S. n. in humans it is different: bottom fibers up to 3 microns - from 3 to 27%, dia. 3.1-5 microns - from 8 to 24%, 5.1 - 10 microns - from 54 to 88%, St. 10 microns - from 0.5 to 10%.

In the shoulder area S. n. located in the fascial sheath of the neurovascular bundle, being in the upper third of the shoulder in front and laterally, and in the lower third - in front and medially from the brachial artery. In the cubital fossa S. n. lies at the medial edge of the tendon of the biceps of the shoulder, then goes under the aponeurosis of the biceps of the shoulder, between the heads of the round pronator and on the forearm is located together with the accompanying median artery (a. mediana) between the superficial and deep flexors of the fingers. In the lower third of the forearm S. n. located in the median sulcus (sulcus medianus), formed laterally by the radial flexor of the wrist and medially by the superficial flexor of the fingers; the sulcus and nerve are covered by the tendon of the long palmar muscle. On S.'s shoulder, N, as a rule, does not give branches, but often forms connections with the musculocutaneous nerve (g. communicans cum n. mus-culocutaneo). Anatomical variants are noted when S. n. completely replaces the musculocutaneous nerve; in such cases, it gives branches in the shoulder region to the flexor muscles - the biceps, coracobrachial and brachial. In the cubital fossa S. n. forms an articular branch (g. articularis), going to the elbow joint, and muscle branches (rr. musculares), going to the round pronator, long palmar, radial flexor of the wrist, humeroulnar muscle, head of the superficial flexor of the fingers. Muscular nerves can depart from S. n. a common trunk, to-ry subsequently gives muscle branches to individual muscles (group method of innervation), or sequentially, branching off from S. n. to the muscles in the form of independent nerves (single method of innervation). In the area of the forearm from S. n. depart: anterior interosseous nerve (forearm); muscular branch to the superficial flexor of the fingers, in particular to the portion going to index finger; palmar branch (g. palmaris n. mediani - inconstantly); connecting branch going to the ulnar nerve (g. communicans cum n. ulnari) - up to 30% of cases. The anterior interosseous nerve lies on the interosseous membrane of the forearm along with the vessels of the same name; it gives muscle branches (rr. musculares) to the long flexor of the thumb, the radial part of the deep flexor of the fingers, the square pronator, the branches to the bones of the forearm, the interosseous membrane of the forearm, the branch to the dorsum of the wrist joint. The palmar branch of S. of N, departing in the lower third of the forearm, innervates part of the skin of the palm. In the palm of S. N., having passed through the canal of the wrist, is divided into three common palmar digital nerves (nn. digitales palmares communes), to-rye near the base proximal phalanges I, II, III fingers are divided into 7 own palmar digital nerves (nn. digitales palmares proprii). These nerves innervate the skin of the radial and ulnar surfaces of fingers I, II, III and the radial surface of the fourth finger, as well as the dorsal surface of the distal phalanges of these fingers. The innervation zones of the skin of the palmar surface of the fingers are unstable, there are overlapping zones of skin innervation of the median and ulnar nerve. Muscular branches (rr. musculares) depart from the I common palmar digital nerve to the muscles of the tenar or elevation of the first finger of the palm - to the short muscle that abducts the thumb, the superficial head of the short flexor of the thumb, the muscle that opposes the thumb; to I, II vermiform muscles. III common digital nerve has a connecting branch with the ulnar nerve (r. communicans cum n. ulnari), the location of which may vary.

Pathology

S.'s defeats of n. are of traumatic, compression-ischemic, inflammatory and intoxication origin. gunshot wounds and mechanical injury S. n. possible at any level from the brachial plexus to the fingers. With domestic injuries S. n. more often damaged on the forearm (especially in its distal third) in combination with a bone fracture (in almost half of S. n injuries) or with damage to the tendons of the flexors of the hand and fingers (for example, with cut wounds of the forearm). Compression and ischemic injury S. n. often occurs at the level of the carpal canal (carpal canal) or in the region of the round pronator of the forearm (see. Tunnel syndromes), as a result of a local fibrous-dystrophic process, with S.'s compression of n. scar tissue in cases of deep thermal burns, after injections of drugs, etc. Ischemia S. n. it is also possible with damage to the axillary or brachial artery. Functions S. n. are violated in its primary tumors (neurinomas, neurofibromas, lipofibromas) or as a result of secondary compression of the nerve trunk by tumors emanating from adjacent tissues (bones, muscles, connective tissue formations). Isolated inflammatory lesion S. n. rarely observed; usually the nerve is involved in the process with deep phlegmon of the shoulder, forearm, osteomyelitis. Intoxication lesions of S. n. noted in cases of poisoning with arsenic preparations, mercury, chlorophos; at endogenous intoxication of S.'s branch of n. are affected along with the distal branches of other nerves of the upper limb (see Ulnar nerve, Radial nerve, Peripheral nervous system, Polyneuritis), for example, in diabetes mellitus, hron. kidney failure and etc.

Wedge, picture of S.'s defeat of n. depends on the level and degree of violation of its conduction, as well as on individual characteristics its structures and connections with neighboring nerves. Symptoms of S.'s defeat of n. in the area from the brachial plexus to the outlet of the muscular branch to the pronator teres are the same: violation of the pronation of the forearm, weakening of the flexion of the hand, I, II and III fingers (during the test of clenching into a fist), difficulty in extending the distal and middle phalanges of the II and III fingers, flexion and opposition thumb, adduction and abduction of II and III fingers (Fig. 1); the most pronounced atrophy of the muscles in the area of the elevation of the first finger, as well as I and II worm-like muscles (mm. lumbricales), as a result of which the palm flattens, the first finger is brought close (in the same plane) to the second finger, which gives the brush a peculiar look - the so-called. monkey hand (Fig. 2). Zones of disturbance of skin sensitivity (anesthesia) are found at defeat of S. of N. on the palm and back surfaces distal and partially middle phalanges II, III and the radial surface of the IV fingers (Fig. 3), there is hypoesthesia of the skin of the palmar surface of the first finger and the radial surface of the hand (hyperpathy is possible in this zone); deep sensitivity is disturbed in the interphalangeal joints of the II and less often of the III finger, vibration - in the distal and middle phalanges of the II and III fingers.

With S.'s lesions, n. at the level of the forearm, movement disorders are limited to only wrist joint and fingers; flexion and opposition of the thumb, adduction and abduction of the II and III fingers, extension of the distal and middle phalanges of these fingers are impossible, flexion of the hand is weakened; sensitivity disorders are more pronounced than with damage to S. n. shoulder. For partial disturbance of S.'s conductivity of n. a half-bent hand, half-bent and adducted fingers, sometimes pronounced extension of the hand and fingers, hypoesthesia with hyperpathy, painful stiffness in the wrist, metacarpophalangeal and interphalangeal joints are characteristic.

Permanent and pronounced signs of S.'s defeat n. are vascular and vegetative-trophic disorders: cyanosis, impaired sweating (with a complete violation of nerve conduction - anhidrosis, with partial - hypo- or hyperhidrosis), thinning of the skin of the fingers, dryness and brittleness of the nails. Occasionally, trophic ulcers develop on the distal phalanges of the II and III fingers. Almost constant symptom S.'s defeats of n. are intense and persistent pain in the hand and fingers (in the zone of hypesthesia). More than in 1/4 supervision of pains get character of a causalgia (see). The most severe forms of causalgia are observed with partial nerve damage and with combined damage (damage to the bone and blood vessels).

To identify paresis of the muscles innervated by S. N, the following tests are used: squeezing the hand into a fist - II and III fingers do not bend enough and do not rest against the palm; pressing the brush to the table with the palm down - the inability to make a scratching movement with the second finger; flexion of the distal phalanges of fingers I and II - the inability to touch the distal phalanx of the index finger with the tip of the thumb. To diagnose the level of S.'s lesion, n. tapping is used along the course of the nerve - sometimes with percussion at the level of the lesion, pain and paresthesias occur in the I - IV fingers and in the palm area. The degree of nerve damage is determined using electrophysiological methods of research (see Chronaxis, Electromyography).

Treatment of S.'s defeat of n. it is defined by character of the patol who caused it. impact. Conservative treatment similar to treatment for injuries of other peripheral nerves of the hand and is aimed at stimulating nerve regeneration and eliminating pain. An operative measure is made at a rupture of S. of N., its tumors, a compression of a nerve callus, tumors emanating from surrounding tissues, with ischemia and compression of the nerve trunk in pathologically altered bone-fibrous canals, as well as with severe and persistent pain syndrome. Operations are carried out in special hospitals using microneurosurgical instruments and optics (see Microsurgery). The principles of treatment and the technique of performing operations for lesions of the peripheral nerves of the hand - see Ulnar nerve, Radial nerve. Operational accesses to S. n. at various levels are shown in fig. 4. A contraindication to surgery is the long term after injury, severe muscle atrophy, irreversible changes in the tendon-ligamentous apparatus with irremovable stiffness or ankylosis in the joints of the hand and fingers. Prevention of pain syndromes in case of damage to S. n. consists in the prevention of adhesions during primary and delayed operations to restore the integrity of the nerve (enveloping the nerve with a film, adipose tissue, pedunculated muscle, etc.). Surgical treatment of pain syndromes that have already arisen, especially causalgia, consists in ganglioectomy (removal of the stellate, Th2 - Th3 nodes of the sympathetic trunk), ramicotomy (see Ganglionectomy, Ramicotomy).

With compression of the nerve in the carpal tunnel, the operation consists in dissection transverse ligament wrist and decompression S. n. Postoperative fixation of the limb ensures the safety of epineural and fascicular sutures.

The effectiveness of nerve repair operations depends on the timing of the operation after injury, the atraumatic nature of manipulations on the nerve, the accuracy of alignment without tension of the ends of the nerve, and the suturing of neurofibrils (see Nerve suture). The use of modern microsurgical methods of the interfascicular suture contributes to the full restoration of the functions of the hand in most patients with S.'s damage to n.

Bibliography: Vishnevsky A. S. and Maksimenkov A. N. Atlas of the peripheral nervous and venous systems, JI., 1949; Intratrunk structure of peripheral nerves, ed. A. N. Maksimenkova, JI., 1963; Grigorovichi. BUT. Surgery nerve damage, L., 1981, bibliogr.; Izvekov O. N. The results of the suture of the median and ulnar nerves at different times surgical intervention, Vestn. hir., t. 101, No. 7, p. 78, 1968, bibliogr.; To and r-ch and to I N of S. I. Traumatic lesions peripheral nerves, L., 1962; K o v a n o v V. V. and Travin A. A. Surgical anatomy upper limbs, M., 1965; The experience of Soviet medicine in the Great Patriotic War of 1941 - 1945, vol. 20, p. 124, M., 1952; Raye R. E. Homoplasty of the median nerve, in the book: plastic surgery in children's trauma. and orthop., ed. P. Ya. Fishchenko, p. 83, L., 1974; Triumfov A. V. Topical diagnosis of diseases nervous system, L., 1974; Filippova R. P., N eiman and L. B. N and R at N d I. R. Long-term results of the suture of the median nerve, Ortop. and traumat., No. 9, p. 39, 1975, bibliogr.; Bauman T. D. a. about. The acute carpal tunnel syndrome, Clin. Orthop., v. 156, p. 151, 1981; Bonn el F.e. a. Bases anatomiques de la chirurgie fasciculaire du nerf median au poignet, Ann. Chir., t. 34, p. 707, 1980; Borchardt M. u. Wjasmenski. Der Nervus medianus, Beitr. klin. Chir., Bd 107, S. 475, 553, 1917; Drosler F. u. Johannes A. Seltener Fall einer fibro-lipoma-tosen Hypertrophie des Nervus medianus, Z. arztl. Fortbild., Bd 72, S. 955, 1978; F igu e i red o U. M. a. Hooper G. Abnormal course of the median nerve associated with an anomalous belly of flexor digitorum superficialis, Hand, v. 12, p. 273, 1980; Galass i E. e. a. La persistenza dell' arteria mediana, una possibile causa di sindrome del tunnel car-pale, Riv. Neurol., v. 50, p. 159, 1980; Jorg J., Gerhard H. u. L elini a n n H. J. Somatosensorische Reizant-wortpotentiale bei Normalpersonen nach Einzel- und Doppelstimulation des N. Medianus, EEG EMG (Stuttg.), Bd 11, S. 211, 1980; K a m a 1 A.S. a. Austin R. T. Dislocation of the median nerve and brachial artery in supracondylar fractures of the humerus, Injury, v. 12, p. 161, 1980; Merrem G. u. Goldhahn W. E. Neurochirurgische Operationen, Lpz., 1966; Nather A., Chacha P. B. a. L i m P. Acute carpal tunnel syndrome secondary to thrombosis of a persistent median artery (with high division of the median nerve), Ann. Acad. Med. Singapore, v. 9, p. 118, 1980; Perneczky G. Etude anatomique des varietgs du nerf median dans le canal carpien et ses consequences cliniques, Neurochirurgie, t. 26, p. 77, 1980; S e d d o n H. J. Surgical disorders of the peripheral nerves, Edinburgh, 1972.

D. K. Bogorodinsky, A. A. Skoromets; S. S. Mikhailov (an.), V. S. Mikhailovsky (neurosurgery).

Tunnel neuropathy - damage to peripheral nerves due to their compression in the anatomical narrowing (tunnels): rigid bone-fibrous and fibromuscular canals, aponeurotic fissures and holes in the ligaments. The main predisposing factor in the development of tunnel neuropathy is the narrowness of one or another anatomical tunnel through which the nerves pass.

CAUSES

In recent years, evidence has accumulated that indicates that narrow anatomical canals may be a genetically determined factor that is passed down from generation to generation. Another reason that can lead to the development of carpal tunnel syndrome is the presence of congenital anomalies development in the form of additional fibrous cords, muscles and tendons, rudimentary bone spurs.

However, only predisposing factors for the development this disease usually not enough. Tunnel syndrome makes itself felt when contributing factors begin to act. And it can be some diseases ( diabetes, acromegaly, hypothyroidism, etc.), professional, household and sports loads on a certain muscle group. Constant microtraumatization of the neurovascular bundle in a narrow canal contributes to the development of aseptic inflammation, leading to local edema of fatty tissue. Edema, in turn, contributes to even greater compression of the anatomical structures. Thus, the vicious circle closes, and this leads to the progression and chronization of the process.

SYMPTOMS

The main symptom of tunnel neuropathy is pain. The pains can be shooting, have a paroxysmal character like an electric shock, or they can have a constant aching character, take on a burning hue, be accompanied by dysesthesia (disturbances in sensitivity) in the innervation zone of the affected nerve. With the infringement of the nerves that take part in the innervation of the muscles, a decrease in strength is possible, fast fatiguability and even muscle atrophy. With compression of the arteries and veins, the development of vascular disorders is possible, which is manifested by blanching, a decrease in local temperature, or the appearance of cyanosis and swelling of a part of the limb.

TREATMENT

Treatment of tunnel neuropathies consists in decompression (pressure reduction) of the contents of the anatomical canal. As a result of this, blood circulation improves, and the myelin sheath of the damaged nerve is regenerated. With the right timely treatment full recovery is possible. The therapy consists in a protective mode, the introduction of a suspension of steroids into an anatomically narrowed canal. In more severe cases, decompression of nerve structures requires surgical treatment- a dissection of the fibrous canal is performed, a revision of the nerve is carried out. The operation is not dangerous and effective, in most cases leading to full recovery function of the damaged nerve, relief of pain.

CARPAL CANAL SYNDROME

Carpal tunnel syndrome is the most common form of tunnel neuropathy. The development of this disease is due to compression of the median nerve in the wrist, in the place where it passes through a narrow rigid tunnel formed by the bones of the wrist and carpal ligament.

Together with the median nerve, 9 tendons pass through this canal, which is involved in the flexion of the fingers. Most of cases of carpal tunnel syndrome is due to the accumulation of fluid and an increase in the volume of the synovial sheaths surrounding these tendons (tenosynovitis or tendovaginitis). The severity of the symptoms of this disease can range from barely noticeable to severe forms. Without treatment, the course of the disease tends to progress.

WHO IS SUFFERING WITH CARPENT TUNING SYNDROME

Most often, carpal tunnel syndrome occurs in women over 30 years of age. Most common cause disease is a nonspecific inflammation of the synovial bags surrounding the flexor tendons of the fingers (tenosynovitis). Carpal tunnel syndrome is often found in people whose work is associated with frequent rhythmic flexion of the fingers (milkmaids), using vibrating tools (perforators, jackhammers). Many diseases, certain medications, trauma to the hand, and even pregnancy can cause the fluid in the synovial sheaths to increase to such an extent that it compresses the median nerve in the rigid canal. The median nerve provides sensory innervation to most of the palm and fingers. In addition, this nerve innervates some muscles in the hand area.

SYMPTOMS

The most common complaint in this disease is a decrease in the sensitivity of any of the five fingers of the hand, with the exception of the little finger. Patients often complain that they cannot hold things in the affected hand due to numbness. Violation of sensitivity is accompanied by pain radiating to the forearm. These symptoms often appear or worsen at night, because at this time the outflow of fluid from the vessels of the limb slows down, which can lead to its accumulation in the synovial sheaths. In addition, during sleep, involuntary flexion of the hand can occur, which can also increase nerve compression. In severe cases, there is atrophy and weakness in the muscles of the eminence of the thumb. Stiffness in the fingers occurs in 25% of patients with carpal tunnel syndrome and is apparently due to the presence of concomitant tendovaginitis.

DIAGNOSTICS

The diagnosis can be established in most cases with careful questioning and physical examination. Often, symptoms appear or worsen 60 seconds after a strong clenching of the hand into a fist (Phalen's symptom) or when tapping with a neurological hammer on the wrist at the site of the median nerve (Tinel's symptom). In diagnostic difficult situations a more painful (and expensive) study of nerve conduction (stimulation electromyography) is used.

TREATMENT

In patients with easy flow diseases in which symptoms have appeared recently or are expressed inconsistently, conservative therapy is successfully used, which consists in taking anti-inflammatory drugs and fixing the hand with a splint bandage for the night. However, in many cases, the symptoms of the disease recur again. In this case, surgical treatment is indicated. Surgery is the method of choice (best known) for classic carpal tunnel syndrome. Usually, 80-90% of patients completely get rid of the symptoms of the disease after dissection of the transverse carpal ligament, which takes part in the formation of the carpal tunnel. In some cases, during the operation, neurolysis is performed - excision of scarred and altered tissues around the nerve, as well as partial excision of the tendon sheaths.