Carpal tunnel syndrome

In the clinical picture, carpal tunnel syndrome is manifested by paresthesias and pains in the fingers. Pains are often irradiated to the forearm, rarely - to the shoulder area. Hypescension is limited to the palmar surface of the first finger, the back and palmar surface of the II - IV fingers. Sensitivity on the palmar surface of the hand is not disturbed, since the cutaneous branch to the inner half of the palm is moving away from the main trunk of the median nerve slightly above the wrist and therefore is not squeezed. In contrast to the syndrome of the round pronator, the compression of the median nerve in the carpal tunnel does not reveal the finger flexor paresis. At the level of the wrist from the median nerve, the motor branch branches innervating the muscles of the outer part of the tenar of the first finger-the opposing, short and short flexor of the thumb. The latter muscle has a double innervation from the median and ulnar nerve, therefore, with the carpal tunnel syndrome, only the weakness of the opposition and withdrawal of the thumb is clearly revealed. Often there is a hypotrophy of the elevation of the 1st finger. Hyperhidrosis in the wrist arises with this disease more often than hypohydrosis. The main diagnostic tests are a wrist flex test and a symptom of effleurage along the projection of the median nerve at the wrist level. Additional diagnostic value is turnstile and elevation tests.

The differential diagnosis of various topographic variants of such syndromes along the course of the median nerve is based on the refinement of the zone of paresthesia, hypalgesia, the involvement of the corresponding muscles (paresis, hypotrophy), data obtained by pocking and squeezing along the nerve, and also electrophysiological. In the clinical picture, paresthesia in the distal parts of the hands occupy the largest proportion.

In the early periods of the disease, the first night paresthesias appear with great consistency and intensity. Patients wake up with a feeling of numbness and tingling mainly in the II - III fingers or the entire hand. In the initial phase of the disease, episodes of paresthesia occur 1 - 2 - Zraza per night and disappear after a few minutes after awakening. Then the night paresthesias become frequent and painful, disturbing sleep. Contribute to night paresthesias, prolonged tense manual labor during the day and the position of the hands on the chest. If a patient with a bilateral tunnel syndrome turns to the side during sleep, the paresthesias appear earlier in the upper limb above. Stop paresthesia is possible when rubbing and shaking the brush, tapping or hanging the upper limbs over the edge of the bed, while walking with swinging movements.

In the subsequent phase of the disease, daytime paresthesia also joins. Provokes daytime paresthesia intensive manual labor with a prolonged strain of flexor muscles (milking, carrying heavy loads, assembly work on the conveyor, writing, etc.), as well as movements of the upper limbs in the raised position (painters, electricians, etc.).

During the attack of paresthesia, most patients experience pain in the corresponding upper limb of indistinct localization, mainly in the distal part of it (fingers, hand, forearm). Sometimes the pain spreads in the proximal direction - up to the shoulder joint. The pain is dull, aching and is felt in deep tissues. As the disease progresses, it intensifies and gradually becomes extremely pronounced, burning.

The earliest symptom of tunnel syndrome is the morning numbness of the hands, which occurs before paresthesia and pain. After sleep, patients feel stiffness and swelling of the hands and fingers, but there is no clearly visible evidence of edema. Morning numbness of the hands gradually weakens and passes through 20 - 60 minutes. The most frequent variants of localization of sensitivity disorders are palmar surface III (92% of patients) and II fingers (71% of patients). Half of the patients have skin hypoplegia of the 4th finger, and 40% have a first finger.

Motor disorders in carpal tunnel syndrome appear in the late stage of the defeat of the branches of the median nerve. Initially, the paresis of the corresponding muscles is revealed, and after 2 to 3 pedules, their atrophy becomes noticeable (first of all, the muscles of the tenar are atrophied). For the clinical analysis of motor disorders, variants of individual innervation of the tenar muscles are of great importance. With dynamometry, the compression force on the side of the tunnel syndrome is less by 10 to 25 kg compared to a healthy brush.

Autonomic disorders in carpal tunnel syndrome occur frequently and are manifested by acrocyanosis or blanching (spasm of the fingers of the fingers), a violation of sweating (hyper- or hypohidrosis, determined by ninhydrin dactylograms), changes in trophic skin and nails (hyperkeratosis of the horny layer of the palm, turbidity of the nail plate, n.). Vasomotor disturbances are manifested in increased sensitivity to cold, coldness of the brush during periods of paresthesia attack, changes in the color of the skin of the fingers. With significant manifestation of such manifestations, a differential diagnosis with Raynaud's disease must be made. The disappearance of clinical manifestations after local injection of hydrocortisone or after surgical decompression of the carpal tunnel confirms the pathogenetic connection of them with the tunnel syndrome.

The most common carpal tunnel syndrome has to be differentiated from neurological manifestations of cervical osteochondrosis in discogenic (spondylogenic) lesions of the spinal roots CVI - CVIII. Both variants of neurologic pathology are often found in the same age groups and it is often possible that these diseases coexist in the same patient. The following differential diagnostic signs can be distinguished.

1. Spondylogenous radicular syndrome is accompanied by vertebral symptoms (cervical lordosis smoothing, restriction of mobility of this part of the spine, soreness of the paravertebral points during palpation, spontaneous neck pain - cervicalgia), paravertebral tension. These symptoms are absent in patients with carpal tunnel syndrome.
2. The localization of sensitivity disorders and the sequence of the spread of pain and paresthesia are different. Disorders of pain and tactile sensitivity in carpal tunnel syndrome are observed only in the distal phalange area of the dorsal surface of the fingers, and with the root syndrome, the hypoesthesia extends to the entire hand and the forearm in the dermatome zone. Cervical osteochondrosis is characterized by the appearance of pain and paresthesia from the area of the spinal column and shoulder girdle with distension in the distal direction. With carpal tunnel syndrome, paresthesia and pain begin in the distal part of the upper limb. Only with a significant increase in intense pain, it spreads in the proximal direction to the elbow joint and not above the shoulder joint.
3. Motor disorders with cervical root syndrome extend to the muscles of the corresponding myotome (these muscles are located on the wrist, forearm and shoulder), deep reflexes on the arm decrease. Carpal tunnel syndrome reveals paresis and hypotrophy of only the muscles of the tenar.
4. Tests that provoke paresthesia in the upper extremities almost always cause paresthesias in the hand and fingers with carpal tunnel syndrome and are absent in cervical osteochondrosis.
5. Local injections of hydrocortisone into the carpal tunnel zone eliminate pain and paresthesia in this tunnel syndrome. With cervical osteochondrosis, such injections are ineffective.

X-ray findings of cervical osteochondrosis should be interpreted only taking into account the peculiarities of the clinical picture, as in Vj patients with carpal tunnel syndrome also X-ray signs of degenerative-dystrophic changes in the cervical spine are found.

It is often necessary to differentiate the carpal tunnel syndrome from the spondylogic staircase syndrome (Nuffziger syndrome), in which paresthesia and pain extend to the entire upper limb, and after the night sleep, paleness (paleness) of the hand and cyanosis are noticeable. The pulsation of the radial artery can be reduced with a deep inspiration and Edson's sample. Hypesesia occurs not only on the skin of the hand, but also on the forearm, the shoulder. The flexion-elbow reflex decreases. Painful palpation and tension of the anterior staircase. All these symptoms are absent in carpal tunnel syndrome.

With bilateral carpal tunnel syndrome, manifestations of polyneuritis (toxic, toxic-infectious), endogenous (dismetabolic) polyneuropathy (diabetic, nephrogenic), and vibration sickness should be excluded.

Local pain with irradiation of them in the distal and proximal directions from the hand can occur with lesions of ligaments and tendon sheaths. Irradiation of pain creates a complex impression of involvement in the process of the nerves of the entire brush. With carpal tunnel syndrome, this group of diseases brings together a common mechanism of the disease development - overstrain of the tendons and muscles of the hand. Often there is a combination of a lesion of ligaments, vagina of tendons and a median nerve. When it should be allocated component of the lesion of the branches of the median nerve and the component of the affected tendons and periosteal formations.

Often there is a bopes de Kerven (styloid radial bone), in which pain extends to the hand and the 1st finger. However, the pain is localized along the radial surface of the hand and the 1st finger, which is not observed in carpal tunnel syndrome. With de Kerven's disease, the pain is most pronounced in the glitter of the subulate process of the radial bone. It is provoked by ulnar withdrawal of the brush; the amplitude of such a lead is limited. To verify the dopyuse, X-rays of the region of the styloid process are performed to identify edema of soft tissues and local thickening of the posterior ligament of the palm over the styloid process. With de Kerven's disease, paresthesia occurs rarely and is associated with the secondary involvement of the superficial branch of the radial nerve. In these cases, the hypoesthesia extends to the dorsal surface of the hand, which is not observed in carpal tunnel syndrome.

Pain and violations of the finger movements occur with stenosing ligament tendon sheath of the finger flexor. At the beginning of the disease, pain occurs at the base of the fingers, sometimes pain spreads on the back surface of the hand and fingers I-II, which can create a false impression of the involvement of the branches of the median nerve. With a differential diagnosis, it is taken into account that the pains increase with flexion and extension of the fingers. To increase the pain leads and palpation of this area or pressure on the base of the fingers working tool. In a later stage, mobility in the interphalangeal joints ("snapping fingers") is difficult, differential diagnosis becomes easy.

The syndrome of the intermetacarpal canal occurs when the common digital nerve (n. Digitalis communis) is damaged at the level of the metacarpal bones, which is located in a special intermetacarpal canal. With multiple forced extension of the fingers in the main phalange, the compression-ischemic lesion of this nerve can develop. The pain is localized in the area of the back surface of the hand and extends to the interdigital zone. In the phase of exacerbation, these pains often radiate in the proximal direction, as well as in the distal parts of the forearm. A similar localization of pain is also observed with an aggravation of the carpal tunnel syndrome, which can serve as the reason for the erroneous determination of the level of lesion of the median nerve. When palpation between the heads of the metacarpal bones, projection paresthesias and pains appear in the facing surfaces of the fingers.

In the developed stage of the disease, the zone of hypalgesia is also determined here. Such local symptoms are not observed in patients with carpal tunnel syndrome.

Syndrome of the anterior interosseous nerve develops when the branch of the median nerve is affected below the round pronator. In such cases, the small distal branch of this nerve is first attached to the anterior interosseous membrane, then to the posterior surface of the periosteum of the inner part of the radius, where it is divided into a series of radical, thin twigs penetrating the back carpal ligament and the capsule of the wrist joints. The anterior interosseous nerve innervates the front of the wrist and interosseous joints.

When the terminal branch of the anterior interosseous nerve is affected, pain occurs in the wrist area. To diagnose this neuropathy, one can carry out a novocaine blockade of the nerve. The needle through the muscle - the round pronator - is inserted before contact with the bone, and then the tip of the needle is slightly retracted toward the center towards the interosseous membrane. After anesthesia, the wrist pain temporarily stops and the function of the wrist improves. The carpal hyperextension test also helps in the diagnosis.

If the common trunk of the median nerve is damaged, paralysis and atrophy of all innervated muscles develops, the possibility of flexion of the first and second fingers, the opposition of the first finger V (fifth), is lost. This makes it difficult to grasp objects. The position of the first finger changes, it is located in the same plane with the others. Atrophy of the muscles of the tenar leads to a flattening of the palm, and the wrist acquires a pathological shape resembling a monkey's paw ("monkey's hand"). The area of sensitivity disorder due to overlapping by neighboring nerves is less than the area of pain, and is mainly localized on the radial half of the palmar surface of the hand and the rear of the distal phalanges of the II-III fingers. Deep sensitivity is lost in the terminal interphalangeal joint of the 2nd finger. Often expressed vasomotor and trophic disorders in the skin of the hand and nails (redness or blanching, hyperhidrosis or anhidrosis, hyperkeratosis or thinning of the skin, opacity of the nails, ulcers of the nail phalanx of the 2nd finger). With a partial lesion of the median nerve, there is causal pain and hypesthesia dolorosa, which is due to the presence of sympathetic fibers in this nerve. With expressed causalgic syndrome, reflex protective immobilization of limbs with antalgic contracture develops.

[1], [2], [3], [4], [5], [6]