Ladder muscle syndrome is a combination of neurogenic and vascular disorders that occur during compression of vessels and nerves passing between the ladder muscles. The clinical picture is represented by cervicalgia, brachyalgia, symptoms of arterial insufficiency or venous congestion, trophic disorders in the upper limb. The diagnosis is established on the basis of examination, neurological status data, results of radiography, CT, MRI, ultrasound, electroneuromyography. Treatment – pharmacotherapy in combination with non-drug methods (manual therapy, physiotherapy, massage, kinesiotherapy, osteopathy), with insufficient effectiveness, surgical operations are performed.
ICD 10
G45.8 Other transient cerebral ischemic attacks and related syndromes
General information
Ladder muscle syndrome (LMS) refers to neurovascular compression syndromes. Got its name from the muscles between which there is compression of subclavian vessels and branches of the brachial plexus, underlying the disease. Since in Latin terminology the stair muscles are called “scaleni”, in neurology this pathology is widely known under the synonymous name “scalenus syndrome”. The most common cause of the disease is osteochondrosis of the cervical spine. The prevalence of scalenus syndrome among patients with clinically manifested cervical osteochondrosis is 6%. The peak incidence occurs in the age period of 20-50 years. Women predominate among the patients.
Causes
There are anterior, middle and posterior stair muscles. They start from the transverse processes of the cervical vertebrae and are attached to the first two ribs. These muscles participate in head turns, raise the upper ribs when inhaling. Between the muscles pass the nerve trunks of the brachial plexus innervating the arm, between the first and second stair muscle — subclavian artery and vein. With a decrease in the interdigital space, compression of the anatomical formations located in it occurs, the syndrome of the staircase muscle develops. The main etiofactors of LMS are:
- Cervical osteochondrosis. The irritating effect of osteophytes on the nerve roots potentiates and supports the reflex tonic contraction of the stair muscles. The upper ribs are raised, the intervertebral distance decreases, causing compression of blood vessels and nerve fibers.
- Curvature of the spine. Excessive cervical lordosis, impaired posture, pathological head position with a forward tilt lead to a change in the anatomical interposition of bone and muscle structures that form the interstitial space. As a result, there is a decrease in the latter and the occurrence of compression.
- Injuries. Fracture of the collarbone, 1-2 ribs, injury to the soft tissues of the neck, upper chest cause a change in the configuration of the intervertebral space, its additional reduction due to swelling of the injured tissues. Nerve injury can cause neurogenic ladder muscle syndrome.
- Congenital anomalies. Due to the presence of an additional rib, the sealing of the ligament connecting the rib and the spine, the distance between the clavicle and the upper ribs is reduced. Conditions are created that cause compression of the neurovascular bundle in the interstitial space.
- Sports activities. Regular weightlifting, certain types of martial arts, swimming lead to an increase in the volume of the neck muscles, which can provoke compression. The development of LMS due to the increased load on the tissues of this area occurs during baseball, basketball, tennis, since they are associated with lifting the arm up.
- Weight gain. A significant gain of body weight in obesity, during pregnancy is accompanied by an increase in the volume of neck tissues. The consequence of this is a decrease in the interstitial gap, leading to the occurrence of LMS.
The formation of scalenus syndrome is facilitated by the disproportionate development of the cervical muscles, prolonged forced position of the hand (for example, when working at a computer). Predisposing factors of neurogenic LMS are endocrine diseases that occur with damage to nerve trunks (diabetes mellitus, hypothyroidism). Risk factors also include female gender, age over 20 and under 50 years.
Pathogenesis
The fibers of the brachial plexus give rise to nerves innervating the shoulder and upper limb. Their compression causes pain, sensory disorders, and a decrease in muscle strength. Functional muscle weakness potentiates violations of the biomechanics of the shoulder joint, changes in the sequence of inclusion of the shoulder girdle muscles in the motor act with the formation of pathological motor patterns. Due to changes in motor stereotypes, the load on the muscles increases, which acts as an additional pathogenetic link in the development of LMS.
The subclavian vein and artery provide blood supply to the upper limb. Due to compression of the artery, the blood filling of the vessels of the hand worsens, trophic disorders occur in its tissues. Compression of the vein leads to a restriction of the outflow of blood from the vessels of the upper limb, venous stagnation develops. The blood supply to the limb is disrupted, trophic disorders are formed.
Classification
In most cases, scalenus syndrome occurs with mixed neurovascular disorders. Depending on the leading mechanism, nervous or vascular symptoms predominate in the clinical picture. According to the pathogenetic classification , there are three main types of ladder muscle syndrome:
- Neurogenic — occurs due to compression of the nerves of the brachial plexus. The clinic is dominated by sensitive disorders, pain syndrome, peripheral paresis of the hand.
- Arterial — develops with compression of the subclavian artery. It is manifested by numbness, pallor and coldness of the skin, a decrease in the pulsation of the arteries of the affected limb.
- Venous — formed by compression of the subclavian vein. It is characterized by swelling, cyanosis, sensitivity disorder of the upper limb.
Symptoms
The pathology is characterized by an acute manifestation of clinical symptoms with intense neck pain (cervicalgia) radiating along the upper limb. A number of patients have headache (cephalgia), isolated pain in the arm (brachyalgia). With left-sided localization of pathology, pseudocardialgia is possible. Patients associate the appearance of pain with previous static overstrain of the muscles of the shoulder girdle and neck. Increased pain is provoked by turns of the head, movements in the shoulder joint, a deep breath. To alleviate the condition, patients restrict these movements.
Along with the pain syndrome, there is a decrease in the tone and strength of the muscles of the affected limb with the gradual development of atrophic changes. First of all, fine motor skills suffer, the patient experiences difficulties when it is necessary to take small objects, fasten buttons. Typical complaints are numbness of the fingers, swelling, tingling or burning in the hand. Arterial compression is accompanied by a violation of sensitivity, pallor of the skin of the hand, difficulty feeling the pulse. The disorder of venous outflow is manifested by cyanosis of the skin, expansion of the subcutaneous venous network, edema.
Complications
Shortening of the ladder muscle leads to the rise of the two upper ribs with their shutdown from the act of breathing. The position of the spinous processes of the vertebrae changes, which causes the formation of a cervical hump. Scalenus syndrome can cause neurodystrophic changes in the tissues of the shoulder joint with the development of shoulder periarthrosis and persistent restriction of movement in the shoulder. A serious complication is vertebrobasilar insufficiency (VI) – a violation of the blood supply to the occipital lobes and the base of the brain. IBD is manifested by dizziness, unsteadiness of gait, cephalgia of occipital localization, nausea, vomiting, decreased visual acuity, photopsias.
Diagnostics
The main diagnostic difficulties are associated with the similarity of the clinical picture of LMS and vertebrogenic radicular syndrome, the presence of signs of osteochondrosis in many patients. Incomplete physical examination of the patient leads to an erroneous diagnosis of cervical sciatica and incorrect treatment. Initially, pronounced vascular disorders allow us to assume the stair muscle syndrome. The list of examinations required to establish a diagnosis includes:
- Neurologist’s examination. There is an antalgic installation of the head, limitation of motor volume in the shoulder and cervical spine. Palpation determines the decrease in the length of the ladder muscle, the high standing of the upper rib, its limited participation in respiratory movements. In the affected limb, hypotension, hyporeflexia, paresis, pain hypesthesia of the radicular type, a decrease in pulsation on the radial artery is detected. Tannocy and Edson’s samples are positive.
- Radiography. Chest x-ray allows you to diagnose the presence of an additional rib and other malformations. Radiography of the cervical spine reveals osteochondrosis, a decrease in the height of the intervertebral spaces.
- Electroneuromyography. ENMG registers neurophysiological signs of partial blocking of the passage of nerve impulses at the subclavian level. With a certain length of the disease, the data indicate degenerative changes in the nerve trunks at the specified level.
- Tomography. CT of the spine in the cervical region provides detailed bone changes. MRI of the cervical spine visualizes soft tissue structures, makes it possible to exclude intervertebral hernia, spinal tumor.
- Dopplerography of the brachiocephalic trunk. Ultrasound of brain vessels is performed to assess blood flow in subclavian vessels. The narrowing of the vascular lumen at the level of the stair muscles is determined.
Scalenus syndrome must be differentiated from intervertebral hernia of the cervical spine, radiculitis, radiculopathy of tumor etiology. Computer and magnetic resonance imaging helps to exclude these diseases. With left-sided LMS with symptoms of cardialgia, diphdiagnosis is performed with angina attacks, myocardial infarction, neurocirculatory dystonia. You may need to consult a cardiologist, ECG, echocardiography.
Treatment
A variety of methods of treating ladder muscle syndrome have been developed, ranging from pharmacotherapy to physical therapy. Understanding of the pathogenetic mechanisms of the syndrome development has led to a wide spread of non-drug techniques that allow restoring normal anatomical relationships between structures that limit the interstitial space and the motor pattern. The effectiveness of pharmacotherapy is limited – it greatly facilitates the condition of patients with intense pain syndrome, promotes relaxation and improves the metabolism of muscle tissues, but cannot affect the causes of the disease. Pronounced vascular and neurological disorders, resistance to conservative therapy cause the need for operations. In the course of treatment, the following methods can be used:
- Drug therapy. Pain relief is carried out with painkillers, nonsteroidal anti-inflammatory drugs in combination with sedatives. Intense pain syndrome is an indication for therapeutic blockades with the introduction of glucocorticoids and local anesthetics. To relieve tonic muscle tension, muscle relaxants are prescribed, and group B vitamins are used to maintain trophic nerve trunks.
- Non-drug methods. Restoration of correct anatomical relationships is achieved by sessions of osteopathy or manual therapy. Muscle relaxation is promoted by myofascial massage, postisometric relaxation. Ultrasound therapy, magnetotherapy, ultraphonophoresis with lidocaine or hydrocortisone has an analgesic and anti-inflammatory effect. Kinesiotherapy is aimed at restoring physiological motor patterns. Physical therapy, massage, mud therapy are used to strengthen muscle tissue.
- Surgical interventions. The main methods of surgical treatment are scalenotomy (dissection of the staircase muscle), resection of the first rib, scalenotomy with simultaneous resection of the rib. Often scalenotomy is supplemented with periarterial sympathectomy. In case of violation of the patency of subclavian vessels, appropriate reconstructive vascular operations are performed. In the presence of bone anomalies, their correction is performed: removal of the cervical rib, hypertrophied transverse process of the VII cervical vertebra.
Prognosis and prevention
Timely diagnosis and complex therapy of ladder muscle syndrome make it possible to achieve a complete recovery of the patient. Incorrect diagnosis and treatment of LMS as cervical sciatica leads to temporary improvement with subsequent recurrence of symptoms. Relapses after surgical treatment, according to various data, amount to 10-20%. Prevention of scalenus syndrome includes a healthy lifestyle, moderate physical activity, regular exercise to strengthen the spine and form correct posture, healthy eating with maintaining optimal body weight, correction of endocrine imbalance, injury prevention.