What is Thoracic Outlet Syndrome?
Thoracic outlet syndrome (TOS) is a condition in which there is compression of the nerves, arteries, or veins in the passageway from the lower neck to the armpit. There are three main types: neurogenic, venous, and arterial. The neurogenic type is the most common and presents with pain, weakness, and occasionally loss of muscle at the base of the thumb. The venous type results in swelling, pain, and possibly a bluish coloration of the arm. The arterial type results in pain, coldness, and paleness of the arm.
Types of Thoracic Outlet Syndrome
There are three main types of TOS, named according to the cause of the symptoms; however, these three classifications have been coming into disfavour because TOS can involve all three types of compression to various degrees. The compression can occur in three anatomical structures (arteries, veins and nerves), it can be isolated, or, more commonly, two or three of the structures are compressed to greater or lesser degrees. In addition, the compressive forces can be of different magnitude in each affected structure. Therefore, symptoms can be variable.
• Neurogenic TOS includes disorders produced by compression of components of the brachial plexus nerves. The neurogenic form of TOS accounts for 95% of all cases of TOS.
• Arterial TOS is due to compression of the subclavian artery. This is less than one percent of cases.
• Venous TOS is due to compression of the subclavian vein. This makes up about 4% of cases.
Signs and Symptoms
Signs and symptoms of Thoracic Outlet Syndrome vary with every patient according to the location of the neurovascular tension and/or compression injury within the thoracic outlet. Symptoms of TOS can range from mild pain and sensory changes to limb- and/or life-threatening complications. Patients can present with multiple unilateral or bilateral signs and symptoms associated with involvement of both neurogenic and vascular components. The quality, location and timing of symptoms all present valuable information to the clinician (Hooper et al. 2010).
Arterial TOS, while infrequent, can produce a series of profound symptoms. Patients suffering from this condition can present with pain, numbness in a nonradicular distribution, coolness to touch and pale discoloration, all of which worsen with cold ambient temperatures (Hooper et al. 2010).
Venous TOS results in excruciating deep pain the chest, shoulder and entire upper extremity, accompanied by a feeling of heaviness that occurs especially after activity. The patient will present with cyanotic discoloration and distended collateral veins, potentially accompanied by edematous increases in the volume of the extremity (Hooper et al. 2010).
Symptoms associated with neurogenic TOS include pain, paresthesia, numbness, and/or weakness (Hooper et al. 2010).
Conditions with similar symptoms
Other conditions that can produce similar symptoms include rotator cuff tear, cervical disc disorders, fibromyalgia, multiple sclerosis, and complex regional pain syndrome
What could have caused Thoracic Outlet Syndrome
There are many causes of Thoracic Outlet Syndrome. The most frequent cause is trauma, either sudden (as in a clavicle fracture caused by a car accident), or repetitive (as in a legal secretary who works with his/her hands, wrists, and arms at a fast paced desk station with non-ergonomic posture for many years). TOS is also found in certain occupations involving lots of lifting of the arms and repetitive use of the wrists and arms.
One cause of arterial compression is trauma, and a recent case involving fracture of the clavicle has been reported.
The two groups of people most likely to develop TOS are those suffering from neck injuries due to traffic accidents and those who use computers in non-ergonomic postures for extended periods of time. TOS is frequently a repetitive stress injury (RSI) caused by certain types of work environments.
Other groups which may develop TOS are athletes who frequently raise their arms above the head (such as swimmers, volleyball players, dancers, badminton players, baseball pitchers, and weightlifters), rock climbers, electricians who work long hours with their hands above their heads, and some musicians.
Neurovascular impingement sites seen in Thoracic Outlet Syndrome
According to Hooper et al. (2010) Neurovascular impingement sites include:
1. Presence of a cervical rib (uncommon)
2. Abnormal Clavicle (collar bone) can create compression through exostosis, tumor, callus or fracture of the first rib, subsequently irritating the brachial plexus
3. Soft tissue abnormalities may create compression or tension loading of the neurovascular structures found within the thoracic outlet container. Scalene muscle variations include hypertrophy of the anterior scalene muscle, passage of the brachial plexus through the substance of the anterior scalene muscle, and a broad, excessively anterior middle scalene muscle insertion on the first rib the container, resulting in an increased potential for neurovascular load
Treatment of Thoracic Outlet Syndrome
Treatment can either involve a conservative non-surgical approach or surgical. The non-surgical approach can involve manual therapy and exercise to treat various neurovascular impingements that occur in thoracic outlet syndrome.
Treatment of the Costoclavicular space
Restoring mobility to the first rib can increase the costoclavicular space and reduce the imposed load on the neurovascular structures in the thoracic outlet container. Investigators have reported decreased TOS symptoms by restoring the mobility of the first rib through manual therapeutic procedures. Other authors have recommended mobilizations or manipulative treatment to the first rib costotransverse and costovertebral joints in order to restore first rib mobility and open the costoclavicular gate (Hooper et al. 2010).
It is possible that these mobilization techniques may reproduce the patient’s symptoms, particularly upper extremity paresthesias. Selected authors discourage the use of first rib mobilization in these patients for this reason. However, if the symptoms are the result of a ‘release phenomenon’, patients should be encouraged to continue with the measures, as the symptoms may be occurring due to a normalization of nerve function associated with unloading of the brachial plexus (Hooper et al. 2010).
Overuse of the scalenes and other accessory respiratory muscles may result in an elevation of the first rib and rib cage, reducing the costoclavicular space. Encouraging diaphragmatic breathing helps reduce the activity of these muscles, increasing the costoclavicular space. Vigorous aerobic activities may increase scalene activity and elevation of the first rib, so careful use of aerobic activities may help reduce symptoms, especially early in the rehabilitation process (Hooper et al. 2010).
Mobilization of the sternoclavicular and acromioclavicular joints is necessary to restore normal end-range arthrokinematics of the clavicle during elevation activities. Additionally, end-range limitations of glenohumeral motion can lead to compromise of the costoclavicular space. These limits can be addressed with mobilizations in the elevated arm position. The humerus can be glided in an anterior, posterior and inferior direction, respecting the orientation of the glenoid (Hooper et al. 2010).
Treatment of the Posterior Scalene Triangle
The posterior scalene triangle can be widened by (1) mobilizing the first rib in the direction of expiration and (2) stretching the scalene muscles. First rib mobilizations are performed as previously described. Once mobility of the first rib has been restored, increased activity of the scalene muscles may be addressed. Patients with hypertrophy or spasm of the scalenes will benefit from diaphragmatic breathing and a reduced reliance on the accessory respiratory muscles. These muscles can be stretched through a caudal mobilization of the first rib with the head rotated towards and laterally flexed away from the side being treated. The first rib self-mobilization technique may be modified to emphasize a stretch of the scalenes (Hooper et al. 2010).
Treatment of Thoraco-Coraco-Pectoral Space
Narrowing of the thoraco-coraco-pectoral space can result from shortening of the pectoralis minor or pectoralis major muscles. The pectoralis minor is stretched in a supine position with the patient’s shoulder over the edge of the table. The patient is brought into 70 degrees of glenohumeral flexion with internal rotation and slight adduction. The clinician’s contralateral hand is placed over the coracoid process, and the shoulder is stretched in a cranial and dorsal direction. The pectoralis major can be stretched with a corner stretch with the shoulders abducted 90 degrees and 125 degrees to stretch the clavicular and sternal heads, respectively. Care must be taken that this position does not increase the patient’s symptoms (Hooper et al. 2010).
Patients, with TOS resulting from narrowing of the thoraco-coraco-pectoral space, often present with a forward head posture and rounded, sagging shoulders. Proper posture should be emphasized throughout the treatment program with these patients. Encouraging a relative retraction of the shoulders increases the thoraco-coraco-pectoral space (Hooper et al. 2010).
A strip of hypoallergenic tape applied across the scapulae while in a comfortably retracted posture provides an effective tactile cue for the patient when the shoulders begin to fall into a protracted position. Another factor that may cause a sagging shoulder posture is heavy breasts in females. Pressure on the neurovascular tissues may be decreased by wearing a good support bra with wide, crossed posterior straps. Reduction mammoplasty has been recommended for extreme cases (Hooper et al. 2010).
Compromised sensorimotor control of the posterior parascapular muscles, particularly the rhomboids, serratus anterior, and lower and middle trapezius, can alter the position of the scapula at rest and during arm elevation activities, ultimately leading to thoracic outlet narrowing (Hooper et al. 2010).
Sensorimotor control exercises for these muscles are begun once relative pain control has been achieved. Novak recommends beginning these exercises in a gravity-assisted position in order to ensure proper recruitment of the lower scapular stabilizers and reduce the influence of the upper scapular elevators (Hooper et al. 2010).
All exercises should focus on muscular endurance rather than strength.7 Because limited upward rotation, posterior tilting and retraction of the scapula during elevation activities may decrease the costoclavicular space, these exercises may be beneficial for patients with symptoms due to narrowing of that passage as well (Hooper et al. 2010).
When a loss of neural mobility is present, neural mobilizations are incorporated in order to improve gliding of the neural tissue in relation to its surroundings and minimize tension and adhesion formation. These techniques are especially important in cases of a double crush phenomenon (Hooper et al. 2010).
Specific neural mobilization techniques can be modified to emphasize the brachial plexus proximally in the costoclavicular or thoraco-coraco-pectoral space while the clinician performs an inferior mobilization of the first rib. Additionally, the median and ulnar nerves more distally can be emphasized. Neural mobilizations should be performed in a pain-free manner; therefore, any increases in symptoms with these exercises are best addressed by either decreasing the number of repetitions or altering the technique used (Hooper et al. 2010).
For a home mobilization program, patients are instructed to initially perform up to 20 repetitions and gradually increase up to 100 repetitions as tolerated. This program may be repeated one to two times daily (Hooper et al. 2010).
Treatment at Cam Osteopathy
The Osteopaths at Cam Osteopathy are very competent to treating the neurological thoracic outlet syndrome. So for more information on thoracic Outlet Syndrome or to book an appointment with an Osteopath.
Hooper TL, Denton J, McGalliard MK, Brismée JM, Sizer PS Jr (2010). Thoracic outlet syndrome: a controversial clinical condition. Part 1: anatomy, and clinical examination/diagnosis. J Man Manip Ther. Jun; 18(2):74-83
Hooper TL, Denton J, McGalliard MK, Brismée JM, Sizer PS Jr (2010). Thoracic outlet syndrome: a controversial clinical condition. Part 2: non-surgical and surgical management. J Man Manip Ther. Sep; 18(3):132-8.