Thoracic Outlet Syndrome (TOS) 2025 PDF

Thoracic outlet syndrome By Dina Othman Shokri  Objectives At the end of this lecture, the student will be able to: I. Overview  Definition of TOS  Etiology , Classification of TOS II. Identify how to diagnosis TOS III. Know what are...

Thoracic outlet syndrome By Dina Othman Shokri  Objectives At the end of this lecture, the student will be able to: I. Overview  Definition of TOS  Etiology , Classification of TOS II. Identify how to diagnosis TOS III. Know what are the physical examination for TOS IV. What are the signs and symptoms for different types of TOS V. Know how to apply a successful patient management.  Thoracic outlet syndrome Thoracic outlet syndrome’ describes compression of the neurovascular structures as they exit through the thoracic outlet. The thoracic outlet is the anatomic space bordered by the first thoracic rib, the clavicle, and the superior border of the scapula (the clavicle anteriorly, the first thoracic rib posteriorly, the insertion of the pectoralis minor muscle onto the coracoid process of the scapula laterally, and the sternum medially). The thoracic outlet is marked by the anterior scalene muscle anteriorly, the middle scalene posteriorly, and The subclavian vasculature and brachial plexus—together termed the neurovascular bundle—pass from the scalene triangle into the costoclavicular space before exiting through the subcoracoid space. The thoracic outlet is both a confined and a dynamic space: compression of the neurovascular bundle resulting in the clinical syndrome generally termed thoracic outlet syndrome (TOS) may occur constantly or intermittently with movement of the neck, thorax, and arm This condition has emerged as one of the most controversial topics in musculoskeletal medicine and rehabilitation. This controversy extends to almost every aspect of the pathology including the definition, incidence, pathoanatomical contributions, diagnosis, and treatment. The pain and discomfort of TOS are generally attributed to the compression of the Subclavian vein, Subclavian artery, brachial plexus. The lowest trunk of the brachial plexus, which is made up of rami from the C8 and T1 nerve roots, is the most commonly compressed neural structure in TOS. These nerve roots provide sensation to the fourth and fifth fingers of the hand and motor innervation to the hand intrinsic muscles. TOS affects approximately 8% of the population and is 3-4 times as frequent in woman as in men between the age of 20 and 50 years (The mean age of people effected with TOS is 30s-40s; it is rarely seen in children). Females have less-developed muscles, a greater tendency for drooping shoulders owing to additional breast tissue, a narrowed thoracic outlet and an anatomical lower sternum, these factors change the angle between the scalene muscles and consequently cause a higher prevalence in women. Almost all cases of TOS (95-98%) affect the brachial plexus; the other 2-5% affecting vascular structures, such as the subclavian artery and vein. Possible 3 sites of compression of the vessels and nerves. Interscalene triangle Costoclavicular space Sub-coracoid tunnel or sub-pectoralis minor space Three spaces of the thoracic outlet.  Classification of thoracic outlet syndrome Vascular Thoracic Outlet Syndrome (vTOS): which represents approximately 3% of cases and compression is of the vascular structures (may be arterial or venous)) Neurological Thoracic Outlet Syndrome (nTOS): represents approximately 97% of cases and compression is of the neural structures of the brachial plexus. It may be divided into: True Neurological TOS (tTOS): is associated with true neurological deficits (mostly muscular atrophy). Disputed / non-specific / Symptomatic TOS (sTOS): is associated with symptoms of TOS, however, there are no objective neurological, electro- physical or radiological abnormalities. Causes Anatomical defects. Congenital may include an extra rib located above the first rib. Cervical ribs are present in approximately 0.5-0.6% of the population, 50-80% of which are bilateral, and 10-20% produce symptoms; the female to male ratio is 2:1. Cervical ribs and the fibromuscular bands connected to them are the cause of most neural compression. Fibrous bands are a more common cause of TOS than rib anomalies. Poor posture Dysfunctions or imbalances of the musculature of the neck and shoulder region. A common feature exhibited by individuals with TOS is a flexed head position, depressed and anteriorly shifted shoulder, and protracted scapula. This abnormal shoulder position, combined with 90° of abduction or flexion (as is commonly observed with those whose occupations require reaching, especially overhead, and repeated loading), could lead to a decrease in the costoclavicular space, increased friction of the neurovascular bundle in the subpectoral area. and a shortening of the sternocleidomastoid. The shortened sternocleidomastoid may cause the scalenes and pectoralis muscle groups to shorten, leading to improper head and neck alignment and postural dysfunction. The most commonly affected muscles in TOS Scalenes: When these muscles tighten, they pull on the first rib. These are accessory respiratory muscles, meaning they should help the diaphragm expand the rib cage while we breathe. If you have a bad habit of not efficiently using the diaphragm, then these muscles get overworked and will hypertrophy. Compression with movement of the scalene muscle. As the anterior scalene muscle goes from rest (A) to contracted (B), it pulls the first thoracic rib cranially and compresses the brachial plexus and subclavian within the costoclavicular space. Presence of a supernumerary cervical rib, as demonstrated in this figure, may constrict this space further. Pectoralis Minor. If this muscle is tight or shortened, it tilts the scapula forward, makes the scapula rotate downward, and promotes adduction of the shoulder which is a BIG problem for an overhead activity. Scapular stability. If the scapular muscle is weak as the Serratus Anterior and the Lower Trapezius. These muscles help posteriorly tilt the scapula while providing an upward rotational force to allow for appropriate positioning of the humeral head. If they are weak and the scapula is allowed to tip forward and rotate downward. Abnormal muscle mechanics at the pelvis. Pelvic alignment has been shown to affect posture, gait, and alignment of the axial skeleton (particularly the head and neck). If the axial skeleton is not aligned properly, stresses exerted on the body from exercise, occupational demands, or even from daily activities, may be distributed to other body segments and tissues that are not accustomed to adapting to these loads. For example, if the hip flexors (particularly the iliopsoas) are tight and the hip extensors are weak (particularly the glutes and hamstrings), the individual may exhibit an anterior pelvic tilt. In addition, abdominal muscles (e.g., Transverse abdominus) which normally generate a torque couple to resist the hip flexors, may be weak, thus causing lumbar vertebrae lordosis. This lordosis may induce thoracic vertebrae kyphosis, a common condition in those diagnosed with TOS. Trauma. This may involve macro-trauma, as in the case of an MVA (The scalene muscle could have been injured and scarred from a previous injury (whiplash), or microtrauma, as in the case of a muscle strain of the scapular stabilizers, resulting from repetitive overhead activities. The onset of symptoms related to a traumatic accident often is delayed. Trauma to the first rib or clavicle, and structural changes in the subclavian muscle or the costocoracoid ligament. Repetitive activity, such as typing on a computer, lifting things above head, as you would if you were stocking shelves. Athletes, such as baseball pitchers and swimmers, also can develop thoracic outlet syndrome from years of repetitive movements.  Diagnosis The diagnosis of TOS is essentially based on history, physical examination, provocative tests, and if needed ultrasound, radiological evaluation and electrodiagnostic evaluation. It must always kept in mind that TOS diagnosis is usually confirmed by elimination of other causes with similar clinical presentation. Especially differential diagnosis of cervical radiculopathies and upper extremity entrapment neuropathies. In order to diagnose accurately, the clinical presentation must be evaluated as either neurogenic (compression of the brachial plexus) or vascular (compression of the subclavian vessels).TOS manifestations are varied and there is no single definitive test, which makes it difficult to diagnose. Electrodiagnostic evaluation and imaging Nerve conduction studies and electromyography are often helpful as components of the diagnostic evaluation of patients with suspected TOS. Nerve conduction studies usually reveal decreased ulnar sensorial potentials, decreased median action potentials, normal or close to normal ulnar motor and median sensorial potentials. Typically TOS does not follow a dermatomal or myotomal pattern unless there is nerve root involvement. Vascular TOS can be identified with venography and arteriography. Imaging studies can provide useful information in the diagnosis of TOS. Cervical spine and chest x-rays are important in the identification of bony abnormalities (such as cervical ribs or a “peaked C7 transverse processes)  The physical examination Physical examination should include the following: Assessment of respiration to ensure patient is using correct abdominodiaphragmatic breathing. Assessment of the thoracic outlet closers muscles: The anterior and middle scalenes, subclavius, pectoralis minor and major These muscles typically are found to be adaptively shortened. Assessment of first rib position and mobility. Rib elevation caused by scalene hypertonicity, A post fracture callus formation of the first rib or presence of cervical rib. To detect the presence of first rib hypomobility. Cervical rotation–side bending test was used. The patient is seated and the clinician stands behind the patient. The test is in two parts. In the first part, the patient’s head is rotated to one side. From this position the patient’s head is flexed forward, and an end-feel assessment is made. The test is then repeated by first rotating the patient’s head to the other side and then flexing the head forward. A hard end-feel at the position of forward flexion indicates an elevated hypomobile first rib on the side opposite to the rotation. Assessment of Clavicle position: Clavicle depression and history of prior fracture, producing abnormal callous formation or malalignment. Assessment of Scapula position. Assessment of scapular muscle strength. Assessment of acromioclavicular and sternoclavicular joint mobility.  Signs and symptoms Patients with thoracic outlet syndrome will most likely present pain anywhere between the neck, face and occipital region or into the chest, shoulder and upper extremity. Signs and symptoms are typically worse when the arm is abducted overhead and externally rotated with the head rotated to the same or the opposite side. Symptoms depend on whether the nerves, the blood vessels, or both are compressed. When nerves are compressed, symptoms of neurogenic thoracic outlet syndrome include: Numbness or tingling in the arm or fingers. Pain or aches in the neck, shoulder, arm or hand. Arm fatigue with activity. A weakening grip. When the upper plexus (C5,6,7) is involved there is pain in the side of the neck and this pain may radiate to the ear and face. Often the pain radiates from the ear posteriorly to the rhomboids and anteriorly over the clavicle and pectoralis regions. The pain may move laterally down the radial nerve area. Headaches are not uncommon when the upper plexus is involved. Patients with lower plexus (C8,T1) involvement typically have symptoms which are present in the anterior and posterior shoulder region and radiate down the ulnar side of the forearm into the hand, the ring and small fingers. True TOS: Pain, paresthesia, numbness, and/or weakness (Objective weakness), S/s present day and/or night (Compressors*: s/s day>night) , loss of fine motor skills. Disputed Neurogenic TOS: Pain, paresthesia, and Subjective weakness "feeling" of weakness. Nocturnal paresthesias that often wake patient (Releasers*: s/s night>day) Occipital headaches Compressors - a patient that experiences symptoms throughout the daytime while using prolonged postures resulting in increased tension or compression of the thoracic outlet. These positions cause an increase in tension or compression of the neurovascular bundle of the brachial plexus. Releasers- Describes patients that often experience parasthesia at night that often wakes them up. It is caused by a release of tension or compression to thoracic outlet, that restores the perineural blood supply to the brachial plexus, signalling a return of normal sensation. This is used an indicator of a favourable outcome and resolution of symptoms. Symptoms of venous thoracic outlet syndrome can include: A change in the color of the hand or one or more fingers (Cyanosis) Hand or arm pain and swelling. Symptoms of arterial thoracic outlet syndrome can include: A pulsating lump near the collarbone. Cold fingers, hands or arms (Cold intolerance). Hand and arm pain (Claudication pain in arms that occurs while using the arms, the pain is caused by too little blood flow to arms). A change in color in one or more of the fingers or the entire hand (Pallor) Weak or no pulse in the affected arm. Special Provocative Testing: Roos Stress Test: It triggers the symptoms spontaneously experienced by the patient in less than one minute In order to determine if the scalene muscle is responsible, the roos test should be followed by the scalene cramp test and the scalene relief test. scalene cramp test: The patient is positioned in sitting and is asked to turn the head toward the painful side and pull the chin down into the supraclavicular fossa. This position causes contraction of the scalenes and should reproduce distal radiation of pain if the scalenes are involved. Scalene relief test: Is performed by asking the patient to actively place the forearm against the forehead on the involved side. This position increases the space between the clavicle and the scalenes and is positive for scalene dysfunction if it relieves the patients pain. The upper limb tension tests (ULTTs) are also known as Brachial Plexus Tension or Elvey Test. Morley’s Sign: Tenderness in the supra-clavicular fossa may have a diagnostic value when it is clearly asymmetrical and triggers distal pain. Supraclavicular pressure test: Tenderness at the root of the neck with pressure over the plexus in the interscalene groove causing neurological symptom. Special Vascular Tests: These include Adson’s Maneuver and Wright’s Test. The aim of these tests is to obliterate distal pulses by causing a dynamic compression of the vascular vessels.  Wright’s test (hyper abduction test): This test is considered by many to be the best provocative test for thoracic outlet compression caused by compression in the costoclavicular space. The test can be performed unilaterally or bilaterally. The patient is seated with his elbows extended. The shoulders are externally rotated and the examiner palpates the radial artery pulse. The examiner then passively abducts the patient’s upper extremities up to 180 degrees, keeping them posterior to the coronal plane. An option is to have the patient take and hold a deep breath. The examiner instructs patient to “tell me if you feel any changes in your arms.” Symptom production and pulse changes are noted.  Treatment Conservative management (medical, physical therapy Medical Management: Nonsteroidal anti-inflammatory drugs have been prescribed to reduce pain and inflammation. Botulinum injections to the anterior and middle scalenes have also found to temporarily reduce pain and spasm from neurovascular compression. Surgical management of TOS should only be considered after conservative treatment has been proven ineffective  Physiotherapy treatment  First rib mobilization and 1st Rib manipulation  MWM for First rib MWM for First rib First rib self-mobilization. The patient is positioned in sitting with spine supported. The cervical spine is retracted, laterally flexed away and rotated towards the treatment side. A thin sheet strap is positioned to contact the first rib on the cranial surface 1 inch lateral to the transverse process of T1. The patient uses her own hands to pull on the sheet loop and produce a mobilization force directed caudal and contralateral (towards the opposite hip).  Cervical, thoracic mobilization  Mobilization of the sternoclavicular and acromioclavicular joints is necessary to restore normal end-range arthrokinematics of the clavicle during elevation activities.  Glenohumeral mobilizations in end-range elevation  Cervical traction in combination with a hot pack and light exercise may reduce pain and irritable symptoms for some acute patients  Massage or myofascial techniques and stretching to scalenes/pectoral muscles/scapular depressors,subclavius. N.B. Stretching of the pectoralis, lower trapezius and scalene muscles (These muscles close the thoracic outlet)  Subclavius stretch Lower trapezius stretch Glenohumeral mobilizations in end-range elevation with the elbow supported in extension Strengthening to the commonly weakened muscles in TOS are scapular stabilizer ,rotator cuff (Facilitate co-contraction of the rotator cuff to help stabilize and centralize the humeral head). Deep cervical flexor and thoracic extensors Scapular depression. Scapular retraction Trapezius (lower)- Rhomboids - Trapezius Latissimus dorsi- Rhomboids Standing external rotation Trapezius (lower)- Infraspinatus- Teres minor-  banded straight arm extension Latissimus dorsi- Teres major- Triceps brachii banded high pull (Row) Latissimus dorsi- Trapezius* Rhomboids- Teres major/minor Prone shoulder extension, abduction, and horizontal abduction Trapezius- Supraspinatus- Infraspinatus- Deltoid -Latissimus dorsi- Teres major (I-Y-T exercices) frontal raise (deltoid) and lateral raise ( Deltoid- Supraspinatus- Trapezius Serratus push (Serratus anterior) chin tuck Abdominal core transverse abdominis and rectus abdominis recruitment. Breathing exercises (diaphragmatic) as TOS characterizes by shallow respiratory pattern (upper thoracic breathing).  Supportive taping  Neural mobilization  Patient education and activity modification  Postural re-education Disturbed sleep patterns are common in many people suffering from TOS, often as a result of either sleeping with the arms in an abducted, overhead position, or the consequence of the ‘release phenomenon’. If position dependent, then patients who cannot avoid the provocative position during the night may benefit from pinning the sleeve of the pajama arm to the pajama leg. Avoid sleeping on the affected side and on your stomach. The patient should sleep on the uninvolved side. Pillows may be placed under each arm when lying supine or between the body and the involved upper extremity when on lying on the side. These patients are instructed in the Cyriax release technique. The goal of this technique is to fully unload the neurovascular structures in the thoracic outlet prior to going to sleep at night, which will allow the patient to sleep through the night without waking. Before going to bed, the patient sits in a chair with adequate arm rests to place the shoulder girdle in a passively elevated position. As the load on the brachial plexus is released, the person’s symptoms begin and then gradually increase. Subsequently, as nerve function is normalized, the paresthesias begin to wane and eventually disappear. As a result of performing this technique, the patient will sleep longer into the night without waking. After one to two weeks of consistent use of this technique, it may be possible for the patient to sleep through the night without waking. Cyriax release maneuver.  Surgery  Supraclavicular Scalenectomy.  Transaxillary resection of the first rib: an effective procedure provided all nervous and vascular structures are completely released.  Some larger-chested women have sagging shoulders that increase pressure on the neurovascular structures in the thoracic outlet. A supportive bra with wide and posterior-crossing straps can help reduce tension. Extreme cases may resort to breast-reduction surgery to relieve TOS and other biomechanical problems Postoperative physical therapy Rehabilitation begins with shoulder and cervical range of motion exercises and gentle neural mobilization techniques. Overhead activities and lifting are avoided for 2–4 weeks. If postural abnormalities or muscle imbalances are found, an exercise program that addresses these issues must be implemented to help prevent a reoccurrence of the patient’s symptoms.