Thoracic Outlet Syndrome (TOS)
Epidemiology
Age:
Types
Neurogenic
The inferior trunk of the brachial plexus is the most commonly compressed neural structure in TOS2
Lower plexus (c8,t1) irritation: Symptoms on ulnar side of arm, hand, ant shoulder, axillary regions1
Upper plexus (C5, 6, 7): Ant aspect of neck from clavicle to mandible, ear, mastoid, occasionally radiating into the side of the face1
Venous
2nd most common cause of TOS (4%)2
Arterial
3rd (least) most common cause of TOS (1% of cases)2
Causes
Although TOS is affected my multiple variables, there are a few structures that directly compress the structures:
- Tumor
- 1st rib elevation
- Pec minor tight (especially at full elevation)
- Ant/mid scalene
- Cervical rib approximation
- Clavicle (movement)
Clavicle
Entrapments
There are 3 main entrapments:
- Interscalene triangle2
- Costoclavicular interval2
- Thoraco-coraco-pectoral space: As it passes thru coracoid process, pec minor, clavipectoral fascia to enter axillary fossa2
Interscalene triangle Entrapment
- Tight scalenes, injury of scalene or scapular suspensory muscles2
- Fibromuscular bands in scalenes or between long transverse processes of the lower cervical vertebrae2
- Entrapment here can result from cervical rib presence2
- Subclavian vein not involved (bc passess anterior to ant scalene)2
Costoclavicular interval Entrapment
- Between ribcage and posterior aspect of clavicle, entrapment can occur here with:
- clavicle depression,
- Rib elevation caused by scalene hypertonicity
- Repetitive shoulder abd
- First rib clavicle deformity
- Post Fracture callus formation of first rib or clavicle
Thoraco-coraco-pectoral space Entrapment
This entrapment occurs as As it passes thru coracoid process, pec minor, clavipectoral fascia to enter axillary fossa
- Subclavian artery/vein become axillary A/V
- Neurovascular bundle compromised with elevation, abduction, especially if ER is added with motion
- Pec minor tendon compression = associated with shoulder hyperabduction
Double crush syndrome refers to peripheral nerve pain caused by 2 or more entrapment sites.
The entrapment sites include the 3 main TOS entrapment sites, but double crush syndrome requires less pressure at each site to produce symptoms2.
Symptoms
- Mild to limb threatening2
- CC - diffuse arm and shoulder pain, especially with arm elevation beyond 90 degrees2
- Symptoms: pain localized in neck, face, head UE, chest,shoulder, axilla, UE paresthesia, numbness, weak, heaviness, fatigability, swelling, ulceration, raynauds, discoloration2
Symptom location:
- Paresthesia in the upper limb (98%)
- Neck pain (88%)
- Trapezius pain (92%)
- Shoulder and/or arm pain(88%)
- Supraclavicular pain(76%)
- Chest pain (72%)
- Occipital headache (76%)
- Paresthesias in all five fingers (58%)
- 4th and 5th fingers only (26%)
- 1-3rd fingers (14%)
Clinical Examination
Clinical examination: - Rounded shoulders, forward head, inc thoracic kyphosis, posterior tilt, downward rotation, depression of scapulae1 - Supraclavicular fullness = first rib prominence indicator or soft tissue swelling1 - Look for: - Cyanosis, edema = venous1 - Paleness - vascular compromise1 - Palpate the supraclavicular fossa1 - Pain = indicator1 - SB away, palpate post to pulsation of subclavian artery1 - If cervical spine, shoulder and TOS testing = negative, peripheral compression neuropathy is suspected1 - Doppler and angiography - arterial TOS tests1 - Venous TOS: venous ultrasound, scintillation scans, plethysmography,1 - Nerve conduction velocities and electromyography - neurogenic1
Diagnosis
Inspect spine, thorax, shoulder, UE for postural abnormalities, shoulder asymmetry, mm atrophy, large breasts, obesity, drooping shoulder girdle2
Palpate supraclavicular fossa for fibromuscular bands, percussion for brachial plexus irritability, auscultation for vascular bruits2
AROM and PROM of neck/shoulder
Neuro exam
Respiration: Determine if patient is using abdominanl diaphragmatic breathing
Assess suspensory mm: middle/upper traps, lev scap, SCM (typically found to be weak)2
Assess scapulothoracic mm (ant/mid scalene, subclavius, pec minor or major)2
- Found to be short in TOS2
First rib position or presence of cervical rib2
Clavicle position2
- Post fx?2
Scapula position2
Peripheral nerve tests/cervical radiculopathy tests2
Symptoms vary1
Diagnoses of the 2 vascular forms of TOS are accepted in all healthcare circles1
Neurogenic TOS are difficult to diagnose bc there is not standard objective test to confirm clinical impressions1
Diagnosis of exclusion1
Diagnosis of entrapment neuropathies of the upper limb does not exclude TOS1
Double crush is observed in 50% of cases1
Testing
- Tests for compromise at the Interscalene Triangle
- Adson’s Vascular Test (Tests Vasculature)1
- Supraclavicular pressure test (Tinel’s Test) (Tests Brachial plexus)1
- Costoclavicular Space
- Thoraco-coraco-pectoral gate
- Loading the plexus thru TOS container
- Unloading the brachial plexus through the TOS container
- Cyriax test1
- Passive Shoulder Shrug (Rules out TOS)
- Neural tissue thru thoracic outlet under a tension load
Validity
TOS maneuvers have low false positive rates when:
- A positive test is defined as pain after adson’s test, costoclavicular maneuver or supraclavicular pressure4
- Discontinuation of elevated arm stress test d/t pain4
- Pain in same arm with >=2 maneuvers4
- Any symptom in the same arm with >= 3 maneuvers4
So there are a lot of false positives for these various tests, IN ISOLATION, EXCEPT with pain (lower false positives for SCP, CCM, AT)4 If there is a discontinuation of EAST d/t pain = low false positive rate (most ppl dont stop it , even if they feel some pain, but if they need to stop d/t pain then that has a low false positive rate)4 Less false positives for combinations of these tests4
Gillard et al showed a cluster of 2 provocative tests displayed the highest sensitivity (90%) while a cluster of 5 tests increased the specificity of TOS to 84%1
DDX
- MI, arthritis, fibromyalgia, cervical disk disease, stenosis, MS, causalgia, carpal tennul, pancoast tumor4
ULTTs can be used to understand whether a patient is suffering from TOS or double crush syndrome
Intervention
Joint mobs: Grade 1-2 used for pain relief for acute conditions2
Costoclavicular space mobility
Restoring mobility to the first rib can inc the costoclavicular space and reduce imposed load on neurovascular structures in teh thoracic outlet container3
Studies reported dec’d TOS symptoms by restoring mobility of first rib thru manual therapy3
Encouraging diaphragmatic breathing helps reduce overuse of scalenes during breathing Accessory muscle of breathing (scalene) Vigorous aerobic activities may inc scalene activity and elevation of first rib, so careful use of aerobic activities may help reduce symptoms, especially early in the rehab Mobilization of SCJ and ACJ is necessary to restore normal end range arthrokinematics of clavicle during elevation activities End range limits of DGJ motion can lead to compromise of costoclavicular space as well Can be addressed w mobs in the elevated arm position (ie humerus gliding ant, post and inf)
First rib mobilization
CVJ mobilization
Rehabilitation
Conservative Management
When should you advise conservative treatment over surgery?
- Conservative measures shld be attempted for pt w/ disputed neuro TOS before surgery is considered but arterial or venous TOS should be treated with surgery to avoid loss of limb3.
- Hooper et al found success in conservative management in disputed neuro TOS patients at both short term (76-100%) and long term (59-88%)3.
When should you advise against conservative therapy?
- Conservative therapy is not recommended for venous or arterial TOS since there is a high chance of limb loss following complications3.
- Poor outcomes w conservative therapy (Novak et al ) → obesity, workers compensation, double crush pathology involving the carpal or cubital tunnel.
Patient education
Sleep hygiene - Avoid provocative positions during night if pain is position dependent3 - Place pillows between arm and body w/ side lying or place under each arm when lying supine3 - Cyriax Release Maneuver: Can unload the neurovascular structures prior to sleeping3
Manual Techniques
- Traction could help3
Pharmacological options
Possible Options:
- NSAIDs3
- Botulinum toxin (ant to middle scalenes)3
- 64% of subjects had a min 50% decrease in pain, numbness, fatigue for at least one month following injection3
- Can take up to 2-3 hours
- Pt education– informing pt about disease process, potential prognosis
- Compliance to exercise program is important for determining outcomes of conservative therapy
Prognosis
Release phenomenon: release of tension/compression of perineural blood supply to brachial plexus and return of normal sensation = prognostic indicator of favorable outcome1