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Thoracic Outlet Syndrome


Thoracic outlet syndrome, abbreviated as TOS, is a rare condition characterized by pain in the arm, shoulders and neck. The condition usually occurs when the nerves beneath the neck region are compressed either due to injury or any other underlying condition [1].


TOS presents with a wide range of symptoms which greatly vary with the nature of compression involved. It has been observed that nerve compression produces more symptoms than when blood vessels are compressed.

When nerve compression occurs, individuals experience pain in the back, neck and shoulders. Development of weakness is a common phenomenon in such cases which eventually leads to weak grip. In addition, affected individuals also complain of tingling sensation and numbness in the 4th and 5th fingers.

Blood vessel compression gives rise to inflammation of the arms accompanied by redness of the affected area. This basically occurs as the blood supply to the affected area is grossly reduced. As a result, the affected arm becomes cool and fatigued.

Arm Pain
  • We report a case of a 17-year-old female volleyball player who presented with months of chronic arm pain. Radiographic imaging demonstrated nonunion fracture of the first rib.[ncbi.nlm.nih.gov]
  • Signs & Symptoms: Neck/shoulder/arm pain, paraesthesia or numbness in arms/fingers, impaired circulation to the extremities.[corehealthcare.com.au]
  • Snapshot A 25-year-old woman with no history of trauma presents with right arm pain. She reports that her right arm is easily fatigable, especially after she cooks.[step1.medbullets.com]
  • Thoracic outlet syndrome symptoms include neck pain , shoulder pain , arm pain , numbness and tingling of the fingers , and impaired circulation to the extremities (causing discoloration).[medicinenet.com]
Forearm Pain
  • Pain and tingling in the surrounding areas such as the base of the neck, chest wall, axilla (armpit), breast, upper back and head.[umcvc.org]
  • Arterial TOS • Symptoms –Digital or hand ischemia –Cutaneous ulcerations –Forearm pain with use –Pulsatile supraclavicular mass/bruit 34.[slideshare.net]
Edema of the Hand
  • Muscles that are innervated by these nerves usually show some atrophy and weakness as well. 1 Vascular symptoms usually present with coldness or edema in the hand or arm, Raynaud's phenomenon (cyanosis), fatigue and superficial vein distention in the[morphopedics.wikidot.com]
Transient Blindness
  • "Rotational vertebrobasilar insufficiency as a component of thoracic outlet syndrome resulting in transient blindness". Journal of Neurosurgery . 81 (4): 617–9. doi : 10.3171/jns.1994.81.4.0617 . PMID 7931599 .[en.wikipedia.org]
Shoulder Pain
  • We report a 50-year-old Indian man, a machine operator by profession, who experienced bilateral shoulder pain and arm paraesthesia for two years, and was diagnosed with bilateral CCJ. The symptoms gradually increased, affecting his daily activities.[ncbi.nlm.nih.gov]
  • A 28-year-old elite archer presented with a feeling of weakness and dull shoulder pain, and experienced decreased grip power and hypoesthesia in the ulnar nerve dermatome in the full-draw position.[ncbi.nlm.nih.gov]
  • The first case is a 46-year-old female with a 2-year history of intermittent unilateral shoulder pain, who was initially diagnosed with intervertebral disk herniation.[ncbi.nlm.nih.gov]
  • Thoracic outlet syndrome symptoms include: neck pain, shoulder pain, arm pain, numbness and tingling of the fingers, impaired circulation to the extremities (causing discoloration, swelling, or pain) Diagnosis of thoracic outlet syndrome is suggested[childrenshospital.org]
  • TOS has been included in the differential diagnosis of shoulder pain in the swimmer 11 . Seven cases of TOS including our case have been reported among swimmers ( Table 2 ).[scielo.br]
Neck Pain
  • Symptoms include swelling, dark discoloration of the arm, and neck pain. Patients with this type of thoracic outlet syndrome often are diagnosed with a deep vein thrombosis in the arm.[wexnermedical.osu.edu]
  • Some people may experience neck pain or headaches in the base of their head. If the vein is affected, there will be swelling and discoloration of the affected arm, as well as pain.[physiofix.com.au]
  • Thoracic outlet syndrome symptoms include: neck pain, shoulder pain, arm pain, numbness and tingling of the fingers, impaired circulation to the extremities (causing discoloration, swelling, or pain) Diagnosis of thoracic outlet syndrome is suggested[childrenshospital.org]
  • Sign Up for FREE to spineadvisor, SpineUniverse's monthly eNewsletter and receive back and neck pain news, treatment updates, and lifestyle tips on managing your pain. No, thanks. Please take me back to the article.[spineuniverse.com]
  • NTOS is an underappreciated and often overlooked cause of shoulder and neck pain and numbness.[practicalpainmanagement.com]
Numbness of the Hand
  • There may be swelling, weakness or numbness in your hand or arm. You may have tightness in your neck. You may have a loss or decrease of the pulse at your wrist.[summitmedicalgroup.com]
  • Symptoms include weakness or numbness of the hand; decreased size of hand muscles, which usually occurs on one side of the body; and/or pain, tingling, prickling, numbness and weakness of the neck, chest, and arms.[my.clevelandclinic.org]
  • Symptoms include weakness or numbness of the hand, decreased size of hand muscles which usually occurs on one side of the body, pain, tingling, prickling, numbness and weakness of the neck, chest, and arms.[medstargoodsam.org]


The following methods are employed to diagnose TOS:

  • Physical examination: A detailed medical history along with a thorough physical examination to evaluate the signs and symptoms is carried out. The arms and hands are evaluated in several positions to arrive at a definitive conclusion.
  • Elevate arm stress test: In this method, the individuals are asked to raise their arms over the head for about 3 minutes. During this period, they are also asked to alternatively open and close their fists. If symptoms occur during this activity it is an indication of TOS.
  • Imaging studies such as CT scan, MRI, ultrasound and x-ray of the bones, blood vessels are carried out to diagnose the condition [7].
  • Other tests such as blood circulation tests and nerve conduction tests also form an important part of the diagnostic procedures [8].


Efforts are channelized to treat TOS with conservative treatment at the initial level. If the disease is diagnosed in the preliminary stages then medications and exercises should be employed. Medications such as pain killers and antiinflammatory drugs are prescribed for reducing the swelling and pain. Regular exercising strengthens the muscles and gradually reduces the pressure exerted on the nerves or blood vessels.

Surgery is the treatment of choice if other modes of treatment have failed to yield positive results [9]. Surgical intervention is employed to correct structural deformities or relieve the nerves or blood vessels from the pressure [10].


In majority of the cases, the prognosis is favorable only after surgical procedures to correct the anatomical defects are carried out. In case of physical trauma too, surgery is an effective option. However, there have been instances when patients have reported recurrence of symptoms even after treatment [6].


Compression of the nerves between the collarbone and the first rib is the major cause of TOS. The nerve compression can occur due to the following reasons:

  • Physical trauma: Car accidents are one of the major causes of nerve compression. Physical trauma can lead to internal changes that cause the nerves or the blood vessels in the thoracic outlet to get compressed.
  • Structural defects: Certain type of congenital defects in the anatomical features can also give rise to nerve compression. Presence of an extra rib or tight fibrous band that connects the spine to rib also causes TOS [3].
  • Postural defects: Poor posture habits such as drooping shoulders or keeping the head in forward position can predispose an individual to develop nerve compression.
  • Sports: TOS is also thought to be a common phenomenon in athletes who regularly participate in sports that force them to undergo repetitive movements using their arms and shoulders. Such a condition can cause wear and tear of the tissue leading to nerve compression.


The exact incidence of TOS is not known. However, with the available data, it can be estimated that such a type of condition occurs in 3 – 80 cases per 1000 population. TOS is more prevalent in women probably due to poor muscular development, poor posture or anatomical defects in this gender [4].

Sex distribution
Age distribution


The thoracic outlet is basically the space between collarbone and first rib. In this space, there are numerous blood vessels, nerves and muscles. In conditions, when the muscles of the shoulder are unable to support the collarbone it may slip from its original position thereby exerting pressure on the nerves, muscles as well as the blood vessels. Such series of events give rise to various symptoms such as pain in the arm, shoulder and neck accompanied by numbness and tingling sensation in the fingers. These are the characteristic features of thoracic outlet syndrome [5].


The onset of TOS cannot be prevented. However the development of debilitating complications can certainly be prevented by following certain simple steps. Individuals experiencing symptoms of TOS are advised to religiously exercise to avoid extra pressure on already compressed nerves. The practice of carrying heavy bags on shoulder should also be discontinued to avoid increase in pressure on the thoracic outlet.


Thoracic outlet syndrome (TOS) is more common in women than men and strikes individuals between 20 to 50 years of age. In addition to the pain in the affected region, the condition can also cause development of tingling sensation in the fingers accompanied by numbness. Physical trauma, repeated injuries, structural abnormalities or physiological conditions such as pregnancy can lead to development of TOS [2].

Patient Information


Thoracic outlet syndrome (TOS) is characterized by development of pain in the arm, shoulder and neck due to nerve compression in the thoracic outlet. It is a common phenomenon for women and athletes. The age of onset of the disease condition is 20 – 50 years.


Nerve or blood vessel compression due to repeated pressure on the thoracic outlet is the sole reason for development of TOS. Physical trauma, structural abnormalities or any underlying disease condition causes the nerves to compress giving rise to debilitating symptoms.


Individuals with TOS experience pain in the neck, shoulder and the arms. They also complain of tingling sensation accompanied by numbness in the fingers. In such individuals the arm movement gets limited which makes it pretty difficult to carry out daily tasks.


Diagnosis of TOS is made after a thorough preliminary physical examination is carried out to carefully study the symptoms reported by the individual. In addition, an elevated stress arm tests is also done to confirm the diagnosis. Imaging studies such as CT scan, MRI, ultrasound and x-ray of the bone are carried out to study the extent of nerve compression.


If TOS is diagnosed in the preliminary stages, then conservative approach is enough to treat the condition. Medications and exercises have proven to be beneficial for patients with TOS. However when these fail to show any effect then surgical intervention to relieve the nerve compression is carried out.



  1. Parziale JR, Akelman E, Weiss AP, Green A. Thoracic outlet syndrome. Am J Orthop. May 2000;29(5):353-60.
  2. Makhoul RG, Machleder HI. Developmental anomalies at the thoracic outlet: an analysis of 200 consecutive cases. J Vasc Surg 1992; 16:534.
  3. Roos DB. Congenital anomalies associated with thoracic outlet syndrome. Anatomy, symptoms, diagnosis, and treatment. Am J Surg 1976; 132:771.
  4. Al-Shekhlee A, Katirji B. Spinal accessory neuropathy, droopy shoulder, and thoracic outlet syndrome.Muscle Nerve. Sep 2003;28(3):383-5.
  5. Casbas L, Chauffour X, Cau J, et al. Post-traumatic thoracic outlet syndromes. Ann Vasc Surg 2005; 19:25.
  6. Dale WA, Lewis MR. Management of thoracic outlet syndrome. Ann Surg. May 1975;181(5):575-85.
  7. Stapleton C, Herrington L, George K. Sonographic evaluation of the subclavian artery during thoracic outlet syndrome shoulder manoeuvres. Man Ther 2009; 14:19.
  8. Oates SD, Daley RA. Thoracic outlet syndrome. Hand Clin. Nov 1996;12(4):705-18. 
  9. Axelrod DA, Proctor MC, Geisser ME, et al. Outcomes after surgery for thoracic outlet syndrome. J Vasc Surg 2001; 33:1220.
  10. Roos DB. Transaxillary approach for first rib resection to relieve thoracic outlet syndrome. Ann Surg 1966; 163:354.

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Last updated: 2018-06-21 22:58