What is thoracic outlet syndrome?
Thoracic outlet syndrome is a medical term for a condition where neck and arm symptoms are created by pressure on the nerves or blood vessels that pass from the neck down towards the arm. The nerves and blood vessels affected are collectively termed the “neurovascular bundle”. The point in which the neurovascular bundle is exposed to potential pressure is called the superior thoracic outlet, hence the name thoracic outlet syndrome or TOS for short. The margins of the thoracic outlet are made of bone and muscle, the neurovascular bundle passes through the outlet between two of the scalene neck muscles. Any enlargement or misplacement of the muscles and bones or surrounding structures can reduce the space of the outlet leading to compression of the bundle. It is the compression that leads to the neck and arm symptoms. TOS can be classified into three main categories. The most common, accounting for roughly 95% of cases is neurogenic TOS caused by compression of the brachial plexus. Arterial TOS is caused by compression to the subclavian artery and venous TOS is caused by compression subclavian vein. These types of TOS are not always exclusive and elements of each compression can happen simultaneously.
Why & when does a thoracic outlet syndrome happen?
TOS most commonly occurs either as a result of severe sudden trauma or as a gradual repetitive trauma. The most common sudden trauma related to TOS is whiplash, straining the muscles in the neck and possibly injury to the clavicle (collar bone). A fracture to the clavicle can also cause bone fragments to impinge and compress the neurovascular bundle. Repetitive trauma normally occurs through slouched poor posture, often caused by poor office ergonomics and sitting at a computer for long periods of time. Other types of work like army training with compressive heavy weighted back packs or activities that involve repetitive overhead stretching such as certain sports like swimming and weightlifting can also cause TOS.
Poor sleeping postures, spinal conditions such as scoliosis or even having a larger bust can reduce the space through the outlet leading to fluctuating levels of compression. Secondary problems from certain conditions such as rheumatoid arthritis or certain lung cancers can also be a factor in a small number of cases.
Cervical rib syndrome is a form of TOS caused by an extra rib that forms in a minority of people that is attached to the base of the neck and above the first rib, hence the name cervical rib. This small additional rib, with its fibrous connections, reduces the space of the thoracic outlet increasing the likelihood of developing TOS.
What does a thoracic outlet syndrome feel like?
Thoracic outlet syndrome symptoms vary, depending on the nature and site of the compression. In most cases there is a gradual onset of symptoms, most commonly starting with pain at the side of the neck that refers down into the arm and hand. The pain can be a dull ache or burning sensation that can amount to a sharp pain particularly on arm movements. Some cases begin with hand pain or hand symptoms, such as pins and needles, tingling or numbness. Occasionally when the circulation is compromised there is a discoloration of the hand and one hand will seem considerably cooler than the other. Pressure on the nerve can lead to weakness in the hand with a loss of grip and strength, many people find they struggle to lift their mug of tea or can’t grasp a heavy shopping bag. The pain and additional symptoms can be felt along the inside of the arm and forearm, as well as into the pectoral area and occasionally into the upper back. The pain levels can be mild, moderate or severe and symptoms vary from constant to fluctuating or only occurring when the arm is raised above the level of the shoulder.
How is thoracic outlet syndrome diagnosed?
Your GP or therapist will be able to diagnose you by both listening to your history and carrying out a full neurological and orthopedic examination. Certain orthopedic tests like Adson’s test or the costoclavicular maneuver can reproduce the symptoms and can be pretty conclusive. No X-rays or further investigation should be needed to confirm diagnosis unless there is any related trauma or a possible presence of a cervical rib however. In Arterial TOS cases an angiogram x-ray may demonstrate compression of the blood vessel.
What treatment options are available for a thoracic outlet syndrome?
The treatment options for TOS are dependent on the root cause of the compression. In cases of trauma where fracture fragments are causing compression or in some cervical rib cases, surgery may be an option. Outside of trauma and cervical rib syndrome surgery is normally reserved for TOS cases that are resistant to conservative treatment.
Your GP may prescribe a short course of anti-inflammatory painkillers to reduce and control any painful inflammation that may have occurred. Applying a covered ice pack to the area may also significantly hasten the healing process by reducing the pain and swelling that is contributing to the compression. Ensure the ice pack is covered to prevent any ice burn and for best results use the icepack regularly for 10-15 minutes with intervals of 30 minutes.
Many people find conservative treatments that correct any neck and upper back tension relieve the constriction of the thoracic outlet. Manipulative therapies such as chiropractic, osteopathy and physiotherapy have been found to be helpful in alleviating any neck, shoulder and upper back tension. Some people also find acupuncture, massage therapy and therapies like bowen technique very helpful at reducing the muscular tension and alleviating the pressure around the neck, shoulders and outlet. Postural therapies like Alexander technique is effective for teaching your body how to hold a good posture, as is Pilates and Yoga for strengthening your postural muscles. Your therapist or GP will be able to advise you on when it is appropriate to start and what exercises you should concentrate on.
Avoiding all aggravating movements, such as lifting weights or reaching over head as well as avoiding any slouched postures is advisable. For office worker or drivers alike, it is extremely important to take a good look at your driving position and your work station ergonomics. This means for drivers, ensuring that they are sitting at the right height and distance from the wheel and for office workers, ensuring that the computer screen is at the right height and distance from your eye line and adjusting your chair to the right height. This will allow you to avoid the awkward repetitive posture of holding your shoulders tense and elevated that can lead to TOS. It is also advisable to avoid sleeping with your arms raised above your head and try to avoid sleeping on your front as these postures may re-flare your condition every night, considerably prolonging the healing process.