Thoracic outlet syndrome (TOS) consists of a group of distinct disorders that affect the nerves in the brachial plexus (nerves that pass into the arms from the neck) and various nerves and blood vessels between the base of the neck and axilla (armpit). For the most part, these disorders have very little in common except the site of occurrence. The disorders are complex, somewhat confusing, and poorly defined, each with various signs and symptoms of the upper limb.
True neurologic TOS is the only type with a clear definition that most scientists agree upon. The disorder is rare and is caused by congenital anomalies (unusual anatomic features present at birth). It generally occurs in middle-aged women and almost always on one side of the body. Symptoms include weakness and wasting of hand muscles, and numbness in the hand.
Disputed TOS, also called common or non-specific TOS, is a highly controversial disorder. Some doctors do not believe it exists while others say it is very common. Because of this controversy, the disorder is referred to as “disputed TOS.” Many scientists believe disputed TOS is caused by injury to the nerves in the brachial plexus. The most prominent symptom of the disorder is pain. Other symptoms include weakness and fatigue.
Arterial TOS occurs on one side of the body. It affects patients of both genders and at any age but often occurs in young people. Like true neurologic TOS, arterial TOS is rare and is caused by a congenital anomaly. Symptoms can include sensitivity to cold in the hands and fingers, numbness or pain in the fingers, and finger ulcers (sores) or severe limb ischemia (inadequate blood circulation).
Venous TOS is also a rare disorder that affects men and women equally.
The exact cause of this type of TOS is unknown. It often develops suddenly, frequently following unusual, prolonged limb exertion.
Traumatic TOS may be caused by traumatic or repetitive activities such as a motor vehicle accident or hyperextension injury (for example, after a person overextends an arm during exercise or while reaching for an object). Pain is the most common symptom of this TOS, and often occurs with tenderness. Paresthesias (an abnormal burning or prickling sensation generally felt in the hands, arms, legs, or feet), sensory loss, and weakness also occur. Certain body postures may exacerbate symptoms of the disorder.
Most TOS requires conservative treatment and chiropractic care is considered most effective in caring for this condition. Other conservative care such as analgesics, and physical therapy to increase range of motion of the neck and shoulders, strengthen muscles, and induce better posture. Some cases of disputed TOS may require surgery (although, like the diagnosis, surgery is controversial). Heat, analgesics, and shoulder exercises have been used with limited success in individuals with traumatic TOS. Surgery may be needed in some cases. Vascular TOS often requires surgery.
The prognosis for individuals with TOS varies according to the type. For the majority of individuals who receive treatment the prognosis for recovery is good.
What research is being done?
Within the NINDS research programs, TOS is addressed through research on pain. NINDS vigorously pursues a research program seeking new treatments for pain and nerve damage with the ultimate goal of reversing disorders such as TOS.
If you are unsure about any aspect of your condition or treatment, please don’t hesitate to contact Dr Michael Rees DC at First Chiropractic.