Thoracic outlet syndrome (TOS) is a little-known condition that’s tricky to diagnose and treat.
This often painful and disabling disorder results from compression of nerves or blood vessels in the thoracic outlet, a narrow, bony, almost-triangular opening between the first rib at the top of the rib cage and the clavicle, or collarbone. It can cause a wide range of symptoms including neck, shoulder or arm pain…tingling or swelling in an arm, a hand or fingers…weakness in a shoulder, an arm or a hand…and/or impaired circulation in a hand.
Many other conditions (such as diabetes, carpal tunnel syndrome, Raynaud’s disease, fibromyalgia or even a heart attack) can cause similar sensations, making it difficult to diagnose. But with the development of a clear set of criteria, vascular surgeons and other specialists can now identify TOS from a careful medical history, basic imaging tests and an in-office physical exam.
Too Close for Comfort
Two major blood vessels, the subclavian artery and vein, pass through the thoracic outlet. So does the brachial plexus, a bundle of nerves that travels to the shoulders, chest, arms and hands. The scalene muscles in the neck border the thoracic outlet.
Anything that crowds the blood vessels or nerves going through the thoracic outlet can cause TOS. This can include an extra rib that protrudes from the neck part of the spine (a cervical rib)…repetitive overhead motions—from activities such as swimming or house painting…and intense weight lifting, whiplash injuries or even weight gain. The symptoms usually affect only one side of the body but can sometimes affect both sides.
Nerves vs. Blood Vessels
Nerve-related TOS symptoms are different from those caused by pressure on an artery or vein…
• Nerve pressure accounts for more than 90% of TOS cases. These patients can have pain, numbness or tingling (or all three) that starts in the neck and radiates down to a hand. The discomfort may come and go but usually worsens when an arm is elevated. Patients will continue to have disabling symptoms without treatment.
• Pressure on a vein or an artery can restrict blood flow and cause swelling and discoloration of the fingers, hand or arm…or feelings of coldness in the hands. This type of pressure also can increase risk for blood clots in the shoulders or arms, which could potentially lead to a pulmonary embolism (a blood clot in the lungs).
A Diagnostic Challenge
If your doctor suspects TOS, you’ll probably be given a chest X-ray to detect rib abnormalities, including the presence of a cervical rib. You’ll also be given an ultrasound to help identify blood-vessel abnormalities and clots. But in many cases, doctors can’t actually see what’s causing the pressure, even with these imaging tests. A thorough medical history, along with an in-office physical exam, are among the best ways to diagnose TOS.
The doctor will take the patient through a variety of maneuvers. Patients with nerve-related TOS will usually notice an increase in pain/other symptoms when they rotate their head or tilt it from the ear to the shoulder. And raising the arms will usually cause an increase in symptoms within 30 to 60 seconds.
Also helpful: An injection of local anesthetic into one of the scalene muscles in the neck. In patients with nerve-related TOS, this will often stop pain almost immediately. The pain relief lasts only for about a day, so it’s not a treatment—but it’s a good diagnostic test.
A doctor also will look for physical signs like abnormal skin color and cool skin, which indicate severely restricted blood flow or a clot.
Surgery (see below) is often advised for vascular-related TOS, while more conservative treatment can often be used to avoid (or delay surgery) for nerve-related TOS…
• Stretches and/or physical therapy can often help patients with nerve-related TOS. The movements stretch and strengthen muscles, restore normal posture and relieve compression of affected nerves. Note: Be sure to get a physical therapist’s consent before trying stretches on your own.
Sample stretch: Make an “OK” sign with your thumb and forefinger…turn your hand upside down…raise your elbow in the air…and place the circle over your eye. Your palm will be facing toward your face and your other three fingers will be touching your cheek. Hold the stretch for about 30 seconds. Other stretches can be found online (try YouTube) or from a physical therapist.
• Massage and acupuncture seem to help some patients with TOS caused by nerve pressure, and there’s no downside to trying them, even though there’s little evidence to prove these approaches work. But do get checked out by your doctor first to make sure you’re not overlooking another problem.
• Botox injections in the scalene muscles will shrink these muscles and potentially open up the space in the thoracic outlet to relieve pressure. For about 10% of my patients, the injections provide long-term relief—sometimes for many years.
But more often, an injection gives relief for only two to four months and repeated injections are needed. Most patients aren’t willing to keep getting injections, particularly because they tend to get less effective over time. If your symptoms have not improved after three or four attempts, the injections are probably not going to work for you.
• Blood thinners are an essential component of therapy when TOS presents with a blood clot in a vein. These patients are at risk for recurrent deep vein thrombosis (DVT) and pulmonary embolism if not treated with surgery (see below). Blood-thinning medications, such as enoxaparin sodium (Lovenox) or rivaroxaban (Xarelto), can be used until the clot is surgically removed.
If Surgery Is Needed…
In some cases, surgery is required to treat TOS.
For nerve-related symptoms, the goal of surgery is to remove the tissue—either bone or muscle—that’s causing the pressure. For clot-related symptoms, surgery is a standard treatment. It’s used to remove clots…reconstruct or replace damaged arteries…or remove bone/muscle that’s pressing on the affected area.
These procedures typically require a one-to-three-night hospital stay, and patients should do physical therapy as part of their rehab.