Thoracic Outlet Syndrome (TOS) is a group of disorders that occur when blood vessels or nerves in the thoracic outlet — the space between your collarbone and first rib — are compressed. This can lead to a variety of symptoms that often worsen at night, leaving sufferers in chronic pain, discomfort, and frustration. Understanding the causes, symptoms, and treatment options for thoracic outlet syndrome is key to managing the condition and improving quality of life, particularly for those who struggle with its effects during the night.

What Is Thoracic Outlet Syndrome?

Thoracic outlet syndrome encompasses several disorders affecting the thoracic outlet’s nerves, arteries, and veins. The thoracic outlet is a narrow space through which key blood vessels and nerves pass from your neck to your arms. These include the subclavian artery, veins, and nerves from the brachial plexus.

TOS is generally divided into three primary types:

• Neurogenic Thoracic Outlet Syndrome (NTOS): This is the most common form, involving compression of the brachial plexus, the network of nerves that control muscle movements and sensation in the shoulder, arm, and hand.
• Vascular Thoracic Outlet Syndrome (VTOS): In this form, blood vessels like the subclavian artery or vein are compressed, leading to circulation problems.
• Venous Thoracic Outlet Syndrome (TOS) is a form of vascular TOS that occurs when veins in the thoracic outlet are compressed. It leads to symptoms like swelling and blood clots in the affected arm.
• Arterial Thoracic Outlet Syndrome: This rarer form involves the arteries and can lead to reduced blood flow, pain, and even ischemia (restricted blood supply).

Each type of thoracic outlet syndrome has distinct causes and symptoms. Still, they all involve the compression of crucial structures, leading to discomfort, particularly at night when many people experience the worst symptoms.

Common Symptoms of Thoracic Outlet Syndrome at Night

Many individuals with thoracic outlet syndrome notice their symptoms become more pronounced at night, especially after lying down or when their arm is in a specific position. Common thoracic outlet syndrome symptoms at night include:

1. Arm Pain and Tingling: People with neurogenic thoracic outlet syndrome may experience arm pain or tingling that worsens as they sleep. This is caused by pressure on the brachial plexus nerves. The pain can extend from the shoulder to the hand, affecting one or both arms.
2. Numbness or Weakness in the Hands: As nerves are compressed, individuals may wake up with numbness in their hands, fingers, or forearms. Weakness may also occur, making performing basic tasks like gripping objects difficult.
3. Shoulder and Neck Pain: Pain in the neck or shoulder muscles is common, particularly in people with poor posture. Due to ongoing compression, the muscles in the upper chest and shoulder area may become tight and painful, leading to more discomfort while lying down.
4. Cold Sensations in the Arm: Individuals with vascular thoracic outlet syndrome may experience poor circulation, causing the affected arm to feel cold to the touch. This is due to limited blood flow through the subclavian artery, which can worsen when lying down for long periods.
5. Swelling and Discoloration: Those with venous thoracic outlet syndrome may notice swelling or a bluish tint in the affected arm. Blood clots, a complication of this form of TOS, can exacerbate these symptoms, particularly when the arm is in a resting position at night.
6. Worsening Symptoms with Arm Elevation: Many people find that raising their arms while sleeping or simply lying flat worsens symptoms. The thoracic outlet becomes further compressed when the arm is elevated, placing more pressure on the blood vessels and nerves.

Why Symptoms Are Worse at Night

Several factors contribute to the worsening of thoracic outlet syndrome symptoms at night. When lying down, the natural position of the shoulders and neck can increase pressure on the thoracic outlet, particularly in individuals with poor posture. Sleeping on your side or with your arms raised can exacerbate brachial plexus compression and blood vessels.

Additionally, inactivity during the night can lead to further discomfort. The affected area may become stiff, and circulation can be reduced, making symptoms like numbness, tingling, and pain more pronounced.

Causes and Risk Factors of Thoracic Outlet Syndrome

Thoracic outlet syndrome can be caused by various factors, ranging from congenital conditions to injuries. Some common causes include:

1. Cervical Rib: Some people are born with an extra rib known as a cervical rib, which can compress the nerves and blood vessels in the thoracic outlet. This congenital abnormality increases the risk of developing TOS.
2. Poor Posture: Slouching, forward head posture, and rounded shoulders can compress nerves and blood vessels in the thoracic outlet. Over time, this posture can tighten the upper chest and shoulder muscles, leading to the development of TOS.
3. Injury: Trauma to the neck, shoulder, or upper body, such as whiplash or a broken collarbone, can result in thoracic outlet syndrome. Scar tissue or misalignment can compress the thoracic outlet, triggering symptoms.
4. Repetitive Movements: Jobs or activities that require repetitive overhead motions, such as lifting, throwing, or swimming, can increase the likelihood of developing TOS. These movements can cause the muscles around the thoracic outlet to become tight, leading to compression.
5. Anatomical Abnormalities: In addition to the cervical rib, other anatomical variations, such as abnormal muscle attachments or unusually thickened muscles, can contribute to thoracic outlet syndrome.

Diagnosis of Thoracic Outlet Syndrome

Diagnosing thoracic outlet syndrome can be complex, as its symptoms often overlap with other conditions, such as carpal tunnel syndrome or rotator cuff injuries. Physicians typically conduct a thorough physical exam and may use specialized tests to determine if thoracic outlet syndrome is the cause of the symptoms.

• Elevated Arm Stress Test (EAST): Also known as the “Roos test,” this is often used to reproduce the symptoms of thoracic outlet syndrome. The patient raises their arms and opens and closes their fists for several minutes. If symptoms such as pain, tingling, or weakness occur, it can indicate TOS.
• Upper Limb Tension Test: This test involves positioning the arm and shoulder in various ways to stress the nerves of the brachial plexus. It helps determine whether the symptoms are related to neurogenic thoracic outlet syndrome.
• Imaging: X-rays or MRIs may be ordered to look for structural abnormalities, such as a cervical rib or compressed blood vessels. Doppler ultrasound may also assess blood flow through the subclavian artery or veins.
• Nerve Conduction Studies: These tests measure the electrical activity of the nerves and can help confirm a diagnosis of neurogenic thoracic outlet syndrome by identifying areas of nerve compression.

Treatment Options for Thoracic Outlet Syndrome

Treatment for thoracic outlet syndrome varies depending on the severity of the symptoms and the type of TOS. Both non-surgical and surgical options are available, and treatment choice depends on the individual’s specific condition and response to initial interventions.

1. Non-Surgical Treatments

Non-surgical treatments are often the first line of defense for thoracic outlet syndrome. These include:

• Physical Therapy: A physical therapist can help design a rehabilitation program that focuses on improving posture, strengthening the shoulder muscles, and increasing the flexibility of the upper chest. Physical therapy is highly effective for neurogenic thoracic outlet syndrome as it helps reduce nerve compression by improving muscle balance and posture.
• Lifestyle Modifications: Adjusting activities that aggravate symptoms, such as avoiding repetitive overhead movements, can prevent thoracic outlet syndrome from worsening.
• Pain Management: Over-the-counter pain relievers, anti-inflammatory medications, and muscle relaxants may be used to manage the pain associated with TOS. Corticosteroid injections may also reduce inflammation and pain in the affected area.

2. Surgical Treatment

Surgical treatment may be necessary in severe cases where non-surgical interventions are ineffective. Surgery for thoracic outlet syndrome often involves removing part of the first rib or scalene muscles to relieve pressure on the thoracic outlet.

• Peripheral Nerve Surgery: This procedure may release the entrapped nerves in the brachial plexus, alleviating neurogenic thoracic outlet syndrome symptoms.
• Vascular Surgery: For individuals with vascular thoracic outlet syndrome, surgery may involve removing blockages in the subclavian artery or veins, particularly if blood clots or other vascular complications are present.
• Winn Neurological Surgery: A specialized surgical procedure, this approach can release entrapped nerves and restore normal function to the affected arm.

Preventing Thoracic Outlet Syndrome

While some risk factors for thoracic outlet syndrome, such as congenital abnormalities, cannot be controlled, others can be minimized through preventive measures. These include maintaining good posture, avoiding repetitive overhead movements, and strengthening the upper body muscles to support proper alignment.

Conclusion

Thoracic outlet syndrome can be a chronic and frustrating condition, particularly when symptoms worsen at night and disrupt sleep. By understanding the underlying causes and taking proactive steps toward treatment, individuals can manage their symptoms and improve their quality of life. Relief is possible through physical therapy, lifestyle changes, or, in some cases, surgical intervention.

Recognizing the importance of early diagnosis and intervention is key to preventing long-term damage and ensuring that the discomfort associated with thoracic outlet syndrome, particularly at night, does not become a permanent hindrance.

References

https://www.mayoclinic.org/diseases-conditions/thoracic-outlet-syndrome/symptoms-causes/syc-20353988

https://my.clevelandclinic.org/health/diseases/17553-thoracic-outlet-syndrome-tos

https://www.ninds.nih.gov/health-information/disorders/thoracic-outlet-syndrome