Pectoralis minor syndrome (PMS) is a condition related to thoracic outlet syndrome (TOS) that results from the pectoralis minor muscle being too tight. [1] PMS results from the brachial plexus being compressed under the pectoralis minor [2] while TOS involves compression of the bundle above the clavicle. In most patients, the nerves are constricted resulting in neurogenic PMS, but venous compression (venous PMS) can also occur. [3]
PMS and TOS often, but not always, occur together. They share similar symptoms including tingling, pain, or weakness in the hand and arm, but in PMS there is also pain or tenderness in the chest wall where the pectoralis minor attaches to the scapula as well as in the armpit. [1] One study of 100 patients diagnosed with neurogenic TOS found that 75 percent also had neurogenic PMS and 30 percent in fact had PMS without TOS. [4]
PMS is often caused by injury to the neck, excessive stretching of the shoulder, or certain sports that involve overhead throwing. [1] Confirmation of the diagnosis can be done by blocking the pectoralis minor muscle or injecting botulinium. [5] First-line treatment for patients with PMS but without TOS is self-stretching of the pectoralis minor muscle. [6] Other treatments include injection of botulinium, or surgery that cuts the pectoralis minor tendon. [7] [8] [2]
For patients with PMS but without TOS, one study found that surgery resulted in a good or excellent outcome in 90 percent of cases. [4] Another study in ten patients with PMS substantially resolved symptoms in all but one case. [9]
PMS was first described in 1945. [10]
Veins are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins.
The phrenic nerve is a mixed motor/sensory nerve that originates from the C3-C5 spinal nerves in the neck. The nerve is important for breathing because it provides exclusive motor control of the diaphragm, the primary muscle of respiration. In humans, the right and left phrenic nerves are primarily supplied by the C4 spinal nerve, but there is also a contribution from the C3 and C5 spinal nerves. From its origin in the neck, the nerve travels downward into the chest to pass between the heart and lungs towards the diaphragm.
The dorsal scapular nerve is a branch of the brachial plexus, usually derived from the ventral ramus of cervical nerve C5. It provides motor innervation to the rhomboid major muscle, rhomboid minor muscle, and levator scapulae muscle.
In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.
The rhomboid major is a skeletal muscle of the back that connects the scapula with the vertebrae of the spinal column. It originates from the spinous processes of the thoracic vertebrae T2–T5 and supraspinous ligament; it inserts onto the lower portion of the medial border of the scapula. It acts together with the rhomboid minor to keep the scapula pressed against thoracic wall and to retract the scapula toward the vertebral column.
In human anatomy, the rhomboid minor is a small skeletal muscle of the back that connects the scapula to the vertebrae of the spinal column. It arises from the nuchal ligament, and the 7th cervical and 1st thoracic vertebrae and intervening supraspinous ligaments; it inserts onto the medial border of the scapula. It is innervated by the dorsal scapular nerve.
Thoracic outlet syndrome (TOS) is a condition in which there is compression of the nerves, arteries, or veins in the superior thoracic aperture, the passageway from the lower neck to the armpit, also known as the thoracic outlet. There are three main types: neurogenic, venous, and arterial. The neurogenic type is the most common and presents with pain, weakness, paraesthesia, and occasionally loss of muscle at the base of the thumb. The venous type results in swelling, pain, and possibly a bluish coloration of the arm. The arterial type results in pain, coldness, and pallor of the arm.
A Pancoast tumor is a tumor of the apex of the lung. It is a type of lung cancer defined primarily by its location situated at the top end of either the right or left lung. It typically spreads to nearby tissues such as the ribs and vertebrae. Most Pancoast tumors are non-small-cell lung cancers.
Adson's sign is the loss of the radial pulse in the arm by rotating head to the ipsilateral side with extended neck following deep inspiration.
Klumpke's paralysis is a variety of partial palsy of the lower roots of the brachial plexus. The brachial plexus is a network of spinal nerves that originates in the back of the neck, extends through the axilla (armpit), and gives rise to nerves to the upper limb. The paralytic condition is named after Augusta Déjerine-Klumpke.
Paget–Schroetter disease is a form of upper extremity deep vein thrombosis (DVT), a medical condition in which blood clots form in the deep veins of the arms. These DVTs typically occur in the axillary and/or subclavian veins.
May–Thurner syndrome (MTS), also known as the iliac vein compression syndrome, is a condition in which compression of the common venous outflow tract of the left lower extremity may cause discomfort, swelling, pain or iliofemoral deep vein thrombosis.
The lateral pectoral nerve arises from the lateral cord of the brachial plexus, and through it from the C5-7.
Parsonage–Turner syndrome, also known as acute brachial neuropathy, neuralgic amyotrophy and abbreviated PTS, is a syndrome of unknown cause; although many specific risk factors have been identified, the cause is still unknown. The condition manifests as a set of symptoms most likely resulting from autoimmune inflammation of unknown cause of the brachial plexus.
The popliteal artery entrapment syndrome (PAES) is an uncommon pathology that occurs when the popliteal artery is compressed by the surrounding popliteal fossa myofascial structures. This results in claudication and chronic leg ischemia. This condition mainly occurs more in young athletes than in the elderlies. Elderlies, who present with similar symptoms, are more likely to be diagnosed with peripheral artery disease with associated atherosclerosis. Patients with PAES mainly present with intermittent feet and calf pain associated with exercises and relieved with rest. PAES can be diagnosed with a combination of medical history, physical examination, and advanced imaging modalities such as duplex ultrasound, computer tomography, or magnetic resonance angiography. Management can range from non-intervention to open surgical decompression with a generally good prognosis. Complications of untreated PAES can include stenotic artery degeneration, complete popliteal artery occlusion, distal arterial thromboembolism, or even formation of an aneurysm.
Chronic venous insufficiency (CVI) is a medical condition in which blood pools in the veins, straining the walls of the vein. The most common cause of CVI is superficial venous reflux which is a treatable condition. As functional venous valves are required to provide for efficient blood return from the lower extremities, this condition typically affects the legs. If the impaired vein function causes significant symptoms, such as swelling and ulcer formation, it is referred to as chronic venous disease. It is sometimes called chronic peripheral venous insufficiency and should not be confused with post-thrombotic syndrome in which the deep veins have been damaged by previous deep vein thrombosis.
Plexopathy is a disorder of the network of nerves in the brachial or lumbosacral plexus. Symptoms include pain, muscle weakness, and sensory deficits (numbness).
Magnetic resonance neurography (MRN) is the direct imaging of nerves in the body by optimizing selectivity for unique MRI water properties of nerves. It is a modification of magnetic resonance imaging. This technique yields a detailed image of a nerve from the resonance signal that arises from in the nerve itself rather than from surrounding tissues or from fat in the nerve lining. Because of the intraneural source of the image signal, the image provides a medically useful set of information about the internal state of the nerve such as the presence of irritation, nerve swelling (edema), compression, pinch or injury. Standard magnetic resonance images can show the outline of some nerves in portions of their courses but do not show the intrinsic signal from nerve water. Magnetic resonance neurography is used to evaluate major nerve compressions such as those affecting the sciatic nerve (e.g. piriformis syndrome), the brachial plexus nerves (e.g. thoracic outlet syndrome), the pudendal nerve, or virtually any named nerve in the body. A related technique for imaging neural tracts in the brain and spinal cord is called magnetic resonance tractography or diffusion tensor imaging.
Anterior interosseous syndrome is a medical condition in which damage to the anterior interosseous nerve (AIN), a distal motor and sensory branch of the median nerve, classically with severe weakness of the pincer movement of the thumb and index finger, and can cause transient pain in the wrist.
First rib resection is a surgical procedure used in humans to treat thoracic outlet syndrome (TOS) and Paget–Schroetter disease. It involves the surgical removal of a segment of the first rib, which is the rib closest to the head, under the collar bone.