A cervical rib is an extra rib in the lower neck, above the normal first rib. Overall, cervical ribs are seen in about 0.5 to 1% of the human population. In detail, a cervical rib may be unilateral or bilateral, small or large, free-floating or fused to the first rib on the same side. While many physicians associate cervical ribs with thoracic outlet syndrome, the presence of a cervical rib does not prove or disprove thoracic outlet syndrome. Demonstration of cervical ribs goes back centuries, but association with TOS was only demonstrated in the early 19th century.
After the advent of the x-ray, physicians thought they had solved the problem of the cervical rib syndrome. Patients with vascular or neurologic symptoms underwent an x-ray examination, and a cervical rib appeared. Shortly after this issue had resolved, a number of reports arose in the medical literature regarding patients with cervical rib syndrome, in whom x-rays demonstrated no cervical rib. Now these same physicians found they faced an entirely new challenge-‘cervical rib syndrome without a cervical rib’ syndrome.
As researchers and anatomists learned about the numerous anatomic variations and causes of symptoms, it became apparent that patients appeared with equally broad and variable presentations. A number of authors published different syndromes that they could explain with a large number of provocative maneuvers. In 1956, Peet created an umbrella term to encompass all of these variable syndromes, and thoracic outlet syndrome was born.
After you have read this far, nobody would blame you if you were confused about the complex history of thoracic outlet syndrome. And while much of the confusion has been clarified, a lot of this story remains to be told. Certainly, diagnosis and treatment of TOS has improved considerably over the past 200 years. At the same time, a lot of TOS specialists in all corners of the country are actively seeking new methods of diagnosis and treatment for patients with TOS. Read here about some of the new directions that are just blossoming.
Where does the name ‘Thoracic Outlet Syndrome’ come from?
The history of terminology used for these patients is almost as fascinating as the medical history. In fact, the terminology evolved as the understanding of the disease evolved, and reflects the evolving school of thought at each time in history.
Cervical rib syndrome
‘Cervical rib syndrome’ was the most well-known and widely used name for the syndrome throughout the late 19th century and into the early 20th century. ‘Cervical rib syndrome’ is still used by some physicians today, and many physicians think primarily of a cervical rib when considering thoracic outlet syndrome.
The invention of radiographs in 1895 enabled the demonstration of cervical ribs in living patients, and established the relationship of cervical ribs and symptoms of brachial plexus entrapment. This relationship was widely recognized in the medical literature of the time, but the first actual use of the term “Cervical Rib Syndrome” is by T. Wingate Todd in 1922.
Brachial Compression Neuritis
This term was first used by Stopford in 1919. However the general term ‘neuritis’ had been used over the prior two decades to describe symptoms in these patients that were thought to be caused by compression of the brachial plexus.
Scalenus anticus syndrome
’Scalenus anticus’ is another name for the anterior scalene muscle. Adson and Coffey wrote a landmark paper in 1927 describing their approach of detaching the scalenus anticus from its insertion on the first rib in patients with a cervical rib. Ochsner, Gage and DeBakey in 1935 were the first to describe patients with cervical rib syndrome without a cervical rib who had been treated successfully with the same procedure. They first used the term “Scalenus Anticus Syndrome,” but credited their work to Howard Naffziger, and suggested the term “Naffziger Syndrome” as well.
Costoclavicular compression syndrome
The mechanism of compression between the clavicle and first rib was first described by Eden in 1939 to explain vascular compression. Falconer and Weddell in 1943 described further cases with vascular compression, along with one case of brachial plexus compression. The term “costoclavicular syndrome” was first used by Telford and Mottershead in 1947.
Todd conducted an experiment upon himself by sleeping with his arm hyperabducted from 1913 to 1921. In the last 3 months of his experiment, he developed skin changes in his hand, but he did not propose a specific mechanism for these changes. In 1945, Irving Wright first described arterial and neurologic symptoms occurring with the arms hyperabducted. Wright proposed “stretching, torsion and pinching” in the costoclavicular interval and in the retropectoralis space. The term ‘hyperabduction syndrome’ was first used by Beyer and Wright in 1951.
Subcoracoid pectoralis minor tendon syndrome
These are other terms for hyperabduction syndrome:
Brachiocephalic vascular syndrome
In 1966, J.D. Devilliers first used the term ‘brachiocephalic vascular syndrome’ to describe a young woman with a stroke related to arterial TOS and a cervical rib.
Nocturnal paresthetic brachialgia
Brachialgia statica paresthetica
Introduced by Richard Wartenberg in 1944.
Effort thrombosis of the subclavian vein
Axillary-subclavian vein thrombosis (ASVT)
In 1875, Sir James Paget described two patients with spontaneous swelling of one arm and prominence of veins over the ipsilateral chest, likely the first described cases of venous TOS. Paget thought the condition was caused by vasospasm. In 1884, Leopold von Schrötter independently described patients with the same condition, and correctly attributed the clinical condition to the formation of occlusive venous thrombus. In 1948, Hughes performed a review of a large number of cases in the medical literature, and proposed the term, “Paget-Schrötter Syndrome,” which is still in use today.
Since von Schrötter, clinicians had suspected that an episode of considerable exertion of the upper extremity could precipitate the thrombosis. Von Schrötter had suggested it as a possible etiologic factor. Willan in 1918 described three cases, two of which he felt were due to “vigorous exercise”. The first actual use of the term ‘effort thrombosis’ I can find in the literature is by Swartley in 1942.
Kenneth Aynesworth first used this term in a paper published in 1940, in which he categorized three types of TOS. It was used again by Hansson in 1941, but since then the name has not come into common use.
First thoracic rib syndrome
Superior outlet syndrome
Fractured clavicle-rib syndrome
Cervical rib and band syndrome
Miscellaneous names which have never come into common use, and are of uncertain origin.
Thoracic inlet syndrome
Anatomists often refer to the space defined by the first ribs at the superior aspect of the thorax as the ‘thoracic inlet,’ because large veins, the trachea, the esophagus and other structures pass into this space (even as other structures pass out of the same space). However, physicians and other authorities almost always refer to this same space as the ‘thoracic outlet’. The terminology ‘thoracic inlet syndrome’ still enjoys limited use by anatomists, but is currently almost never used in clinical practice.
Pectoralis minor syndrome
In 1956, Jere Lord and Peter Stone performed the first documented pectoralis minor tenotomy in 5 patients with hyperabduction syndrome. Although Lord and Stone apparently understood the importance of the retropectoralis space, the earliest mention of the name, “pectoralis minor syndrome” occurs in a paper published by Erich Lang in 1966.
First described in the literature by Paul Nelson in 1957 in an attempt to simplify and group the various neurovascular syndromes of the thoracic outlet, this term has not come into common use.
Proposed by Don Ranney in 1996, to include subclassifications ‘cervical outlet syndrome,’ ‘thoracic outlet syndrome,’ ‘costoclavicular syndrome,’ and ‘pectoralis minor syndrome,’ and to eliminate ‘thoracic inlet syndrome’.
Thoracic Outlet Syndrome
Thoracic Outlet Compression Syndrome
In 1956, Peet published a paper with the first instance of ‘Throracic-outlet syndrome”. This was the first documented attempt to unify the multitude of names and syndromes in the current medical literature. In 1958, C.G. Rob and A. Standeven published a paper entitled, “Arterial Occlusion Complicating Thoracic Outlet Compression Syndrome”.
This surprising array of names and syndromes may appear confusing and overwhelming. In fact, most physicians haven’t heard of these syndromes. For these reasons, the creation of the term, ‘thoracic outlet syndrome’ may have been an unfortunate simplification. The unification of multiple syndromes under a single umbrella term blurs the differences between closely related but different underlying pathologies. On the other hand, when we are able to accurately understand the anatomy in each individual, we are more able to make an effective diagnosis and treatment. That is our purpose and mission.