Thoracic Outlet Syndrome is a manifestation of whiplash trauma that often occurs as the result of a car accident or other traumatic event. This condition is often overlooked/ignored by medical doctors, but detected and diagnosed by Doctors of Chiropractic.
Your attention is called to the description of Thoracic Outlet Syndrome by Dr. Rene Cailliet in his famous textbook entitled Shoulder Pain, Edition 3. Dr. Cailliet describes TOS as follows:
Another form of neurologically referred shoulder-arm pain can be from en¬croachment of neurologic tissues in the region of the shoulder girdle complex. The neurovascular elements responsible for symptoms in the upper extremity exit at the root of the neck in their progression to the upper extremity through a limited space termed the thoracic outlet. Any constriction of this outlet may lead to painful disabling symptoms.
Within this outlet are found the brachial plexus, the subclavian artery, and the subclavian vein. Compression of any of these structures can produce symp¬toms of pain, paresthesias, swelling, temperature changes, and motor weakness, which affect the shoulder, arm, forearm, and hand.
Dr. Cailliet describes the anatomical mechanism of TOS in this way:
The neurovascular bundle, which is the collective term for all the exiting nerves and vessels through this outlet (Fig. 8-13), passes through a series of nar¬row rigid spaces wherein the slightest anatomic or physiologic deviation can re¬sult in compression with resultant symptoms. Some of the tissues that may en¬croach on the neurovascular bundle have been designated as cervical rib, fascias remnants, abnormality of the first thoracic rib, interscalene muscle spasm or fi¬brous contraction, thickening of the normal fascia from persistent mechanical irritation, and prolonged abnormalities of posture. Mechanical compression of the neurovascular bundle between the bony components of the outlet is also considered a predominant cause.
The resultant symptoms from encroachment on the bundle nay be neuro¬logic or vascular, dependent on which component of the bundle is under compression or traction.
The term thoracic outlet (also termed cervical dorsal outlet) syndrome was used synonymously %OW scalene anticus syndrome w1Tn neurovascular compression was attributed to spasm and shortening of the anterior scalene muscle (Naffziger and Grant). The thoracic outlet syndrome (TOS) was thought to be caused by tightening, sustained contraction, fibrosis, or hypertrophy of the anterior scalene muscle.
Inasmuch as the fascia has been incriminated as a factor in symptomatic TOS, it merits description. The prevertebral fascia is a firm membrane lying anteriorly to the prevertebral muscle (longus cervicis; longus capitis; anterior, mid¬dle, and posterior scalenes; amid the rectos capitis muscles) (Fig. 8-14). The fascia is attached to the base of the skull just anterior to the capitis muscles and travels downward and laterally ultimately to blend with the fascia of the trapezius muscle. In its course it envelops the scalene muscles and also binds down the subclavian artery and the three trunks of the brachial plexus.
The prevertebral fascia is firmly adherent to the anterior aspect of the cervical Vertebrae and clavicle. It proceeds medially to attach to the transverse processes (Fig. 8-15) of cervical vertebrae and in its course covers all the cervical nerve roots. The fascia does not ensheathe the sublcavian or axillary veins and therefore cannot cause venous congestion, but with all the other nerves and vessels so ensheathed, it is apparent that constriction of these vital structures is possible.
Because the nerves of the sympathetic outflow from the setllate gangilia penetrate this fascia, it stands to reason that fibrous constriction can entrap or at least irritate the sympathetic nerves and cause symptoms attributable to sympathetic nerve stimulation
Dr. Caillet describes the classic symptoms of TOS as follows:
Numbness, tingling, pain, and paresthesias are the most common com¬plaints. The characteristics of this complaint are variable, and often the patient cannot specifically locate the complaints.
The symptoms are often generalized and may include all of the upper ex tremity as xvell as the shoulder and scapular area. From a careful detailed his¬tory the symptoms are usually related to a particular position or movement. A pattern of severe pain upon arising in the morning may incriminate ‘the sleeping position wherein the person sleeps with the arms overhead or folded beneath the head and thus serving as a pillow. Occurrence during the day may also be related to the arm positions assumed during the daily occupation. Reproduction of the symptoms is a major part of the examination, indicating the position as¬certained as the causative factor in activities of daily living.
The medial cord, the most inferior portion of the brachial plexus, is most vulnerable to compression or angulation. Symptoms, therefore, are distributed mostly from C8 to Tt. These nerves subserve the medial brachial and medial an¬tebrachial cutaneous nerves and the ulnar nerve. They implicate C8 dermatomal sensation of the medial aspect of the arm and forearm and the fifth and ring fingers as well as the hypothenar eminence.
Compromise of the arterial (subclavian) aspect of the bundle produces symptoms of coldness, weakness, cyanosis, and pallor. Rarely, gangrene-like symptoms and ultimately an objective finding may be produced, but usually the subjective findings are complained of by the patient and reproduced by the examiner.
Dr. Caillet recormmends the following physical examination:
Objective documentation of the specific dermatome(s) involved can be documented by light touch, pinprick, or scratch. Wasting and atrophy of the hy¬pothenar and ulnar intrinsic musculature can be noted in long-lasting cases. Fasciculation can be noted with nerve compression.
Dr. Caillet states thlat the diagnosis of TOS is usually made by reproducing the symptoms clinically. The following syndromes are diagnosed and confirmed by reproducing the symptoms using the tests or maneuvers described below.
Scalene Anticus Syndrome and the Adson Maneuver. The patient ful¬ly extends (posteriorly flexes) the head and neck, turns the chin toward the side of the symptoms, and holds the breath after a deep inspiration. If the pulse be¬comes obliterated when it is simultaneously palpated, it is a positive test result. Because the pulse can be obliterated in many normal asymptomatic persons, it is the reproduction of the symptoms that determines the diagnosis.
The mechanism that explains the Adson test is that the extension and turn¬ing of the head causes elongation of the scalenes and their prevertebral fascia and thus compresses the neurovascular bundle. The inspiration invokes the res¬piratory effect of the scalenes on the rib cage inasmuch as they are accessory respiratory muscles (Fig. 8-16).
It must be remembered that cervical radiculopathy, compression of nerve roots as they emerge from their foramina, can also be reproduced by extending and rotating the neck to the ipsilateral side (Cailliet), causing dermatomal sub¬jective and objective encroachment. The Adson maneuver must be evaluated critically before implicating dermatomal and myotomal from encroachment on the thoracic outlet and not on the cervical foramenal sites.
Claviculocostal Syndrome. Presence of the claviculocostal syndrome is ascertained by performing the costoclavicular maneuver (Fig. 8-17). This re¬quires placing the patient in an exaggerated military position with the shoulder posteriorly braced and depressed. This exaggerated position depresses the clav¬icle on the first rib and compresses the neurovascular bundle. The pulse(s) are obliterated, and the symptoms of paresthesia are reproduced.
Pectoralis Minor Syndrome and Test. The test for pectoralis minor syndrome (B in Fig. 8-17), a maneuver that can reproduce TOS, is merely an abduction of the arms and a retracting of them posteriorly downward. This ma¬neuver is essentially a modification of the hyperabduction test.
Dr. Caillet recommends conservative treatment that can and should be provided by the Chiropractic doctor:
Conservative nonsurgical treatment must be thoroughly pursued before any surgical intervention is contemplated, unless there are significant progressive objective neurologic or vascular signs.
Educating the patient on the mechanical basis of the symptoms in a man¬ner the patient can understand will ensure greater acceptance of and adherence to a program. This is better than merely giving the patient a list of exercises that may or may not be performed effectively.
Correcting posture, as has been stated in Chapter 5, is the major compo¬nent of therapy. This indicates proper posture in sitting, standing, walking, and in every daily activity. It implies that the patient must fully understand that good posture is constant, not something assumed merely during the concentrated ex¬ercise; it must become a matter of daily unconscious habit.
When symptoms can be reproduced, the offending position and/or posture can be brought immediately to the patient’s attention to educate him or her on the rationale of corrective therapy.
Flexibility exercises are valuable, but which tissue(s) must be made flexible demands careful evaluation and precise physical therapy of stretch with or with¬out spray (Travel] and Simons). A daily home exercise program enhances the as¬surance of increased flexibility. Strengthening and improving endurance of the scapular elevators are considered valuable in correcting posture and relieving symptoms of TOS (Fig. 8-18).
Mechanical or manual traction has limited value, as does the use of a collar, for ensuring correct posture. A cervical pillow may afford relief of the patient who awakens with TOS symptoms.
Emotional correction must be entertained when tension, anxiety, depression, and/or anger is considered a major or contributing factor. Stress management has become a valuable adjunct to persistent postural tension TOS.
Operative intervention is indicated when there is confirmed evidence of objective TOS that is failing to respond to appropriate conservative management for a significant period of time or when there may be objective neurological and/or vascular findings. Objective evidence or neuralgic impairment can be documented by EMG studies (Urschel and associates) and conduction velocity and cortically evoked potential studies, which enhance the advisability of surgical intervention over clinical diagnosis with the attendant possible surgical failure (Derkash and colleagues).