Transcript Thoracic Outlet Syndrome - Learning

Thoracic Outlet Syndrome
Elana Deacon
Definition
• Thoracic outlet syndrome (TOS) is a syndrome involving
compression at the superior thoracic outlet where excess
pressure is placed on a neurovascular bundle passing between
the anterior scalene and middle scalene muscles.
• It can affect one or more of the brachial plexus nerves, the
subclavian artery, and - rarely - the vein, which does not
normally pass through the scalene hiatus.
Definition
• TOS may occur due to a positional cause - for example, by abnormal
compression from the clavicle and shoulder girdle on arm
movement.
• There are also several static forms, caused by abnormalities,
enlargement, or spasm of the various muscles surrounding the
arteries, veins, and/or brachial plexus, a fixation of a first rib, or a
cervical rib.
• Common orthopaedic tests used are the Adson's test, the
Costoclavicular Manoeuvre, and the "Hands-Up" test. Careful
examination and X-ray are required to differentially diagnose
between the positional and static aetiologies, first rib
fixations, scalene muscle spasm, and a cervical rib or
fibrous band
Pathophysiology
Neurovascular structures run from the thorax to the upper
extremities through the thoracic outlet. Four areas are seen
where these neurovascular bundles undergo compression:
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Superior Thoracic Outlet
Scalene Triangle
Costo-clavicular Area
Pathway of the Coracoid Pectoralis
Pathophysiology
• TOS involves compression, injury, or irritation to the neurovascular
structures at the root of the neck or upper thoracic region, bounded by
the anterior and middle scalenes; between the clavicle and first rib or
beneath the pectoralis minor muscle.
• The syndrome of compression at this site could be primarily neurologic,
involving the brachial plexus, most often the lower trunk or medial cord
• It could involve compression of the subclavian artery and/or vein.
Thrombosis, embolus, or aneurysm of these vessels is a less likely
possibility.
• In addition, imaging with diagnostic ultrasound has been able to identify
deformation of the pectoralis minor in TOS that may be related
to the pathophysiology, due to excessive tightness or shortening
of the muscle that impinges on the neurovascular bundle.
Pathophysiology
• BY STRUCTURES AFFECTED & SYMPTOMATOLOGY
• There are three main types of TOS, named according to the cause of
the symptoms.
• The compression can occur:
• In three anatomical structures: arteries, veins and nerves
• Can be isolated: two or three of the structures are compressed to
greater or lesser degrees.
• Neurogenic TOS:
Disorders produced by compression of
components of the brachial plexus nerves.
Accounts for 95% of all cases of TOS.
• Arterial TOS: Due to compression of the subclavian artery.
• Venous TOS: Due to compression of the subclavian vein.
Pathophysiology
• BY EVENT
• Trauma
• Sudden (Clavicle fracture caused by a car accident)
• Repetitive (Legal secretary who works with his/her hands, wrists,
and arms at a fast paced desk station with non-ergonomic
posture for many years).
• Occupations involving lots of lifting of the arms and repetitive
use of the wrists and arms.
E.g. swimmers, volleyball players, weightlifters, rock climbers,
and electricians
Pathophysiology
• BY STRUCTURE CAUSING CONSTRICTION
• Classify TOS by the location of the obstruction:
• Scalenusanticus syndrome
= Compression on brachial plexus and/or subclavian artery
caused by muscle growth
Diagnosed by using Adson's sign with patient's head turned
outward.
• Cervical rib syndrome
= Compression on brachial plexus and/or subclavian artery
caused by bone growth
Diagnosed by using Adson's sign with patient's
head turned inward.
Pathophysiology
• Costo-clavicular syndrome
= Narrowing between the clavicle and the first rib.
Diagnosed with the costo-clavicular manoeuvre.
• Some people are born with an extra incomplete and very
small rib above their first rib, which protrudes out into the
superior thoracic outlet space.
• Causes fibrous changes around the brachial plexus nerves, inducing
compression and causing the symptoms and signs of TOS.
• This is called a "cervical rib" because of its attachment to C-7 and its
surgical removal is almost always recommended. The symptoms of
TOS can first appear in the early teen years as a child
is becoming more athletic.
Causes
• Trauma i.e. whiplash from a motor vehicle accident,
• Repetitive activities i.e. job duties
• Poor posture i.e. forward head, and forward shoulders
• Anatomical abnormalities i.e. extra rib or abnormal positioning
• Entrapment at the costo-clavicular space (space between the first rib
and collarbone) i.e. back pack or purse over shoulder, carrying heavy
objects.
• A Pancoast tumor (a rare form of lung cancer in the
apex of the lung) may be the cause.
Risk Factors
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Abnormal Scalene Triangle
Cervical Rib
Fibro-muscular Band
Elongated Transverse Process of C7
Poor Posture
Age
Neck Spasms
Obesity
Pregnancy
Sign and Symptoms
• Depends on specific structures that are being pinched
• Structures that may be impinged:
Brachial plexus
Subclavial arteries
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Neurological, vascular or both
Loss of sterognosis and fine co-ordination
Clumsiness of the hands
Swollen hands / hands feel heavy and lame
Fingers feel numb / cramps in fingers
Vascular symptoms worsen with elevation of the shoulders
and if heavy object is carried, i.e. jacket
Signs and Symptoms
• Neurological Symptoms:
• Pain (Neuralgia / Nerve Root)
• Abnormal sensation
• Weakness
• Vascular Symptoms:
• Pain (Ischaemic)
• Weakness
• Claudication
Signs and Symptoms
• Aggravated by abduction of arm
• Onset:
Usually spontaneous
Followed after trauma of arm or neck
• Neurological signs seen with the 3 min stress test
• Vascular signs seen with abduction, extension and lateral
rotation during palpation of the radial pulse
No changes – rotation of head or deep breathing added
Positive test shows signs of: Pain
Reduced pulse
Pallor of hands
Consequences
• Pain that can be sharp, burning, or aching.
• It can involve only part of the hand (as in the 4th and 5th finger only), all
of the hand, or the inner aspect of the forearm and upper arm.
• Pain in the side of the neck, the pectoral area below the clavicle, the
axillary area, and the upper back (i.e. the trapezius and rhomboid area).
• Decoloration of the hands, one hand colder than the other hand,
weakness of the hand and arm muscles, and tingling are commonly
present.
• TOS is often the underlying cause of refractory upper
limb conditions like frozen shoulder and carpal tunnel syndrome
that frequently defy standard treatment protocols.
Consequences
• Related to Cerebrovascular arterial insufficiency when
affecting the subclavian artery.
• Affect the vertebral artery - Producing transient blindness,
and embolic cerebral infarction.
• A painful, swollen and blue arm, particularly when occurring
after strenuous physical activity, could be a sign of a venous
compression or subclavian vein thrombosis.
Medical Management
• Most patients respond to conservative measures:
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Medications
Rest
Relaxation exercises
Chiropractic or physical therapy
Stretching of m. Scaleni and M. Trapezius
Posture correction
Handling of fear and ignorance
Exercises of strengthening of pectoral girdle
Mobilisation of 1st rib, cervical as well as upper and mid-thoracic
Trigger points in m. Scaleni and m. Trapezius
• Only a minority of patients with signs and symptoms
of TOS ultimately proceed to surgery.
Resection of 1st rib or clavicle
Illustrations / X-Rays
Evidence-Based Article
Physical Medicine and Rehabilitation for Thoracic Outlet Syndrome
• Frequency
• United States
• The inability to make a definitive and accurate diagnosis makes determination of the exact
prevalence of this condition impossible. The prevalence of nonspecific thoracic outlet syndrome
(TOS) has been reported as high as 23% of soft-tissue injuries of the cervical spine.
• Mortality/Morbidity
• No known mortality is associated directly with thoracic outlet syndrome (TOS). Morbidity often
encompasses debilitating functional loss of the involved upper extremity, loss of livelihood or
occupation, especially if the work involves overhead activity (e.g. hairdressing, carpentry,
painting).
• Sex
• Females are diagnosed more commonly with thoracic outlet syndrome than males, with some
reports of a 9:1 female-to-male ratio.
• . Age
• Age of onset is from the second to the eighth decade, with a peak occurring in the fourth decade
Evidence-Based Article
• Progressive postural decompensation with neurovascular
compression. A: Normal resting posture. B: Shoulder
protraction beginning; the sternomastoid muscles are
shortening, drawing the head anteriorly and inferiorly.
C: Advanced deformity with adaptive shortening of scalene
and pectoralis minor muscles. Also note narrowed costoclavicular space (ribs 1-5 have been relatively elevated).
Neurovascular compression is evident at all 3 sites.
References
• Lee J., Laker S., Fredericson M.I. 2010. Thoracic outlet
syndrome. Physical Medicine & Rehabilitation. 2:64-70.
(http://emedicine.medscape.com/article/316715-overview).
retrieved on 19 August 2012.
• Laulan, J., Fouquet, B., Rodaix, C., Jauffret, P., Roquelaure, Y.,
Descatha, A. 2011. Thoracic outlet syndrome: definition,
aetiological factors, diagnosis, management and occupational
impact. 21(3):366-73.
(http://www.ncbi.nlm.nih.gov/pubmed/21193950).
Retrieved on 19 August 2012.
• Neuromusculo-skeletal Rehabilitation Dictate. Thoracic
Outlet Syndrome. Pg. 208.