Thoracic outlet syndrome

1. DR. SUNIL KUMAR SHARMA
SENIOR RESIDENT,DEPT. OF NEUROLOGY
G.M.C., KOTA

2.  The term ‘thoracic outlet syndrome’ (TOS) was
originally coined in 1956 by RM Peet.
 The simple definition of thoracic outlet syndrome
is neurovascular symptoms in the upper
extremities due to pressure on the nerves and
vessels in the thoracic outlet area.
 The specific structures compressed are usually the
nerves of the branchial plexus and occasionally the
subclavian artery or subclavian vein.( RICHARD J.
SANDERS, M.D)

3.  Depending on the exact site of injury and the injury
component of the neurovascular bundle, three
distinct syndromes or a combination of these may
be encountered.
I. Neurological syndrome (95%)
II. Venous syndrome.(4%)
III. Arterial syndrome (1%)

4.  The symptoms and signs are mixed among these
three types.
 They should be called Predominant Neurogenic,
Arterial, or Venous.
 Before the complications of TOS occurs, there is a
period where uncomplicated TOS is misdiagnosed.
 Delay from symptoms to diagnosis -3 months to 15
years

5.  Uncomplicated TOS
(Disputed TOS, Nonspecific TOS, Common TOS)
The Uncomplicated Form should also be divided in
-Predominant Neurogenic,
-Predominant Arterial, and
-Predominant Venous types.
 Complicated Form(true TOS)

6.  The Uncomplicated Form is the most common and the
most undiagnosed, or misdiagnosed.
 The Uncomplicated Form can present with
- mild-to-severe pain,
- positional paresthesias as the only symptom.
- no atrophy of the hand muscles
 The symptoms are frequently intermittent and oscillating.

7.  The Complicated Form is easy to diagnose, but too late,
 Symptoms and signs
- Slowly progressive unilateral atrophic weakness of
the intrinsic hand muscles & Sensory abnormalities
in the C8- T1 distribution in the Neurogenic type.
-Non-positional ischemia of the fingers and hands,
Thrombosis and or embolism of the arteries of the
upper extremities, subclavian aneurysm, and cerebral
embolism ,are symptoms of Arterial TOS.
-Venous thrombosis of the subclavian/axillary veins,
Paget-von Schrötter syndrome, these are the signs
and symptoms of the Venous type.

8.  Pain and paresthesias of the upper extremities are
common in all the three types.
 Shoulder, neck, and chest pains, facial pain, and occipital
headaches are usually ignored symptoms in the
Predominant Neurogenic type, both in the Uncomplicated
or Complicated Forms.

9.  Incidence 1-2%
 Age – usually seen 20-50 yrs of age
 Sex- Female: Male – 3:1
 No Racial predilection
 Neurogenic TOS >95 %
 Venous TOS – 4 %
 Arterial TOS – 1%

10.  Interscalene triangle ( most commonly involved)
-Inferiorly : 1st rib
-Ant : scaleneus anterior
-Post : scaleneus medius.
 Costoclavicular space
-Ant : clavicle, subclavius muscle
-Post medial: 1st rib
-Post lateral: superior border of scapula
Pectoralis minor space
-Anteriorly by Pectoralis minor and posteriorly by Chest wall

13.  Brachial plexus
 Subclavian artery
 Subclavian vein
Interscalene
triangle
Coracoclavicular
space
Pectoralis
minor space

14. Anatomical defects-
Bony abnormalities-
 Cervical rib
 Long C7 transverse process
 Abnormal bands, ligaments
 Fracture clavicle/ 1st rib
 Exostosis

15. Muscle anomalies
 Anomalous insertion of scalene muscles
 Scalene muscle hypertrophy
 Scaleneus minimus
 Passage of the brachial plexus through the substance of the
anterior scalene muscle,
 A broad, excessively anterior middle scalene muscle insertion on
the first rib

16. Tumours
Trauma
 Brachial plexus trauma/Whiplash injury
Poor posture.
 Drooping the shoulders or holding the head in a
forward position.

17. Repetitive activity.
 Typing on a computer,
 Athletes and swimmers
 Baseball pitcher
Obesity
Pregnancy.

18.  A cervical rib is a supernumerary (or extra) rib
which arises from the seventh cervical vertebra.
 Sometimes known as "neck ribs"
 Congenital abnormality located above the normal
first rib.
 A cervical rib is present in less than 1% of the
normal population, have been reported in 5%–9%
of patients with TOS
 B/L in 50%, common in right side.
 Usually asymptomatic

21.  Neurogenic TOS (95 %) f/b Venous variant of
TOS(4%) & arterial TOS (1%)variant.
 Such big difference in the frequency of clinical
manifestations of neurogenic and vascular (venous
and arterial) TOS is due to the high sensitivity of
nerves for compression and irritation.
 The subclavian vessels: artery and vein are
compressed almost as often as nerves

22.  Paraesthesia
 Pain in shoulder, arm, forearm and fingers
 Occipital headache – referred from tight scalene
muscles
 Weakness of forearm, hand.

23.  Cervical outlet syndrome(Upper TOS) –
when brachial plexus nerve roots are compressed
in the scalene triangle ,Upper nerve roots (C5 C6
C7) are most forcefully compressed.
 True thoracic outlet Syndrome(Lower TOS)-
When the compression of brachial plexus is in the
costoclavicular space ,usually lower roots (C8-T1) of
the brachial nerve plexus are compressed.

24.  Fatigue
 Weakness
 Coldness
 Upper limb claudication
 Thrombosis
 Paraesthesia
 Gangrene
 Raynaud's phenomenon due to thrombosis with
distal embolisation

25.  Edema
 Venous distension
 Collateral formation
 Cyanosis
 Paget-Schroetter syndrome – effort thrombosis
 "Effort" axillary-subclavian vein thrombosis (Paget-
Schroetter syndrome) is an uncommon deep venous
thrombosis due to repetitive activity of the upper limbs.

26. Diagnosis

27. Clinical tests

28.  Patient seated with arms above 90 degrees of
abduction and full external rotation with head in
neutral position. Patient opens and closes hands
into fists while holding the elevated position for 3
minutes.
 Positive test: pain and/or paresthesia and
discontinuation with dropping of the arms for relief
of pain.
 Sensitivity- 52–84%
 Specificity- 30–100

29. False +ve in
• Carpal tunnel syndrome,
• Ulnar neuropathy,
• fibromyalgia

30.  Adson maneuver may be performed seated or standing.
 The patient is requested to take a deep breath and rotate
and extend their head as far as possible towards the
unaffected side.
 The affected side arm is abducted with the elbow flexed,
and the examiner’s fingers should be placed on the
radial pulse.
 The test will reproduce symptoms or obliterate the
ipsilateral radial pulse
 One can also listen for a bruit underneath the clavicle
during the Adson’s test to document compression.

32.  Arm hyperabducted to 180°-
diminishing radial pulse.
 Neurovascular structures
compressed in subcoracoid
region by pectoralis minor
tendon, head of humerus or
coracoid process.
 Sens.-70–90
 Spec.-29–53

34.  Patient sits straight with arms at the side. Radial
pulse is assessed. Patient retracts and depresses
shoulders while protruding the chest. Position is
held for up to 1 minute.
 Positive test: change in radial pulse and/or pain and
paresthesia.
 Sens.-NT
 Spes.-53–100

36.  Patient seated, Examiner passively rotates the head
away from the affected side and gently flexes the
neck forward to end range moving the ear toward
the ventral chest.
 Positive test: forward flexion part of the movement
is notably decreased with a hard end feel.
 Sens.-100
 Spec.-NT

38.  Upper limb tension testing is sensitive for irritation of
the neural tissue including cervical roots, brachial
plexus and peripheral nerves .
 It has been advocated for the diagnosis of neurogenic
TOS with reported high sensitivity.
 The test appears to be excellent for screening for
sensitization of the neural tissue in the cervical spine,
brachial plexus and upper limb but is not specific for
one area.

39.  Head is turned contralaterally, the arm is abducted
with the elbow extended
 Sens-90%, Spec.-38%.

40.  A more objective examination is the lidocaine scalene
block test.
 Under image guidance, either computed tomography,
ultrasound, or fluoroscopy, the anterior scalene muscle
is injected with lidocaine.
 Patients with nTOS should have some decrease or
complete relief of symptoms for four hours.
 An initial lidocaine block, if positive, predicts 90%
success for subsequent treatments including physical
therapy and surgical intervention

41.  Carpel tunnel syndrome
 Spinal canal tumors
 Shoulder myositis
 Angina pectoris
 Reynaud's disease
 Ulnar nerve compression - epicondylitis

42. Investigations

43.  Chest x ray, cervical spine x ray
 USG/Colour Doppler
 MRI, cervical myelography
 r/o narrowing of intrevertebral foramen, disc
compression,intraspinal SOL.
 Vascular imaging(angiogram/venogram)
 r/o aneurysm, thrombosis
 Nerve conduction study, electromyography
 confirm neurogenic TOS, localise the area of
compression- r/o CTS

44.  Cervical ribs,
 Elongated C7 transverse process,
 Degenerative spine disease,
 Bone destruction related to a primary or secondary
neoplasm

45. Cervical plain radiograph
of a 27-year-old woman
shows both a cervical rib
(arrow) and an elongated
C7 transverse process
(arrowhead).

46. Anteroposterior plain
radiograph of the clavicle
Showing Excessive callus of
the clavicle in a 36-year-old
patient with neurologic TOS.

47. Duplex ultrasound
 Highly sensitive and specific test for venous stenosis or
occlusion
 May demonstrate an increased flow velocity in the
subclavian artery at the site of a stenosis in aTOS.

48.  Conventional arteriography and venography may
demonstrate the presence of extrinsic compression.
 Do not allow a clear depiction of the impinging
anatomic structure,
 Replaced by less invasive procedures (CT, MR
imaging,ultrasonography).

49. Angiography
 CTA / MRA or traditional angiography can be utilized to
identify more clearly the occlusion, aneurysm,
thrombolyisis/ distal embolization.
 To plan surgical reconstruction

50. A 38-year-old female
presented with intermittent
pain and numbness in her
fingers, exacerbated by
certain movements.
The images show a subtracted
three-dimensional contrast-
enhanced MRA sequence with
(A) arms down and (B) arms
raised.
Severe compression of the
subclavian artery can be seen
on both sides (arrows)

51. •Arterial compression in a
24-year-old woman.
•MR angiogram shows the
subclavian artery
stenosis (arrow).

52. three-dimensional
reformatted CT Image shows
the arterial compression and
the relationship of the artery
(arrow) to the surrounding
anatomic structures.

53. Sagittal T1-weighted MR
image show a scalenus
minimus muscle (straight
arrow), which passes
between the C8 nerve root
(arrowhead) and
subclavian artery (curved
arrow)

54.  Nerve conduction studies can be normal in uncomplicated
nTOS
 Ulnar sensory potential amplitude is reduced or absent
 Ulnar motor potential is reduced out of proportion to the
median

55. Treatment

56.  Posture improving exercises.
 Breathing exercises.
 Avoid aggravating activities.
 Avoid repetitive upper extremity mechanical work
and muscular trauma.
 Analgesics,muscle relaxants, antidepressants.
 Physiotherapy .

57.  Botulinum toxin A (botox) can be used for
temporary symptom relief.
 Botox takes two weeks to work but can last three
months and can help patients progress with physical
therapy.
 Botulinum toxin injection with ultrasound/EMG
guidance is safe and well tolerated in subjects with
suspected nTOS .

58. Indications:
 Symptoms persists with non operative treatment.
 Associated vascular compression.
 Progression of neurological symptoms.
 Nerve conduction velocity < 60m/s

59.  First rib resection-complete resection of the first rib
resulted in superior outcomes
 Anterior scalenectomy – ant and middle scaleni resected
 Cervical Rib resection if present
 Transaxillary approach or supraclavicular approach
 If an aneurysm is present, the patient may require an
arterial reconstruction in addition to FRRS.

60. aTOS
 Surgical intervention, specifically is indicated for
both venous and arterial TOS
 Uniformly, all patients with arterial thoracic outlet
syndrome will need full anticoagulation and varying
degrees of surgical intervention
 Milder – Catheter directed thrombolysis before repair
 Severe ischemia usually requires surgical embolectomy
(with or without intraoperative thrombolysis) in
conjunction with thoracic outlet decompression

61.  Anticoagulation is resumed three days after FRRS in vTOS
 Invasive venography is performed two weeks postoperatively
-Lesion-free patent subclavian veins -stop anticoagulation
-Those undergoing additional endovascular treatment are
continued on anticoagulation for 1- 2 months until followup
 Followup-(N)-stop Anticoagulant
- Thrombosis-cont. for 6 months

62.  Approximately 60–70% of patients with nTOS can be
successfully treated with
-Avoidance of activities that precipitate symptoms,
-Ergonomic modifications to the workplace,
-selective use of pharmacologic agents such as
nonsteroidal anti-inflammatories, antidepressants,
and muscle relaxants.

63.  Physical therapy is also a very important
component for these patients.
 Conservative management should be attempted for
8–12 weeks before considering surgery.
 Those that fail, should undergo a lidocaine scalene muscle
injection.
 If they respond to this block, they may be evaluated to see
if they are physically fit for FRRS.

64.  As more and more patients are treated for TOS, the
referral pattern has begun to change.
 Now, patients are being referred earlier with a shorter
duration of symptoms, which improves their chance of a
successful surgical treatment.
 A rise of presentation in adolescents has also been
observed.
 Modern experience indicates that a multidisciplinary
comprehensive approach to TOS improves outcomes.

65.  Although TOS has come a long way in the last half
century, there are many avenues left to explore.
 Diagnosis still remains the most debated aspect of
neurogenic TOS.
 Despite multiple maneuvers and even the lidocaine
scalene block, the test results rely on patient
symptomatology alone.
 Continued research would be beneficial to find a more
objective analysis.
 Some have suggested using MRI or CTAs preoperatively
to compare TOS patients with control patients.

66. Thank You

67.  Bradley‘s Neurology in Clinical Practice – 6th edition
 Understanding Thoracic Outlet Syndrome
Julie freishchlag and kristine orion
 Imaging Assessment of Thoracic Outlet Syndrome-
Xavier Demondion el al.
 Neurogenic thoracic outlet sndrome: A case report and
review of the literature. Boezaart, AP, et al. International
Journal of Shoulder Surgery. 2010;4:27-35.
 Epidemiology and pathogenesis of thoracic outlet
syndrome-Gustaw Wojcik1,2*, Barbara Sokolowska3 ,
Jolanta Piskorz
 Thoracic outlet syndrome : anatomy, symptoms,
diagnostic evaluation and surgical treatment
Prof., Dr. Scs. Povilas Pauliukas