From the Guidelines
Thoracic outlet syndrome (TOS) diagnosis should be approached through a combination of clinical evaluation, provocative maneuvers, and imaging studies, prioritizing MRI and CT angiography for confirmation, as recommended by the most recent guidelines 1. The diagnosis begins with a thorough history and physical examination, focusing on symptoms like pain, numbness, or weakness in the neck, shoulder, arm, or hand.
- Provocative tests such as the Adson's test, Wright's test, and Roos test can help identify vascular or neurogenic compression when the patient's arm is placed in specific positions.
- Imaging studies are essential for confirmation, with chest X-rays to rule out cervical ribs or bony abnormalities,
- MRI to evaluate soft tissue structures, particularly for neurogenic TOS, as it can delineate the brachial plexus and cervical spine, and dynamic evaluation of neurovascular bundles in the costoclavicular, interscalene, and pectoralis minor spaces 1.
- CT angiography to assess vascular compression, especially for arterial and venous TOS, as it can evaluate arterial stenosis and venous thrombosis, and provide information on the severity of compression 1. A multidisciplinary approach involving neurologists, vascular surgeons, and physical therapists is often necessary for accurate diagnosis, as TOS can mimic many other conditions.
- Early diagnosis is important as conservative management with physical therapy and pain management is often effective for neurogenic TOS, while vascular forms may require more urgent surgical intervention.
- The choice of imaging modality should be guided by the clinical presentation and the suspected type of TOS, with MRI being more suitable for neurogenic TOS and CT angiography for vascular TOS 1.
From the Research
Diagnosis of Thoracic Outlet Syndrome
- Thoracic outlet syndrome (TOS) is a group of diverse disorders that can be challenging to diagnose, with symptoms including pain, numbness, and tingling in the shoulder and upper extremity area 2.
- A careful history and thorough physical examination are the most important components in establishing the diagnosis of TOS, with radiographic and laboratory tests used as adjuncts when indicated 3.
- Clinical diagnostic tests, such as the Halstead maneuver, Wright's test, Cyriax Release test, and supraclavicular pressure test, can be used to provoke symptoms in patients presenting with upper extremity pathology, but may not allow for the differential diagnosis of TOS exclusively 4.
- The upper limb tension test (ULTT) is considered the best initial provocative test to screen for TOS, with a negative test suggesting against brachial plexus compression, and a positive test followed up with an elevated arm stress test (EAST) to further support the diagnosis 5.
Classification of Thoracic Outlet Syndrome
- TOS can be classified into three types: neurogenic TOS (NTOS), venous TOS (VTOS), and arterial TOS (ATOS) 6.
- NTOS presents with upper-extremity symptoms attributable to compression of the brachial plexus, while VTOS involves subclavian-axillary venous occlusion, thrombus formation, and rare embolization, and ATOS results from obstruction of the subclavian artery with claudication, thrombus formation, and possible embolization 6.
Diagnostic Tests for Thoracic Outlet Syndrome
- Adjunct diagnostic studies, such as ultrasound, electromyography (EMG), or magnetic resonance imaging/magnetic resonance angiography (MRI/MRA), may be used to further distinguish the vascular or neurological etiologies of TOS symptoms 5.
- The use of certain clinical diagnostic tests, such as Adson's test and Roos test, is not recommended for the differential diagnosis of TOS due to high false-positive rates 4.