From the Guidelines
The work-up for thoracic outlet syndrome (TOS) should start with a thorough history and physical examination, followed by imaging studies and specialized tests, as outlined in the American College of Radiology (ACR) Appropriateness Criteria for TOS 1.
Initial Evaluation
The initial evaluation should include:
- A thorough history and physical examination, focusing on symptoms and provocative maneuvers
- Basic neurological and vascular examinations of the upper extremities
Imaging Studies
Initial imaging studies should include:
- Chest X-ray to rule out cervical rib or other bony abnormalities
- Cervical spine X-ray to assess for degenerative changes
Specialized Tests
Specialized tests should be conducted based on the suspected type of TOS:
- For vascular TOS, proceed with:
- Duplex ultrasound of the subclavian vessels
- CT angiography or MR angiography of the thoracic outlet
- For neurogenic TOS, consider:
- Electromyography (EMG) and nerve conduction studies
- MRI of the brachial plexus
Disputed Diagnosis or Surgical Intervention
In cases of disputed diagnosis or when considering surgical intervention:
- Scalene muscle block with local anesthetic
- Selective arteriography or venography This approach allows for a systematic evaluation of potential vascular and neurogenic causes of TOS, and helps guide appropriate treatment decisions 1. It is essential to note that TOS can be challenging to diagnose, and a multidisciplinary approach involving neurology, vascular surgery, and physical therapy may be beneficial in complex cases 1.
From the Research
Diagnostic Approach
The diagnostic workup for Thoracic Outlet Syndrome (TOS) involves a combination of history, physical examination, and imaging studies. Key components of the diagnostic approach include:
- A thorough medical history to identify symptoms such as arm pain, swelling, fatigue, paresthesias, weakness, and discoloration of the hand 2, 3
- Physical examination maneuvers to assess for signs of neurovascular compression 2, 3
- Imaging studies such as chest x-ray, computed tomographic angiography, or duplex ultrasonography to identify anatomic abnormalities and arterial or venous compression 4, 5
Classification and Diagnosis
TOS can be classified into three types: neurogenic, arterial, and venous, based on the compressed structure(s) 2, 3, 5. Diagnosis of TOS should be based on evidence of physical anomaly that can be corrected, rather than a diagnosis of exclusion 2.
Diagnostic Tests
Diagnostic tests that may be used to evaluate TOS include:
- Electromyography and nerve conduction studies to assess for nerve compression 3
- Imaging of the cervical spine and chest to identify anatomic abnormalities 3
- Arterial imaging, such as computed tomographic angiography or duplex ultrasonography, to identify arterial abnormalities 4
Treatment Approach
Treatment of TOS depends on the type and severity of the condition. Key components of the treatment approach include:
- Conservative management, including anti-inflammatory medication, weight loss, physical therapy, and botulinum toxin injections, as the initial treatment strategy for neurogenic TOS 2, 6
- Surgical intervention, including brachial plexus decompression, neurolysis, and scalenotomy with or without first rib resection, for symptomatic vascular TOS and neurovascular TOS that has failed conservative treatment 2, 3, 4, 5