From the Guidelines
The workup for thoracic outlet syndrome (TOS) should begin with a detailed history and physical examination, focusing on symptoms like arm pain, numbness, weakness, and vascular changes, as recommended by the American College of Radiology Appropriateness Criteria 1.
Initial Diagnostic Testing
Initial diagnostic testing should include:
- Cervical spine and chest radiographs to rule out structural abnormalities like cervical ribs or bony anomalies
- Provocative maneuvers such as Adson's test, Wright's test, and the elevated arm stress test (EAST) to help identify TOS, though these have limited specificity
Electrodiagnostic Studies
Electrodiagnostic studies, including nerve conduction studies and electromyography, are useful for neurogenic TOS to document nerve compression 1.
Vascular Studies
Vascular studies are essential when arterial or venous TOS is suspected, including:
- Duplex ultrasound
- CT angiography
- MR angiography to visualize vascular compression
Imaging Modalities
For neurogenic TOS, MRI of the brachial plexus may help identify nerve compression 1.
Laboratory Tests
Laboratory tests should be performed to exclude conditions that mimic TOS, such as autoimmune disorders or coagulopathies.
Comprehensive Approach
This comprehensive approach helps differentiate between the three types of TOS (neurogenic, arterial, and venous) and guides appropriate management, as outlined in the ACR Appropriateness Criteria 1.
From the Research
Diagnostic Tests for Thoracic Outlet Syndrome
- A thorough patient history and physical exam are essential for diagnosing thoracic outlet syndrome (TOS) 2, 3, 4
- Imaging studies, such as radiography, can help identify anatomical abnormalities, like cervical ribs, that may be contributing to TOS 2, 5
- Electrophysiological tests, including electromyography (EMG), nerve conduction studies, and sensory conduction studies, can provide valuable information for diagnosing neurogenic TOS 3, 5, 6
- Specific electrophysiological features, such as reduced amplitude of the medial antebrachial cutaneous sensory nerve (MACN) and ulnar nerve SNAPs, can support the diagnosis of neurogenic TOS 5, 6
Treatment Options for Thoracic Outlet Syndrome
- Conservative treatment, including physical therapy, lifestyle modifications, NSAIDs, and injection therapy with botulinum toxin A or steroids, is often the first line of treatment for TOS 2, 3, 4
- Surgical decompression, such as brachial plexus decompression, neurolysis, and scalenotomy with or without first rib resection, may be necessary for patients who have failed conservative therapy or have severe symptoms 2, 3
- Postoperative care, including passive/assisted mobilization of the shoulder and resistance strength training, is important for optimizing outcomes after surgical treatment for TOS 2