From the Guidelines
The best way to diagnose thoracic outlet syndrome (TOS) involves a comprehensive approach combining clinical evaluation, provocative maneuvers, and imaging studies, with MRI being particularly valuable for visualizing soft tissue structures and nerve compression 1.
Diagnostic Approach
The diagnostic approach to TOS should begin 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 elevated arm stress test (EAST) can help identify vascular or neurogenic compression when they reproduce the patient's symptoms.
- Diagnostic imaging is essential for confirmation, with MRI being particularly valuable for visualizing soft tissue structures and nerve compression 1.
Imaging Studies
Vascular studies including duplex ultrasound, CT angiography, or MR angiography may be necessary when vascular TOS is suspected.
- Electrodiagnostic studies like nerve conduction studies and electromyography can help differentiate TOS from other neurological conditions 1.
- A multidisciplinary approach involving neurologists, vascular surgeons, and physical therapists often yields the most accurate diagnosis.
Importance of Early Diagnosis
Early diagnosis is important as prompt treatment can prevent permanent nerve damage and improve outcomes for patients suffering from this often challenging condition 1.
Radiation Level Information
Relative radiation level information should be considered when choosing imaging studies, with options such as radiography of the chest and MRI without and with IV contrast of the chest being usually appropriate for the initial and follow-up imaging after surgery or intervention for patients with nTOS 1.
From the Research
Diagnosis of Thoracic Outlet Syndrome
The diagnosis of thoracic outlet syndrome (TOS) is complex and requires a thorough clinical examination, patient history, and appropriate clinical testing 2, 3, 4.
- Clinical evaluation is paramount in making the diagnosis of TOS, with complaints of paresthesia and numbness relating to the nerve compression component, and pain associated with muscle imbalance in the neck, shoulders, and upper back 2.
- Utilization of a pain evaluation scale assists in assessing a functional overlay to the pain complaints, and detailed sensory testing at rest and after provocation of the patient's symptoms with overhead activity can aid in diagnosis 2, 5.
- Radiographic test results are frequently normal in TOS patients, while vascular testing results are frequently abnormal in a normal patient population 2.
- Electrodiagnostic tests are useful in ruling out other, more distal nerve entrapments 2.
- Provocative tests, such as the Adson test, hyperabduction test, and Wright test, can be useful in diagnosing TOS, with improved specificity when used in combination 6.
- Doppler ultrasonography can visualize vascular parietal abnormalities and confirm the diagnosis in patients with at least five positive provocative tests 6.
- Electrophysiological studies are useful mainly for differential diagnosis or detecting concomitant abnormalities 6.
- Helical CT angiography can provide accurate information on the location and mechanism of vascular compression, but its usefulness in establishing the diagnosis of TOS and obtaining pretherapeutic information remains unclear 6.