From the Guidelines
The assessment of carpal tunnel syndrome (CTS) should begin with a thorough clinical evaluation combined with electrophysiologic studies, and further imaging such as wrist US or MRI without contrast may be considered in selected circumstances. The clinical assessment includes history, physical examination, and provocative tests such as Tinel's sign and Phalen's test. According to the American College of Radiology Appropriateness Criteria 1, suspected CTS is diagnosed by clinical evaluation combined with electrophysiologic studies, and further imaging is usually not needed. However, a more recent study 1 suggests that ultrasound (US) can be highly sensitive and specific for the diagnosis of CTS, and may be used as a complementary test or as the confirmatory test of choice.
Some key points to consider in the assessment and management of CTS include:
- Clinical evaluation: history, physical examination, and provocative tests such as Tinel's sign and Phalen's test
- Electrophysiologic studies: nerve conduction studies and electromyography to confirm the diagnosis and assess severity
- Imaging: wrist US or MRI without contrast may be considered in selected circumstances, such as when the diagnosis is unclear or when there are suspected space-occupying lesions or anatomic variants
- Conservative management: wrist splinting, nonsteroidal anti-inflammatory drugs, activity modification, and ergonomic workplace adjustments
- Surgical decompression: recommended for patients with severe or persistent symptoms, muscle weakness, or evidence of denervation on electrodiagnostic studies, as supported by the pathophysiology of CTS which involves median nerve compression within the carpal tunnel 1.
The use of US as a diagnostic tool for CTS has been supported by multiple systematic reviews and meta-analyses, which have demonstrated its high sensitivity and specificity 1. The measurements and calculations used in US evaluation of the median nerve are heterogeneous, but cross-sectional area measurements and ratios or differences in cross-sectional area comparing different locations in the forearm and wrist have been reported to be useful. Some authors have advocated for the use of US as the confirmatory test of choice or as a complementary test for the suspected diagnosis of CTS due to its ability to identify space-occupying lesions, anatomic variants, and tendon pathology in the carpal tunnel, as well as its potential to reduce the false-positive rate of electrodiagnostic studies 1.
From the Research
Carpal Tunnel Syndrome Assessment
- Carpal tunnel syndrome (CTS) is a clinical diagnosis that can be made based on patient history and physical examination, with additional tests such as nerve conduction studies and ultrasonography used to confirm the diagnosis 2.
- The diagnosis of CTS is based on the use of clinical criteria, including symptoms such as numbness, tingling, and pain in the hand and wrist, as well as physical examination findings such as Phalen's test and Tinel's sign 3.
Recommended Assessment Approach
- A thorough clinical evaluation, including a detailed patient history and physical examination, is essential for diagnosing CTS 3.
- Nerve conduction studies can be used to confirm the diagnosis of CTS, especially in cases where the diagnosis is uncertain or the patient has severe symptoms 3.
- Ultrasonography can also be used as a diagnostic tool in the investigation of patients with CTS, and can provide valuable information about the median nerve and carpal tunnel 2.
Management Approach
- Conservative management of CTS includes nocturnal splinting and steroid injections, which have been shown to be effective in the short-term management of symptoms 4, 5, 6.
- Surgery, such as open carpal tunnel release, is often necessary for long-term relief of symptoms, especially in cases where conservative management has failed 4, 5.
- The choice of management approach depends on the severity of symptoms, the duration of symptoms, and the presence of any underlying medical conditions 4, 3.
Factors Influencing Treatment Outcome
- The duration of symptoms and the presence of sensory impairment at presentation can influence the outcome of treatment, with patients who have shorter symptom duration and less sensory impairment being more likely to respond to conservative management 4.
- The approach used for steroid injection, either proximal or distal, does not appear to affect the outcome of treatment 6.