From the Guidelines
Bilateral carpal tunnel syndrome is primarily caused by increased pressure within the carpal tunnel, leading to median nerve compression, which can result from various factors including inflammation, fluid retention, anatomical abnormalities, or thickening of the transverse carpal ligament, as supported by recent studies such as the 2023 update on ACR Appropriateness Criteria for chronic hand and wrist pain 1. The pathophysiology of bilateral carpal tunnel syndrome involves the compression of both median nerves as they pass through the carpal tunnel in each wrist, resulting in reduced blood flow (ischemia) to the nerve, disrupting normal nerve function and signal transmission. Key factors contributing to this increased pressure include:
- Inflammation of the synovial tissue lining the tendons
- Fluid retention
- Anatomical abnormalities, such as bifid median nerve or persistent median artery, which can be identified using ultrasound (US) evaluation 1
- Thickening of the transverse carpal ligament As compression persists, it leads to myelin sheath damage, slowing nerve conduction, and eventually axonal damage, resulting in permanent sensory loss and muscle weakness, particularly affecting the thenar muscles at the base of the thumb. The use of US as a diagnostic tool has been advocated due to its high sensitivity and specificity for diagnosing carpal tunnel syndrome, as well as its ability to identify space-occupying lesions and tendon pathology in the carpal tunnel 1. Bilateral involvement often indicates an underlying systemic condition, such as diabetes, hypothyroidism, rheumatoid arthritis, pregnancy, obesity, or genetic predisposition, requiring comprehensive evaluation and management.
From the Research
Pathophysiology of Bilateral Carpal Tunnel Syndrome
- Bilateral carpal tunnel syndrome is a condition where the median nerve is compressed at the wrist, leading to symptoms such as numbness, tingling, and pain in both hands 2.
- The pathophysiology of bilateral carpal tunnel syndrome is similar to that of unilateral carpal tunnel syndrome, involving compression of the median nerve at the wrist due to various factors such as repetitive motion, trauma, or systemic conditions 3.
Risk Factors and Causes
- Risk factors for developing bilateral carpal tunnel syndrome include repetitive motion, vibration, and trauma to the wrist, as well as systemic conditions such as diabetes, thyroid disorders, and rheumatoid arthritis 2, 3.
- Other causes of bilateral carpal tunnel syndrome may include anatomical abnormalities, such as a narrow carpal tunnel or a thickened transverse carpal ligament 2.
Symptoms and Diagnosis
- Symptoms of bilateral carpal tunnel syndrome may include numbness, tingling, and pain in both hands, particularly in the thumb, index, and middle fingers 2, 3.
- Diagnosis of bilateral carpal tunnel syndrome is typically made through a combination of physical examination, medical history, and electrodiagnostic tests such as nerve conduction studies and electromyography 2, 3.
Treatment Options
- Treatment options for bilateral carpal tunnel syndrome may include conservative management with wrist splints, physical therapy, and corticosteroid injections, as well as surgical release of the transverse carpal ligament 4, 5, 6.
- The effectiveness of conservative treatment may vary depending on the severity of the condition and the presence of systemic diseases, with some studies suggesting that pharmacological treatments, manual therapy, and electrotherapy may be beneficial for patients with severe carpal tunnel syndrome and systemic conditions 3.