Comparing Efficacies of Median Nerve Hydrodissection With Dexamethasone and Dextrose in Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment neuropathy worldwide, resulting from the compression of the median nerve in the carpal tunnel, an osteofibrous canal whose roof is formed by the flexor retinaculum and whose floor is formed by the carpal bones. CTS accounts for approximately 90% of all entrapment neuropathies, and an individual's lifetime risk of diagnosis is estimated to be 10%. It is estimated that about 5% of the population suffers from CTS. It is more common in women compared to men and at least half of the cases manifests between the ages of 40 and 60.

In clinical practice, the most common complaints of patients include neuropathic symptoms along the distribution of the median nerve. These complaints, which initially occur and flare up at night and intermittently during the day, may become continuous and worsen in the later stages of the disease.

Taking an accurate history and clinical assessment is crucial for diagnosis. Evaluation of sensory abnormalities, loss of two point discrimination, and the strength of abductor pollicis brevis muscle can provide information about functional impairment. Tinel's sign and Phalen's manoeuvre are some of diagnostic tests. Some scales and questionnaires are used in diagnosis and assessment of functionality. Ultrasonography is a useful, inexpensive and easily accessible method to simultaneously observe morphological changes in the median nerve and scan the surrounding anatomy. Electrophysiological assessment is very sensitive in examining median nerve dysfunction caused by nerve damage. Nerve conduction studies are considered the gold standard method in diagnosis, determining prognosis and making treatment decisions.

The management of CTS in patients depends on the severity of the disease. In mild and moderate circumstances conservative treatments are recommended for the patients. Surgery is typically considered for patients with moderate to severe CTS or individuals who do not experience significant improvement with conservative treatments. Conservative treatments include patient education, wrist splinting, medical treatments, physical therapy, and perineural injections.

Ultrasound-guided nerve hydrodissection injection has emerged as a therapeutic approach with less complications for CTS. This method aims to achieve mechanical release from perineural adhesions by creating a perineural fluid plane.Various injectates such as normal saline, 5% dextrose, and platelet-rich plasma,viscosupplements are commonly used for hydrodissection. Many studies have been conducted with the hypothesis that the injection volume, in addition to the injection preparation, would also be important in median nerve hydrodissection, and different results have been obtained.

This study aimed to compare the clinical, ultrasonographic and electrophysiological improvement in patients by applying different volumes of dexamethasone and dextrose in median nerve hydrodissection. Patients will be evaluated before and after treatment at 2nd, 4th and 12th weeks ultrasonographically, electrophysiologically and clinically with pain scores, handgrip strength assesment, two-point discrimination values, functional and disability scales.

Inclusion criteria

• Patients who are 18 years of age or older
• Patients who are clinically diagnosed with CTS
• Patients who have mild or moderate CTS confirmed by EMG study
• Patients unresponsive to 2-weeks of nightly volar wrist splinting

Exclusion criteria

• Patients who are younger than 18 years of age
• Patients with severe EMG study
• Presence of thenar atrophy
• Patients diagnosed with cervical radiculopathy, myelopathy, brachial plexopathy or polyneuropathy
• Patients diagnosed with thoracic outlet syndrome
• Patients diagnosed with inflammatory rheumatic disease
• Patients diagnosed with connective tissue disease
• Patients diagnosed with neuromuscular disease
• Patients diagnosed with peripheral vascular disease
• Patients with history of malignancy
• Patients who have uncontrolled hypothyroidism, hyperthyroidism or diabetes mellitus
• Patients diagnosed with chronic renal failure
• Patients diagnosed with acromegaly
• Patients with history of surgery and/or fracture at the symptomatic upper extremity
• Patients with a history of injection into the median nerve lasting less than 6 months at the symptomatic wrist
• Patients who are pregnant
• Patients with history of chronic steroid or chronic alcohol use