Carpal tunnel syndrome (CTS) is one of the top ten occupational injuries associated with work disability in the United States. These claims result in an average of 20 days lost from work per claim. Prompt diagnosis is important to providing optimal treatment. The combination of physical findings and abnormal nerve conduction studies is the standard for diagnosis.
Numbness and tingling in the hand are often the first signs of CTS. Loss of strength and decreased hand muscle size is a later finding. The location and quality of the symptoms will often raise the suspicion of CTS. The diagnosis is confirmed by measuring the time it takes an electrical impulse to travel down the median nerve (Nerve Conduction Study). A slowing or latency of this impulse is associated with CTS. Thyroid disease, diabetes, arthritis and pregnancy can all cause CTS.
Studies show that highly repetitive work is associated with CTS. For every 10 hours of repetitive, non-forceful work performed, there is an increased incidence of CTS by 0.62 percent on the working hand and 0.44 percent on the non-working hand. The general population has an overall incidence of 14.4 percent CTS symptoms regardless of the type of work.
Treatment of CTS should be based on the severity of the symptoms and the results of nerve conduction studies. Mild CTS can usually be treated very conservatively, often with bracing and anti-inflammatory medications. Conservative treatment should be also tried prior to surgical release for moderate CTS. Studies show that severely prolonged nerve conduction at the wrist will benefit from surgical release. Studies also indicate that about 50 percent of patients can have symptom relief lasting greater than one year from oral steroids taken for two to four weeks. Early surgical treatment for moderate and severe CTS allows earlier return to work.
Post-offer screening with automated nerve conduction testing has been utilized to identify employees with CTS, as well as employees with the potential for problems due to highly repetitive labor or use of power tools with a frequency of 0.53 to 0.79 cycles per second. Ergonomic screening of work stations has helped to decrease the average of 4.9 new cases per 10,000 workers. Instruction by physical therapists of daily exercises to stretch the carpal tunnel has had great success to decrease symptom development for employees and help contain treatment costs for employers. IBI