By John P. Morgan, MD

Surgery might be answer for carpal tunnel syndrome

Numbnes and tingling? The most common symptoms of carpal tunnel syndrome are numbness and tingling affecting the hand, especially the long (middle) and index fingers, thumb, and partially the ring finger. Occasionally the entirety of the hand is involved. Pain is also common and can be described as either aching or burning, at times extending out to the wrist and forearm. Occasionally, abnormal sensations or pain may even extend to the shoulder. As the problem progresses, patients may complain of weakness and decreased grip strength, clumsiness, and dropping of objects from their hands. Symptoms are especially common at night, frequently awakening patients from sleep. Tingling of the fingers may also be noted upon awakening. Many patients will notice that their hands fall asleep when driving, or holding a book or newspaper.

Carpal tunnel syndrome is common in both hands, but one hand may be more symptomatic than the other. The condition is usually progressive, increasing in severity over time. It is somewhat more common in women and with advancing age.

Diagnosis is based on patient history and physical examination. Confirmation and extent of the problem are determined objectively by nerve conduction testing. During testing, the nerve is electrically stimulated at certain points throughout the hand and forearm, and data is retrieved and interpreted. At times, electromyography may be used to stimulate various muscles innervated by the nerve and record the electrical activity. Radiology and blood testing may be ordered in selected circumstances to rule out a suspected medical condition or anatomic abnormality. These tests, however, generally play limited roles in the diagnosis.

Causes are numerous So what causes carpal tunnel syndrome? In most cases, the cause in unknown (idiopathic). It is likely due to several factors, with anatomic, systemic, and perhaps functional, exertional, or occupational factors contributing. Although carpal tunnel syndrome can occur acutely in the presence of trauma, bleeding, swelling, or infection, chronic cases are much more prevalent. Multiple medical conditions can be associated with carpal tunnel syndrome and include diabetes, thyroid and kidney disorders, obesity, heart disease, and rheumatologic illnesses. It is also common in pregnancy and with advancing age. Anatomic causes include a tight carpal canal, changes in the wrist from trauma, and anomalous muscles, masses, or tumors. Exertional contributors – potentially occupational – include chronic exposure to vibration, repetitive impact to the hand and wrist, and extreme or prolonged positions of flexion or extension of the wrist. Something as simple as the position of the hand and wrist during sleep may lead to the eventual development of the problem.

The goals of treatment of carpal tunnel syndrome are to eliminate or effectively reduce symptoms and return the patient to more normal activity and function. At the very least, treatment will prevent further symptoms from appearing and a later decline of function. Prognosis for recovery is based on the severity of findings from nerve studies, the duration and extent of symptoms, the age of the patient, and confounding variables such as associated medical conditions. The earlier the detection, the better the prognosis and results of intervention.

Conservative treatments first

Once the diagnosis of carpal tunnel syndrome has been established, conservative measures are generally appropriate for initial management. Splinting the wrist in a neutral position (no flexion or extension) at night is the first line of treatment. This position is achieved through the use of a brace and decreases the pressure on the median nerve throughout the period of sleep. At times, a brace or splint during the day may also help alleviate symptoms. Activity modification or ergonomic changes in the work environment may also help. When using medications, anti-inflammatory drugs may decrease edema, swelling, and pain; but generally medication will not cure carpal tunnel syndrome. Tendon and nerve gliding exercises and perhaps local manipulation or ultrasound may also offer some relief. Steroid iontophoresis, a noninvasive method of sending electrical charge, laser therapy, and other modalities remain controversial, with few objectively reviewed or reliable medical studies suggesting efficacy. On the other hand, a cortisone injection in the carpal tunnel has been demonstrated to show a positive effect on symptom resolution, depending on the patient. Careful injection technique is required to increase the likelihood of success and to avoid injury to surrounding tendons, arteries, and the nerve itself.

Overall, management decisions are based on several factors. These include the presumed cause, symptom severity and recurrence frequency, as well as objective testing and patient choice. Conservative treatment may only be temporary or yield partial improvement. When symptoms or objective test results are significant – or if the condition does not improve – surgery is recommended.

Outpatient surgery

Carpal tunnel surgery is an outpatient procedure best performed in the operating room. Typically with tourniquet control, a small incision is made in the palm of the hand. Deeper dissection reveals the transverse carpal ligament (the roof of the carpal tunnel). This ligament and the corresponding fascia is incised and released and the median nerve, which passes down the middle of the front of the arm, is freed of overlying pressure and constriction. The nerve and contents of the carpal tunnel (tendons) are inspected for additional abnormalities, and subsequently the wound is irrigated with fluid and closed.

Surgery is effective in the majority of cases. Results may be immediate or delayed over many months. I find it to be a very satisfying surgery in that the majority of patients note definite relief, whether it is partial or complete, and the complication rate is low.

Surgery may not be curative in some advanced cases, but neither will any other form of treatment be effective. Surgery gives the best opportunity for improvement of symptoms since the problem is one of compression and increased pressure on the median nerve that is relieved via surgery.

Tenderness in the palm of the hand is common postoperatively, but severe pain is not. Occasional complications can include wound healing issues or infection, nerve or vascular insult, and excessive scarring. Symptoms may not resolve despite surgery in advanced cases due to the potential permanency of nerve dysfunction. In the majority of these cases, however, surgery will halt further progression and decline.

After surgery

Rehabilitation after surgery is directed at decreasing adhesions to the nerve and tendons, early wrist and finger mobility, scar massage, and subsequent strengthening. Sutures are typically removed 10 to 14 days after surgery. Most people can resume light activities with their hand within days after surgery, and it is typically encouraged. Depending on occupation, the majority of people can return to work quickly after surgery, at least with restrictions, if they can be met. Recurrence of carpal tunnel syndrome after a good surgical result is uncommon.

Carpal tunnel syndrome is a problem of nerve constriction and excessive pressure within the narrow space of the wrist. It is important to remember that numbness and tingling in the hand – frequently with aching or burning pain – is not a normal condition. Although other causes of numbness and tingling exist (such as cervical spine pathology, systemic and central nervous system disease, or other neurological abnormalities), carpal tunnel syndrome remains the most common diagnosis. Know the facts, know that it can be treated, and seek relief.