The Anatomy of Carpal Tunnel Syndrome

Chances are that you’ve heard of carpal tunnel syndrome or possibly experienced it yourself. Characterized by hand numbness and tingling in the fingers, many people experience this phenomenon. It’s perhaps the most widespread nerve disorder, affecting 4-10 million Americans per year.

In fact, carpal tunnel syndrome is one of the most common disorders we treat at the Orthopaedic Hospital of Wisconsin. Our specialists are well-versed in wrist and hand concerns and can help you get back to comfortable movement quickly. If you suspect you might be suffering from this prevalent syndrome, please contact us for an assessment.

Today, OHOW’s Dr. David Meister of Hand to Shoulder Specialists of Wisconsin discusses the anatomy of carpal tunnel syndrome and what you should know about the causes, symptoms, and treatment options. 

What is Carpal Tunnel Syndrome?

When you hear about carpal tunnel syndrome, you may wonder where exactly the carpal tunnel is located and what it means. To understand the anatomy of the carpal tunnel, imagine looking at a cross-section of the wrist. The carpal tunnel is a space where nine tendons (two for each finger and one for the thumb) pass from the forearm into the hand and the median nerve.

The carpal tunnel space can decrease in size over time. It may become smaller in certain wrist positions such as flexion or extension. Maintaining a neutral wrist position can help to keep this space open. Still, in many repetitive daily activities, you may flex or extend your wrist over and over, making you more aware of discomfort.

Carpal tunnel syndrome occurs from pressure in the wrist. When pressure builds on a nerve within the wrist structure, people may experience hand numbness and a tingling sensation in their thumb, index, middle, and ring fingers.

In mild cases of carpal tunnel syndrome, the symptoms tend to be intermittent—often only at night. In moderate to severe cases, symptoms like hand numbness become more frequent and persistent. These symptoms may make everyday activities, like typing on a computer, challenging.

When carpal tunnel symptoms become ubiquitous or interfere with your day-to-day pursuits, your physician may recommend a procedure called a carpal tunnel release.

Causes of Carpal Tunnel Syndrome

So, what causes carpal tunnel syndrome? Many people wonder if certain activities don’t cause it. But the reality is that there’s often not a specific cause of carpal tunnel syndrome. It may simply occur over time.

Several conditions are associated with the syndrome, including swelling of the tendons (tenosynovitis), trauma, rheumatoid arthritis, diabetes, or thyroid conditions. Fluid retention during pregnancy can also lead to carpal tunnel syndrome, but the syndrome is usually only temporary in those cases.

Aside from hand numbness and tingling in the fingers, some people may also develop pain, weakness, and a lack of dexterity. Sufferers of carpal tunnel syndrome may experience clumsiness with fine motor activities like buttoning their shirts or dropping items due to a lack of sensation in their fingers.

A thorough physical examination and a review of medical history will help physicians diagnose carpal tunnel syndrome. In a typical carpal tunnel assessment, your practitioner will review your medical conditions, how you use your hands for daily activities, as well as any prior injuries. Your physician will also document baseline sensory measurements. In most cases, practitioners will also order electrodiagnostic studies or ultrasound of the wrist to ascertain the severity of the condition.

Treatment of Carpal Tunnel Syndrome

Should your physician diagnose you with carpal tunnel syndrome, you may be wondering what to expect from the treatment. Fortunately, symptoms of carpal tunnel may improve without surgery. Your practitioner may recommend activities to help you keep the wrist in a neutral (straight) position.

Doctors may encourage patients to focus on maintaining a neutral wrist position throughout their daily activities. They may also recommend wearing a wrist brace or splint at night. Steroid or “cortisone” injections may help ease discomfort as well, although the results are often temporary.

In more severe cases of carpal tunnel syndrome, or if symptoms do not improve, physicians may recommend surgery to increase space and relieve the pressure on the median nerve. The surgery is known as “carpal tunnel release” and involves making an incision through the transverse carpal ligament on the top of the tunnel. Think of it as opening lanes on a highway to help increase traffic flow (in this case, nerve conduction in the wrist).

There are several different techniques surgeons use for carpal tunnel release—either the traditional open method or in a minimally invasive endoscopic procedure. Surgical results are typically the same at 12-months post-surgery, although the minimally invasive manner often has a slightly faster initial recovery time.

After carpal tunnel surgery, most patients experience a full recovery and a return to regular, comfortable activities.

If you’re experiencing symptoms of carpal tunnel syndrome, schedule an appointment with our talented hand and wrist specialists today. They will diagnose and assess your condition and help you begin your healing journey.