What Are They & What Causes Them?
Numbness. Weakness. Pins and needles. Burning sensations. If any or all of these things resonate with your experience, then you might also be acquainted with the term “pinched nerve.” “Pinched nerve” is a layman’s term for an injury to a nerve or set of nerves resulting from compression, constriction or stretching. All of these actions place pressure on the nerve(s), leading to nerve dysfunction and potentially, painful symptoms.
By Rashad J. Gober
A nerve is a fiber or bundle of fibers that transmits electrical impulses containing information between the brain or spinal cord and the body. Nerves are differentiated based on the kinds of information they send. Motor or “efferent” nerves relay information from the brain to the rest of the body, causing the appropriate organs to contract, relax, work slower or work faster. Sensory or “afferent” nerves communicate in the opposite direction, relaying back information about pain, taste, touch and temperature to the brain for processing. A pinched nerve may cause dysfunction with signals going in either direction, leading to a variety of symptoms.
Think of a nerve like a telephone cord connecting a landline phone to the telephone jack: just as the telephone cord needs to have an uninhibited path to transmit voice signals, nerves need a clear path to communicate electrical impulses. Just as compression, constriction, or stretching beyond natural elasticity may inhibit a telephone cord from relaying voice signals, “pinching” a nerve through compression, constriction, or stretching interrupts communication along a nerve path.
Most frequently, “pinching” occurs when an anatomical structure—such as a bone, cartilage, muscle, disc, or tendon—applies an excessive amount of pressure to a nerve. This pressure can cause inflammation and conditions ranging from uncomfortable nerve irritation on one end to complete nerve dysfunction on the other. For example, having a leg or foot “fall asleep” is a symptom of a single compressed nerve and classified as nerve irritation.
However, the common conception of a pinched nerve falls more on the dysfunctional end of the spectrum. Symptoms of dysfunction include numbness, a “pins and needles” tingling sensation, burning sensations, pain radiating outward from the area of injury and muscle weakness. These symptoms may develop gradually or come on suddenly.
It’s important to understand that a pinched nerve can cause symptoms at any location down the path of the affected nerve as well as the site of damage. For example, a pinched nerve in the neck may not only cause neck pain or stiffness, but also symptoms affecting certain parts of the arm. Similarly, a pinched nerve in the lower back may not only cause symptoms there, but also down the leg.
If certain symptoms develop like progressive muscle atrophy, fecal or urinary incontinence, or pain that disrupts sleep or does not respond to over-the-counter pain meds, prompt medical care is imperative.
Causes and Conditions
There are several reasons why nerve compression might occur. A direct blow may put pressure on a nerve, causing symptoms of tingling and pain. Most people are familiar with this experience when the “funny bone” is hit. As mentioned previously, having a foot fall asleep is another type of nerve compression. These temporary types of compression are not serious or likely to cause permanent damage.
However, a more serious cause of nerve compression seen frequently in patients of middle age is disc herniation. Disc herniation occurs when a disc slips out of place, placing pressure on a nerve in the lower back (lumbar spine) or neck area (cervical spine). The narrowing of disc space in the spine sometimes results in a condition called spinal stenosis. Dr. Todd Bonvallet of The Spine Center explains this phenomenon by encouraging his patients to think of a disc like a grape. “[A disc] is plump, holds water, and is a shock absorber,” he says. “When the disc space collapses for various reasons, pressure is placed on the nerve or nerves in that disc space.”
Nerve compression can also occur as a result of the natural degenerative process that accompanies aging. For example, arthritis can cause a narrowing of the spinal canal, leading to more pressure put on the neural structure. Repetitive use over a long period of time—for example, through occupational stress, hobbies, or sports— can also cause degeneration of surrounding neural structures, leading to nerve compression. Factors such as obesity and poor posture also increase the risk of having a pinched nerve.
Dr. David Lowry of Chattanooga Bone and Joint Surgeons says that a pinched nerve is “most common in the lower back, followed by the neck.” These are common locations because of the possibilities for both disc herniation and degeneration. Dr. Bonvallet says that nerve compression is also common in the wrist where the nerve narrows going into the hand. This is because of the wrist’s propensity for overuse, leading to swelling and inflammation around the nerve.
Nerve compression at the wrist often leads to carpal tunnel syndrome, which is damage to the median nerve traveling through the wrist. The Mayo Clinic reports that women are three times more likely to develop the syndrome, possibly due to the fact that they have smaller carpal tunnels. Other conditions caused by nerve compression include sciatia, which is pain in the lower back or buttocks caused by compression of the sciatic nerve, and cubital tunnel syndrome, which is compression of the ulnar nerve in the elbow.
Diagnosis and Treatment
Simply talking with a physician about pain or that “pins and needles” feeling in your lower back is the first step toward diagnosis. “A patient’s history is one of the most important things we look at,” Dr. Lowry says. After this initial assessment, an equally weighted physical exam is conducted in order to identify any neurological deficit in a specific pattern or muscle group, such as loss of sensation, loss or decrease of motor function or strength, or a change in reflexes.
Depending on a patient’s medical history and physical exam, a physician may order more diagnostic tests. To properly diagnose nerve compression, “x-rays are beneficial, but MRIs are more helpful,” Dr. Bonvallet says. When even MRIs are unable to confirm the diagnosis, a nerve conduction study is ordered. A nerve conduction study determines the function of nerves in the body and is a guaranteed way to diagnose whether or not a nerve is compressed.
Treatment for a pinched nerve always begins as conservatively as possible. Many cases only require rest or ice to heal naturally over time. Depending on the location of the nerve, a physician may recommend activity restriction or a brace to restrict movement around the nerve, non-steroidal anti-inflammatory drugs (NSAIDs), prednisone, and/or physical therapy.
If symptoms do not respond to these treatments, a physician may consider epidural injections. Epidural injections in the spine can help with the symptoms of nerve compression. They are typically administered in a series of three, and are stopped when symptoms reside. If symptoms persist beyond this treatment, surgical decompression is usually necessary.
While not substitutes for full medical care, alternative methods of treatment may also help a patient find relief from the symptoms of a pinched nerve. These complementary methods include chiropractic, acupuncture, decompression therapy, herbal medication and yoga.
Focusing on good posture, maintaining appropriate cholesterol levels, and not smoking are a few ways to set yourself up for proper nerve function. Also, avoiding activities that put you at increased risk for injury—such as improper form when lifting objects—is also important.
“The best way to prevent nerve compression would be to maintain a regular exercise program with some aspect of core muscular strengthening, as well as whole body muscular strengthening,” Dr. Lowry says.
While pinched nerves can be painful and frustrating, there are many available treatment options and the prognosis is good. If you think you may have a pinched nerve, don’t suffer pain or discomfort in silence. Talk to your health care provider and get started on a path to good health.
Rashad J. Gober holds a Bachelor of Arts in Psychology from Covenant College. He currently works as a Mental Health Technician and resides in North Chattanooga.