On Pins and Needles: Understanding Peripheral Neuropathy

Your legs and feet are tingling again. You call it “pins and needles,” a common annoyance. But your doctor might call it something else: peripheral neuropathy.

The literal meaning of neuropathy is nerve disease, damage or dysfunction. That may sound like an overblown medical description for what appears to you to be a minor problem. But neuropathy can be a serious degenerative condition that acts as a signpost for other illnesses. The sooner you address it, the better your result will be.

Could You Have Neuropathy?

Neuropathy is a complex condition that affects more than 20 million people in the United States, yet it is poorly understood by patients and even researchers. Many patients don’t even mention the early symptoms to their doctors. The problem is significant enough that May 12-16 has been named National Neuropathy Awareness Week by the U.S. Department of Health and Human Services.

“It’s very common. After back pain and headaches, this is one of the most common ailments we see in neurology offices,” said Heber Varela, M.D., a neuro-muscular specialist at Baptist Hospital and West Kendall Baptist Hospital.

Symptoms of peripheral neuropathy are not limited to prickling sensations. They can range from numbness or tingling to muscle weakness. Areas of the body may become abnormally sensitive, leading to an exaggeratedly intense response to touch. In such cases, pain may occur in response to contact that would not normally provoke discomfort. Severe symptoms may include a burning pain, especially at night, as well as muscle wasting and organ or gland dysfunction. Damage to nerves that supply internal organs may impair digestion, sweating, sexual function, and urination.

In its early stages, neuropathy might produce symptoms that patients dismiss as minor ailments. “Typically, they start out complaining that they have pins and needles in their feet, or that their feet are burning,” Dr. Varela said. “In some cases they feel like they are walking on sponges and can’t feel the floor, which can result in balance problems. The symptoms may also progress to their arms and hands.”

Why You Should Be Concerned

Because nerve damage can’t be fully reversed and is likely to get worse, Dr. Varela said it is important to bring all symptoms to the attention of your doctor for careful evaluation. “Sometimes patients think the symptoms are related to their circulation, so they start going to the wrong doctor, maybe a cardiologist or a vascular specialist, when what they really need is a neurologist.”

The most important thing to determine is whether peripheral neuropathy is the result of a serious underlying condition. Neuropathy can be caused by diabetes, kidney disease, thyroid problems, and even some cancers, Dr. Varela said. “It could be the heralding symptom for something much more serious that might be going on.”

Understanding How It Works

Your peripheral nervous system is like a huge communications network that connects your central nervous system  — the brain and spinal cord — to every other part of the body. These peripheral nerves form an information highway to and from your extremities such as your legs, feet, arms and hands, as well as to your mouth and face, muscles and internal organs.

The information carried to the brain by peripheral nerves includes details about sensations, such as the perception of the ground through your feet when you stand, which helps you keep your balance. Peripheral nerves also carry signals from the brain and spinal cord to the muscles to generate movement. For example, they tell your brain to pull back your hand when your coffee cup is too hot.

Peripheral neuropathy occurs when these nerves malfunction because they’re damaged or destroyed, misfiring information to your brain. Damage to these vital connections is like static on your cell phone, distorting or interrupting messages between the brain and spinal cord and the rest of the body. The damaged nerves may send signals of pain when there’s nothing causing pain, or they might not send a pain signal even if something is harming you.

What Causes Neuropathy?

The disorder is complex and may be due to a wide range of factors, including physical trauma, repetitive injury, illness, infection, metabolic problems, exposure to toxins, reactions to medicines, or an imbalance in vitamins. In some cases, a specific cause cannot be identified. Doctors usually refer to neuropathies with no known cause as idiopathic, which occur typically in middle-aged and elderly individuals. The Foundation for Peripheral Neuropathy estimates that one in five neuropathy patients are diagnosed with idiopathic neuropathy.

The most common cause, however, is diabetes. According to the National Institutes of Health, about 60 percent of diabetes patients have mild to moderate nerve damage that results when the tiny blood vessels to the nerves get clogged due to high blood sugar. The condition worsens if blood sugar is not kept under control.

Why You Should Talk to Your Doctor

Among people who don’t normally maintain routine doctors’ appointments and regular preventative care, neuropathy can bring to light important issues, said Deepa Sharma, D.O., a family medicine physician with Baptist Health Primary Care in Coral Gables. “It can be a wake-up call,” she said. “They come in with certain symptoms and discover they have diabetes when they had no idea they had diabetes.”

Lester Carrodeguas, M.D., a family medicine physician with Baptist Health Primary Care in Kendall, agreed.  “There can be many causes for neuropathy, but most of the cases we see in a primary care setting are due to uncontrolled diabetes,” he said.

Regular checkups are key to detecting hidden health issues, he noted. “You have to be really good about scheduling your annual visit, that way things can be caught early,” he said. “If you address these issues early, there is a good chance you can regain some of the feeling lost due to neuropathy.”

Dr. Carrodeguas also urges patients to discuss all of their symptom with their physician, even the things they may think are minor. “Unless you discuss it with your primary care physician, the physician is not going to know,” he said. “I always tell patients to be very truthful with their physician. Don’t hold anything back. The small things that you may take for granted may be symptoms of something else. Good open communication with your physician is key.”

Tags: diabetes management, neuropathy, neuroscience, Neuroscience Center