In September 2015, Rebecca Cole noticed tingling in her toes. Within a few weeks, the tingling changed to numbness, which spread to the soles of her feet.
Cole had never had chronic or serious back ailments, but her parents had suffered from sciatica, a painful condition that affects the back, hips and legs and is caused by the compression of a spinal nerve root in the lower back. Given her parents' experience, Cole suspected the tingling and numbness in her feet could be related to her back. Cole, 31, saw an orthopedist in late October who took X-rays of her back, which showed no problems. Still, the orthopedist believed Cole would benefit from strengthening her back and recommended six to eight weeks of physical therapy. But by May, Cole's condition had worsened, and neither her orthopedist nor physical therapist could pinpoint the source of her problem. "My feet were numb all the time," Cole says. At times, the numbness moved up to her waist; she continued to walk, but slowly and with great difficulty, and she also began experiencing pain in her back.
Cole was suffering from peripheral neuropathy, a condition that develops when the peripheral nervous system – the body's communications network that transmits information between the brain and spinal cord and the rest of the body – is severely damaged. After months of fruitless tests and physical therapy, a neurologist took MRIs of Cole's brain, thoracic spine, lumbar spine and cervical area. The thoracic spine MRI revealed Cole had a herniated disc that was compressing her spinal cord below her shoulder blades. "[The doctor] looked at the images and said the only thing that would prevent me from getting worse is surgery," Cole recalls. So she underwent four hours of surgery, as the surgeon conducted a transpedicular excision of the thoracic herniated disc. After her surgery, Cole spent more than two weeks at a subacute rehabilitation center – less intense than a typical rehab facility – doing physical and occupational therapy exercises six days a week to regain the strength in her legs. Three months later, Cole had recovered about 70 percent of her leg capacity.
Cole's case is unusual. The odds that tingling or numbness in your feet means you need surgery to avoid paralysis are quite long, several physicians say. The symptoms Cole experienced typically signal causes other than a herniated disc for peripheral neuropathy, which affects 40 million people nationwide, according to the Foundation for Peripheral Neuropathy. It could cause serious damage to the nerves that go to your feet, which is why it should be treated promptly, whatever is causing it, says Dr. Steven Neufeld, a foot and ankle orthopedic surgeon and director of the Orthopaedic Foot and Ankle Center in Falls Church, Virginia.
Doctors use an array of methods, including full physical exams with blood tests, MRIs, nerve biopsies and nerve conduction velocity tests, to determine the cause of peripheral neuropathy. Here are the leading causes of peripheral neuropathy and ways to treat them:
Diabetes. Between 60 and 70 percent of people with diabetes suffer from diabetic neuropathies, a family of nerve disorders that can cause tingling and numbness in the feet, hands, arms and legs. Prolonged exposure to high blood sugar can seriously damage nerve fibers, causing diabetic neuropathy. High blood sugar disrupts the ability of the nerves to transmit signals and weakens small blood vessels that provide the nerves with oxygen and nutrients. These neuropathies are treated by treating the patient's diabetes, says Dr. Kenneth Jung, an orthopedic foot and ankle surgeon at the Kerlan-Jobe Orthopedic Clinic in Los Angeles. An improved diet that lowers the patient's blood-sugar levels and lifestyle changes, such as increased levels of exercise that lead to weight loss, are typical methods of treating the disease, Jung says. Some patients may also require medication, such as insulin. Treating diabetes successfully can slow or stop the nerve damage to the feet, but may not reverse the harm that's already been caused, Jung says. Whether a patient regains the use of nerves depends on how much damage he or she has already sustained.
Alcoholism. Some people who drink excessively experience tingling or numbness in their feet from alcoholic neuropathy. This is caused when peripheral nerves are damaged by the consumption of too much alcohol, which is toxic to nerves. Drinking alcoholically can also alter the body's levels of vitamin B12, vitamin B1 and vitamin B7 – nutrients that nerves need to function properly. Clinical studies have shown between 25 and 66 percent of diagnosable alcoholics suffer from this kind of nerve damage, according to Promises Treatment Centers, which has two for-profit alcoholism treatment centers in Los Angeles. That translates to between 4 and more than 10 million people with alcoholic neuropathy. Successful treatment of alcoholism – getting the patient to stop drinking – can restore the person's nutritional health and prevent future nerve damage. But it may not restore the nerves that are already harmed, Jung says. If the patient drank excessively for years, the nerves may be too damaged to repair.
Chemotherapy. The toxic effects of chemotherapy attack cancer cells but also damage nerves, which can cause neuropathy. Between 30 to 40 percent of the nation's cancer patients who are treated with chemotherapy experience chemotherapy-induced peripheral neuropathy, according to the Foundation for Peripheral Neuropathy. Some patients may experience neuropathy symptoms right after their first dose of chemo; for others, the effects may not surface for months or even years. Physicians can treat this type of neuropathy with several medications, including pregablin and gabapentin, says Dr. Damon Raskin, an internist in private practice who is affiliated with Concierge Choice Physicians in Pacific Palisades, California. Doctors can prescribe these and other medications by themselves or in combination with other drugs. These drugs "don't always restore the patient back to [their] original baseline, but they can lead to a marked improvement," Raskin says. Whether the patient regains their nerve function depends on how much damage the chemo has caused.
No known cause. Doctors cannot determine a specific cause for about 23 percent – or more than 9 million people – of all neuropathy sufferers, according to the Foundation for Peripheral Neuropathy. This is known as idiopathic peripheral neuropathy. Doctors treat this kind of neuropathy with the same medications they would prescribe to patients with chemotherapy-induced neuropathy, Raskin says. As is the case with all kinds of neuropathy, whether the patient's nerves are fully restored depends on how much damage they've sustained. Everyone reacts differently to medication, so what is effective for one patient may not be as successful for another.