Ask the Doctors: Peripheral neuropathy develops with other conditions

Dear Doctors: Why does someone get peripheral neuropathy? Are there drugs or treatments that can cure it?

Dear Reader: Peripheral neuropathy, or just neuropathy, refers to symptoms that can arise when certain nerves become damaged.

The condition involves the peripheral nervous system — the vast neural network that allows the body to communicate with the spinal cord and the brain. These nerves are involved in physical sensation, the control of movement and involuntary processes such as bladder function, digestion and blood pressure regulation.

A number of diseases and conditions can lead to the development of peripheral neuropathy. It also can be a side effect of some medical treatments.

A common cause is Type 2 diabetes, particularly when it’s unmanaged, because chronically high blood glucose levels can damage the capillaries, including those that nourish the nerves and keep them healthy.

Other causes include physical injury or trauma, chronic inflammation, alcoholism, autoimmune diseases, chemotherapy drugs, certain medications, smoking, nutritional deficiencies, toxins and inherited conditions. In some instances, a cause can’t be determined. This is known as idiopathic neuropathy.

Symptoms include numbness, sensations of tingling, prickling or burning, difficulty discerning hot or cold temperatures, a dulled pain reflex and a loss of spatial awareness of the hands or feet, which can lead to difficulties with balance.

When the motor nerves are affected, muscle cramps, twitching and muscle weakness or wasting can occur.

When the autonomic nervous system is affected, the involuntary processes it oversees can be affected, which can cause sudden changes in blood pressure, excessive sweating, rapid heartbeat, sexual dysfunction and poor bladder or bowel control.

The condition is estimated to affect between 8% and 10% of people over 50. It isn’t a direct result of the aging process but because older adults are at increased risk of developing the diseases or conditions or undergoing the medical treatments that can lead to neuropathic pain.

In cases in which the cause isn’t evident, diagnosis typically involves a neurological exam, tests to measure muscle strength, blood tests and possibly a nerve biopsy, diagnostic scans such as an MRI and genetic testing.

Treatment focuses on managing the disease or the condition believed to be the cause. For someone with diabetes, that would be diet, medication and behaviors to manage blood glucose. For anyone who uses tobacco, quitting is imperative.

Physical therapy, supportive footwear, neurostimulation, acupuncture and certain medications might be used. Getting regular exercise, maintaining a healthy weight and limiting alcohol also can help.

Dr. Eve Glazier and Dr. Elizabeth Ko are UCLA Health internists.