What Is Peripheral Neuropathy?

Overview

Peripheral neuropathy is the term used to refer to a group of conditions in which the nerve cells (neurons) in your hands, feet and arms become damaged. The word ‘peripheral’ refers to any nerve cells that are outside of the brain and spinal cord. This damage can affect just one, several or all nerves in the body. The nerve cells that are affected could be sensory nerves, which deliver sensations from pain or touch; motor nerves, which control muscles; or autonomic nerves, which maintain functions such as blood pressure and bladder activity. To put it simply, if one or more nerve cells are not working properly, it is like a circuit missing a battery or a bulb, meaning that the signals can’t do their job. There are a range of causes and symptoms for peripheral neuropathy, so the long-term outlook can vary.

What are the symptoms of peripheral neuropathy?

The symptoms of peripheral neuropathy depend on which types of nerve cells, described as sensory, motor or autonomic, are damaged, as described below:

Motor nerve damage:

• Muscle weakness and paralysis, for example, difficulty moving the toes
• Muscle shrinkage and weakening, particularly in the feet, lower legs and hands 
• Involuntary muscle movements, such as cramps

Sensory nerve damage:

• Pins and needles sensations, causing tingling and numbness. This can affect your ability to detect heat, such as not feeling a hot coffee cup
• Difficulties with balance and coordination leading to clumsiness
• Pain in areas such as your arms or feet, which can be more intense and happen spontaneously

Autonomic nerve damage:

• Blood pressure fluctuations, such as when you stand up
• Changes in sweating, such as too much or too little being released
• Bladder and bowel issues, such as constipation or incontinence
• Sexual dysfunction, such as lower arousal

Mark Reid, aged 61, shares his experience of peripheral neuropathy symptoms:

“I get tingling sensations in my feet and hands. Normally it’s low-level. Occasionally, things will slip out of my fingers. The first time that happened it was strange because my body wasn’t doing what I wanted it to.

In my case, the peripheral neuropathy was caused by drinking too much alcohol (known as alcoholic neuropathy), and I still experience the symptoms now despite being twelve years sober.”

If you think you or someone you know may be experiencing any of these symptoms, it is important to speak to your healthcare provider to get the right support. 

How common is peripheral neuropathy?

Peripheral neuropathy is a common condition, with a prevalence of 2.4% of people worldwide and 5–7% of people aged 45 and over, due in part to the loss of nerve cells as you age and higher incidence of diseases affecting nerve cells among older people.¹  

Peripheral neuropathy is more common in Caucasian individuals than African-Caribbean, Indian and Asian individuals.²

What are the risk factors for peripheral neuropathy?

The list below gives some of the key risk factors for peripheral neuropathy:²

• Being assigned male at birth
• Being elderly
• Having a high body mass
• Being tall  

What are the causes of peripheral neuropathy?

There are a range of causes of peripheral neuropathy, with diabetes and inheriting faulty genes that can lead to peripheral neuropathy being the most common.³ Other causes can include excessive alcohol consumption, immune disorders, chemotherapy, smoking, vitamin B₁, B₆ and B₁₂ deficiency and injuries. Vitamin B₆ is unusual in that both a deficiency and an excess can lead to peripheral neuropathy.⁸ Some individuals may develop the condition spontaneously.  This is known as idiopathic neuropathy. Most cases develop slowly and are not severe.

Some medicines are thought to cause peripheral neuropathy as one of their side effects. These include any of the following:

• Some chemotherapies, such as those used for bowel cancer, myeloma or lymphoma
• Some types of antibiotics, when taken for several months, including metronidazole and nitrofurantoin
• An epilepsy medication called phenytoin, if taken for a long period of time
• Thalidomide and amiodarone

What happens in the body during peripheral neuropathy?

The diagram below shows what happens to the nerve cells affected by peripheral neuropathy:⁴

Image source: Parr-Reid S. BioRender.

How is peripheral neuropathy diagnosed?

When diagnosing peripheral neuropathy, your healthcare provider will first ask about your symptoms and will then carry out a physical examination of the affected area of the body. This may include testing your sensations, muscle strength and reflex reactions.

They may then take blood to test to look for signs of any underlying causes, such as diabetes.

If a diagnosis has not been made after these tests, you may be referred to a neurologist who specialises in health conditions of the nervous system. They may carry out tests such as:

1. Nerve conduction test – placing electrodes on the skin and passing small electric shocks to the nerves to test the speed and strength of nerve signals
2. Electromyography – using a needle to measure electrical signals within muscles

How is peripheral neuropathy treated?

Medications

The first-line treatments for peripheral neuropathy are medications called gabapentinoids, such as gabapentin and pregabalin, which help manage nerve pain by lowering the concentration of a chemical called GABA, which is involved in sending pain signals to the brain.^5,6 Some types of antidepressants, such as tricyclic antidepressants and serotonin-noradrenaline reuptake inhibitors (SNRIs) can also manage peripheral neuropathy by increasing the concentrations of noradrenaline and serotonin, which help relieve pain by blocking pain signals.⁷ If these don’t work, second-line medications include lidocaine and opioids such as tramadol.⁵ If vitamin deficiency is identified as the root cause, supplements may be prescribed. ⁸

Therapies

Therapies, such as ‘scrambler therapy’ can be used. This passes “non-pain” electrical signals to the brain on behalf of the affected nerves, with the aim of retraining the brain to not detect nerve pain.

Physical therapies for muscle weakness or balance difficulties can help improve movement. Walking aids such as foot braces, walkers, and canes can also be used.

Managing peripheral neuropathy

The infographic below shows some of the key ways to manage peripheral neuropathy:

Image source: Parr-Reid S. Canva.

Mark discusses how he manages his symptoms and his outlook on peripheral neuropathy following his diagnosis:

“To manage it, I do some exercises to help my feet. I would say much of the work should be prevention. People think about their brains but not so much about their hands and feet. I didn’t do anything to look after myself when I first found out years ago, but I recommend others do.”

What is the outlook for peripheral neuropathy? 

The prognosis for peripheral neuropathy is dependent on the cause. If the cause of peripheral neuropathy is not managed, complications such as foot ulcers and tissue death (necrosis) can occur. This is why it is important to consult a healthcare provider as early as possible. 

Summary

Peripheral neuropathy is a condition in which nerve damage outside of the brain and spinal cord can cause symptoms such as tingling, numbness or pain. It is common and more often diagnosed in those over 45 years old. The condition is chronic and usually develops slowly as a result of diabetes, excessive alcohol consumption, smoking, injuries or genetic causes. Neuropathy may affect the nerves involved in muscle movement, those involved in detecting external sensations such as heat, or those involved in regulating the bladder and blood pressure. Peripheral neuropathy can be managed through medications and therapies.