Peripheral neuropathy: everything there is to know!

What is peripheral neuropathy? 

Our nervous system is made up of the central part (the brain and spinal cord) and the peripheral part (the nerves). The term "neuropathy" refers to damage to one or more nerves in the peripheral nervous system. When neuropathy affects only one nerve, it is known as "mononeuropathy"; when it affects several nerves, it is known as "polyneuropathy".

The symptoms of peripheral neuropathy depend on the type of nerves that are affected and vary in intensity from person to person.

What are the different types of peripheral neuropathy? 

Peripheral mononeuropathy

Carpal tunnel syndrome 

Carpal tunnel syndrome refers to a group of symptoms - tingling, pain, sensitivity problems and reduced muscle strength - in the first 3 fingers of the hand. These symptoms are caused by compression of the median nerve as it passes through the carpal tunnel (located in the wrist).

Ulnar nerve dysfunction (ulnar neuropathy)

The ulnar nerve extends from the neck to the hand and passes through the elbow. The symptoms of this condition are tingling, numbness in the last 2 fingers of the hand, pain in the hand, reduced muscle strength, motor disorders, etc. 

Femoral nerve dysfunction (femoral neuropathy) 

This condition is generally caused by pinching of the cutaneous nerve in the groin. Most sufferers are middle-aged and overweight. The main symptoms are tingling, reduced sensitivity and a burning sensation in the thigh.

Peroneal nerve dysfunction (peroneal neuropathy)

This condition weakens the muscles that lift the foot. As a result, sufferers cannot flex their ankle to lift the front of their foot.

Radial nerve dysfunction (radial neuropathy)

This leads to weakness in the fingers and wrist. Loss of sensitivity in the back of the hand can also be observed.

Peripheral polyneuropathy 

When several peripheral nerves in the body are malfunctioning, this condition is called peripheral polyneuropathy.

Polyneuropathy can have a variety of causes, including infection (HIV, hepatitis C, etc.), toxins, certain drugs, cancer, nutritional deficiencies, diabetes, certain autoimmune diseases, excessive alcohol consumption, etc.

Sensations, movements and strength in the feet, hands and legs are frequently impaired.

Polyneuropathy can also affect the nerves of the autonomic nervous system, which control the body's involuntary functions such as blood pressure, digestion, urination, etc. Their dysfunction may thus cause constipation, fluctuations in blood pressure, sexual dysfunction, etc.

Polyneuropathy can appear suddenly and sometimes develops rapidly, in which case it is often referred to as acute. When it develops gradually, it is known as chronic neuropathy.

How is peripheral neuropathy diagnosed? 

Peripheral neuropathy can be diagnosed via clinical and neurological examination.

Questioning the patient helps to discover a possible cause or an aggravating factor, such as diabetes, medication or chronic renal failure, for example.

Neurological examination includes the assessment of overall strength and the strength of each limb and that of osteotendinous reflexes and sensitivity (to pressure, hot and cold, pain, etc.). The doctor will also look for the lack of stability. These tests are supplemented by autonomic testing to assess the functions of the autonomic nervous system.

These tests are generally supplemented by a full blood test and an ENMG (electroneuromyogram - recording the electrical activity of muscles and nerves).

How to treat peripheral neuropathy? 

The treatment of peripheral neuropathy depends mainly on the underlying cause. If it is a problem of injury, or repeated poor posture, wearing a splint can solve the problem.

If neuropathy is caused by a chronic disease such as diabetes or an infection, the underlying condition must be treated.

If neuropathy occurs as a result of taking a specific medication, the treatment plan can be modified.

In the event of pain, analgesic or anti-inflammatory treatment may be prescribed. A specific treatment can be used to manage certain neurovegetative disorders (constipation, diarrhoea, erectile problems, etc.). In addition, certain physical or occupational therapy exercises can help improve balance and coordination.

A varied and well-balanced diet is important to avoid any deficiencies that could aggravate the symptoms of neuropathy.

Key information 

Peripheral neuropathy can take several forms. It is called mononeuropathy when only one nerve is affected and polyneuropathy when several nerves are damaged. The causes can be varied (infections, medication, diabetes, alcohol dependence or injury).

Diagnosis requires a clinical examination of the patient and a number of tests.

Treatment is mainly aetiological and aims to treat the cause of the neuropathy.