Peripheral neuropathies

• What is Peripheral Neuropathies
• Statistics on Peripheral Neuropathies
• Risk Factors for Peripheral Neuropathies
• Progression of Peripheral Neuropathies
• Symptoms of Peripheral Neuropathies
• Clinical Examination of Peripheral Neuropathies
• How is Peripheral Neuropathies Diagnosed?
• Prognosis of Peripheral Neuropathies
• How is Peripheral Neuropathies Treated?
• Peripheral Neuropathies References

What is Peripheral Neuropathies

Peripheral neuropathy refers to a diverse group of disease affecting the motor sensory and autonomic nerves lying outside the central nervous system. This can cause a wide variety of symptoms, such as weakness, numbness or sensitivity to touch.

The peripheral nerves make up a vast network that transmit information from/to the brain and spinal cord (the central nervous system) to/from every other part of the body. Information for movement is conveyed from the central nervous system via the nerves (motor pathways) and information regarding sensation from the peripheries to the central nervous system (sensory pathways).

Statistics on Peripheral Neuropathies

Peripheral neuropathy is fairly common, but frequency varies with the cause of the condition. Up to one half of patients with diabetes mellitus have a neuropathy depending on the criteria used for diagnosis. It is the most common acute polyneuropathy. Worldwide, leprosy is also an important cause.

Risk Factors for Peripheral Neuropathies

Peripheral neuropathy may be either inherited or acquired. There are many different causes of peripheral neuropathies, which vary in terms of symptoms and severity. Possible causes include:

• Alcohol
• Nutritional deficiencies (vitamin B1,6,12 and E)
• Toxins (carbon disulfide, acrylamide)
• Endocrine causes (diabetes, thyroid disease)
• Metabolic causes (renal failure)
• Infections (HIV, Lyme disease, Leprosy)
• Connective tissue disease (scleroderma, SLE, sarcoidosis)
• Immune disorders (Guillain-Barre syndrome, chronic inflammatory demyelinating neuropathy)
• Cancer
• Medications/Drugs
• Inherited conditions (Charcot-Marie-Tooth disease)

Progression of Peripheral Neuropathies

The course of the peripheral neuropathy will depend on the underlying cause. In acute neuropathies, such as Guillain-Barre syndrome where there is an immune attack on the nerves following an infection, symptoms appear suddenly, progress rapidly, and resolve slowly as damaged nerves heal.

In chronic forms, symptoms begin subtly and progress slowly. Some people may have periods of relief followed by relapse. Others may reach a plateau stage where symptoms stay the same for many months or years. Some chronic neuropathies worsen over time, but very few forms prove fatal unless complicated by other diseases. Occasionally the neuropathy is a symptom of another disorder.

Recovery from peripheral neuropathy is usually slow. Depending on the type of peripheral neuropathy, the patient may fully recover without residual effects or may partially recover and have sensory, motor, and vasomotor (blood vessel) deficits. If severely affected, the patient may develop chronic muscular wasting.

How is Peripheral Neuropathies Diagnosed?

A number of tests may be performed:

• Blood tests measuring haemoglobin, inflammatory markers, vitamin levels, blood sugar and thyroid function, infection markers and antibody levels
• Urinalysis
• Chest x-ray
• Nerve conduction studies and electromyography
• Genetic testing is available for the evaluation of specific types of hereditary sensorimotor neuropathies.

Prognosis of Peripheral Neuropathies

Recovery from peripheral neuropathy is usually slow. Depending on the type of peripheral neuropathy and cause, the patient may fully recover without residual effects or may partially recover and have sensory, motor, and vasomotor (blood vessel) deficits. If severely affected, the patient may develop chronic muscle wasting.

How is Peripheral Neuropathies Treated?

Any underlying condition is treated first, followed by symptomatic treatment. Symptoms often can be controlled, and eliminating the causes of specific forms of neuropathy often can prevent new damage.

In general, adopting healthy habits, such as maintaining optimal weight, avoiding exposure to toxins, following a physiotherapist supervised exercise program, eating a balanced diet, correcting vitamin deficiencies, and limiting or avoiding alcohol consumption can reduce the physical and emotional effects of peripheral neuropathy.

Quitting smoking is particularly important because smoking constricts the blood vessels that supply nutrients to the peripheral nerves and can worsen neuropathic symptoms.

Systemic diseases frequently require more complex treatments. Strict control of blood glucose levels has been shown to reduce neuropathic symptoms and help people with diabetic neuropathy avoid further nerve damage. Inflammatory and autoimmune conditions leading to neuropathy can be controlled with steroids or immunosupressive medications.

 

Article kindly reviewed by:

Associate Professor Karl Ng MB BS (Hons I) FRCP FRACP PhD CCT Clinical Neurophysiology (UK) Consultant Neurologist – Sydney North Neurology and Neurophysiology (download referral form and map); Conjoint Associate Professor – Sydney Medical School, University of Sydney; and Editorial Advisory Board Member of the Virtual Neuro Centre.

 

Peripheral Neuropathies References

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