MedifocusHealth

There are several different ways to classify peripheral neuropathy. One of the most common classification systems takes into account the pattern and distribution of the pain and includes:

Mononeuropathy

Mononeuropathy is characterized by involvement of a single peripheral nerve. This is most likely to be the result of:

• Nerve entrapment such as carpal tunnel syndrome which is the most common cause of mononeuropathy or ulnar nerve entrapment (near the elbow) which is the second most common cause of mononeuropathy
• Trauma

Mononeuropathy multiplex

In mononeuropathy multiplex, two or more non-contiguous peripheral nerves in separate parts of the body are affected. The pattern of involvement is random, multifocal, and typically evolves quickly. Mononeuropathy multiplex is associated with:

• Vasculitis - inflammation in the part of the vascular system that is innervated by the affected nerves. Vasculitis could also be systemic. Vasculitis needs to be diagnosed and treated quickly.
• Diabetic amyotrophy - a type of neuropathy with acute pain, weakness and/or wasting of the muscles in the lower extremity
• Sarcoidosis - inflammation that produces tiny lumps of cells in various organs in the body
• Lyme disease
• Lymphoma
• Carcinoma
• HIV
• Amyloidosis - amyloid protein deposits in limited organs or throughout the body
• Polyarteritis nodosa - An autoimmune disease that causes inflammation of the small and medium-sized arteries and can lead to problems with muscles, joints, and other organs

Polyneuropathy

While mononeuropathy affects a single nerve, polyneuropathy affects multiple nerves and may affect more than one extremity - often on both sides of the body (symmetric). Symptoms appear more commonly in the legs than the arms and usually are felt first in the toes and soles of the feet. It is the most common type of peripheral neuropathy and is associated with diabetes, alcoholism, vitamin B deficiency or HIV. Polyneuropathy can also involve the autonomic nervous system which can lead to symptoms described above.

Most polyneuropathies evolve slowly, involve sensory and motor nerves, and progress symmetrically. Polyneuropathies involve more than one type of nerve but there is usually one (e.g. sensory or motor, large fiber or small fiber) that is predominant.

The most common type of polyneuropathy is called distal symmetric polyneuropathy. It involves long sensory nerves and symptoms usually appear first in the toes and the soles of the feet. Early symptoms include numbness, tingling, paresthesia, and burning. As the name implies, symptoms are symmetric and involve both legs. Distal symmetric polyneuropathy is associated with:

• Diabetes
• Idiopathic neuropathy
• Connective tissue disease
• Inherited neuropathies
• HIV
• Cancer
• Chemotherapy
• Metabolic disorders

There are several types of polyneuropathy, including acute and chronic polyneuropathy.

Acute Polyneuropathy

This type of polyneuropathy evolves suddenly and tends to progress rapidly. Approximately half of the patients have a history of respiratory or gastrointestinal infection within the 2-3 weeks prior to onset. Acute polyneuropathy is associated with:

• Guillain-Barre syndrome - a disorder in which the body's immune system attacks part of the peripheral nervous system. Symptoms usually begin with weakness or tingling sensations in the leg and can progress to the arms and upper body. This condition requires immediate diagnosis and treatment since it can deteriorate quickly and cause paralysis and respiratory insufficiency if respiratory muscles are affected. Approximately 25-30% of patients with Guillain-Barre syndrome require ventilation support.