Peripheral Neuropathic Pain

27th November 2006 at 09:24 GMT by Dr.C.A.Jenner MB BS, FRCA. Permalink.

Article on the clinical features and treatment of Peripheral Neuropathic Pain

Introduction

Peripheral neuropathic pain refers to the pain associated with the condition of peripheral neuropathy.

Peripheral neuropathy refers to the damage caused to the peripheral nervous system, which is the vast communications network that transmits information from the brain and spinal cord to every other part of the body. The term is also generally used to describe changes in the way the particular nerves work.

Key Symptoms

Since every peripheral nerve has a highly specialized function in a specific part of the body, a wide array of symptoms can occur when nerves are damaged.

However, muscle weakness is the most common symptom of motor nerve damage. Some of the most common list of symptoms includes:

• Temporary numbness
• Tingling
• Pricking sensations (paresthesia)
• Sensitivity to touch
• Muscle weakness
• Burning pain (especially at night)
• Muscle wasting
• Paralysis
• Gland dysfunction
• Inability to digest food
• Maintain a balanced blood pressure level
• Abnormal level of sweating
• Sexual dysfunction

Causative Factors

Peripheral neuropathy that causes the peripheral neuropathic pain can be either inherited or acquired. Here we briefly explain each one of them:

A) Acquired peripheral neuropathy

Acquired peripheral neuropathies are grouped into three broad categories, as discussed below.

i) Systemic disease

These are the disorders that affect the entire body, causing peripheral neuropathy. These disorders include:

• Kidney disorders
• Diabetes mellitus
• Hormonal imbalances
• Vitamin deficiencies and alcoholism
• Vascular damage and blood diseases
• Connective tissue disorders and chronic inflammation
• Cancers and benign tumors
• Repetitive stress and toxins

ii) Physical injury (trauma)

This is the most common cause of an injury to a nerve. The most frequently observed forms of injury including automobile accidents, falls and sports-related activities could cause nerves to be partially or completely severed, crushed, compressed or stretched.

Broken or dislocated bones can also exert damaging pressure on the neighboring nerves.

iii) Infections and autoimmune disorders

There are various viruses and bacteria that can attack nerve tissues, including herpes varicella-zoster, Epstein-Barr virus, cytomegalovirus and herpes simplex.

These viruses severely damage the sensory nerves, causing attacks of sharp, lighting-like pain.

B) Inherited forms of peripheral neuropathy

These result from the inborn mistakes in the genetic code or by new genetic mutations. The most common inherited neuropathies are a group of disorders referred to as Charcot-Marie-Tooth disease, resulting from flaws in genes responsible for manufacturing neurons or the myelin sheath.

Diagnostic Tools

General physical examination and related tests are often carried out to detect the presence of a systemic disease causing nerve damage.

The main tests include:

• Computed tomography
• Magnetic resonance imaging (MRI)
• Electromyography (EMG)
• Nerve conduction velocity (NCV)
• Nerve biopsy
• Skin biopsy

Treatment Options

The various treatment options for relief from peripheral neuropathic pain include:

A) Medications / Procedures

• Immunosuppressive drugs, such as prednisone, cyclosporine or azathioprine
• Plasmapheresis
• Immunoglobins
• Analgesics
• Antiepileptic drugs
• Tricyclic antidepressants, such as amitriptyline
• Topical patches
• Local anesthetic injections
• Surgical procedures

B) Self-care

• Adopt healthy habits
• Main optimal weight
• Exercise regularly
• Correct vitamin deficiencies
• Reduce alcohol consumption
• Quit smoking
• Use hand or foot braces and orthopedic shoes