Neuropathic Pain

Pain is often assumed to be caused only by physical injuries such as a broken bone or skin cut and once the injury is healing the pain subsides and eventually disappears. However, nerves can also produce pain and this type of pain can be difficult to manage. It is called neuropathic pain.

Pain caused by nerve damage can be agonising and often fails to improve with time. It can originate from the peripheral and/or central nervous system. Neuropathic pain is often used as an umbrella term to include:

• Phantom limb pain
• Peripheral neuropathy
• Post herpetic neuralgia
• Trigeminal neuralgia
• Complex Regional Pain Syndrome (CRPS)

With neuropathic pain the nerves may be damaged or injured and they send incorrect pain messages to the brain. The cause is often difficult to discover. This sort of chronic pain may result from conditions such as Diabetes, Shingles, and Multiple Sclerosis or from injury, surgery or amputation. Although it can also occur without any of these factors.

Nerve pain is often described as:

• Shooting
• Stabbing
• Burning
• Searing

These pains may be accompanied with:

• Increased skin sensitivity
• Changes in skin temperature and colour
• Muscle weakness
• Loss of feeling
• Swelling and stiffness in the affected joints

In some types of neuropathic pain the diagram shown below may help to establish the area of nerve damage or injury.

Phantom limb pain

Pain in a limb that no longer exists is a common phenomenon after amputation. For some people the phantom limb pain gets better without treatment but for others the management of this pain can be difficult. Phantom pain is more common after the loss of an arm or leg but can also occur after the removal of any body part such as an eye or breast.

To receive the correct treatment for your condition it is important for your doctor or specialist to determine whether you are experiencing phantom limb pain or stump pain.

Phantom limb pain: is pain that feels as if it is in the area of the lost limb
Stump pain: is pain or discomfort felt at the site of amputation

Phantom limb pain is an unfortunate term as it seems to imply that the pain is a psychological rather than a physical problem. In fact the pain may not have a psychological component at all. Although the longer pain continues it is more likely that physical and psychological influences are involved.

Contributing factors to phantom limb pain are thought to be:

• Nerve damage or injury
• Existing pain prior to amputation
• Neuroma, which is a growth containing nerve cells. This can form on the nerve endings in a stump after amputation

If you are experiencing phantom limb pain you may benefit from a pain management programme.

Peripheral neuropathy

The peripheral nervous system includes nerves in the face, legs, arms, torso and some nerves in the skull. It often affects people with diabetes and auto-immune diseases. Certain vitamin deficiencies and alcoholism can also damage the peripheral nerves.

Symptoms will depend upon the cause of a persons’ neuropathy and on which nerve or nerves are involved. These can often begin gradually and are sometimes barely noticeable but for others the symptoms are constant and may be almost unbearable especially at night.

Symptoms may include:

• Pain
• Numbness
• Tingling
• Muscle weakness
• Burning
• Loss of feeling
• Sharp, stabbing pain
• Extreme sensitivity to touch
• Lack of coordination

If you experience any of these symptoms you should consult your doctor.
For others with a diagnosis but who have poor pain control a pain management programme may be beneficial.

Post herpatic neuralgia

This type of nerve pain often happens after a viral infection such as shingles. The pain manifests itself as listed under neuropathic pain. Consult your doctor if you think that you have nerve damage or injury caused by a viral infection. If the pain persists you may benefit from a pain management programme or a review of your medications by a pain specialist.

Trigeminal neuralgia

This type of nerve pain affects the forehead, nose, cheeks, lips, teeth and jaw and can affect the most basic of daily activities such as eating, swallowing, teeth brushing and face washing.

The cause is not completely understood although it can occur when the trigeminal nerve becomes irritated or trapped causing pain to the face. Dental work has been identified as being the most common trigger for trigeminal neuralgia.

Symptoms include:

• Sharp, ‘electric shock’ type pain
• Dull ache
• Sensitivity to touch

If you have any of these symptoms you should consult your doctor who will advise you of the treatment options.

Complex Regional Pain Syndrome (CRPS)

This is a chronic pain condition. The key symptom of CRPS is continuous intense pain which may appear to be out of proportion to the severity of the injury. The pain commonly worsens with time.

CRPS I is often triggered by tissue injury but has no apparent nerve damage.
CRPS II has the same symptoms but is also associated with a nerve injury.

Symptoms include:

• Burning pain
• Increased skin sensitivity
• Changes in skin temperature
• Sweating and swelling of the affected area
• Changes in skin colour and texture
• Changes in nail and hair growth
• Decreased ability to move the affected body part
• Muscle spasm
• Reduced muscle tone
• Continuous pain

The cause of CRPS remains unknown and it is very difficult to diagnose. Diagnosis is usually achieved by ruling out other conditions.

There is no cure for CRPS but pain can be reduced or controlled by using a mixture of symptomatic pain management therapies. If you have been diagnosed with CRPS you and your doctor may decide that you could benefit from consulting a pain specialist. There are many treatment options available which can help you to gain control over this disabilitating pain.