What is the Difference Between Nociceptive and Neuropathic Pain?

There are two main types of pain, known as nociceptive and neuropathic pain. Each of these has particular characteristics that define the type of pain and the ideal way in which it should be managed.

This article consists of an overview of both of nociceptive and neuropathic pain, followed by the distinct differences in their cause and management.

Nociceptive Pain

Nociceptive pain is the most common type of pain and is caused by the detection of noxious or potentially harmful stimuli by the nociceptors around the body.

Nociceptors are receptors that are specifically designed to detect stimuli that may cause harm to the body, which may be mechanical, chemical or thermal in nature. For example, they may sense when there is physical damage to the skin, muscles, bones or connective tissue in the body, or when they are exposed to toxic chemicals or extreme temperatures.

They usually have a high threshold, but when they are activated, they send electrical signals of pain to the central nervous system and the brain to deliver the perception of pain.

Neuropathic Pain

Neuropathic pain is associated with damage to the neurons in the body, following an infection of injury to the area, resulting in messages of pain being sent to the central nervous system and brain regardless of noxious stimuli.

This type of pain is often described as shooting pain, as it travels along the nerves in an abnormal manner causing abnormal sensations of pain. Some patients with neuropathic pain report a constant sensation of pain, whereas other experience intermittent episodes, which may or may not be aggravated by stimuli or touch.

Differentiating Causative Factors

The cause of nociceptive and neuropathic pain is a significant differentiating factor between the two types and is important to understand the appropriate management techniques for each.

Nociceptive pain occurs when nociceptors in the body detect noxious stimuli that have the potential to cause harm to the body. This includes mechanical pressure, chemical toxins and extreme temperatures, all of which may harm the body. The receptors then send electrical signals via the nervous system to the brain, leading to the perception of pain.

Neuropathic pain is caused by damage to the neurons that are involved in the pain signaling pathways in the nervous system. There are a variety of circumstances that may lead to nerve damage, including certain infections, diabetes and surgery, among many others.

Differentiating Management Factors

As the pathology of nociceptive and neuropathic pain differs considerably, the recommendations in the management of the pain contrast accordingly.

For nociceptive pain, the first-line management is with pharmacological analgesic medication, such as paracetamol, ibuprofen and aspirin. For more severe pain, prescription medications such as opioids can often help to provide effective pain relief. These medications have different mechanisms of actions but all help to disrupt the transmission of pain signals from the nociceptors to the brain.

For neuropathic pain, the aim of the treatment is to relieve the pain caused by damage to the nerves. In most cases, analgesic medications are unable to provide effective relief and, instead, the nerves themselves must be targeted. Neurostimulation therapy is used to excite the nervous tissue in the central nervous system, altering the conductivity of the nerves and often helping to relieve symptoms.

References

• http://www.medscape.org/viewarticle/489495_4
• http://www.ajmc.com/journals/supplement/2006/2006-06-vol12-n9suppl/jun06-2326ps256-s262/
• http://www.ncbi.nlm.nih.gov/pubmed/17718686