The 5 differences between nociceptive pain and neuropathic pain
Among the advances and scientific knowledge brought by the 20th century is the detailed description of physiological mechanisms that allow us to experience pain . From there, the latter has been defined taking into account different elements.
For example, according to its cause and specific course, the pain has been divided into three main types: neuropathic, nociceptive and psychogenic . In this article we will see what are the main characteristics of these types, as well as the differences between neuropathic pain and nociceptive pain.
- Related article: "Chronic pain: what it is and how it is treated from Psychology"
Types of pain and their characteristics
According to the International Association for Pain Studies, "pain is an unpleasant sensory and emotional experience with actual or potential tissue damage or described in terms of such damage" (1994).
Depending on their functions and location, this sensory and emotional experience can be classified in the following ways: nociceptive pain, neuropathic pain or psychogenic pain.
1. Nociceptive pain
Also known as somatic pain, nociceptive pain is defined as a normal response of the organism to an offensive stimulus , and its goal is to prevent further damage. It is an adaptive pain, called nociceptive precisely because its main function is to perceive, alert and protect the organism from a noxious stimulus. An example would be to withdraw the hand when we begin to feel a hot object.
This type of pain is understood as an alert mechanism , an alarm signal or as an adaptive reaction to real or apparent noxious stimuli. The latter, the noxious stimuli, are transmitted through messages that are also known as "nociceptive messages". They begin in the periphery and move towards the dorsal horn of the marrow, and then, towards different structures that allow it to reach the thalamus and the cortex (considered the higher centers of pain).
In the same sense, nociceptive pain receptors can be found in the skin, muscles, joints or vicesas. For this reason it is a pain well localized and that the person can write without major difficulty. A persistent experience of nociceptive pain can also cause a series of local sympathetic effects, muscle contractions and postural changes .
- Maybe you're interested: "Nociceptors (pain receptors): definition and types"
2. Neuropathic pain
On the other hand, neuropathic pain is one that is no longer considered an adaptive response, and is characterized by changes in the physiology of the response. This type of pain results from injuries or chronic alterations in peripheral or central nervous ways. It develops before a noxious stimulus, but it can also do without this. For their description, people often use unusual terms, while represents a new and difficult to describe experience .
It can occur through the following forms, which at the same time are part of a hypersensitivity to pain known as hyperpathia:
- Dysesthesia : Basal pain, burning or burning sensation.
- Hyperalgesia : as an excessive or exaggerated response.
- Alodinia : through perceiving any stimulus as painful.
In addition, neuropathic pain can be divided into the following types according to the specific location:
2.1.Pain of central origin
This may be the case, for example, of a cardiovascular accident or multiple sclerosis. Its location is in the central nervous system and It is usually a pain more resistant to treatment .
2.2. Pain of peripheral origin
In this case it is a pain that has a generally favorable response to treatment and that originates in areas of the peripheral nervous system. Over time, this type of neuropathic pain can develop not only as peripheral but central pain, through a process called precisely "centralization" and It is characterized by plastic changes in the posterior horn of the spinal cord .
3. Psychogenic pain
Psychogenic pain refers to psychological experience (eg anxiety or depression) described in terms of tissue damage. This description can be made in both verbal and behavioral terms, regardless of whether the tissue damage has existed or not. It is a pain experience that has its genesis in a psychological state , and that is not locatable in the organic structures of the nervous system.
Differences between neuropathic pain and nociceptive pain
Once the general characteristics of the different types of pain are described, we can explain and summarize some differences between nociceptive and neuropathic pain. We follow Dagnino (1994) in the following five points.
1. The stimulus
In the case of nociceptive pain, the stimulus that causes the pain is evident and easily locatable both by the person who experiences it and by the specialist. In the case of neuropathic pain, there is no obvious stimulus.
2. The location
Related to the above, the place where the pain occurs is easily locatable by the person who experiences it, for which he describes it easily. On the other hand, Neuropathic pain is usually diffuse in location .
3. The description and its characteristics
The experience reported by people with nociceptive pain is often similar. On the other hand, the experience reported by people with neuropathic pain is difficult to report, it seems to be an unusual and different pain, which is why it's more difficult to explain and it can vary between each person.
4. The response to the narcotic
The differences in responses to pharmacological treatment in both cases are also different. While nociceptive pain has reported an effective effect, in the case of neuropathic pain partial relief reported .
5. The response to placebos
Contrary to the above, neuropathic pain usually responds better to placebo treatments, and nociceptive pain responds in a practically ineffective manner. According to Dagnino (1994) the figures are 60% effective in the first case, and 20-30% in the second.
- ChangePain (2018) How is chronic pain defined? Retrieved August 9, 2018. Available at //www.change-pain.org/grt-change-pain-portal/change_pain_home/chronic_pain/insight/definition/en_GB/324800317.jsp.
- Cruciani, R.A., Nieto, M.J. (2006). Pathophysiology and treatment of neuropathic pain: more recent advances. Journal of the Spanish society of pain. 5: 312-327.
- Perena, M.J., Perena, M.F., Rodrigo-Royo, M.D., et al. (2000). Neuroanatomy of pain. Journal of the Spanish Pain Society (7) II: 5-10.
- Dagnino, J. (1994). Definitions and classifications of pain. Bulletin of the School of Medicine. Catholic University of Chile. 23 (3). Retrieved August 9, 2018. Available at //www.arsmedica.cl/index.php/MED/
- IASP (1994). Part III: (pp 209-214). Classification of Chronic Pain, Second Edition, IASP Task Force on Taxonomy, edited by H. Merskey and N. Bogduk, ISAP Press, Seattle, 1994. //www.iasp-pain.org.