Feeling pain at some point is something that happens to everyone.
We hit ourselves, cut ourselves or simply make a bad gesture and our nervous system quickly detects and informs us that there is injured tissue and causes us that undesirable and annoying aversive sensation that we call pain. Undesirable but adaptive, since it warns us that something is wrong and allows us to act to remedy it.
However, Sometimes the pain appears without there being a real problem and stops having a meaning.or, as occurs in people with neuropathic pain.
The sensation of pain is a mechanism of our body, mainly somatosensory.which detects the presence of a stimulation or situation that is damaging or has the potential to damage our tissues. And it not only affects us on a physical level, but also on an emotional and mental level. The perception of pain allows us to launch a series of actions and behaviors that will make us distance ourselves from the harmful stimulus or prevent it from harming us. It is therefore a mechanism of innate origin although modifiable through experience and habit that allows our survival and prevents our death and incapacitation.
Thus, although we know pain primarily through the subjective experience it produces, we must keep in mind that this phenomenon It is not something that only exists for us, in our imagination.. In fact, as much as we are the first interested in not suffering pain, this comes from a material process that can be objectively investigated through observation and measurement. Thanks to this we know certain objective and verifiable aspects about pain in general and neuropathic pain in particular; Otherwise we couldn’t say anything about it.
What we know about this physiological and psychological process
At a neurological level, pain is experienced due to the activation of a series of receptors present in the vast majority of our body.the nociceptors, which are activated when broken, pinched or intensely pressed and send signals to the nervous system.
Specifically, the signal is sent through fibers and ganglia to the posterior horn of the spinal cord, with which they communicate through the use of glutamate and what is known as substance P. The cord will cause an immediate response in the form of a reflex while sending the pain signal to the brain (the best-known pathway being the spinothalamic tract).
However, not always when there is an injury we will feel pain, as there is a circuit of nerve fibers that can inhibit the transmission of signals. This circuit is visible when the level of pain decreases when we rub an injured area or its surroundings. Depending on whether the excitatory or inhibitory pain pathways are activated or not, we will end up perceiving a painful sensation. Furthermore, once the injury is perceived, the brain proceeds to send endorphins that counteract the painful perception, allowing us to ignore the pain and focus on fighting or escaping the stimulus.
This would be the process that would normally lead to the perception of pain, but as we have said There are people who feel pain without any stimulus that should produce it, people who suffer from neuropathic pain. What happens in these cases?
Neuropathic pain: what is it and how does it occur?
Neuropathic pain is known as the type of pain that appears in situations and contexts in which there is no stimulation that is intense or harmful enough for pain perceptions to appear. Stimuli that do not normally cause pain do. Thus, small friction and even some generally pleasant contacts such as a caress or a kiss can become a real ordeal for people with this type of problem, since their nervous systems perceive them as extremely painful.
The type of pain experienced can vary enormously depending on the cause of the damage and the level of involvement and reactivity of the nerve pathways. It is very common for it to appear in the form of burning pain, that is, as if suffering from a burn, or in the form of pricks or stings. In some cases, numbness in the area may also appear. The pain can be maintained continuously over time or appear and disappear.
Neuropathic pain poses serious difficulties for those who suffer from it, maintaining a high level of discomfort and frustration. Many people with this type of pain may end up suffering from anxiety disorders or severe depression, in some cases with suicidal ideation. It is not uncommon for them to avoid leaving their home as much as possible, avoid physical contact with other people and actively limit their social, family and work life, being a very disabling condition. It also causes sleep problems, which in many cases causes great fatigue and stress..
The reason for this disorder is the presence of damage to the somatosensory system, with damage to the nerve bundles that transmit somesthetic information to the brain. This damage can be located at both the central and peripheral nervous systems. As a consequence, the neurons that transmit pain become hyperexcitable and react with a smaller amount of stimulation, and sometimes even without any real stimulation.
Damage to nerve pathways that causes neuropathic pain can come from a wide variety of disorders. and conditions, with neuropathic pain receiving different names depending on its cause.
1. Neurodegenerative diseases
When neuropathic pain occurs due to damage to the nerve pathways It is logical to think that disorders in which there is an alteration or degeneration of the nerves this type of problem may appear. Thus, both in diseases such as multiple sclerosis and in some dementia processes, pain linked to nerve degeneration may appear.
2. Diabetes mellitus
People who suffer from diabetes mellitus can develop alterations in the nervous pathways over time.when the nerves weaken as a result of vascular alterations or lack or excess of glucose in the blood. In this case we would be talking about painful diabetic neuropathies. The most common is diabetic peripheral neuropathy, in which there are paresthesias, burning or cooling sensations, loss of sensitivity and pain in the extremities.
3. Poor nutrition
The absence of sufficient nutrients in the body can cause nerve cells to alter and weaken.eventually causing the peripheral nerves to end up reacting abnormally.
4. Viral infections: Herpes and HIV
Some viral infections can cause an alteration in the nerve pathways that can lead to neuropathic pain.. It is common in the case of the shingles virus, in which pain usually appears in both the torso and the face.
Also in the case of acquired immunodeficiency syndrome or AIDS, caused by HIV, a degeneration of the nervous tissue may appear that can cause pain of this type to appear.
5. Tumors
Some cancers and tumors can damage nerve pathwaysboth due to the direct effect of the tumor and by producing a possible pinching of the fibers that conduct painful information.
6. Trauma, hemorrhage and ischemic accidents
Whether due to partial or complete asphyxiation of the neurons or their impingement with other parts of the body, strokes and head injuries In many cases they can be the source of neuropathic pain.
Treatments
The treatment of neuropathic pain is complex and requires a multidisciplinary approach.. It is a chronic disorder, although it is possible to reduce the patient’s pain and greatly improve their quality of life.
Sometimes the reason causing the pain can be treated more or less directly and prevent permanent damage to the nervous tissue from occurring, as in some cases of diabetes. Some of the treatments contemplated are the following.
The use of antidepressants is common to alleviate both the level of pain and its psychological effects. However, they should be used with caution, since The aim is to reduce the level of pain and not sedate the patient..
In the case of antidepressants, it has been proven that those that have an effect that regulates the level of pain are those that affect both serotonin and norepinephrine, which is why SNRIs such as duloxatin are usually used with some success. They seem to work especially well in some cases of neuropathic pain resulting from diabetes.
2. Anticonvulsants
The medications used to treat epilepsy have also proven to be very useful against neuropathic pain, both in cases derived from sclerosis and viral infections, diabetes or others. For example, Carbamazepine is used as the treatment of choice for trigeminal neuralgia.one of the most painful disorders that affects the nerves of the face.
3. Opioids and cannabinoids
As with the pain caused by some types of cancer, in the case of neuropathic pain, substances such as morphine have been used, marijuana or other derivatives of opium and cannabis to help reduce and manage pain level.
4. Other substances: Capsaicin
In addition to those already mentioned, it has been found that other substances such as capsaicin can help combat paineither orally or applied cutaneously or subcutaneously.
5. Transcranial magnetic stimulation
Stimulation of the nervous centers and the somatic system It has been shown to reduce the pain level of patients with this problem.
6. Surgery
If the cause of the pain is localized and its performance is feasible, corrective surgery can be applied to help improve and remedy the problem. As a last resort, ablation of damaged nervous tissue could be performed..
In addition to this, at a medical level it is possible to block the damaged nerve pathway, either by infiltration of drugs or by radiofrequency.
7. Psychotherapy
Neuropathic pain often causes patients to engage in maladaptive coping strategies. to deal with day-to-day events, as well as anxiety and depression problems. Psychological treatment and psychotherapy can contribute greatly through programs and therapies that help to confront and learn how to manage pain, establish appropriate routines and action strategies, and facilitate the expression and communication of emotions and sensations that their condition produces.
8. Physiotherapy
Rehabilitation and physical conditioning of the patient can help make them less sensitive to pain and improve your quality of life, being able to reduce the intensity and frequency of pain and improving your state both physically and emotionally.
