How to distinguish neuropathic pain and inflammatory pain?

Each of us has felt at least one day in his flesh and his spirit: the pain is covered under different sensations, the universe, the other mind, the others. In other words, feeling a pain, “it is having a pain in the body, but it is also suffering emotionally,” one speaks then of an inflammatory pain, or of an attack of the nerves, which is then worth to be at the pain described as neuropathic. To distinguish them is of great importance. Because one and the other pains are not treated. inflammatory pain, the most common, is due to tissue injury (sting, infection …), while neuropathic pain is caused by nerve damage.

how to describe neuropathic pain?

Neuropathic pain is often described as throbbing or burning pain. He can appear alone and he is often chronic. Sometimes it is implacable and severe, and sometimes it comes and goes. This is often the result of nerve damage or dysfunction of the nervous system. The impact of nerve damage is a change in nerve function both at the site of the injury and in the surrounding areas.

An example of neuropathic pain is called phantom limb syndrome. This rare condition occurs when an arm or leg has been removed due to illness or injury, but the brain continues to receive pain messages from nerves responsible for missing limb impulses. These nerves are missing now and are causing pain.

how is neuropathic pain characterized?

“Neuropathic pain significantly alters the quality of life of patients and is characterized by a permanent painful permanent burn with sometimes stab wounds, burns or electric shocks, which may be spontaneous or pain-induced. touch, emotions, tiredness … “

These sensations are usually accompanied by tingling or itching. So many symptoms resulting from an injury or a dysfunction of the nervous system:

At the level of the peripheral nervous system: we distinguish the secondary lesions of the diabetes, the AIDS or the cancers and the traumatic lesions: nerve sections, post-surgical pain then located at the level of the stock or in the “ghost member”, one speaks about algohallucinose) and finally certain chemotherapies.

In the central nervous system (brain): These pains can be caused by a stroke or multiple sclerosis that causes lesions in the areas involved in the transmission and control of pain.

These pains have the bad habit of resisting conventional treatments. Thus, it is not uncommon to see patients in therapeutic failure years before receiving a correct diagnosis … “The diagnosis is based primarily on the interrogation and clinical examination (symptoms mentioned, search for lesions of the system nervous – no “condition of neuropathic pain.

subsequent studies confirm the nature and severity of the nerve injury, particularly if surgery is envisaged.

what are the treatments for neuropathic pain?

Treatments for these difficult cases are usually done in specialized centers for the treatment of pain. There are three main types of treatments that can in some cases be associated:

• Medications: Drug treatment may be based on antidepressants (especially tricyclic antidepressants) and antiepileptics (also known as anticonvulsants). “It goes without saying that the prescription of such compounds requires an explanation of the prescription to the patient. The use of opioid analgesics (derivatives of morphine) remains controversial because the high doses usually required are not without side effects, or cause dramatic analgesic effect “Local anesthetics administered intravenously are sometimes offered as part of hospitalization;

• Non-medicated treatments: Other local treatments such as transcutaneous neurostimulation can provide relief. Frequency high and low intensity, the current (sent via electrodes glued to the skin) activates the nerves of touch that go from the back to the brain, which partially blocks the message of painful fibers.

 “But the effectiveness of this system is too often temporary and its tedious use can discourage some patients”, it should be stressed that “the use of relaxation techniques, cognitive-behavioral therapies or acupuncture can also relieve patient, allowing him to better manage persistent treatments.

• Surgical Solutions: Surgical solutions are reserved for pain resistant to the other supported. Injections of pharmacological substances in the cerebrospinal fluid or in the hyper-selective section of the nerve fibers that lead to painful information (bréotomie) are techniques reserved for a few cases. This is another solution that is sometimes favored by neurosurgeons: medullary stimulation.

how is spinal stimulation done?

The origin of neuropathic pain is explained by the “gate control” theory proposed in 1965 by researchers Melzak and Wall. At the level of the spinal cord, we distinguish:

Nerve fibers of small diameter that transmit the message of pain to the brain;

Large nerve fibers that transmit non-painful information on touch and pressure and have a much faster conduction rate than painless fibers

According to this theory, a portal at the entrance of the spinal cord controls the flow of pain signals to the brain. The body closes the door to these signals by the inhibitory action of other harmless signals. This counter-stimulation is practiced without knowing it, when to reduce the pain, we rub the knee we just hit. But when there is an imbalance in favor of the small caliber fibers and that the messages of pain become predominant, one can face in particular with neuropathic pains. Medullary stimulation is thus intended to deliver electrical impulses to large nerve fibers responsible for tactile sensations and thus block the painful sensations (without eliminating the cause). The system consisting of an electrode and a stimulator is installed in two stages. First, the electrode is implanted under

local anesthesia for the patient to confirm correct positioning. This device is then tested with a portable external stimulator for 10 days to three weeks, in the context of the patient’s usual life. In a second step, the definitive placement of the stimulator can be performed under general anesthesia. The life of the battery is 3 to 5 years.

The results of this technique are closely linked to the good choice of patients (chronic neuropathic pain evolving by convulsions, rebellious to other treatments, confirmation of a nerve injury by complementary examinations, absence of contraindications such as psychiatric disorders, sepsis , addiction or coagulation disorders …). “Such a selection is made in the pain treatment centers and requires in the best case a period of 3 to 4 months between the first consultation and the establishment of a stimulation system.” If the conditions are right, the advantage of this technique 3,4,5,6,7 is a long-lasting pain relief (in 55 to 60% of cases), a decrease in analgesic consumption and a frequent recovery pain.

“Depending on the location of the neuropathic pain, the spinal cord stimulation is not always usable.A new but experimental technique could be an alternative: the central stimulation (at the level of the motor zone of the brain)” before insisting on the need for a true multidisciplinary care “Whatever the technical progress made, the management of neuropathic pain must include a psychological assessment and support, and in this sense, trust between the doctor and the patient is largely a guarantee of the success of these highly specialized treatments “.

What is inflammatory pain?

The first, by far the most common, is referred to as “nociceptive pain specialist”, the name of the receptors that cover the skin, joints, muscles and viscera with variable density. A blow, a pinch, a bite, hot and cold, a toxic substance, inflammation induced by an infection … All this will activate the pain receptors, which come in the form of nerve endings.

Of course, they only react if the stimulation exceeds a certain threshold and the integrity of the tissues they are responsible for monitoring is threatened. Their role is to inform the brain: a warning signal is transmitted by the nerves to different brain structures to decrypt. Then comes a cascade of bodily and psychic reactions, including the release of endorphins, hormones having the same effect as morphine to calm the pain.

favor local treatments

This is why morphine is a medicine used when inflammatory pain becomes acute. But it is not a great help to relieve the other pain, the neuropathic. “For morphine to be effective in these cases, it should be administered in high doses, which goes hand in hand with many side effects, some very dangerous. Aspirin and the anti-inflammatories prescribed when pain is inflammatory will have little effect if the pain is neuropathic. Because it is not triggered by the same mechanisms, since it comes from nerve damage.

 Neuropathic pain can be established “when a nerve is damaged by surgery, shingles, amputation, a tumor …”. What to do in these cases? Local treatments with anesthetic patches, or capsaicin, the active component of pepper, which destroys small nerves, or transcutaneous electrical treatments, should be preferred.

But neuropathic pain can also be more diffuse when it comes from central nervous system damage, and then you have to go to other treatments: antidepressants or antiepileptics, even if there is neither depression nor epilepsy, to modulate the pathways of pain. And indeed, have emphasized, “we will use the morphine or its derivatives that third intention”.

David Brown, a resident of California, has had this difficult experience for 21 years. Operated in 1998, for a lumbago become chronic, it is first relieved, but sees the pain resurface after 3 years. he then resorts to all sorts of treatments to put an end to his sufferings. Without success. Ultimately, appeasement will come from self-hypnosis sessions and the installation of an electrical neurostimulator, a device that cheats the brain and thus alleviates pain, via small electrical shocks. However, his pains have not completely disappeared: “I continue to feel them, but they do not invade me anymore,” he says.

A reality that must accept all those who suffer from chronic, inflammatory, neuropathic or mixed pain …