Painful sensations acute pain with. Internal organs - what hurts? Discomfort in the legs

Chapter 2. Pain: from pathogenesis to drug selection

Pain is the most frequent and subjectively complex complaint of patients. In 40% of all primary visits to the doctor, pain is the leading complaint. The high prevalence of pain syndromes results in significant material, social and spiritual losses.

As discussed above, the classification committee of the International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or described in terms of, existing or potential tissue damage." This definition emphasizes that the sensation of pain can occur not only with tissue damage, but even in the absence of any damage, which indicates important role mental factors in the formation and maintenance of pain.

Pain classification

Pain is a clinically and pathogenetically complex and heterogeneous concept. It differs in intensity, localization and in its subjective manifestations. The pain can be shooting, pressing, throbbing, cutting, and also constant or intermittent. All the existing variety of pain characteristics is largely related to the very cause that caused it, the anatomical region in which the nociceptive impulse occurs, and is very important for determining the cause of pain and subsequent treatment.

One of the most significant factors in understanding this phenomenon is the division of pain into acute and chronic (Fig. 8).

acute pain- this is a sensory reaction with the subsequent inclusion of emotional-motivational vegetative and other factors in violation of the integrity of the body. The development of acute pain is associated, as a rule, with well-defined painful irritations of superficial or deep tissues and internal organs, dysfunction smooth muscle. Acute pain syndrome develops in 80% of cases, has a protective, preventive value, as it indicates “damage” and forces a person to take measures to find out the cause of pain and eliminate it. The duration of acute pain is determined by the recovery time of damaged tissues and/or impaired smooth muscle function and usually does not exceed 3 months. Acute pain is usually well relieved with analgesics.

In 10-20% of cases sharp pain becomes chronic, which lasts more than 3-6 months. However, the main difference between chronic pain and acute pain is not the time factor, but qualitatively different neurophysiological, psychophysiological and clinical relationships. Chronic pain is not protective. chronic pain in last years began to be considered not only as a syndrome, but also as a separate nosology. Its formation and maintenance depends to a greater extent on the complex psychological factors rather than on the nature and intensity of peripheral nociceptive effects. Chronic pain may persist after the healing process is complete, i.e. exist regardless of damage (presence of nociceptive influence). Chronic pain is not relieved by analgesics and often leads to psychological and social maladjustment of patients.

One of possible causes, contributing to the chronicity of pain, is a treatment that is inadequate to the cause and pathogenesis pain syndrome. Elimination of the cause of acute pain and / or its most effective treatment is the key to preventing the transformation of acute pain into chronic pain.

Importance For successful treatment pain has a definition of its pathogenesis. Most common nociceptive pain, arising from irritation of peripheral pain receptors - "nociceptors", localized in almost all organs and systems ( coronary syndrome, pleurisy, pancreatitis, gastric ulcer, renal colic, articular syndrome, damage to the skin, ligaments, muscles, etc.). neuropathic pain occurs as a result of injury various departments(peripheral and central) somatosensory nervous system.

Nociceptive pain syndromes are most often acute (burns, cuts, bruises, abrasions, fractures, sprains), but can also be chronic (osteoarthritis). With this type of pain, the factor that caused it is usually obvious, the pain is usually clearly localized (usually in the area of damage). When describing nociceptive pain, patients most often use the terms "compressive", "aching", "throbbing", "cutting". Good in the treatment of nociceptive pain therapeutic effect can be obtained by prescribing simple analgesics and NSAIDs. When the cause is eliminated (cessation of irritation of the “nociceptors”), nociceptive pain disappears.

The causes of neuropathic pain can be damage to the afferent somatosensory system at any level, from peripheral sensory nerves to the cerebral cortex, as well as disturbances in descending antinociceptive systems. With damage to the peripheral nervous system, pain is called peripheral, with damage to the central nervous system - central (Fig. 9).

Neuropathic pain that occurs when various parts of the nervous system are damaged is characterized by patients as burning, shooting, cooling, and is accompanied by objective symptoms of nerve irritation (hyperesthesia, paresthesia, hyperalgesia) and / or impaired function (hypesthesia, anesthesia). A characteristic symptom of neuropathic pain is allodynia - a phenomenon characterized by the occurrence of pain in response to the action of a painless stimulus (stroking with a brush, cotton wool, temperature factor).

Neuropathic pain is characteristic of chronic pain syndromes of various etiologies. At the same time, they are united by common pathophysiological mechanisms for the formation and maintenance of pain.

Neuropathic pain responds poorly to standard analgesics and NSAIDs and often leads to severe maladjustment of patients.

In the practice of a neurologist, traumatologist, oncologist, there are pain syndromes, in the clinical picture of which symptoms of both nociceptive and neuropathic pain are observed - “mixed pain” (Fig. 10). Such a situation can occur, for example, when a tumor compresses the nerve trunk, irritation of the intervertebral hernia of the spinal nerve (radiculopathy), or when the nerve is compressed in the bone or muscle canal ( tunnel syndromes). In the treatment of mixed pain syndromes, it is necessary to influence both, nociceptive and neuropathic components of pain.

Nociceptive and antinociceptive systems

Today's ideas about the formation of pain are based on the idea of the existence of two systems: nociceptive (NS) and antinociceptive (ANS) (Fig. 11).

The nociceptive system (is ascending) provides pain conduction from peripheral (nociceptive) receptors to the cerebral cortex. The antinociceptive system (is descending) is for pain control.

At the first stage of pain formation, pain (nociceptive) receptors are activated. An inflammatory process, for example, can lead to the activation of pain receptors. This causes the conduction of pain impulses to the posterior horns of the spinal cord.

At the segmental spinal level, modulation of nociceptive afferentation occurs, which is carried out by the influence of descending antinociceptive systems on various opiate, adrenergic, glutamate, purine and other receptors located on the neurons of the posterior horn. This pain impulse is then transmitted to the overlying parts of the central nervous system (thalamus, cerebral cortex), where information about the nature and location of pain is processed and interpreted.

However, the final perception of pain is highly dependent on the activity of the ANS. ANS of the brain play a key role in the formation of pain and change in response to pain. Their wide representation in the brain and their inclusion in various neurotransmitter mechanisms (norepinephrine, serotonin, opioids, dopamine) are obvious. ANS do not work in isolation, but, interacting with each other and with other systems, they regulate not only pain sensitivity, but also autonomic, motor, neuroendocrine, emotional and behavioral manifestations of pain associated with pain. This circumstance allows us to consider them as essential system, which determines not only the characteristics of pain sensation, but also its diverse psychophysiological and behavioral correlates. Depending on the activity of the ANS, the pain may increase or decrease.

Pain medications

Drugs for the treatment of pain are prescribed taking into account the alleged mechanisms of pain. Understanding the mechanisms of pain syndrome formation allows for individual selection of treatment. For nociceptive pain the best side non-steroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics have proven themselves. In neuropathic pain, it is reasonable to use antidepressants, anticonvulsants, local anesthetics and potassium channel blockers.

Non-steroidal anti-inflammatory drugs

If the mechanisms of inflammation play a leading role in the pathogenesis of the pain syndrome, then the most appropriate in this case is the use of NSAIDs. Their use makes it possible to suppress the synthesis of algogens in damaged tissues, which prevents the development of peripheral and central sensitization. In addition to the analgesic effect, drugs from the NSAID group have anti-inflammatory and antipyretic effects.

The modern classification of NSAIDs involves the division of these drugs into several groups that differ in selectivity for type 1 and type 2 cyclooxygenase enzymes, which are involved in a number of physiological and pathological processes (Fig. 12).

It is believed that the analgesic effect of drugs from the NSAID group is associated mainly with their effect on COX2, and gastrointestinal complications are due to their effect on COX1. However, recent studies reveal other mechanisms of analgesic action of some drugs from the NSAID group. So, it was shown that diclofenac (Voltaren) can have an analgesic effect not only through COX-dependent, but also other peripheral, as well as central mechanisms.

Local anesthetics

Restrictions on the flow of nociceptive information into the CNS can be achieved with the use of various local anesthetics, which can not only prevent the sensitization of nociceptive neurons, but also contribute to the normalization of microcirculation in the area of damage, reduce inflammation and improve metabolism. Along with this, local anesthetics relax the striated muscles, eliminate pathological muscle tension, which is an additional source of pain.
Local anesthetics include substances that cause a temporary loss of tissue sensitivity as a result of blockade of the conduction of impulses in nerve fibers. Most widespread among them received lidocaine, novocaine, articaine and bupivacaine. The mechanism of action of local anesthetics is associated with the blocking of Na + channels on the membrane nerve fibers and inhibition of the generation of action potentials.

Anticonvulsants

Long-term irritation of nociceptors or peripheral nerves leads to the development of peripheral and central sensitization (hyperexcitability).

The current anticonvulsants used to treat pain have different points of application. Difenin, carbamazepine, oxcarbazepine, lamotrigine, valproates, topiromate act mainly by suppressing the activity of voltage-dependent sodium channels, preventing spontaneous generation of ectopic discharges in the damaged nerve. The effectiveness of these drugs has been proven in patients with trigeminal neuralgia, diabetic neuropathy, phantom pain syndrome.

Gabapentin and pregabalin inhibit the entry of calcium ions into the presynaptic terminal of nociceptors, thereby reducing the release of glutamate, which leads to a decrease in the excitability of spinal cord nociceptive neurons (reduces central sensitization). These drugs also modulate the activity of NMDA receptors and reduce the activity of Na + channels.

Antidepressants

Antidepressants and drugs from the opioid group are prescribed to enhance antinociceptive effects. In the treatment of pain syndromes, drugs are mainly used, the mechanism of action of which is associated with the blockade of the reuptake of monoamines (serotonin and norepinephrine) in the central nervous system. The analgesic effect of antidepressants may also be partly due to indirect analgesic effects, as improvement in mood favorably affects pain assessment and reduces pain perception. In addition, antidepressants potentiate the action narcotic analgesics, increasing their affinity for opioid receptors.

Muscle relaxers

Muscle relaxants are used in cases where muscle spasm contributes to the formation of pain. It should be noted that muscle relaxants act at the level of the spinal cord and not at the level of the muscles.
In our country, tizanidine, baclofen, midokalm, as well as drugs from the benzodiazepine group (diazepam) are used to treat painful muscle spasms. IN Lately In order to relax the muscles in the treatment of myofascial pain syndromes, injections of botulinum toxin type A are used. The drugs presented different points applications. Baclofen is a GABA receptor agonist that inhibits the activity of interneurons at the spinal level.
Tolperisone blocks Na + - and Ca 2+ -channels of interneurons of the spinal cord and reduces the release of pain mediators in spinal cord neurons. Tizanidine is a muscle relaxant central action. The main point of application of its action is in the spinal cord. By stimulating presynaptic a2 receptors, it inhibits the release of excitatory amino acids that stimulate N-methyl-D-aspartate receptors (NMDA receptors). As a result, at the level intermediate neurons in the spinal cord, polysynaptic transmission of excitation is suppressed. Since it is this mechanism that is responsible for excessive muscle tone, when it is suppressed, muscle tone decreases. In addition to muscle relaxant properties, tizanidine also has a central moderate analgesic effect.
Initially, tizanidine was developed for the treatment of muscle spasm in various neurological diseases (with traumatic injuries of the brain and spinal cord, multiple sclerosis, stroke). However, soon after the start of its use, the analgesic properties of tizanidine were revealed. Currently, the use of tizanidine in monotherapy and in the complex treatment of pain syndromes has become widespread.

Selective Neuronal Potassium Channel Activators (SNEPCO)

A fundamentally new class of drugs for the treatment of pain syndromes are selective activators of neuronal potassium channels - SNEPCO (Selective Neuronal Potassium Channel Opener), which affect the processes of sensitization of posterior horn neurons due to stabilization membrane potential rest.

The first representative of this class medicines- flupirtine (Katadolon), which has a wide range valuable pharmacological properties that distinguish it from other painkillers.

The following chapters provide details on pharmacological properties and the mechanism of action of Katadolon, the results of studies of its efficacy and safety are presented, the experience of using the drug in different countries world, recommendations are given on the use of Katadolon in various pain syndromes.

PAIN. EXTREME CONDITIONS

Compiled by: Doctor of Medical Sciences, Professor D.D. Tsyrendorzhiev

Candidate of Medical Sciences, Associate Professor F.F. Mizulin

Discussed at the methodological meeting of the Department of Pathophysiology "____" _______________ 1999

Protocol No.

Lecture plan

I.PAIN, MECHANISMS OF DEVELOPMENT,

GENERAL CHARACTERISTICS AND TYPES

Introduction

Since time immemorial, people have looked at pain as a harsh and inevitable companion. Not always a person understands that she is a faithful guardian, a vigilant sentry of the body, a constant ally and an active assistant to the doctor. It is pain that teaches a person caution, makes him take care of his body, warning of imminent danger and signaling illness. In many cases, pain allows you to assess the degree and nature of the violation of the integrity of the body.

"Pain is guard dog health,” they said in ancient Greece. And in fact, despite the fact that pain is always painful, despite the fact that it depresses a person, reduces his efficiency, deprives him of sleep, it is necessary and useful to a certain extent. The feeling of pain protects us from frostbite and burns, warns of imminent danger.

For a physiologist, pain is reduced to an affective, emotional coloring of sensation caused by a rough touch, heat, cold, blow, prick, injury. For a doctor, the problem of pain is solved relatively simply - this is a warning about dysfunction. Medicine considers pain in terms of the benefits that it brings to the body and without which the disease can become incurable even before it can be detected.

Defeating pain, destroying in the bud this sometimes incomprehensible "evil" that haunts all living things is a constant dream of mankind, rooted in the depths of centuries. Throughout the history of civilization, thousands of means have been found to relieve pain: herbs, medicines, physical effects.

The mechanisms of pain sensation are both simple and extremely complex. It is no coincidence that disputes between representatives of different specialties studying the problem of pain still do not subside.

So what is pain?

1.1. The concept of pain and its definitions

Pain- a complex concept that includes a peculiar sensation of pain and a reaction to this sensation with emotional stress, changes in the functions of internal organs, motor unconditioned reflexes and volitional efforts aimed at getting rid of the pain factor.

Pain is realized by a special system of pain sensitivity and emotional structures of the brain. It signals about the effects that cause damage, or about already existing damage resulting from the action of exogenous damaging factors or the development of pathological processes in tissues.

Pain is the result of irritation in the system of receptors, conductors and centers of pain sensitivity at different levels of the uneven system. The most pronounced pain syndromes occur when the nerves and their branches of the sensory posterior roots of the spinal cord and the roots of the sensory cranial nerves and the membranes of the brain and spinal cord are damaged, and finally, the thalamus.

Distinguish pain:

local pain- localized in the focus of the development of the pathological process;

Projection pain felt along the periphery of the nerve when irritated in its proximal area;

radiating call pain sensations in the region of innervation of one branch in the presence of an irritating focus in the zone of another branch of the same nerve;

Reflected pain arise as a viscerocutaneous reflex in diseases of the internal organs. In this case, the painful process in the internal organ, causing irritation of the afferent autonomic nerve fibers, leads to the appearance of pain in a certain area of the skin associated with the somatic nerve. The areas where viscerosensory pains occur are called Zakharyin-Ged zones.

Causalgia(burning, intense, often unbearable pain) is a special category of pain that sometimes occurs after a nerve injury (often the median nerve is rich in sympathetic fibers). Causalgia is based on partial nerve damage with incomplete conduction disturbance and irritation of autonomic fibers. At the same time, nodes of the border border are involved in the process. sympathetic trunk and optic tubercle.

phantom pains- sometimes appear after amputation of a limb. Pain is caused by irritation of the nerve scar in the stump. Painful irritation is projected by consciousness into those areas that were previously associated with these cortical centers, in the norm.

In addition to physiological pain, there is pathological pain- having disadaptive and pathogenetic significance for the organism. Irresistible, severe, chronic pathological pain causes mental and emotional disorders and disintegration of the central nervous system, often leading to suicidal attempts.

pathological pain has a number characteristic features which are absent in physiological pain.

Signs of pathological pain include:

causalgia;

hyperpathy (preservation severe pain after cessation of the provocative stimulus).

hyperalgesia (intense pain with nocisive irritation of the damaged area - primary hyperalgesia); either adjacent or distant zones - secondary hyperalgesia):

allodynia (provocation of pain under the action of non-nociceptive stimuli, reflected pain, phantom pain, etc.)

Peripheral sources irritations that cause pathologically increased pain may be tissue nociceptors. When they are activated - in inflammatory processes in the tissues; with compression by a scar or overgrown bone tissue of the nerves; under the action of tissue decay products (for example, tumors); under the influence of biologically active substances produced at the same time, the excitability of nociceptors significantly increases. Moreover, the latter acquire the ability to respond even to ordinary, non-notic influences (the phenomenon of sensitization of receptors).

central source pathologically increased pain may be altered formations of the central nervous system that are part of the pain sensitivity system or modulate its activity. Thus, aggregates of hyperactive nociceptive neurons that form HPUV in the dorsal organ or in the caudal nucleus of the trigeminal nerve serve as sources that involve the pain sensitivity system in the process. This kind of pain of central origin also occurs with changes in other formations of the pain sensitivity system - for example, the reticular formations of the medulla oblongata, in the thalamic nuclei, etc.

All these pain information of central origin appear under the action on the indicated formations during trauma, intoxication, ischemia, etc.

What are the mechanisms of pain and its biological significance?

1.2. Peripheral mechanisms of pain.

Until now, there is no consensus on the existence of strictly specialized structures (receptors) that perceive pain.

There are 2 theories of pain perception:

Proponents of the first theory, the so-called "specificity theory", formulated at the end of the 19th century by the German scientist Max Frey, recognize the existence of 4 independent perceiving "devices" in the skin - heat, cold, touch and pain - with 4 separate systems for transmitting impulses to the CNS.

Adherents of the second theory - the "intensity theory" of Goldscheider compatriot Frey - admit that the same receptors and the same systems respond, depending on the strength of the stimulation, to both non-painful and painful sensations. The feeling of touch, pressure, cold, heat can become painful if the stimulus that caused it is too strong.

Many researchers believe that the truth is somewhere in between, and most modern scientists recognize that pain is perceived by the free endings of nerve fibers that branch into surface layers skin. These endings can have a wide variety of shapes: hairs, plexuses, spirals, plates, etc. They are pain receptors nociceptors.

Pain signal transmission is transmitted by 2 types of pain nerves: thick myelinated type A nerve fibers, through which signals are transmitted quickly (at a speed of about 50-140 m / s) and thinner unmyelinated type C nerve fibers - signals are transmitted much more slowly (at a speed of approximately 0.6-2 m / s). The corresponding signals are called fast and slow pain. Fast burning pain is a reaction to injury or other damage and is usually strictly localized. Slow pain is often a dull pain sensation and is usually less clearly localized.

Pain from a medical point of view

From a medical point of view, pain is:

reaction on this sensation, which is characterized by a certain emotional coloring, reflex changes in the functions of internal organs, unconditioned motor reflexes, as well as volitional efforts aimed at getting rid of the pain factor.
an unpleasant sensory and emotional experience associated with real or perceived tissue damage, and at the same time the reaction of the body, mobilizing various functional systems to protect it from pathogens.

Prolonged pain is accompanied by a change in physiological parameters (blood pressure, pulse, dilated pupils, changes in hormone concentration).

International definition

Nociception is a neurophysiological concept that refers to the perception, conduction and central processing of signals about harmful processes or influences. That is it physiological mechanism transmission of pain, and it does not affect the description of its emotional component. Of great importance is the fact that the conduction of pain signals in the nociceptive system itself is not equivalent to felt pain.

Types of physical pain

acute pain

Acute pain is defined as pain of short duration with an easily identifiable cause. Acute pain is a warning to the body about the current danger of organic damage or disease. Often persistent and sharp pain is also accompanied by aching pain. Acute pain is usually concentrated in a certain area before it somehow spreads wider. This type of pain usually responds well to treatment.

chronic pain

Chronic pain was originally defined as pain that lasts for about 6 months or more. It is now defined as pain that stubbornly persists beyond the appropriate length of time during which it should normally end. It is often more difficult to heal than acute pain. Particular attention is required when addressing any pain that has become chronic. In exceptional cases, neurosurgeons may perform complex operation to remove parts of the patient's brain to cope with chronic pain. Such an intervention can save the patient from the subjective sensation of pain, but since the signals from the painful focus will still be transmitted through neurons, the body will continue to respond to them.

Skin pain

Skin pain occurs when the skin or subcutaneous tissues are damaged. Cutaneous nociceptors terminate just below the skin, and thanks to high concentration nerve endings provide a highly accurate, localized pain sensation of short duration.

Somatic pain

Somatic pain occurs in ligaments, tendons, joints, bones, blood vessels, and even in the nerves themselves. It is determined by somatic nociceptors. Due to the lack of pain receptors in these areas, they produce a dull, poorly localized, longer lasting pain than skin pain. This includes, for example, sprained joints and broken bones.

inner pain

Internal pain arises from the internal organs of the body. Internal nociceptors are located in organs and in internal cavities. An even greater shortage of pain receptors in these parts of the body leads to the appearance of more nagging and prolonged pain compared to somatic pain. Internal pain is particularly difficult to localize, and some internal organic lesions are "attributed" pains, where the sensation of pain is attributed to a part of the body that has nothing to do with the site of the injury itself. Cardiac ischemia (insufficient blood supply to the heart muscle) is perhaps the most famous example of pain attributed; the sensation can be located as a separate feeling of pain just above the chest, in the left shoulder, arm, or even in the palm of your hand. The attributed pain may be due to the discovery that pain receptors in the internal organs also excite spinal neurons that are activated by skin lesions. Once the brain associates the firing of these spinal neurons with stimulation of somatic tissues in the skin or muscles, pain signals coming from the internal organs begin to be interpreted by the brain as coming from the skin.

Phantom pain

Phantom limb pain is a sensation of pain that occurs in a lost limb or in a limb that is not felt with normal sensations. This phenomenon is almost always associated with cases of amputation and paralysis.

neuropathic pain

Neuropathic pain (“neuralgia”) may occur as a result of damage or disease to the nerve tissues themselves (for example, toothache). This can interfere with the ability of sensory nerves to transmit correct information thalamus (department diencephalon), and hence the brain misinterprets pain stimuli, even if there are no obvious physiological causes pain.

Psychogenic pain

Psychogenic pain is diagnosed in the absence of an organic disease or when the latter cannot explain the nature and severity of the pain syndrome. Psychogenic pain is always chronic and occurs against the background of mental disorders: depression, anxiety, hypochondria, hysteria, phobias. In a significant proportion of patients, psychosocial factors play an important role (dissatisfaction with work, the desire to obtain moral or material benefits). There are particularly strong links between chronic pain and depression.

pathological pain

pathological pain- altered perception of pain impulses as a result of disturbances in the cortical and subcortical parts of the central nervous system.

Violations can occur at any level of the nociceptive system, as well as when there is a violation of the connection between the nociceptive ascending structures and the antinociceptive system.

heartache

Mental pain is a specific mental experience that is not associated with organic or functional disorders. Often accompanied by depression, mental disorder. More often long and associated with the loss of a loved one.

Physiological role

Despite its nuisance, pain is one of the main components protective system organism. This major signal about tissue damage and the development of a pathological process, a permanent regulator of homeostatic reactions, including their higher behavioral forms. However, this does not mean that pain has only protective properties. Under certain conditions, having played its informational role, the pain itself becomes part of the pathological process, often more dangerous than the damage that caused it.

According to one hypothesis, pain is not specific physical sensation, and there are no special receptors that perceive only pain stimulation. The appearance of a feeling of pain can be caused by irritation of any type of receptor, if the strength of the irritation is high enough.

According to another point of view, there are special pain receptors characterized by high threshold perception. They are excited only by stimuli of damaging intensity. All pain receptors do not have specialized endings. They are present as free nerve endings. There are mechanical, thermal and chemical pain receptors. They are located in the skin and in internal surfaces such as the periosteum or articular surfaces. Deeply located internal surfaces are weakly associated with pain receptors, and therefore the sensations of chronic, aching pain are transmitted only if organic damage has arisen directly in this part of the body.

It is believed that pain receptors do not adapt to external stimuli. However, in some cases, the activation of the pain fibers becomes too strong, as if the pain stimulus continues to recur, leading to a condition called increased pain sensitivity (hyperalgesia). In fact, there are people with different pain thresholds. And this may depend on the emotional and subjective characteristics of the human psyche.

Nociceptive nerves contain small diameter primary fibers with sensory endings in various bodies and fabrics. Their sensory endings resemble small branched bushes.

The two major classes of nociceptors, Aδ- and C-fibers, transmit fast and slow pain sensations, respectively. A class of Aδ-myelinated fibers (coated with a thin myelin sheath) conduct signals at speeds of 5 to 30 m/s and serve to transmit rapid pain signals. This type of pain is felt within one tenth of a second from the moment the painful stimulus occurs. Slow pain, whose signals travel through the slower, unmyelinated ("bare") C-fibers, at a speed of 0.5 to 2 m / s, is aching, throbbing, burning pain. Chemical pain (whether poisoning through food, air, water, accumulation of residues in the body of alcohol, drugs, medicines or radiation poisoning, etc.) is an example of slow pain.

Other points of view

The study of pain has expanded in recent years various areas from pharmacology to psychology and neuropsychiatry. It was previously unimaginable that fruit flies would be used as an object for pharmacological research on pain. Some psychiatrists also try to use pain to find a neurological "substitute" for human awareness, since pain has many subjective psychological aspects besides pure physiology.

Interestingly, the brain itself is devoid of nociceptive tissues, and therefore cannot feel pain. Thus, the headache cannot possibly originate in the brain itself. Some have suggested that the membrane that surrounds the brain and spinal cord, which is called the dura mater, is supplied with nerves with pain receptors, and these dural (related to the dura) are stimulated meninges) nociceptors, and they are likely to be involved in the "production" of headache.

Alternative medicine

Surveys conducted National Center US Complementary and Alternative Medicine (NCCAM) found that pain is a common reason people turn to complementary and alternative medicine. CAM). Among American adults who used C.A.M. in 2002, 16.8% wanted to be treated for back pain, 6.6% neck pain, 4.9% - arthritis, 4.9% - joint pain, 3.1% - headache and 2.4% struggled with recurrent pain.

One such alternative, traditional Chinese medicine, sees pain as a blockage of "Qi" energy, which resembles resistance in an electrical circuit, or as "blood stasis", which is theoretically similar to dehydration, which impairs the body's metabolism. A traditional Chinese practice, acupuncture, has been found to be more effective for non-traumatic pain than for trauma-related pain.

In recent decades, there has been a trend to prevent or treat pain and diseases that create pain with proper nutrition. This approach sometimes consists of taking dietary supplements (BAA) and vitamins in large quantities, which is considered from a medical point of view as a harmful attempt at self-medication. In the works of Robert Atkins and Earl Mindel, much attention is paid to the relationship between the activity of amino acids and the health of the body. For example, they claim that the essential amino acid DL-phenylalanine promotes the production of endorphins and has a non-addictive analgesic effect. But in any case, they urge you to always consult a doctor.

Notes

Links

Virtual reality relieves phantom pain Compulent

Emotional processes
Emotions
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Nocigenic (somatic) pain is pain that occurs when nociceptors of the skin, mucous membranes, deep tissues (in the musculoskeletal system) or internal organs are irritated. The resulting nerve (nociceptive) impulses, following the ascending nociceptive paths, reach the higher parts of the nervous system and are displayed by consciousness, as a result, a sensation of pain is formed. Somatic pain is usually well localized. Examples: pain due to burns, skin damage (scratches, injuries), joint pain, muscle (myofascial) pain, pain due to sprains, bone fractures.

Visceral pain is pain originating from the soft tissues (cavity) of the internal organs. Such pains are the result of irritation of receptors localized in the walls of internal organs. Examples: pain in the heart (with angina), in chest(against the background of colds, tuberculosis), stomach pain ( peptic ulcer), intestines (with constipation), liver (hepatic colic), pancreas (with pancreatitis), kidneys and bladder(renal colic), etc. Neuropathic pain is pain resulting from damage to the peripheral or central nervous system. Such pain is not explained by irritation of nociceptors (the sensation of pain occurs even in healthy organ). Pain is usually noted in response to low-intensity (normally not causing pain) irritants. For example, a light touch, a breath of air, or combing with trigeminal neuralgia causes a "pain volley" in response. Such pain, in particular, may occur in conditions of inflammation, damage to the nerves or other components of the nervous system. Damage to the nerves or the influence of inflammatory factors on them (edema, inflammatory mediators, acidification of the intercellular fluid in the focus of inflammation, etc.) leads to an increase in their sensitivity (excitability) and conductivity. Examples: neuralgia trigeminal nerve(against the background of inflammation), toothache (against the background of infection and inflammation), joint pain (against the background of rheumatoid arthritis), back pain (for example, against the background of a herniated disc in the lumbar region, causing compression of the nerve roots), etc. Psychogenic pain ("phantom", or psychalgia, or somatoform pain) - pain caused by mental, emotional or behavioral factors. Such pain, as a rule, is poorly treatable by conservative methods, in particular with the use of analgesics. In the case of their exact establishment, the appointment of antidepressants and other psychotropic drugs is required. Examples: pain after amputation operations, some cases of headaches, back pain and stomach pain