Pain

Pain is a complex subjective sensation, which has as acute event the character of a warning and beacon signal and can range in intensity from uncomfortable to unbearable. As chronic pain, it has lost the character of the warning signal and is now seen and treated as an independent disease ( chronic pain syndrome).

The annual economic cost of pain as the sum of medical treatments, lost productivity and compensation for disability amount in developed and industrialized countries to around one trillion U.S. dollars.

• 7.1 Nozizeptorenschmerz
• 7.2 Neuropathic pain
• 7.3 pain due to functional disorders
• 7.4 Acute versus chronic
• 7.5 Visceral versus somatic
• 7.6 Transferred pain
• 7.7 Emotional / psychological / social pain

Etymology and Synonyms

The term is derived from the Old High German feminine smerza pain, later isolated smerzo ( masc ), corresponding to MHG smerze, then Smerz. Sense are equal nl. smerte, fries smart (the latter primarily means mental anguish, while the physical pain is expressed by PIN). Related words are engl. smart ( < me. smerte ) " sharp, bitter ," Greek σμερδνός, σμερδαλέος "terrible", lat mordere " bite wound ", slaw smrt, lit. smertis "death."

The obsolete word pain comes as the adjective embarrassing back on MHG pine, pin, OHG Pina. (: Has become Pena, whose ê î in Old High German to Middle Latin pronunciation ) This comes as well from the Latin poena pain english from. The literal translation from the Latin poena, " punishment, punishment, revenge " refers to subjective interpretations of pain.

Medical terminology is Dolor (Latin dolor ) and from the Greek algesia ( antonym: analgesia), as a root - algie, analgesia (all of άλγος algos "pain" ) or odynie (of οδύνη "pain" ).

The recording, transmission and processing of pain stimuli in the nervous system is referred to as nociception. The awareness gerückte perception of sensory stimuli is called perception.

Definition

The International Association for the Study of Pain ( IASP, International Association for the Study of Pain ) defines pain as follows:

" Pain is an unpleasant sensory or emotional experience associated with actual or potential tissue damage or described by affected persons as if such tissue damage the cause. "

The sensation of pain is assumed to be complex interactions between biological, psychological and social factors ( biopsychosocial pain concept ). The pain is therefore a subjective perception, which is not only determined by neural signals of pain nerve fibers, but it is a feeling which is strongly regulated by complex processes (see a Schmerzmodulierung ). Pain is so what the patient feels as such. Because it is a highly subjective perception colored, there may be difficulty understanding between patient and treated, particularly in terms of the degrees of suffering.

Development of pain

After its creation, a distinction Nozizeptorenschmerz, neuropathic pain and functional disorders caused by pain. Pain receptors ( nociceptors ) are free nerve endings of the classes C and A-delta and respond to different types of stimulation:

• Thermal ( heat, cold )
• Chemical

The origin of the pain while running as follows:

All pain mediators excite the nociceptors via specific receptors, namely the free nerve endings that are responsible for pain conduction. Through this excitement it comes to neurogenic reflex, the nociceptors pour Nerve Growth Factor (NGF ) and calcitonin gene-related peptide (CGRP ) from. This has two consequences:

• The nociceptors sensitize themselves and attract so-called sleeping pain receptors in the immediate vicinity. Thus, they increase the pain stimulus and it comes to neurogenic inflammation.
• By NGF nerve fibers are stimulated to sprouting. They grow also in the surrounding tissue. This, and the awakening of dormant receptors cause also adjacent to the tissue damage is sensitive to pain.

Pain receptors require a relatively strong stimulus to be excited. They adapt not, that is, a prolonged stimulus does not result in a reduction of the excitability.

Pain management

The nerve fibers that transmit the pain information, and can slow (C- fibers, 0.5-2 m / s ) can be divided into fast (5-25 m / s A- delta fibers ). C- fibers are evolutionarily older and have no insulating myelin sheath. This explains the reduced nerve conduction velocity. In the spinal cord there is a hand to Reflexverschaltungen that trigger an exodus. Here, the pain has not yet become aware (for example, reflexive withdrawal of the hand before touching the hot stove was perceived as painful ). On the other hand, enters the information on the front line ( spinothalamic tract ) to Ventrobasalkern of the thalamus and from there to the cerebral cortex (cortex ). In the cerebral cortex, the pain is conscious and in the limbic system evaluates emotional. The conscious perception of pain and exact localization of pain is a learning process. In the sensitive cortex, more specifically in the dentate gyrus, there is for each skin area representative and responsible areas (so-called sensitive Homunculus ), by experience, it is a stab in the left little finger also immediately aware as such.

While the interconnection in the spinal cord the pain can be reduced by endogenous substances ( endorphins ). Some painkillers, such as opiates put on at this point.

Schmerzmodulierung

Pain is a subjective perception, which is not determined solely by the neural signals from the pain nerve fibers to the brain. Rather, such as filter processes our central nervous system to ensure that a physical injury is not necessarily pain leads ( Stressanalgesie, for example, are injuries during a traffic accident, competition, in combat or during intercourse often not noticed ) and vice versa pain even without physical can be made damage ( eg phantom limb pain ). In addition, the subjective perception of pain, and this especially in chronic pain conditions, always characterized by cognitive and motivational influences.

Pain can be learned for the body. Recurrent attacks of pain while more intense and longer pain, because there, the pain threshold is lowered. Therefore, an early and adequate pain control with medication is important. Studies have shown that, compared to other countries, pain is often inadequately treated in Germany. This applies not only to patients with cancer pain and after surgery. This is probably due to the deep-rooted and often overvalued fear of dependence on pain medications esp. in the use of opioids in non- cancer pain, back. A comprehensive, interdisciplinary pain management is crucial.

Pain description

The pain is always subjective. Pain descriptions can be divided into affective ( feeling, expressing, eg tormenting, marternd, paralyzing, awful, violent) and sensory ( sensory quality concerning: pungent, oppressive, burning) divide aspects. The affective aspect can be further divided into an immediate emotional component and an emotional long-term component. The doctor asks these in the patient interview and thus obtains evidence of the nature and cause of the pain.

These three qualities are attributed to localization theoretically different brain areas of the so-called pain matrix:

• Sensory component: primary and secondary somatosensory cortex
• Immediate emotional component: the insula cortex and anterior cingulate gyrus
• Long-term emotional component: prefrontal cortex

In particular, in chronic pain conditions, structural changes in the CNS must also be considered as well as changes in the so-called peace networks, such as the Default Mode Network.

Severity

Pain can range from uncomfortable to unbearable. With a self-assessment scale for the assessment of pain can be present in the subjectively comparable range. For example, numerical rating scale (short: NRS ) or the Visual Analogue Scale (VAS ). Furthermore, there is the verbal rating scale on the pain scale: no pain - mild pain - moderate pain - severe pain - maximum pain imaginable are divided. For children still exists a smiley scale that smiling reflects depending on pain intensity to crying faces. In case of external observation, (eg Doloplus scale, Saint -Antoine- QDSA any) via Pain Questionnaire subjective and objective changes capture (muscle tension, movement patterns changed ). Although there is to date no validated scales for it, yet it is important to know the pain - even by patients who can not express themselves - to assess repeated to improve the therapy. In this case, at least two projections are generally required: one before and one during treatment. The relative comparison is meaningful only for the individual patient.

Breakthrough pain

An estimated half of all cancer patients suffering from breakthrough pain. This is according to the European Association for Palliative Medicine is a temporary intensification of complaints in otherwise stable pain conditions.

Types of Pain

The Pschyrembel ( Clinical Dictionary ) divides the pain after its etiology in three forms: 1 Nozizeptorenschmerz, 2nd neuropathic pain, pain due to functional disorders 3. Psychosomatic pain belong to the third group. There are also various other inputs and subdivisions of pain.

Nozizeptorenschmerz

This pain is caused by excitation of pain receptors ( nociceptors ) by the threat or actual injury of body tissue. This can be traumatic, inflammatory or neoplastic. He is consciously perceived by forwarding the pulse to the central nervous system.

Neuropathic pain

The cause of neuropathic pain is an injury to or compression of the peripheral or central ( spinal cord, brain) nervous system. These include, for example, pain caused by amputation ( phantom limb pain ), spinal cord injury, viral infectious disease or polyneuropathy. Depending on the character can neuropathic pain in neuralgiform ( paroxysmal, einschießend ) or kausalgiform ( burning, dull ) can be distinguished. The neuropathic pain include evoked pain and deafferentation pain.

Under evoked pain refers to pain, which by inadequate stimuli ( stimuli that normally cause no pain ) to be triggered. Including allodynia and hyperalgesia.

Neuralgia refers to a nerve pain in the area supplied by one (or more ) nervous spreads (see a neuralgia).

Can Deafferent pain with complete transection of large nerves ( eg amputation) or nerves (eg, a transverse lesions of the spinal cord ). The cause is an absence inhibiting A-beta fibers. These are nerve fibers for pressure and touch sensitivity. About interneurons in the spinal cord to inhibit the transmission of pain. If off this inhibition, it may be a hyperactivity of not more inhibited neurons.

When central pain the pain originates in the central nervous system (see a central pain).

Pain due to functional disorders

This group includes pain, which are not caused by injury, but by defective function of sub-systems of the body. These include, inter alia, migraine due to circulatory dysregulation, back pain. Due to wrong posture of the body as well as pain with psychosomatic causes

Reflex pain caused by errors in control circuits. Often, this results in a vicious circle, whereby the pain become self-reinforcing. An example are caused by muscle tension pain. This lead to a further muscular tension and to further pain.

Psychosomatic pain: As is known from Psychosomatics, different mental states can cause physical symptoms. Such pain usually not or only poorly responsive to traditional pain medications. A change of lifestyle and psychosomatic therapy usually achieve significantly better results.

Acute versus chronic

With regard to the duration of pain can always be categorized into acute and chronic.

Acute pain is a time- limited pain, which is perceived as a response to the above-mentioned development of pain and pain transmission. He has the character of a warning and beacon signal, which can be a guiding for diagnosing the cause. In addition to a generally effective analgesic therapy following the diagnosis of the causal therapy is crucial both to treat the underlying cause as well as for pain therapy.

Chronic pain is a time- prolonged pain, but the exact time frame has been defined in various ways, typically three to twelve months. Prolonged pain may develop into a chronic pain illness (own clinical significance ). The pain then have lost their control and warning function. This pain disorder is defined in addition to the organic by the psychosocial changes consequent that must be included in the integrative treatment of pain.

Chronic pain has - in contrast to acute - almost never a single trigger or entertaining cause, they are multi-causal. The pain therapy concept follows logically on the bio-psycho- social model, which alone it is clear that the one-sided treatment with analgesics is the chronic pain patients do not meet alone.

Examples are certain headaches and back pain ( even after several operations ), stump and phantom limb pain, postherpetic neuralgia, trigeminal neuralgia, cancer pain, sympathetic maintained, called post-operative and post-traumatic pain. From a neurobiological perspective as psychosomatic chronic non-malignant pain can also be an expression of mental disorders or certain life or childhood experiences, which is mapped on a neurobiological level.

Primary chronic pain, for example, migraine, cluster headache, trigeminal neuralgia, stump and phantom pain, thalamic pain and cancer pain. Especially with such pain and the acute pain that can not be eliminated after the expected time, treatment measures must be taken to have a preventive effect, ie to counteract the development of pain disease.

Visceral versus somatic

When abdominal pain is often differentiated into visceral and somatic pain. Visceral, ie originating from the internal organs pain, are usually dull, cramping or colicky. An accurate localization is usually difficult. Persons with visceral pain is often restless and roll around in bed. The transmission takes place via the unmyelinated C- fibers.

For somatic abdominal pain, the origin of the pain is an irritation or injury to the peritoneum, more parietal peritoneum. He is described as a sharp and / or burning pain duration, whose localization is usually quite possible. People often take a rest and posture and movements try to avoid if possible.

Transferred pain

A special phenomenon is the transmitted pain. Since the internal organs by means of segmental spinal nerves (whose viszeroafferenter share ) are innervated, but due to the rarity of the event and the lack of knowledge regarding the localization of the actual pain site, a learning process hardly takes place, are pain from internal organs from the brain to areas of the skin ( dermatomes ) or muscle ( myotome ) assigned the corresponding spinal nerve. These areas on the surface are referred to by Sir Henry Head as Headsche zones. These do not always coincide with the localization of the corresponding organ, but an approximate local application is the rule.

Emotional / psychological / social pain

Various studies show that strong emotions (eg, sadness, relationship crises or separation from a partner ) activate similar brain regions as physical pain.

Social pain, eg as a result of loss experience or rejections shows in terms of its affective processing and more neural overlaps with physical pain because differences. Similar findings can be collected due to recent imaging studies, if we - without feeling even pain - the pain of the other perceive in situations that trigger pain, hear, for example, (human ) pain sounds or presented visually get (so-called pain empathy).

Assessment of chronic pain

On 31 May 2012 the guideline of AWMF for medical assessment of people with chronic pain has been updated. The assessment of pain is an interdisciplinary medical task. It serves to unify and quality assurance of the assessment for applicants of a pension or compensation which complain as symptom pain.

In the gutachtlichen situation are simplified three categories of pain to be distinguished:

• Pain as an accompanying symptom of a physical disorder with the subgroups " Usual pain " as an accompanying symptom of a physically tangible disease or nerve damage.
• " Exceptional pain " eg stump and phantom pain or
• As part of a " complex regional pain syndrome " ( CRPS).

The expert's assessment is mainly based on answering two questions:

• Are the defendants pain and related disorders " without reasonable doubt " detectably ( " consistency check " )?
• If the detected malfunctions caused by " reasonable effort of will " at least partially overcome ( "Examination of voluntary controllability " )?

Are pain-related dysfunction detected, the expert has this in general to quantify. In line with the categories of chronic pain syndromes thereby following differences:

• Pain as an accompanying symptom of tissue damage or disease.
• Pain related to tissue damage / disorder with psychological comorbidity.
• Pain as a symptom of mental illness.

See also Tübingen sheet for the detection of pain behavior

Pain treatment

The Algesiology is the science that deals with the diagnosis, prevention and treatment of chronic pain and pain diseases. The specific treatment of chronic pain and pain diseases is also called pain management. The modern pain therapy integrated in the respective individual treatment concept, various methods, such as psychotherapy, physiotherapy, pharmacotherapy, therapeutic local and conduction anesthesia. It includes physically and mentally activating method. Prerequisite for treatment is a careful analysis of pain.

Pain theories

Past pain theories

In antiquity, Aristotle saw the center of the senses in the heart, and accordingly he located there, also the center of the pain sensation. This theory remained effective through the reception of Aristotle in the Middle Ages through the ancient world beyond. In contrast, Hippocrates of Kos was considered according to the humoral imbalance of " humors " (eg, blood, lymph, black and yellow bile, water) as a cause of pain. There were also from anatomical studies of prisoners be -derived findings.

One finds the ancient pain theories in their main positions gathered in Cicero font Tusculanae Disputationes. There Cicero defines pain as " rough movement in the body, which is rejected by the senses " ( asper motus in corpore, alienus a sensoribus; Tusc disp II, 35. . ), After which the pain is not a mental state. Incoming criticized Cicero in the books III and IV according to his subdivision of physical pain ( dolor ) and the specific emotion of grief ( aegritudo ) especially the pleasure or pain doctrine of Epicurus as well as the pain theory of the Stoics, because both schools of philosophy commend only cognitive awareness techniques and therefore choose the wrong starting point. Culture Historically noteworthy is Cicero's catalog ( Tusc. disp II, 34-41. ) Of persons who in his opinion actually manages an endurance of pain: Spartan, Roman soldiers, hunters, sportsmen, gladiators.

Within the Christian traditions of pain in the context of sin and guilt is made, since the original plan of creation God provides no place for pain. After teaching Christian theology, the people had in paradise supernatural gifts of the full integrity and health ( dona integritatis, in detail, the donum immortalitatis, impassibilitatis, scientiae, perfecti dominii ), for example, a freedom from suffering of the body and the outer misfortune ( donum impassibilitatis; cf. Saint Augustine, City of God XIV 10.26; . Aquinas, Summa theologiae I, qu 97, art 2. ). Only by the offense committed by the people fall occurs, the pain or the Schmerzempfänglichkeit into the world of man. In Christianity, refers to the understanding and management of pain, which always adheres a moment of Unverstehbaren, on the sufferings of Christ, the suffering of the Virgin Mary ( see especially the Stabat mater dolorosa sequence ), to biblical models (esp. Job ) and to the example of the saints and martyrs. A Christian special shaping is the suffering mysticism. Pope John Paul II, who himself to life end seriously ill, wrote in 1984 the Apostolic Letter " Salvifici Doloris. About the Christian meaning of human suffering " as a theological meditation on the pain.

In the 17th and 18th centuries, certain mechanistic explanations understanding of pain. So Descartes explained in his essay De homine pain management, by comparing the nerves with a rope, on which hangs a bell. The pain stimulus ( A) caused a train at the nerve terminus (B ), which is passed through the nerve cable ( C) into the brain (F ), where the train is registered as a pain signal. He also gave the appearance of phantom pain for the first time a physiological explanation. According to him, this would arise by the ending amputation stump nerves continue to function as if the limbs were still intact. Despite such scientific approaches nevertheless remained almost quack methods in vogue, such as the " pulling out " of pain with the invented and patented by the American physician Elisha Perkins called " Perkins Tractors" in the actual treatment of pain.

In the 19th century, new theories of the cause of pain were formulated in research. So put Moritz 1856, the ship called " specificity theory " on. Thus, pain is a specific sensory experience that is forwarded on specific neural pathways. As a counter- theory to Wilhelm Heinrich Erb developed in 1874 the " summation theory," which states that any stimulus can be perceived as pain, if it is only as intense.

The relationship to pain is subject to the social role understanding. Pain is endured differently in different situations and depending on membership in particular social groups. A cultural presentation explains voluntarily endured pain to a salvation -bringing suffering. Depending on the mythological background of lossy extract the Ursippe is quoted to the promised land for it, for example, saved the cultural or physical survival of the people and role models has.

At the time of initiation, a ritual of traditional societies, the enduring of added pain is indispensable and has something liberating, because it receives the initiates in the group of initiates. The Hamar in southern Ethiopia are a people who are insured through collective infliction of pain its cultural identity.

In addition to physical pain, there are also emotional pain. The Jewish culture knows, for example, the concept of Tzar Gidul Banim, who describes the pain and tension, to be raised by the parents, the children, accompanied commonplace, for example through illness, death or the insubordination of these children.

Modern theories of pain

• Pattern theory ( Sinclair, 1955)
• Neuro theory ( Hedway, 1961)
• Gate Control Theory ( Melzack & Wall, 1965)
• Primal theory ( Arthur Janov deals in his oeuvre with both neurological and psychological aspects of pain processing. )