The soul is the nervous system

08/16/1999 00:00

Chronic pain affects body and soul

Dipl. Biol. Barbara Ritzert Press work
Working group of the scientific medical societies

Brain researchers, physicians and psychologists can now prove on many levels what chronic pain can do in the body and soul of affected people. Such insights form the basis of new treatment concepts to prevent chronic pain or to alleviate persistent pain. Pain researchers, doctors and psychologists will discuss this at a satellite symposium of the Vienna World Pain Congress in Heidelberg.

At the beginning the nervous system changes, then other bodily functions and the psyche are impaired: Chronic pain takes possession of the whole person. What happens in the organism when the "barking watchdog of health", the acute pain, loses its warning function and becomes permanent torture, scientists have discovered in recent years. Because the changes are detectable today on many levels: in the genome of nerve cells, in the production of brain messenger substances (neurotransmitters), in the communication of cells and cell associations, in the activity of the brain and in the psyche. This means that the highly subjective feeling of "pain" can be objectified by the researchers. "You can see and quantify pain," says Professor Walter Zieglgänsberger from the Max Planck Institute for Psychiatry in Munich.
If nerve fibers conduct a strong pain stimulus from the body to the nerve cells of the spinal cord, "the devil" breaks loose in the system within fractions of a second: The cells release messenger substances such as the substance P (P = pain) or glutamate, and ion channels open which " "Gate" of the cells, calcium flows in. Via complex signal cascades, messenger substances activate certain enzymes that increase the cells' susceptibility to further stimuli. Binding sites (receptors) on the cell surface for messenger substances can thus be activated more easily and their production is ramped up.
But at the same time this turmoil is dampened in a healthy organism: the brain sends inhibitory signals and nerve cells produce the body's own pain relievers, the opiate-like endorphins and substances that are similar to cannabinoids. If this body's own defense against pain is strong enough and if there are no further pain impulses, the system comes to rest and the memory trace in the nervous system fades within days to weeks.
Vicious circle: when the nervous system intensifies the pain
On the other hand, persistent and severe pain leads to a real vicious circle: when the nerve cells in the spinal cord "fire" without a break, more calcium flows into the cells. The result: the transmission of stimuli from the pain-conducting nerve pathways to the transmission points (synapses) to the neurons is upregulated. In technical jargon this is called "potentiating the synaptic transmission strength". "You can compare it to turning up an amplifier in the music system," says Professor Jürgen Sandkühler from the University of Heidelberg, translating this process into everyday experience. "If the constant firing of the neurons is not broken early by adequate pain treatment," explains the expert, "the process becomes independent because the body's own pain inhibition alone can no longer control this mechanism." The nerve cells become hypersensitive and report the signal "pain" even to harmless, weak stimuli, even if the actual cause of the pain no longer exists.
The constant bombardment changes the processing of pain and the reflection of body areas in the brain (see press release no. 2) "and at some point," says Zieglgänsberger, "the pain image is burned into the nervous system". Similar to the processing of other sensory stimuli, the system has "learned" pain.
But the fateful pain cascade not only affects the nervous system: The link between the nervous and immune systems via messenger substances, for example, also means that substance P, for example, intensifies inflammatory processes or triggers it itself. "Substance P also acts as an inflammatory messenger," explains Professor Manfred Zimmermann. So a so-called "neurogenic inflammation" can arise, which can "plug" itself onto an already existing inflammation in the body and intensify it. "We observe such mechanisms," says Zimmermann, "not only in rheumatic diseases, but also, for example, in inflammatory diseases of the intestinal tract, such as Crohn's disease."
Scientists from the University in Aalborg, Denmark, report at the Heidelberg Symposium, for example, that patients with soft tissue rheumatism (fibromyalgia) or irritable bowel syndrome are more sensitive to painful stimuli than healthy people due to such mechanisms.
Pain and Psyche, Psyche and Pain
It is obvious that the painful turmoil in the nervous system also affects the psychological functions of a person, his zest for life and his performance. But in the meantime psychologists have found out that these processes are not a one-way street: How a person deals with pain also plays a major role in the chronification of pain. "Because psychological processes, too," explains Zimmermann, "ultimately influence pain processes via neurotransmitters and nerve signals." It is therefore not surprising that psychologists, such as Professor Monika Hasenbring from the University of Bochum, have discovered certain behavioral reactions in pain patients as risk factors for chronification. For example, people who react to pain with helplessness or disaster, who limit their social and physical activities or who act as "cheerful perseverers" ("grit their teeth and through") have a high risk of persistent pain.
For these reasons, the experts agree, pain must not only be treated early and adequately with medication, but also with psychological and behavioral strategies. Because these too ultimately - similar to medicinal products - influence the biochemistry of the pain system.

Questions to:
Prof. Dr. med. Jürgen Sandkühler
II. Physiological Institute
University of Heidelberg
In Neuenheimer Feld 326
69120 Heidelberg
Tel .: 06221-54-4052
Tel .: 06221-54-4692 (secretariat)
Fax: 06221-54-4047
e-mail: [email protected]

Prof. Dr. med. Walter Zieglgänsberger
Max Plank Institute for Psychiatry
Kraepelinstrasse 2
80804 Munich
Tel .: 089 - 30622-1 (head office)
Tel .: 089 - 30622-350
Fax: 089 - 30622-402
e-mail: [email protected]

Prof. Dr. Dr. h.c. Manfred Zimmermann
II. Physiological Institute
University of Heidelberg
In Neuenheimer Feld 326
69120 Heidelberg
Tel .: 06221-54-4050 or 4051
Fax: 06221-54-6364
e-mail: [email protected]

Criteria of this press release:
Medicine, Nutrition / healthcare / nursing
transregional, national
Miscellaneous scientific news / publications, Scientific conferences