Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The "disinhibited" brain: New findings on CRPS - RUB physicians report in "Neurology"

21.09.2011
The Complex Regional Pain Syndrome (CRPS), also known as Morbus Sudeck, is characterised by "disinhibition" of various sensory and motor areas in the brain.

A multidisciplinary Bochum-based research group, led by Prof. Dr. Martin Tegenthoff (Bergmannsheil Neurology Department) and Prof. Dr. Christoph Maier (Bergmannsheil Department of Pain Therapy), has now demonstrated for the first time that with unilateral CRPS excitability increases not only in the brain area processing the sense of touch of the affected hand. In addition, the brain region representing the healthy hand is simultaneously "disinhibited". The researchers report the new findings in the renowned journal "Neurology".


The figure shows fMRI signals of a CRPS patient´s somatosensory cortex after stimulation of the affected and unaffected hand compared to a healthy subject. While fMRI activation is smaller in the affected side, the diagram shows disinhibition of paired-pulse SEPs in both hemispheres of CRPS patients - although only one hand is affected

The "disinhibited" brain

New findings on CRPS – a disease characterized by severe pain
Changes to the nervous system: RUB physicians report in "Neurology"
The Complex Regional Pain Syndrome (CRPS), also known as Morbus Sudeck, is characterised by "disinhibition" of various sensory and motor areas in the brain. A multidisciplinary Bochum-based research group, led by Prof. Dr. Martin Tegenthoff (Bergmannsheil Neurology Department) and Prof. Dr. Christoph Maier (Bergmannsheil Department of Pain Therapy), has now demonstrated for the first time that with unilateral CRPS excitability increases not only in the brain area processing the sense of touch of the affected hand. In addition, the brain region representing the healthy hand is simultaneously "disinhibited". The group has been performing research on and treatment of CRPS for a number of years. The researchers report the new findings in the renowned journal "Neurology". The study was supported by the Research Funds of the Deutsche Gesetzliche Unfallversicherung (DGUV).

Is there a predisposition for CRPS?

CRPS can develop after even slight injuries and often leads to long-lasting severe pain, impairment of sensation and movement, as well as changes to the skin and the bones of the affected extremity - in many cases it even causes permanent disability. The precise cause of the syndrome is not known. Alongside inflammatory phenomena, changes in the brain also contribute to the disease becoming chronic. "Although the symptoms are mainly limited to one side of the body, some changes in the brain appear to affect both sides - a finding which could hint at an individual predisposition for the development of CRPS“, says Prof. Martin Tegenthoff.

Faulty programming in the brain

As yet, the origins of the disease remain largely unclear. Pain researchers assume that not only inflammatory factors, but also changes in the central nervous system may be a possible cause. For example, in a number of studies researchers found the representation of the affected hand on the brain’s "body map" to have shrunk, a phenomenon closely associated with the patients' pain intensity and tactile discrimination abilities.

Excitability changes on both sides

In a previous study, the Bochum group already made an astonishing discovery in the motor system of CRPS patients: the excitability of their motor hand area in the brain is increased - not only in the half of the brain controlling the affected side, but also in the half correlating to the healthy side. Following these findings hinting at a systemic disorder of the central nervous system, in the current study the group examined whether bilateral disinhibition can also be found in the brain area processing the sense of touch (somatosensory cortex). CRPS patients with unilateral symptoms of the hand were examined. After an electrical stimulation, the researchers measured the brain waves in the somatosensory brain area of the affected and the unaffected hand. Results show: the reduction of inhibition which is found on both sides in CRPS is not limited to motor areas. Those areas of the brain that process sensory perception of the hands exhibit distinct changes too.

"Disinhibition": typical of neuropathic pain

The scientists validated these findings by comparing CRPS patients with healthy volunteers and with patients suffering from pain that – in contrast to CRPS – was not caused by a disease of the nerves (so-called non-neuropathic pain). Here too, the researchers found an amazing result: the control patients showed no altered inhibition whatsoever in the hand area, they did not differ from the healthy volunteers. "This shows that the disinhibition of the brain in CRPS patients appears to be specific for neuropathic pain“, says Prof. Tegenthoff.

Systemic changes raise questions

The results indicate that the changes in the central nervous system caused by CRPS are much more complex than scientists have assumed up to now. Bilateral changes in the central sensorimotor systems that manifest in unilateral symptoms raise questions - for example: are they a cause or a consequence of the disease? The RUB scientists are presently undertaking a first approach at answering this question: in a long-term study they will accompany the patients to perform two further measurements in intervals of six months between dates. In this way, they can relate potential changes in the brain to the healing process. If a successful therapy reverses these changes, they are most probably a consequence of the disease.

Factoring in the brain

"Our research results make clear that changes in the brain play a prominent role in CRPS", says Prof. Dr. Christoph Maier. "As we already do in current pilot studies performed in the Department of Pain Therapy at Bergmannsheil, future therapies should take this aspect into account, in order to improve the treatment of what continues to be a problematic illness."

Title

Lenz M, Höffken O, Stude P, Lissek S, Schwenkreis P, Reinersmann A, Frettlöh J, Richter H, Tegenthoff M, Maier C.: Bilateral somatosensory cortex disinhibition in complex regional pain syndrome type I. Neurology. 2011 Sep 13;77(11):1096-101. Epub 2011 Aug 31.

Further information

Prof. Dr. Martin Tegenthoff, Neurological Department and Out-Patients',BG-Universitätsklinikum Bergmannsheil, Tel. +49 234 302 6810, martin.tegenthoff@rub.de

Prof. Dr. Christoph Maier, Department of Pain Therapy, BG-Universitätsklinikum Bergmannsheil, Tel. +49 234 302 6366, christoph.maier@rub.de

Editorial: Jens Wylkop

Dr. Josef König | idw
Further information:
http://www.ruhr-uni-bochum.de/

More articles from Life Sciences:

nachricht Nesting aids make agricultural fields attractive for bees
20.07.2017 | Julius-Maximilians-Universität Würzburg

nachricht The Kitchen Sponge – Breeding Ground for Germs
20.07.2017 | Hochschule Furtwangen

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>