Neurophysiological Observation of Chronification: System Identification Concepts for Effective Pain Treatment

More effective treatments for chronic pain

This project aims to develop better diagnostic and evaluation methods to enable more efficient therapies for prevention or treatment of chronic pain. Chronic pain is an ubiquitous problem, leading to a severe disease burden and large healthcare costs. It arises from disturbed processes in the central nervous system. Normally, a nerve cell responds to potentially damaging stimuli by sending signals to the spinal cord and brain (central nervous system), resulting in a pain sensation. In the case of chronic pain, the central nervous system does not process the nerve signals properly. Since often the exact malfunctioning mechanism is not known, the current choice for treatments is non-specific and thus not always effective.

Response to electrical pulses
In a previous project a method has been developed which is able to distinguish between different malfunctioning mechanisms underlying chronic pain. A specific set of varying electrical pulses is administered to the nerves and the patient is subsequently asked to report and scale the resulting pain sensation. In the current project, this method will be expanded with objective measurements of the central nervous system’s response by recording the resulting brain activity with 4DEEG techniques. The goal is to visualise how and in what area the stimuli are processed in the brain, to be able to pinpoint problems in the nociceptive system.

Technological challenges
This is not an easy task, however. The electrical stimuli given to the nerves are very small. It is not yet certain whether the result of these stimuli can in fact be detected in the brain. And if they indeed can be detected, it will be another challenge to differentiate the resulting electrical brain signals from the initial pulses administered.

Point-of-care application
Since the focus of the NeuroCIMT programme is on applications which will make it to the clinic, the initially used 128-channel 4DEEG will be reduced towards a point-of-care applicable headset. Furthermore, the actual measurements will have to be as short as possible. These technological challenges will be faced within the scope of the project. Besides technology development, the research will also focus on modelling the expected cortical activity resulting from the nerve stimulation.

Wrist and knee
Eventually a small proof-of-concept study will be performed focusing on patients with chronic pain after wrist fractures and after a specific type of knee surgery. In these studies, the newly developed method will be both applied to determine the cause of the problems, and to evaluate the result of interventions with medicines targeting either the central sensitization, or merely the sensitization of a local region.

Application perspective
Leo Hoogendoorn, CEO Twente Medical Systems International

‘Undergoing an EEG measurement in the current setup has large disadvantages. Patients need to put on a gel-filled cap, and sometimes their skin even gets scratched to improve the electrical conductance. Our company has developed special electrodes, where plain tap water is used and no scratching is required. In this project, we hope to adapt this technology and turn it into a small, energy efficient system to record only the pain related signals in the brain. For us, this project is a way of exploring new application areas, which will hopefully enable us to broaden our market perspective.’

Partners
Centre for Human Drug Research, Delft University of Technology, EuroCept, NociTRACK, Twente Medical Systems International, University of Twente, VU University Medical Center Amsterdam