Finding the Key to Chronic Pain

Chronic pain is one of the most common medical conditions and has a big impact on the quality of a patient’s life. Yet, it is often difficult to treat. The Clinical Research Priority Program (CRPP) Pain intends to better understand pain mechanisms and improve diagnosis. We asked Michèle Hubli, of the Balgrist University Hospital and group leader of the CRPP, about the research goals.

ZNZ News: What are the aims of the CRPP Pain?
Dr. Michèle Hubli: The overall objective of the CRPP Pain is to gain knowledge about pain mechanisms underlying different chronic pain entities, such as neuropathic pain after spinal cord injury, complex regional pain syndrome, as wells as low back pain. We just don’t have a sound scientific basis of understanding of the individual pathophysiology of pain and this is a prerequisite for improved mechanism-based patient treatment and informed clinical trials. Such personalized targeting of pain mechanisms will be an important step toward precision medicine in pain.

What triggered the start of the CRPP?
The idea of a CRPP on the topic of pain was initiated by the desire to foster collaborations between basic and clinical research in this challenging topic. Prof. Hanns Ulrich Zeilhofer, as a preclinical pain expert, and Prof. Armin Curt, a clinical expert on the topic of neuropathic pain, started the idea of truly translational research on chronic pain. Zurich has a huge expertise in this field and, step-by-step, several collaborators from the University Hospital, the University and ETH Zurich were brought on board for the CRPP Pain.

Why is pain still an unmet medical need?
Pain has a high prevalence, i.e., roughly 20% in the general population suffers from chronic pain. Yet its complex nature means that most treatment is unsatisfactory. Pain arises from the interaction of multiple neural systems along the whole neuraxis, such as peripheral sensory nerves, spinal cord, brainstem and the brain. On top of that, long-ignored interactions of the nervous system with the immune system make major contributions to chronic pain syndromes. Within the scope of the CRPP Pain we try to identify pathophysiological differences and commonalities across different diagnostic chronic pain entities by dissecting the impact of peripheral, spinal and supra-spinal sensitization processes.

What are the biggest challenges in pain research?
Next to the complex nature of pain, one of the biggest challenges in studying pain is the reliance on subjective pain ratings in humans. Pain patients are often asked how intense their pain is rated on a scale from 0 (no pain) to 10 (worst pain imaginable). Expectedly, these psychophysical read-outs measured in clinical or experimental settings are highly variable. In laboratory animals we face even bigger challenges to quantify pain. Classical readout of pain in laboratory animals relies on withdrawal threshold measurements. Even the more sophisticated, recently developed methods are still indirect correlates of the conscious perception of pain that humans can report. Therefore, major attempts are currently made to generate better read-outs for pain in humans and in rodents.

Which groups contribute to the program?
As the CRPP Pain is a truly multi-disciplinary endeavour it requires collaborations between many different clinical and basic science disciplines. The main contributor from the clinical side is Balgrist University Hospital with the Spinal Cord Injury Center (Prof. Armin Curt and myself) and the Departments of Physical Medicine and Rheumatology (Prof. Florian Brunner), Orthopedics (Prof. Mazda Farshad) and Chiropractic (PD Dr. Petra Schweinhardt). The Institute of Pharmacology and Toxicology at University of Zurich (Prof. Ulrich Zeilhofer) has the main lead for the basic research part. In addition, the University Hospital Zurich with the Department of Rheumatology (Prof. Oliver Distler), and the Institute of Complementary and Integrative Medicine (Prof. Claudia Witt), as well as the Institute of Biomedical Engineering, Translation Neuromodeling Unit, University and ETH Zurich (Prof. Klaas Enno Stephan) are part of this CRPP.

What do you hope to achieve in 5 years’ time within the scope of the CRPP?
On a broad perspective, we hope to improve the diagnostic work-up of pain patients in order to unravel the contribution of peripheral, spinal and supra-spinal mechanisms to the clinical presentation of pain. Our ultimate goal is of course to improve the diagnosis and therapy of patients suffering from chronic pain.

For more information visit: CRPP Pain

CRPP Pain Seminar on 31.3.2020 – Find more information here