What a pain – why differentiation matters. A story about research with a view, frozen limbs and the PD – PCS

Jonathan Hunger1, Florian Brugger2, Georg Kägi2,3, Jens Carsten Möller4, 5, 6, 7, Nathalie Hollenstein1,  David H Benninger8, 9, 10, Michele Tinazzi11, Julien F Bally, Roman Gonzenbach1, Daniel Ciampi de Andrade12, Santiago Perez Lloret13, 14, Veit Mylius1, 4, 15

  1. Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
  2. Department of Neurology, Kantonsspital, St. Gallen, Switzerland
  3. Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
  4. Department of Neurology, Philipps University, Marburg, Germany
  5. Parkinson Center, Center for Neurological Rehabilitation, Zihlschlacht, Switzerland
  6. Service of Neurology and Stroke Unit, HFR Fribourg-Cantonal Hospital, Fribourg, Switzerland
  7. Service de Neuroréadaptation, HFR Meyriez-Murten, Meyriez, Switzerland
  8. Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
  9. Center for Parkinson and Movement Disorders, Reha Rheinfelden, Switzerland
  10. Department of Neurology, University of Basel, Basel, Switzerland
  11. Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy
  12. Department of Health Science and Technology, Faculty of Medicine, Center for Neuroplasticity and Pain (CNAP), Aalborg University, Aalborg, Denmark
  13. Instituto Universitario de Ciencias de la Salud, Fundación H.A Barceló, Consejo de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
  14. Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
  15. Department of Neurology, Kantonsspital Graubünden, Chur Switzerland

Background

Although it seems intuitive that a medical condition defined by postural abnormalities and movement disorders may cause and aggravate pain, this most common non – motor symptom in Parkinson’s Disease (PD) has thus far not been sufficiently classified and categorised.  Based on the research  - oriented medical expertise of several neurological departments in Switzerland, Parkinson’s Disease Pain Classification System (PD - PCS) was developed to guide clinical diagnostic and support specific treatment strategies. In the meanwhile, this diagnostic tool has been internationally recognised to make a validated distinction between pain associated with Parkinson’s disease and pain caused by other medical conditions. 

Objectives

Starting from a brief overview of current findings on the underlying different mechanism of so called nociceptive, neuropathic and nociplastic pain, the PD-PCS classification system and its relevance in clinical practice will be outlined. Subsequently, actual study results from “Distinction and mutual influences between Parkinson’s Disease-related and unrelated Chronic Pain” will be presented to highlight clinical applications, limitations and further questions of the research topic.

Methods

Presentation of the research journey towards - and results of a cross-sectional, national, multicenter study involving 120 patients with Parkinson’s disease using the PD – PCS to differentiate between PD related and unrelated chronic pain.

Results

Chronic pain affects over 90 % of PD patients and has a relevant impact on their quality of life.  By assessing periods of either low or high dopaminergic stimulation, the PD – PCS criteria allow to differentiate between PD related and PD – unrelated pain. It therefore proofs valuable to advance personalised treatment strategies, including pharmacological, non‑pharmacological, and invasive approaches.

Conclusion

The findings emphasis the relevance of distinguishing underlying pain mechanisms to adjust clinical treatment strategies. Given the high prevalence of pain in the general population, this approach might by also of broader interest beyond the specific condition of Parkinson’s Disease.

To overview