#45 Exploring Radiation and spatial summation in the context of pain

<p><strong>Does Perceived Spatial Extent Mediate the Spatial Summation of Pain?</strong></p><p>In this episode, recorded live at the Pain Science in Motion Congress in Brussels, we sit down with clinical physiotherapist and researcher Tom Frankenstein. This special episode was brought to you in close collaboration with Pain in Motion. Tom dives into the intriguing findings from his oral presentation, exploring whether the perceived spatial extent of a stimulus mediates the well-known phenomenon of spatial summation of pain (SSp).</p><p><br></p><p>🎙️ Featured Guest: Tom Frankenstein </p><p>Clinical physiotherapist, lecturer, and PhD candidate at the University of Lübeck, Germany. Tom splits his time between managing chronic pain patients in the clinic and conducting advanced research in experimental pain science, aiming to uncover the complex supraspinal mechanisms behind spatial pain perception.</p><p><br></p><p><strong>The Central Question: Spatial Summation &amp; Perception</strong></p><p>Tom explains his research into whether spatial summation of pain (SSp) is driven solely by actual noxious stimulus inputs or if it is significantly mediated by how large a person perceives the painful area to be (perceived spatial extent).</p><p><br></p><p><strong>The Discrepancy of Pain Radiation</strong></p><p>Building on an evolution of research—specifically a 2025 study by Adamczyk et al.—Tom outlines the concept of &quot;pain radiation.&quot; This highlights a massive discrepancy between actual physical stimulus boundaries and a person&#39;s spatial perception, sparking key questions about the underlying brain mechanisms.</p><p><br></p><p><strong>Experimental Setup and Methodology</strong></p><p>The study was conducted in a specialized research laboratory environment at the university with 53 healthy participants. Using a trackball, participants continuously rated both pain intensity and their perceived spatial extent during the application of noxious heat (contact heat) as well as innoxious tactile and warmth stimuli for comparative analysis.</p><p><br></p><p><strong>Uncovering Supraspinal Mechanisms</strong></p><p>While spatial summation is typically a mix of peripheral, spinal, and supraspinal pathways, this project isolates spatial perception as a key supraspinal factor, showing how top-down cognitive and perceptual processing directly influences the experienced intensity of pain.</p><p><br></p><p><strong>Moving Toward Clinical Populations</strong></p><p>With his PhD thesis submission imminent, Tom looks ahead to the future of pain science. He calls for these experimental models to be expanded into clinical populations, noting that conditions like Complex Regional Pain Syndrome (CRPS)—which currently lacks spatial summation studies—low back pain, fibromyalgia, knee osteoarthritis, and polyneuropathy could benefit enormously from clearer spatial perception data.</p><p><br></p><p><strong>References &amp; Resources</strong></p><p>2025 Foundation Paper (Adamczyk et al.):<a href="https://pubmed.ncbi.nlm.nih.gov/39626033/" target="_blank" rel="ugc noopener noreferrer"> PubMed Link</a></p><p>SSp Supraspinal Involvement Studies: </p><p><a href="https://pubmed.ncbi.nlm.nih.gov/36965648/" target="_blank" rel="ugc noopener noreferrer">Exploring Supraspinal Pathways Paper 1</a></p><p><a href="https://pubmed.ncbi.nlm.nih.gov/38300918/" target="_blank" rel="ugc noopener noreferrer">Exploring Supraspinal Pathways Paper 2</a></p><p>Preprint on Clinical Relevance of Spatial Pain:<a href="https://www.medrxiv.org/content/10.64898/2026.04.02.26349577v1" target="_blank" rel="ugc noopener noreferrer"> </a></p><p><a href="https://www.medrxiv.org/content/10.64898/2026.04.02.26349577v1" target="_blank" rel="ugc noopener noreferrer">medRxiv Preprint</a></p><p><br></p><p><strong>Speaker Info &amp; Contact</strong></p><p>ResearchGate Profile:<a href="https://www.researchgate.net/profile/Tom-Frankenstein" target="_blank" rel="ugc noopener noreferrer"> Tom Fra