BackWards — Unveiling the brain’s topographic organization of paraspinal sensory input
Alexandros Guekos,
David M. Cole,
Monika Dörig,
Philipp Stämpfli,
Louis Schibli,
Philipp Schuetz,
Petra Schweinhardt,
Michael L. Meier
Affiliations
Alexandros Guekos
Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Decision Neuroscience Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), Zurich, Switzerland; Correspondence to: Integrative Spinal Research, Balgrist Campus, Lengghalde 5, 8008 Zurich, Switzerland.
David M. Cole
Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital, University of Zurich, Switzerland
Monika Dörig
Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; School of Engineering and Architecture, Lucerne University of Applied Sciences and Arts, Horw, Switzerland
Philipp Stämpfli
Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital, University of Zurich, Switzerland; MR-Center of the Psychiatric University Hospital, Department of Child and Adolescent Psychiatry, University of Zurich, Zurich, Switzerland
Louis Schibli
Competence Center Thermal Energy Storage, Lucerne University of Applied Sciences and Art, Horw, Switzerland
Philipp Schuetz
Competence Center Thermal Energy Storage, Lucerne University of Applied Sciences and Art, Horw, Switzerland
Petra Schweinhardt
Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), Zurich, Switzerland
Michael L. Meier
Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), Zurich, Switzerland
Cortical reorganization and its potential pathological significance are being increasingly studied in musculoskeletal disorders such as chronic low back pain (CLBP) patients. However, detailed sensory-topographic maps of the human back are lacking, and a baseline characterization of such representations, reflecting the somatosensory organization of the healthy back, is needed before exploring potential sensory map reorganization. To this end, a novel pneumatic vibrotactile stimulation method was used to stimulate paraspinal sensory afferents, while studying their cortical representations in unprecedented detail. In 41 young healthy participants, vibrotactile stimulations at 20 Hz and 80 Hz were applied bilaterally at nine locations along the thoracolumbar axis while functional magnetic resonance imaging (fMRI) was performed. Model-based whole-brain searchlight representational similarity analysis (RSA) was used to investigate the organizational structure of brain activity patterns evoked by thoracolumbar sensory inputs. A model based on segmental distances best explained the similarity structure of brain activity patterns that were located in different areas of sensorimotor cortices, including the primary somatosensory and motor cortices and parts of the superior parietal cortex, suggesting that these brain areas process sensory input from the back in a “dermatomal” manner. The current findings provide a sound basis for testing the “cortical map reorganization theory” and its pathological relevance in CLBP.
