16/11/2023 
CHUV | Auditoire Mathias Mayor
17:00 - 18:00
After a spinal cord injury, there is rapid atrophy of the spinal cord beyond the lesion, with evidence of disruption of the corticospinal tracts and reductions in somatotopically distinct gray matter regions of sensory and motor cortices. Patients with spinal cord injuries often experience neuropathic pain below the lesion level that is difficult to manage. The below-level pain is perceived in regions of anesthesia or hypoesthesia and is commonly described as sharp, burning, electrical, stabbing, or pins-and-needles. Since below-level pain persists despite complete (surgically transected) spinal lesions, it has been considered a form of phantom pain.
- First, evidence will be presented that Cognitive Multisensory Rehabilitation (CMR), an intervention aimed at improving body awareness to reduce pain and improve sensorimotor recovery, led to significant neuropathic pain reduction and strengthened resting-state parietal operculum connectivity.
- Second, evidence from a surgical treatment study will be presented, indicating that neuroelectrically guided DREZ microcoagulation alters a medial prefrontal-somatosensory-limbic network that is separate from classical pain pathways, suggesting that below-level SCI pain originates in hyperactive dorsal root entry zones and can be relayed to the brain via the sympathetic ganglion chain.
- Third, preliminary results in another form of phantom experience, tinnitus, will be discussed. Results from our second clinical trial on a form of auditory mirror therapy for tinnitus will be presented. The hope is to then have a larger discussion on potential models for how we react to deprivation of sensory stimuli and whether multisensory integration mechanisms can be a treatment target.
Dr. Linnman is a psychologist trained in Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) with 15 years of experience in multimodal imaging of pain and negative affect. In his work, he has used PET with multiple tracers to define monoaminergic, peptidergic and inflammatory aspect of clinical pain and clinical anxiety. He has further used fMRI and PET-fMRI combined to study pavlovian conditioning mechanisms for defining emotional circuits in psychiatric disease states. He is currently developing state of the art fMRI, PET and simultaneous PET-MR to visualize and quantify nociceptive processes, from peripheral lesions —via CNS changes in structure, function and receptor expression — to behavioral consequences.
Dr. Linnman also has experience in neuroimaging of animal models of spinal cord injury, as well as extensive expertise in MRI and PET of SCI and other complex neurological-, pain-, and psychiatric conditions.