Circuits of pain memory in chronic pain patients
The project will examine the neural circuitry of memory functions in chronic pain patients and how they relate to the memory of pain. Pain memory circuits will then be modulated using transcranial magnetic stimulation in order to interfere with pain chronicity. This project should enable a better understanding of the interactions between pain and memory functions and could potentially help to reduce pain symptoms in chronic pain.
Markers of cortical reorganisation in Complex Regional Pain SyndromeAn altered limb or body schema is a hallmark of CRPS, but the efficacy of physical therapies aimed at restoring normal body perception varies between individuals, with poorer efficacy in the chronic stage. Earlier recognition of CRPS in the acute phase is likely to improve long-term outcomes. Hence, there is a clear need to identify perceptual abnormalities that are specific and predictive of CRPS to facilitate early diagnosis and treatment. This study aims to investigate cortical correlates of perceptual abnormalities and develop a novel biomarker, based on repetition suppression of somatosensory ERPs, to improve clinical recognition of CRPS.
Epigenetics and pain - uncovering the mechanisms
Patients carrying single gene mutations resulting in congenital analgesia provide a unique opportunity to identify critical mechanisms in pain processing and novel targets for analgesic drugs. This project will use fibroblast-derived sensory neurons from such a patient to study whether their epigenetic profile is altered with respect to healthy controls. The results will help contribute to a growing body of evidence suggesting that epigenetic mechanisms are important for the evolution of persistent pain.
The attentional effects of peripheral and trigeminal pain in healthy subjects and patients with post-herpetic neuralgiaPain is a biologically relevant stimulus that interferes with cognition. Identifying factors that modulate this interruptive function of pain is essential to therapeutically overcome the maladaptive attentional demands of chronic pain. This project investigates differential effects of peripheral and trigeminal pain on episodic memory in healthy subjects and patients suffering from post-herpetic neuralgia. We will use an established visual encoding paradigm to test site-specific effects of acute pain (face vs. arm; affected vs. unaffected body site) on memory performance. To further examine long-term effects of persistent clinical pain, patients’ neuropsychological functioning will be retested after 6 months.
Adaptive plasticity in the discrimination of noxious stimuliThroughout our life, experience shapes how our brain process sensory events. For instance, we can become more efficient at discriminating sensory stimuli when we receive feedback on performance. This ability, called perceptual learning, is essential for survival, and is mediated by adaptive and durable changes in brain regions that process the information that is learned. This project combines psychophysics and neuroimaging to investigate how adults learn to discriminate sensory features of noxious stimuli, such as their intensity and spatial location.
Cortical and peripheral beta oscillations in painBeta oscillations are suppressed during the anticipation of somatosensory innocuous stimuli. This project will explore the possibility of using beta oscillations recorded at the cortical and muscular level to: i) characterize, in normal volunteers, the activity during the anticipation of nociceptive stimuli; ii) examine, in chronic pain patients, whether beta oscillation suppression before the administration of somatosensory stimuli could be used to measure changes in the state of the somatosensory system associated with chronic pain.
Breaking dogmas: a neurophysiological and neuroimaging study showing that non-nociceptive Aβ-fibres mediate paroxysmal pain in healthy humansThis study aims at testing whether the selective activation of non-nociceptive Aβ-fibres can produce paroxysmal pain and activate nociceptive related brain areas in healthy humans. To do so it is planned to assess whether a high-frequency, low-intensity electrical stimulation, selectively activating Aβ-fibres, can induce electrical-shock like pain and whether this pain persists during selective block of nociceptive fibres. Then, using functional MRI it is planned to verify whether this type of electrical stimulation can activate nociceptive related brain areas, such as the periaqueductal grey.