FOR 2690: Translational Pruritus Research - WP: Central Processing of Inflammatory, Neuropathic and Uremic Pruritus (PRUSEARCH)

Basic data for this project

Description

Magnetic resonance imaging (MRI) is a non-invasive technique to assess brain structure (volumety, white matter integrity) as well as brain function (functional magnetic resonance imaging (fMRI) in humans. MRI studies on pruritus, however, are scarce: to our knowledge there exist no study on alterations in structure and no study that investigated central processing by fMRI during rest and pruritus challenge in patients with uraemic pruritus (UP), brachioradial pruritus (BRP), atopic dermatitis (AD) in chronic scratched skin as compared to healthy controls, respectively. Lacking are also clinically relevant data on the impact of skin properties of patients on central itch processing (lichenified vs non-lichenified itchy skin). Moreover, most fMRI results are based on a few subjects and healthy volunteers and studies comparing representative clinical entities of chronic pruritus with a more clinically relevant itch model are missing (i.e. cowhage-stimulation to activate epidermal CMH fibers).To close this gap we aim here to investigate the influence of skin alterations by chronic scratching (lichenified vs. non-lichenified skin) on the peripheral and central level and to get a deeper knowledge on the functional changes of the peripheral and central nervous system including inhibitory descending pathways and central sensitization. We will perform fMRI in response to cowhage in patients with AD, UP, BRP and healthy controls; perform psychophysical experiments like quantitative sensory testing (QST) and conditioned pain/itch modulation (CPM/CIM) as well as clinical itch assessments. These data will be correlated and analysed in a multimodal approach. In addition, dermatohistiopathological profiles of skin biopsies with special regard to nerve fiber anatomy (project #2) will be correlated with brain responses to experimentally induced itch by cowhage stimulation and psychophysical results. This will enable us to analyze and correlate multiple physiological parameters to clinical data and gain knowledge (together with project #2) on the influence of chronic scratching on the skin, peripheral and central nervous system.