The primary aim of this study is to evaluate the induction of sensory-motor cortex plasticity after motor cortex stimulation in healthy subjects, using laser-evoked nociceptive cortical potentials, and in chronic neuropathic pain patients using functional MRI. As a secondary goal, the project will analyse possible correlations between the magnitude of cortical plasticity and that of the pain-relieving effect. In healthy subjects, cortical plasticity is evaluated by the comparison of somatosensory cortical maps before and after two isolated sessions of 20 Hz and theta-burst rTMS, in a cross-over randomized study. Two sessions of 5 consecutive days of rTMS are proposed to the patients with a minimum of 4 weeks between the two sessions, defined by 20 Hz and theta-burst stimulation in a cross-over randomized order. Cortical plasticity of the motor cortex is evaluated via functional MRI (motor activation) performed before the first rTMS session and the last day of each session of rTMS.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
65
20Hz and Theta Burst stimulation, both at 80% of motor threshold in contralateral intrinsic hand muscles. Five consecutive days of each mode of stimulation, separated by a minimum of 4 weeks. Daily self-monitoring of pain, sleep quality and fatigue by mans of a 10-item questionnaire
Service d'Exploration, Centre Hospitalier Lyon Est, Hospices civils de Lyon, Lyon, F-69495, France et NeuroPain lab - CRNL (Inserm U1028 - UCBL)
Bron, France
cortical plasticity induced by rTMS - - Somatosensory evoked potentials
Assessment of plastic changes induced in sensori-motor cortex by the application of repetitive magnetic stimulation in healthy subjects and chronic pain patients. * In healthy subjects, mapping of cortical responses amplitude and source reconstruction techniques (dipole modelisation, BESA) before / after a single rTMS session * In chronic pain patients, contrast analysis between extent and location of motor activations (to hand, foot and mouth contraction) before / after one week of daily rTMS, analysed with Statistical Parametric Mapping (SPM12)
Time frame: just before the isolated 20 Hz or theta-burst stimulation for healthy subjects
cortical plasticity induced by rTMS - - Somatosensory evoked potentials
Assessment of plastic changes induced in sensori-motor cortex by the application of repetitive magnetic stimulation in healthy subjects and chronic pain patients. * In healthy subjects, mapping of cortical responses amplitude and source reconstruction techniques (dipole modelisation, BESA) before / after a single rTMS session * In chronic pain patients, contrast analysis between extent and location of motor activations (to hand, foot and mouth contraction) before / after one week of daily rTMS, analysed with Statistical Parametric Mapping (SPM12)
Time frame: just after the isolated 20 Hz or theta-burst stimulation for healthy subjects
cortical plasticity induced by rTMS -- fMRI
Assessment of plastic changes induced in sensori-motor cortex by the application of repetitive magnetic stimulation in healthy subjects and chronic pain patients. * In healthy subjects, mapping of cortical responses amplitude and source reconstruction techniques (dipole modelisation, BESA) before / after a single rTMS session * In chronic pain patients, contrast analysis between extent and location of motor activations (to hand, foot and mouth contraction) before / after one week of daily rTMS, analysed with Statistical Parametric Mapping (SPM12)
Time frame: within 1 week before the first day of stimulation (20 Hz or theta-burst) for the patients
cortical plasticity induced by rTMS -- fMRI
Assessment of plastic changes induced in sensori-motor cortex by the application of repetitive magnetic stimulation in healthy subjects and chronic pain patients. * In healthy subjects, mapping of cortical responses amplitude and source reconstruction techniques (dipole modelisation, BESA) before / after a single rTMS session * In chronic pain patients, contrast analysis between extent and location of motor activations (to hand, foot and mouth contraction) before / after one week of daily rTMS, analysed with Statistical Parametric Mapping (SPM12)
Time frame: after the 5th day of stimulation (20 Hz or theta-burst) for the patients
Nonparametric (Chi-2) contrast of dichotomized pain reports before/after rTMS and extent of fMRI activation change (also dichotomized) MRI T1 3D and T2*
Time frame: within 1 week before the first day of stimulation Stats after 40 patients studied.
Nonparametric (Chi-2) contrast of dichotomized pain reports before/after rTMS and extent of fMRI activation change (also dichotomized) MRI T1 3D and T2*
Time frame: after the 5th day of stimulation. Stats after 40 patients studied.
Linear and nonlinear correlation between the magnitude of induced cortical plasticity and the magnitude of pain relief induced by rTMS. MRI T1 3D and T2*,
Time frame: within 1 week before the first day of stimulation Stats after 40 patients studied.
Linear and nonlinear correlation between the magnitude of induced cortical plasticity and the magnitude of pain relief induced by rTMS. MRI T1 3D and T2*,
Time frame: after the 5th day of stimulation. Stats after 40 patients studied.
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