P 174. Effects of paired associative stimulation on developmental motor plasticity in children

Introduction: Transcranial magnetic stimulation (TMS) offers increasingly sophisticated means of assessing neurophysiology and neuroplasticity mechanisms but applications in children have been limited. Paired associative stimulation (PAS) is an advanced TMS method that pairs peripheral sensory stimulation with TMS primary motor cortex (M1) stimulation. PAS induces rapid, reversible and topographically specific increases in adult motor cortex excitability consistent with NMDAR-dependent long-term potentiation. PAS has not been studied in the more plastic brains of children.Objectives: Our aim wasto define the developmental profile of PAS in children. We hypothesized that rates of PAS MEP enhancement would be higher in children compared to adults.Methods: Healthy, right-handed children aged 6–18years were recruited from the Alberta Perinatal Stroke Project (APSP) healthy control cohort and general population. Median nerve stimulation (300% sensory threshold) was delivered 25ms prior to suprathreshold (1mV) left M1 stimulation (90 pairings, 7min).Difference in mean peak-to-peak amplitude of right APB motor evoked potentials (MEP) was the primary outcome. Forty single pulse TMS measures were obtained at baseline, immediately after, and 15, 30, 45, and 75min post-PAS. PAS effects were categorized as definitive (significantly elevated post-MEP at multiple timepoints), possible (single timepoint only) or no effect. Secondary outcomes included change in slope of stimulus response c...
Source: Clinical Neurophysiology - Category: Neuroscience Authors: Tags: Society Proceedings Source Type: research