Somatosensory Plasticity in Hemiplegic Cerebral Palsy Following Constraint Induced Movement Therapy.

Background: Children with hemiplegic cerebral palsy (HCP) experience upper limb somatosensory and motor deficits. Although constraint-induced movement therapy (CIMT) improves motor function, its impact on somatosensory function remains underinvestigated.

Objective: The objective of this study was to evaluate somatosensory perception and related brain responses in children with HCP, before and after a somatosensory enhanced CIMT protocol, as measured using clinical sensory and motor assessments and magnetoencephalography.

Task-related enhancement in corticomotor excitability during haptic sensing with the contra- or ipsilateral hand in young and senior adults.

Background: Haptic sensing with the fingers represents a unique class of manipulative actions, engaging motor, somatosensory and associative areas of the cortex while requiring only minimal forces and relatively simple movement patterns. Using transcranial magnetic stimulation (TMS), we investigated task-related changes in motor evoked potential (MEP) amplitude associated with unimanual haptic sensing in two related experiments. In Experiment I, we contrasted changes in the excitability of the hemisphere controlling the task hand in young and old adults under two trial conditions, i.

Differential modulation of corticospinal excitability during haptic sensing of 2-D patterns vs. textures.

Background: Recently, we showed a selective enhancement in corticospinal excitability when participants actively discriminated raised 2-D symbols with the index finger. This extra-facilitation likely reflected activation in the premotor and dorsal prefrontal cortices modulating motor cortical activity during attention to haptic sensing. However, this parieto-frontal network appears to be finely modulated depending upon whether haptic sensing is directed towards material or geometric properties.

Characterization of human tactile pattern recognition performance at different ages.

This study examined tactile pattern recognition performance in human observers (N = 44) in the context of a letter recognition task at the fingertip. Participants were recruited from three different age groups (youth, n = 17; young adults, n = 14; seniors, n = 13) to examine age-related differences in performance. The influence of gender (males vs females) and hand (right vs left) was also examined.

Tactile-dependant corticomotor facilitation is influenced by discrimination performance in seniors.

Background: Active contraction leads to facilitation of motor responses evoked by transcranial magnetic stimulation (TMS). In small hand muscles, motor facilitation is known to be also influenced by the nature of the task. Recently, we showed that corticomotor facilitation was selectively enhanced when young participants actively discriminated tactile symbols with the tip of their index or little finger.

Selective increase in motor excitability with intraactive (self) versus interactive touch.

Corticomotor facilitation was investigated using transcranial magnetic stimulation in healthy young adults when they actively stroked either their own left palm (intraactive) or the experimenter's palm (interactive touch) with their right index finger. We predicted, based on the sensory cancellation hypothesis, that corticomotor facilitation would be lower with intraactive touch. Motor evoked potential amplitude in the right first dorsal interosseous was affected by mode of touch, but not by sex.

Task-specific increase in corticomotor excitability during tactile discrimination.

Task-dependant changes in corticomotor excitability have been described mainly in the context of grasp-oriented actions, neglecting the sensory aspects of hand function. Here, we contrasted task-dependant facilitation in small hand muscles [i.e.