Physiological and introspective antecedents of tics and movements in adults with tic disorders.

Objective: To investigate the subjective phenomenon and the neural underpinnings of tics compared with voluntary movements in patients with tic disorders.

Methods: We recorded electroencephalographic and electromyographic data while subjects completed a Libet clock paradigm. Patients and healthy volunteers reported the times of W (willing to move) and M (movement occurrence) while performing voluntary movements.

Spinal use-dependent plasticity of synaptic transmission in humans after a single cycling session.

The spinal cord is able to express use-dependent plasticity, as demonstrated in spinalized cats following treadmill training. In humans, spinal use-dependent plasticity is inferred from modifications in the size of H reflex, which are often more prominent after skilled motor training. Plasticity can develop at synaptic connections between afferent fibres and/or descending tracts and motoneurones or interneurones interposed in the spinal pathways.

Contralateral hand anesthesia transiently improves poststroke sensory deficits.

Objective: To test a possible strategy to alleviate somatosensory deficits after stroke.

Methods: Here, we applied ischemic nerve block to the intact hand of patients with chronic stroke, which in healthy subjects elicits improvements in sensibility of the other hand.

Results: We found that sensibility in the affected hand improved with intact hand anesthesia, but not with intact foot anesthesia or no anesthesia.

Influence of somatosensory input on motor function in patients with chronic stroke.

In healthy volunteers, reduction of somatosensory input from one hand leads to rapid performance improvements in the other hand. Thus, it is possible that reduction of somatosensory input from the healthy hand can influence motor function in the paretic hand of chronic stroke patients with unilateral hand weakness. To test this hypothesis, we had 13 chronic stroke patients perform motor tasks with the paretic hand and arm during cutaneous anesthesia of the healthy hand and healthy foot in separate sessions.