Transcranial magnetic stimulation in sleep fragmentation: a model to better understand sleep disorders.

Objective: To investigate practice-dependent plasticity and cortical inhibition/excitability in good sleepers after a night of sleep fragmentation (SF), by means of transcranial magnetic stimulation (TMS).

Methods: In basal condition (BC), after a full night of spontaneous sleep, and in fragmented condition (FC), after a fragmented night of sleep, motor evoked potential (MEP) amplitude, motor threshold (MT), silent period (SP), and intracortical inhibition were assessed. In both conditions subjects performed, also, a bimanual motor task: MEPs were recorded before and after exercise, and after rest.

Changes of cortical excitability after dopaminergic treatment in restless legs syndrome.

Objective: Dopaminergic pathways are most likely involved in the pathophysiology of restless legs syndrome (RLS). In previous investigations, an alteration of cortical excitability was suggested to be related to a dopaminergic dysfunction in RLS. The purpose of our study was to compare practice-dependent plasticity in RLS patients before and after a month of dopaminergic treatment.

Sensory gating deficit assessed by P50/Pb middle latency event related potential in Alzheimer's disease.

Sensory gating is defined as the brain's ability to inhibit repetitive and irrelevant incoming sensory stimuli and is supposed to be related to cholinergic transmission. Indeed, Alzheimer's disease (AD) is characterized by a cholinergic deficit that is believed to be involved in cerebral cortex hyperexcitability and short latency afferent inhibition deficit. Therefore, a sensory gating deficit may be supposed present in AD within the frame of cortex hyperexcitability and loss of cortex modulation of sensory inputs.

Absence of postexercise and delayed facilitation of motor cortex excitability in restless legs syndrome: evidence of altered cortical plasticity?

Study Objective: Restless legs syndrome (RLS) is a neurologic disorder with well-defined clinical and diagnostic criteria but the pathophysiology of which is unclear. Previous studies have suggested alterations in motor cortex function in RLS. We aimed to compare motor cortex plasticity in subjects with RLS versus healthy controls.

Motor cortex excitability in restless legs syndrome.

Background And Purpose: A review of the literature shows that the transcranial magnetic stimulation (TMS) is a useful neurophysiological tool to investigate the pathophysiology of the restless legs syndrome (RLS). In this study we used TMS to define motor cortical excitability in RLS subjects.

Patients And Methods: Six RLS patients and two healthy control subjects underwent TMS (single and paired) examination using two protocols: (1) the evaluation of motor cortical excitability changes occurring at various times after a repetitive finger movement task; (2) the evaluation of the time course of intracortical motor activity tested with pairs of magnetic stimuli applied at inter-stimulus intervals of 1-6 ms.