Brain Stimul
-
The ventrointermediate nucleus (Vim) of the thalamus is still considered "invisible" on current magnetic resonance imaging (MRI), requiring indirect methods based on stereotactic atlases for estimation of its location. Direct visualization of Vim is desirable to improve targeting. ⋯ 1.5-T MRI with WAIR sequence provides high-quality images of Vim suitable in DBS surgery, for accurate preoperative planning, direct targeting and anatomic analysis.
-
Functional magnetic resonance imaging (fMRI) has shown that transcranial direct current stimulation (tDCS) of the hand motor cortex modulates cortical activity of the healthy human brain. However, few studies have assessed the effects of tDCS on the leg motor cortex. We therefore used fMRI to examine the modulating effects of tDCS on lower limb motor cortex responses. ⋯ Anodal tDCS increased corticospinal excitability of the lower limb motor cortex in healthy subjects, suggesting that multiple brain cortical areas may be associated with leg motor performance via involvement of variable corticocortical connections.
-
Transcranial direct current stimulation (tDCS) is a noninvasive method of modulating cortical excitability. The aim of this study was to investigate the effects of short-duration tDCS (1.6 seconds per trial) on memory performance, and whether the effects were affected by stimulation administered early or late in a trial. Participants memorize words under anodal and cathodal tDCS to the left dorsolateral prefrontal cortex (DLPFC) in two separate sessions in no-stimulation, early stimulation, and late stimulation trials. ⋯ Early anodal tDCS led to significantly better accuracy and speed in a subsequent recognition test compared to anodal late or no-stimulation conditions. Early cathodal tDCS, on the other hand, led to significantly worse accuracy and speed in a subsequent recognition test compared with cathodal late or no-stimulation conditions. The results of this study suggest that short-duration tDCS can modulate memory performance and highlight the importance of period of stimulation.
-
Empathic responses to facial cues are a main social competency. Both appraisal processes (facial emotion detection) and self-perceived empathy (empathic responsiveness) in response to emotional faces are thought to be related to empathic behavior, although no systematic analysis has been performed to assess their relationship. ⋯ The ability to monitor emotional cues and the behavioral empathic responsiveness to emotional situations was shown to be partially compromised in the case of frontal activity disruption, highlighting the main role of the sensorimotor system for empathic social skills.
-
Clinical Trial
Transient effects of 80 Hz stimulation on gait in STN DBS treated PD patients: a 15 months follow-up study.
Subthalamic nucleus deep brain stimulation (STN DBS) is an effective therapeutic option for advanced Parkinson's disease (PD). Nevertheless, some patients develop gait disturbances despite a persistent improvement of PD segmental symptoms. Recent studies reported that stimulation of STN with low frequencies produced a positive effect on gait disorders and freezing episodes. ⋯ Stimulation frequency at 80 Hz has an immediate positive effect on gait in STN DBS treated patients; however, the objective gait improvement is not maintained over time, limiting the use of this frequency modulation strategy in the clinical setting.