Objective: Motor recovery after stroke depends on the integrity of ipsilesional motor circuits and interactions between the ipsilesional and contralesional hemispheres. In this sham-controlled randomized trial, we investigated whether noninvasive modulation of regional excitability of bilateral motor cortices in combination with physical and occupational therapy improves motor outcome after stroke.
Methods:Twenty chronic stroke patients were randomly assigned to receive 5 consecutive sessions of either 1) bihemispheric transcranial direct current stimulation (tDCS) (anodal tDCS to upregulate excitability of ipsilesional motor cortex and cathodal tDCS to downregulate excitability of contralesional motor cortex) with simultaneous physical/occupational therapy or 2) sham stimulation with simultaneous physical/occupational therapy. Changes in motor impairment (Upper Extremity Fugl-Meyer) and motor activity (Wolf Motor Function Test) assessments were outcome measures while functional imaging parameters were used to identify neural correlates of motor improvement.
Background—
Percutaneous aortic valve replacement is a new emerging technology for interventional treatment of severe aortic valve stenosis in surgical high-risk patients. This study was intended to provide a summary of the development and current safety and efficacy status of the self-expanding CoreValve Revalving prosthesis.
Method and Results—
Between 2005 and 2008, we have enrolled 136 consecutive patients with percutaneous aortic valve replacement using the CoreValve prosthesis. In this prospective nonrandomized, single-center trial, we analyzed procedural outcome, complications and clinical status up to 1 year. First, second, and third generation of the CoreValve prosthesis were implanted in 10, 24, and 102 consecutive high-risk patients (logistic EuroScore: 23.1�15.0%) with severe symptomatic aortic valve stenosis. Mean transvalvular pressure gradient was 41.5�16.7 mm Hg. The procedural success rate increased from generation 1/2 to 3 from 70.0%/70.8% to 91.2% (
P
=0.003). The 30-day combined rate of death/stroke/myocardial infarction was 40.0%/20.8%/14.7% (
P
=0.11) for generation 1, 2, and 3, with no procedural death in generation 3. Pressure gradients improved significantly with a final mean gradient of 8.1�3.8 mm Hg. Overall functional status assessed by New York Heart Association class improved from 3.3�0.5 (pre) to 1.7�0.7 (post) (
P
<0.001) and remained stable in the follow-up.
Conclusion—
In experienced hands, percutaneous aortic valve replacement with the CoreValve system for selected patients with severe aortic valve stenosis has a high acute success rate associated with a low periprocedural mortality/stroke rate as well as remarkable clinical and hemodynamic improvements, which persist over time. Additional studies are now required to confirm these findings, particularly head-to-head comparisons with surgical valve replacement in different risk populations.
Transcranial direct current stimulation over the left motor area influenced both contralateral and ipsilateral finger sequence movements in seven healthy adults. Effects for the two hands were reversed: anodal stimulation improved right-hand performance significantly more than cathodal stimulation, whereas cathodal stimulation improved left-hand performance significantly more than anodal stimulation. The results show that stimulating a motor region directly, or indirectly by modulating activity in the homologous region on the opposite hemisphere, can affect motor skill acquisition, presumably by facilitating effective synaptic connectivity. This outcome provides evidence for the role of interhemispheric inhibition in corticomotor functioning, and also has implications for treatment methods aimed at facilitating motor recovery after stroke.
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