European research priorities for intracerebral haemorrhage

Over 2 million people are affected by intracerebral haemorrhage (ICH) worldwide every year, one third of them dying within 1 month, and many survivors being left with permanent disability. Unlike most other stroke types, the incidence, morbidity and mortality of ICH have not declined over time. No standardised diagnostic workup for the detection of the various underlying causes of ICH currently exists, and the evidence for medical or surgical therapeutic interventions remains limited. A dedicated European research programme for ICH is needed to identify ways to reduce the burden of ICH-related death and disability. The European Research Network on Intracerebral Haemorrhage EURONICH is a multidisciplinary academic research collaboration that has been established to define current research priorities and to conduct large clinical studies on all aspects of ICH. Copyright (C) 2011 S. Karger AG, Base

Efficient neuroplasticity induction in chronic stroke patients by an associative brain-computer interface

Brain-computer interfaces (BCIs) have the potential to improve functionality in chronic stoke patients when applied over a large number of sessions. Here we evaluated the effect and the underlying mechanisms of three BCI training sessions in a double-blind sham-controlled design. The applied BCI is based on Hebbian principles of associativity that hypothesize that neural assemblies activated in a correlated manner will strengthen synaptic connections. Twenty-two chronic stroke patients were divided into two training groups. Movement-related cortical potentials (MRCPs) were detected by electroencephalography during repetitions of foot dorsiflexion. Detection triggered a single electrical stimulation of the common peroneal nerve timed so that the resulting afferent volley arrived at the peak negative phase of the MRCP (BCI(associative) group) or randomly (BCI(nonassociative) group). Fugl-Meyer motor assessment (FM), 10-m walking speed, foot and hand tapping frequency, diffusion tensor imaging (DTI) data, and the excitability of the corticospinal tract to the target muscle [tibialis anterior (TA)] were quantified. The TA motor evoked potential (MEP) increased significantly after the BCI(associative) intervention, but not for the BCI(nonassociative) group. FM scores (0.8 ± 0.46 point difference, P = 0.01), foot (but not finger) tapping frequency, and 10-m walking speed improved significantly for the BCI(associative) group, indicating clinically relevant improvements. Corticospinal tract integrity on DTI did not correlate with clinical or physiological changes. For the BCI as applied here, the precise coupling between the brain command and the afferent signal was imperative for the behavioral, clinical, and neurophysiological changes reported. This association may become the driving principle for the design of BCI rehabilitation in the future. Indeed, no available BCIs can match this degree of functional improvement with such a short intervention

Neuroimaging of Hemorrhage and Vascular Defects

Intracranial hemorrhage is the third most common cause of stroke and involves the accumulation of blood within brain parenchyma or the surrounding meningeal spaces. Accurate identification of acute hemorrhage and correct characterization of the underlying pathology, such as tumor, vascular malformation, or infarction, is a critical step in planning appropriate therapy. Neuroimaging studies are required not only for diagnosis, but they also provide important information on the type of hemorrhage, etiology, and the pathophysiological process. Historically, computed tomography (CT) scan has been the diagnostic imaging study of choice; however, there is growing evidence suggesting that magnetic resonance imaging (MRI) is at least as sensitive as CT to detect intraparenchymal hemorrhages in the hyperacute setting, and actually superior to CT in the subacute and chronic settings. Unique MRI and CT characteristics differentiate secondary causes of hemorrhage from the more common hypertensive hemorrhage. Baseline and serial studies can be used to identify patients who might benefit from acute interventions. In addition, new imaging modalities, (such as magnetic resonance spectroscopy, diffusion tensor imaging, and 320-row CT) are promising research techniques that have the potential to enhance our understanding of the tissue injury and recovery after intracranial hemorrhages