Posts Tagged Lesions

[WEB SITE] How to help patients recover after a stroke

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Credit: CC0 Public Domain

The existing approach to brain stimulation for rehabilitation after a stroke does not take into account the diversity of lesions and the individual characteristics of patients’ brains. This was the conclusion made by researchers of the Higher School of Economics (HSE University) and the Max Planck Institute of Cognitive Sciences in their article, “Predicting the Response to Non-Invasive Brain Stimulation in Stroke.”

Among the most common causes of death worldwide,  ranks second only to myocardial infarction (heart attack). In addition, a stroke is also a chronic disease that leaves patients disabled for many years.

In , non-invasive neuromodulation methods such as electric and magnetic stimulation of various parts of the nervous system have been increasingly used to rehabilitate patients after a stroke. Stimulation selectively affects different parts of the , which allows you to functionally enhance activity in some areas while suppressing unwanted processes in others that impede the restoration of brain functions. This is a promising mean of rehabilitation after a stroke. However, its results in patients remain highly variable.

The study authors argue that the main reason for the lack of effectiveness in neuromodulation approaches after a stroke is an inadequate selection of patients for the application of a particular brain stimulation technique.

According to the authors, the existing approach does not take into account the diversity of lesions after a stroke and the variability of individual responses to brain stimulation as a whole. Researchers propose two criteria for selecting the optimal brain  strategy. The first is an analysis of the interactions between the hemispheres. Now, all patients, regardless of the severity of injury after a stroke, are offered a relatively standard treatment regimen. This approach relies on the idea of interhemispheric competition.

“For a long time, it was believed that when one hemisphere is bad, the second, instead of helping it, suppresses it even more,” explains Maria Nazarova, one of the authors of the article and a researcher at the HSE Institute of Cognitive Neurosciences. “In this regard, the suppression of the activity of the “unaffected” hemisphere should help restore the affected side of the brain. However, the fact is that this particular scheme does not work in many  after a stroke. Each time it is necessary to check what the impact of the unaffected hemisphere is—whether it is suppressive or activating.”

The second criterion, scientists call the neuronal phenotype. This is an individual characteristic of the activity of the brain, which is “as unique to each person as their fingerprints.” Such a phenotype is determined, firstly, by the ability of the brain to build effective structural and functional connections between different areas (connectivity). And, secondly, the individual characteristics of neuronal dynamics, including its ability to reach a . This is the state of the neuronal system in which it is the most plastic and capable of change.

Only by taking these criteria into account, the authors posit, can neuromodulation methods be brought to a new level and be effectively used in clinical practice. To do this, it is necessary to change the paradigm of the universal approach and select methods based on the individual characteristics of the brain of a particular person and the course of his or her disease.


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via How to help patients recover after a stroke

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[Abstract + References] Complex network changes during a virtual reality rehabilitation protocol following stroke: a case study

Abstract

Stroke is one of the main causes of disabilities caused by injuries to the human central nervous system, yielding a wide range of mild to severe impairments that can compromise sensorimotor and cognitive functions. Although rehabilitation protocols may improve function of stroke survivors, patients often reach plateaus while undergoing therapy. Recently, virtual reality (VR) technologies have been paired with traditional rehabilitation aiming to improve function recovery after stroke. Aiming to better understand structural brain changes due to VR rehabilitation protocols, we modeled the brain as a graph and extracted three measures representing the network’s topology: degree, clustering coefficient and betweenness centrality (BC). In this single case study, our results indicate that all metrics increased on the ipsilesional hemisphere, while remaining about the same at the contrale-sional site. Particularly, the number of functional connections increased in the lesion area overtime. In addition, the BC displayed the highest variations, and in brain regions related to the patient’s cognitive and motor impairments; hence, we argue that this measure could be regarded as an indicative for brain plasticity mechanisms.
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9. de Campos, B. M. , Coan, A. C. , Lin Yasuda, C. , Casseb, R. F. and Cendes, F. (2016), Large-scale brain networks are distinctly affected in right and left mesial temporal lobe epilepsy. Hum. Brain Mapp. doi: 10.1002/hbm.23231

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via Complex network changes during a virtual reality rehabilitation protocol following stroke: a case study – IEEE Conference Publication

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[TEDx Talks] A critical window for recovery after stroke – John Krakauer – Johns Hopkins University – YouTube

Δημοσιεύτηκε στις 8 Απρ 2015
Dr. John Krakauer, a Professor of Neurology and Neuroscience at Johns Hopkins University, co-founded the KATA project that combines concepts of neurology and neuroscience with interactive entertainment and motion capture technology to learn how lesions affect motor learning and to aid patients in recovering from brain injury.
Dr. John Krakauer is a Professor of Neurology and Neuroscience, the Director of the Center for the Study of Motor Learning and Brain Repair, and the Director of Brain, Learning, Animation, and Movement Lab (BLAM) at Johns Hopkins. He received his undergraduate and master’s degree from Cambridge University and earned his medical degree from Columbia University College of Physicians and Surgeons, where he was elected to Alpha Omega Alpha Medical Honor Society. His clinical and research expertise is in stroke, ischemic cerebrovascular disease, cerebral aneurysms, arteriovenous malformations, and venous and sinus thrombosis.
He co-founded the KATA project that combines concepts of neurology and neuroscience with interactive entertainment and motion capture technology to learn how lesions affect motor learning and to aid patients in recovering from brain injury.
This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx

 

via A critical window for recovery after stroke | John Krakauer | TEDxJohnsHopkinsUniversity – YouTube

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[VIDEO] Visual Pathway and Lesions – YouTube

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