Movement Recovery after Stroke Depends on the Integrity of Connections between the Cerebral Cortex and the Spinal Cord
A team of scientists, with the first author from the HSE University, were investigating which factors are the most important for the upper limb motor recovery after a stroke. The study is published in Stroke, the world's leading journal for cerebrovascular pathology.
The extent to which the brain is damaged and movements are impaired after a stroke varies greatly among patients. How effectively a patient will regain his/her functions after a stroke depends both on the severity of the damage and the adequacy of the rehabilitation interventions. Assessment can be conducted using functional and structural approaches of brain imaging.
The published article is dedicated to a study of the relationship between the degree of movement recovery in the upper limb and the structural and functional state of the motor system, assessed using methods of transcranial magnetic stimulation (TMS) and magnetic resonance imaging (MRI). The study included 35 patients of young and middle age (in average 47 years old), who had a stroke more than six months prior to the study. The patients were divided into three groups depending on the level to which they regained movement in their upper limb: good, moderate, and bad.
A stroke occurs when there is a blockage or rupture of a blood vessel feeding the brain. About 400,000 stroke cases are registered in Russia annually. Stroke is a disease, which occurs mostly in older ages but not only, for instance in Russia every 7th stroke happens in young people. Today there are more than 1.5 million people living in Russia who are in need of motor, speech, or cognitive rehabilitation due to stroke. The impairment in the upper limb is the most common and one of the most challenging for rehabilitation.
The study showed that the structural integrity of the corticospinal tract assessed using structural MRI is the best predictor for the upper limb motor recovery. At the same time, the assessment of the state of the unaffected cerebral hemisphere and the integrity of the connections between the hemispheres did not have an additional value for classification when data on the integrity of the corticospinal tract were available.
The corticospinal tract is a pathway that connects the cerebral cortex with the spinal cord, allowing voluntary limb movement.
In addition, the study showed that the methods of MRI and TMS are equally effective for assessing the condition of the corticospinal tract in patients in chronic phase after stroke and can be used interchangeably when it is necessary to select a group of patients with low levels of recovery.
Maria Nazarova, Research Fellow at the Institute for Cognitive Neurosciences of HSE University
However, it is important to consider that when assessing the motor system using TMS, it is necessary to study the evoked motor responses in several muscles of the upper limb. This makes it possible to reduce the number of false negative results—cases in which muscle responses to stimulation were not found, although the corticospinal tract was partially preserved.
The findings of the study can be used both to better understand the processes of recovery after a stroke and to plan individual motor rehabilitation in stroke survivors.
Maria Nazarova
See also:
Smoking Habit Affects Response to False Feedback
A team of scientists at HSE University, in collaboration with the Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences, studied how people respond to deception when under stress and cognitive load. The study revealed that smoking habits interfere with performance on cognitive tasks involving memory and attention and impairs a person’s ability to detect deception. The study findings have been published in Frontiers in Neuroscience.
'Neurotechnologies Are Already Helping Individuals with Language Disorders'
On November 4-6, as part of Inventing the Future International Symposium hosted by the National Centre RUSSIA, the HSE Centre for Language and Brain facilitated a discussion titled 'Evolution of the Brain: How Does the World Change Us?' Researchers from the country's leading universities, along with health professionals and neuroscience popularisers, discussed specific aspects of human brain function.
‘Scientists Work to Make This World a Better Place’
Federico Gallo is a Research Fellow at the Centre for Cognition and Decision Making of the HSE Institute for Cognitive Research. In 2023, he won the Award for Special Achievements in Career and Public Life Among Foreign Alumni of HSE University. In this interview, Federico discusses how he entered science and why he chose to stay, and shares a secret to effective protection against cognitive decline in old age.
'Science Is Akin to Creativity, as It Requires Constantly Generating Ideas'
Olga Buivolova investigates post-stroke language impairments and aims to ensure that scientific breakthroughs reach those who need them. In this interview with the HSE Young Scientists project, she spoke about the unique Russian Aphasia Test and helping people with aphasia, and about her place of power in Skhodnensky district.
Neuroscientists from HSE University Learn to Predict Human Behaviour by Their Facial Expressions
Researchers at the Institute for Cognitive Neuroscience at HSE University are using automatic emotion recognition technologies to study charitable behaviour. In an experiment, scientists presented 45 participants with photographs of dogs in need and invited them to make donations to support these animals. Emotional reactions to the images were determined through facial activity using the FaceReader program. It turned out that the stronger the participants felt sadness and anger, the more money they were willing to donate to charity funds, regardless of their personal financial well-being. The study was published in the journal Heliyon.
Spelling Sensitivity in Russian Speakers Develops by Early Adolescence
Scientists at the RAS Institute of Higher Nervous Activity and Neurophysiology and HSE University have uncovered how the foundations of literacy develop in the brain. To achieve this, they compared error recognition processes across three age groups: children aged 8 to 10, early adolescents aged 11 to 14, and adults. The experiment revealed that a child's sensitivity to spelling errors first emerges in primary school and continues to develop well into the teenage years, at least until age 14. Before that age, children are less adept at recognising misspelled words compared to older teenagers and adults. The study findings have beenpublished in Scientific Reports .
Meditation Can Cause Increased Tension in the Body
Researchers at the HSE Centre for Bioelectric Interfaces have studied how physiological parameters change in individuals who start practicing meditation. It turns out that when novices learn meditation, they do not experience relaxation but tend towards increased physical tension instead. This may be the reason why many beginners give up on practicing meditation. The study findings have been published in Scientific Reports.
Processing Temporal Information Requires Brain Activation
HSE scientists used magnetoencephalography and magnetic resonance imaging to study how people store and process temporal and spatial information in their working memory. The experiment has demonstrated that dealing with temporal information is more challenging for the brain than handling spatial information. The brain expends more resources when processing temporal data and needs to employ additional coding using 'spatial' cues. The paper has been published in the Journal of Cognitive Neuroscience.
Neuroscientists Inflict 'Damage' on Computational Model of Human Brain
An international team of researchers, including neuroscientists at HSE University, has developed a computational model for simulating semantic dementia, a severe neurodegenerative condition that progressively deprives patients of their ability to comprehend the meaning of words. The neural network model represents processes occurring in the brain regions critical for language function. The results indicate that initially, the patient's brain forgets the meanings of object-related words, followed by action-related words. Additionally, the degradation of white matter tends to produce more severe language impairments than the decay of grey matter. The study findings have been published in Scientific Reports.
New Method Enables Dyslexia Detection within Minutes
HSE scientists have developed a novel method for detecting dyslexia in primary school students. It relies on a combination of machine learning algorithms, technology for recording eye movements during reading, and demographic data. The new method enables more accurate and faster detection of reading disorders, even at early stages, compared to traditional diagnostic assessments. The results have been published in PLOS ONE.