Magnetic Impulses Help Create Muscle Activity Maps to Diagnose Motor Disorders
Using transcranial magnetic stimulation, Russians scientists were able to precisely track inter-muscle interactions between cortical representations of arm muscles. In the future, this method will help track brain changes in patients with motor disorders. The study was published in Human Brain Mapping. The project was supported by the Presidential Programme of the Russian Science Foundation (RSF).
Today, transcranial magnetic stimulation is actively used in psychiatry and neurology to treat depression, pain, and other conditions. But the method is still underused for the assessment of the motor cortex and musculoskeletal conditions in different disorders, exercise, or rehabilitation.
Russian researchers examined the reliability of motor mapping with the use of this method. The scholars managed to precisely track inter-muscle interactions between cortical representations of arm muscles. In the future, this will help track brain changes in patients with motor disorders.
Transcranial magnetic stimulation (TMS) helps doctors and researchers activate the human cortex with short magnetic impulses. Today, this method is used in psychiatry and neurology to treat, for example, such conditions as depression, pain, Parkinson’s disease and many disorders. In addition, TMS looks quite promising in terms of brain research and its functional mapping — the creation of brain maps. Combining TMS with MRI navigation is particularly effective. This method is called navigated TMS or nTMS. For some tasks, it is more precise than other brain mapping methods, such as functional MRI. In nTMS, the motor cortex is stimulated. This leads to muscle contractions, which are assessed by researchers who register muscle electric activity. The spatial accuracy of nTMS mapping may be as small as two millimeters, and its results are called muscle cortical representation (MCR) or a TMS motor map. This approach may be used to assess motor cortex changes in different disorders, exercise, or rehabilitation.
Despite the advantages of nTMS mapping, in practice this method is rarely used. Further confirmation of data received with this method is needed. This issue was tackled by Russian researchers of the Centre for Cognition & Decision Making of HSE University’s Institute for Cognitive Neuroscience, the Research Centre of Neurology, and the Federal Centre of Brain Research and Neurotechnologies. They carried out a study of the absolute and comparative reliability of mapping data (muscle cortical representations) of arm muscles. For this purpose, they invited healthy male volunteers aged 19 to 33. None of them had any neurological or mental disorders; the scholars also excluded athletes, musicians, and surgeons, since they are likely to have highly precise motor function due to their work.
The volunteers participated in two nTMS mapping sessions separated by 5-10 days. The researchers registered contractions of three muscles that control the movement of hand and fingers. This way, they received TMS muscle cortical representations. Reliability analysis showed that the commonly used metrics, such as areas, volumes, and centres of gravity had a high relative and low absolute reliability for the muscles. The former assesses the results of repeated measurements, while the latter tracks the change of data in one participant. Overlaps between different muscle MCRs were highly reliable, which allowed the researchers to track the interactions between these maps.
‘Our study is important not only for fundamental science. It also opens new opportunities for the use of nTMS motor mapping to evaluate cortical changes in healthy people and patients with neurological conditions, such as those who are undergoing rehabilitation after a stroke,’ said Maria Nazarova, head of the RSF grant project, Candidate of Science (Medicine), and researcher of the Centre for Cognition & Decision Making (Institute for Cognitive Neuroscience, HSE University) and the Federal Centre of Brain Research and Neurotechnologies.
The Federal Brain and Neural Technology Centre at the Federal Medical and Biological Agency is launching the Laboratory of Medical Neural Interfaces and Artificial Intelligence for Clinical Applications, which has been created by employees of HSE University. Read below to find out about the Laboratory and its objectives.
A team of researchers from the HSE Centre for Cognition and Decision Making and the Central State Medical Academy conducted a study on sleep disorders, mood and fatigue after COVID-19. These factors are interrelated and the researchers recommend a comprehensive approach to treat the problem effectively. The work was published in the journal Neuroscience and Behavioral Psychology.
Medical advances are causing a gradual increase in average life expectancy. However, this comes at a price, as the number of cases of dementia and other neurodegenerative diseases grows with age. Researchers from HSE University (Russia) and Northumbria University (UK) have found that bilingualism can slow down and mitigate the course of age-related changes in the human brain. The study was published in Frontiers in Psychology.
Neurobiologists from HSE University and the RAS Institute of Higher Nervous Activity and Neurophysiology proved that the human brain unconsciously distinguishes between even very similar sound signals during passive listening. The study was published in Neuropsychologia.
Researchers from HSE University and St. Petersburg State University of Architecture and Civil Engineering (SPSUACE) used eye tracking to study how residents who own cars and those who don’t look at the shared courtyards of multistorey apartment buildings. The study was published in Urban Forestry & Urban Greening.
HSE academics joined researchers from the Turner Scientific Research Institute for Children's Orthopaedics to study how the brains of children with arthrogryposis control elbow flexion after muscle transplantation. They found that in such patients, more motor neuron activity occurs, which means that the start of a new movement requires more effort from the brain. The paper ‘Feasibility and Challenges of Performing Magnetoencephalography Experiments in Children with Arthrogryposis Multiplex Congenita’ was published in Frontiers in Pediatrics.
The mega-grant allocated by the Russian government to the International Laboratory of Social Neurobiology, has been extended for 2022-23. The laboratory was founded two years ago and is headed by Iiro Jaaskelainen, a leading neurobiologist from Finland. Laboratory Head Vasily Klucharev spoke to the HSE News Service about the results the lab has already achieved and the prospects for the next two years.
HSE University researchers have found that if cortical excitability is suppressed, the conflict between self-interest and prosocial motivations is resolved in favour of the latter—but only in cases when this conflict is really present.
Alexios Kouzalis, from Cyprus, is a first-year PhD student at the HSE University School of Psychology. We talked with Alexis about his reasons for coming to HSE Moscow, his achievements and his observations on life in the Russian capital.
A unique awake brain surgery has been carried out in Nizhny Novgorod with the participation of staff of the Centre for Language and Brain Studies. For the first time, neurolinguists in Nizhny Novgorod assisted in the removal of a brain tumour with mapping of a bilingual patient who is a native speaker of Tatar and Russian. The participants—Natalia Gronskaya, Director of the Centre for Language and Brain Studies, Alina Minnigulova, research assistant, and Lilia Mavlekhanova, invited expert and native speaker of Tatar—spoke about the specifics of the operation.