Three graduates of the NSU V. Zelman Institute of Medicine and Psychology successfully defended their theses that were dedicated to patient recovery and rehabilitation after an ischemic stroke. Their work covers various methods of early diagnosis, monitoring patient condition, and predicting the restoration of body functions after a stroke. The graduate’s topics are interconnected and aimed at achieving one goal, providing effective rehabilitation for patients and reducing their post stroke disability.
Active Rehabilitation
Denis Klebansky’s research combined the use of modern technologies with active patient participation. He described his approach,
Stroke is still a major health problem so we started looking for new methods of motor non-invasive neurorehabilitation based on a biofeedback system. Our proposed technology is interactive brain stimulation, a form of neurofeedback, with the choice of a feedback target based on fMRI and EEG data.
During the study, the patient was placed in a magnetic resonance imaging (MRI) machine. There, he was taught to consciously stimulate different parts of the brain that activate neuroplasticity processes to improve motor rehabilitation. Simultaneously, experts analyzed the structure of brain tissue. They were interested in the processes that occur in the lesion during rehabilitation, as well as in the opposite hemisphere, and in segments of the corpus callosum, which connects pathways fr om brain regions responsible for the motor function of the body. The data obtained was analyzed using the reconstruction of the conducting pathways (axons) of the brain and their diffusion parameters were identified.
It was discovered that the whole brain is involved in the restoration of motor function and not just the hemisphere wh ere the lesion was formed. Demyelination processes took place in the stroke focus with selective damage to the myelin sheath passing around the nerve fibers of the central or peripheral nervous system. This leads to the dysfunction of myelinated nerve fibers.
In the symmetrical hemisphere, a decrease in the density of axons was observed, which transmits an impulse outside the cell. This causes, for example, a muscle contraction. An increase in their diameter was also observed. The volitional self-stimulation of the necessary areas of the cortex using interactive brain stimulation made it possible to minimize the loss of pathways in the stroke focus and improve interhemispheric interaction.
Twelve patients with ischemic stroke participated in the study. Each of them went through 11 tomography sessions - three test, two training self-stimulation, and six research sessions. During these sessions, five specialists worked simultaneously with each patient.
Klebansky explained.
We are entering a new stage in the development of neurology. Earlier it was believed that a stroke causes point damage to the brain, now functional tests have demonstrated that both its hemispheres and the cerebellum are impacted. The patient's coordination of movements, volitional characteristics, and sometimes the psyche are disturbed. We observed in real time how in patients who had a stroke, the whole brain is restructured. This indicates confirmation of the hypothesis that a stroke is a disease of neural networks by showing that all neurons are interconnected and represent a single dynamic network.
Early Diagnosis
In his thesis, Vladimir Popov was engaged in the dynamic assessment of functional and cognitive changes in the brain in the early post-stroke period according to perfusion MRI data.
Popov explained.
One of the main causes of disability today is a stroke. Therefore, the development of new imaging techniques for early detection and effective response is required. In my thesis, I tried to evaluate the effectiveness of the ASL method on clinical examples of stroke 1-3 days, 7-10 days, and 3 months after its onset. The results obtained allow us to speak reliably about changes in perfusion parameters in the early post-stroke period not only in the stroke focus, but in other areas of the brain. The thesis notes the high applied value of this method in clinical practice for early diagnosis, treatment, and rehabilitation of patients.
This research was conducted at the International Tomography Center SB RAS. 42 patients who had identified and confirmed ischemic stroke participated.
Popov continued,
We were among the first in the country to apply the ASL methodology, which includes both qualitative and quantitative assessment. It can detect ischemic disorders during the earliest stages, when this is not possible with other methods. The ASL technique is advanced and relatively new. Let's hope that over time it will be introduced into widespread routine practice.
Recovery Forecast
The diploma work of Ilya Karabanov is devoted to the study of the structural reorganization of the brain in the early post-stroke period using methods based on diffusion MRI.
Karabanov described his method,
The DTI and GQI methods make it possible to obtain unique data on the course of ischemia and its possible outcomes. In the future this will help to comprehensively assess the condition of patients after a stroke, to carry out their correct routing, and develop optimal management and treatment tactics. We conducted a full cycle of patient examination from MRI and clinical assessment to post-processing and statistical analysis of the data obtained. We managed to optimize the post-processing of diffusion MRI data for a dynamic assessment of the structural reorganization of the brain in the early post-stroke period based on DTI and GQI analysis.
The researchers identified the key quantitative characteristics of the DTI and GQI methods, reflecting the structural reorganization of the brain in the early post-stroke period. They also determined indices and ratios of DTI/GQI metrics to predict clinical outcome. An algorithm and methods for interpreting various formulas have been developed that evaluate prognostic markers of ischemic stroke outcomes. Thanks to this development, it is possible to obtain diffusion metrics, that is, diffusion values. With their help, using special formulas, it is possible to calculate a specific indicator and predict the outcome of an ischemic stroke in a patient for several years.
Karabanov explained,
We will be able to predict at an early stage of rehabilitation how the patient will recover; how complete it will be, and in what time frame. We will find out what the clinician should pay attention to and help him to correctly determine patient treatment and further rehabilitation. In the future, perhaps, these prognostic markers and diffusion metrics will be used to select drug treatment individually for each patient.
The three Institute graduates plan to continue their research. Denis Klebansky and Vladimir Popov, as part of their NSU residency and Ilya Karabanov , as part of a targeted residency at the E.N. Meshalkin National Medical Research Center. Also, graduates of the NSU ZIMP will continue to exchange information so the results of their research will be introduced into clinical medicine.
