Vol 16, No 2 (2022)

Introduction. Treatment with MRI-guided focused ultrasound (MRgFUS) is a new, non-invasive surgical technique for treating extrapyramidal movement disorders. This article presents the first use of MRgFUS in Russia for treating patients with essential tremor (ET).

Materials and methods. Patients (n = 26; 17 men and 9 women) aged 21–82 years (median age 46.0 years) and with severe and refractory ET, underwent MRgFUS thalamotomy (ExAblate 4000, Insightec). One side was treated in 22 patients (left thalamus in 18 and right thalamus in 6), both sides were treated concurrently in two patients, and both sides were treated consecutively in two patients. Tremor was assessed using the Clinical Rating Scale for Tremor (CRST). Because international clinical specialists could not visit Russia due to the COVID-19 pandemic, MRgFUS was performed via telehealth on May 5, 2020, in a world first.

Results. A satisfactory result was achieved in 25 (96%) out of 26 patients. CRST scores improved by 64.7% on the side of the operation, by 10.2% on the control side, and by 37.5% overall. Intraoperative side effects included headache during sonication (42.3%), vertigo (15.4%), nausea (11.5%), vomiting (7.7%), numbness (3.8%), ataxia (3.8%), and pathological response to cold exposure (3.8%). The symptoms resolved immediately after surgery. Unstable gait was noted in five patients, which completely resolved two weeks after surgery. Median postoperative follow-up duration was 109 days [53; 231], with a maximum of 625 days. No relapses (if the hyperkinesia had completely disappeared) or increased tremor (if reduced after surgery) were observed.

Conclusion. The efficacy of MRgFUS for ET was 96%, with no long-term complications. Both bilateral concurrent and bilateral consecutive MRgFUS thalamotomy is possible, but its efficacy and safety should be assessed in a randomized study. In a world first, MRgFUS was successfully implemented using telehealth.

Introduction. More than 50,000 haematopoietic stem cell transplantations (HSCTs) are performed worldwide each year to treat malignant blood cancers, solid tumours, bone marrow aplasia, primary immunodeficiency conditions, autoimmune disorders, and storage disorders. The success of HSCTs depends on many factors, including patient's past medical history.

Purpose. To assess the effect of an acute cerebrovascular accident (CVA) that occurred before the HSCT on the transplantation outcome in patients with blood cancer.

Materials and methods. We examined the results of 899 transplantations conducted between 2016 and 2018 at the R.M. Gorbacheva Research Institute for Pediatric Oncology, Haematology and Transplantation of the Pavlov First Saint Petersburg State Medical University. We analysed transplantation parameters, as well as donor and recipient characteristics. Apart from intergroup comparisons, pseudo-randomization was performed using the Propensity Score Matching method. The survival rate analysis was conducted using the Kaplan–Meier estimate and the log rank test.

Results. Sixteen patients (1.8%) had cerebrovascular events in their past history before the HSCT: ischaemic stroke in 0.4% of cases and haemorrhagic stroke or intracerebral haemorrhage in 1.4% of cases. Patients with a history of cerebrovascular events included more people with leukaemia (p = 0.02), had more often received an allogenic transplant (р = 0.01), the donors more often had a partial rather than a full HLA match with the recipient (р = 0.06), had a lower body mass index (р = 0.02), and a lower Karnofsky/Lansky score (р = 0.01) than patients in the control group. The presence of a cardiovascular event had a statistically significant association with reduced overall survival rate of HSCT recipients (р = 0.0012).

Conclusion. Patients with blood cancer and stroke preceding the transplantation do not typically have any 'classical' risk factors (diabetes mellitus, venous system disorders, decreased cardiac output, significant atherosclerotic changes in precerebral arteries), therefore, secondary prevention guidelines for CVA during treatment of the main disease may not be effective and cannot be relied on. This article discusses the most likely causes of CVA in patients with blood cancer. A history of CVA before HSCT may have a significant effect on the transplantation outcome, but is not a contraindication for this treatment method. Recipient selection is a very important stage in HSCT planning. A multidisciplinary team should find a balance between the indications and contraindications for performing HSCT from an unrelated donor.

Introduction. Cerebral small vessel disease (CSVD), associated with age and vascular risk factors, as well as the main cause of vascular and degenerative mixed cognitive impairment (CI). Previously established microstructural predictors of CI (axial diffusion in normal-appearing periventricular white matter of the posterior left frontal lobe, the right midcingulate cortex, and the middle posterior part of the corpus callosum) can be used to calculate an integrative factor, exceeding the threshold value for which indicates the presence of CI. The use of this factor in the diagnosis of CI in CSVD is supported by the fact that leading mechanisms of CSVD are involved in the damage to areas of the brain that are strategic for CI.

The aim of this study was to clarify the link between the known microstructural predictors of CI in CSVD and MRI findings that correspond to the main mechanisms of CSVD.

Materials and methods. Patients (n = 74; including 48 women; average age 60.6 ± 6.9 years) with CSVD and CI of varying severity underwent phase-contrast MRI and voxel-based morphometry (3T) to assess arterial, venous and CSF flow, as well as atrophy.

Results. The established microstructural predictors of CI correlated with measures of arterial and venous blood flow, as well as atrophy. Linear regression models allow us to estimate cognitive impairment (CI) predictors in cerebral small vessel disease (CSVD), based on increased arterial velocity pulse index, CSF flow at the level of the cerebral aqueduct, cerebral aqueduct area and lateral ventricles volume, when there is reduced blood flow in the superior sagittal sinus and the overall arterial blood flow.

Conclusion. The ability to calculate microstructural predictors of CI due to CSVD, based on MRI findings, indicates the validity of using an integrative measure of microstructural predictors of CI as a diagnostic tool of CI in CSVD.

Cerebellar degeneration remains a poorly studied topic. Excitotoxicity, i.e. neuronal damage and death due to excess activation of postsynaptic N-methyl-D-aspartate receptors (NMDAR) by glutamate, is considered to be a universal mechanism of most neurodegenerative conditions. The use of antagonists that predominantly block NMDAR in cases of excitotoxicity is a very promising treatment strategy for neurodegenerative disorders.

This review presents the known structure and function of NMDAR. Information on studies investigating the use of NMDAR antagonists in the treatment of neurodegenerative diseases is provided. Creation of new therapies to correct excitotoxicity in various neurodegenerative disorders, for example, spinocerebellar ataxias, requires further study of the subunit composition and the role of NMDAR in the cerebellum. Treatment methods that combine the use of extrasynaptic NMDAR antagonists or synaptic NMDAR agonists with drugs that affect the total amount of glutamate in the synaptic cleft are promising.

This review contains up-to-date information on the fundamentals and clinical aspects of white matter disease in chronic progressive cerebrovascular disease with cognitive impairment, the leading risk factors for which are hypertension and cerebral atherosclerosis. Highly informative methods of neuroimaging have contributed significantly to the study of this problem, confirming the important role of white matter changes in the development and progression of cognitive impairment. The full range of the morphological changes in white matter, typical of vascular encephalopathy and cognitive dysfunction, is presented. Chronic hypoperfusion and white matter ischaemia play a leading role in the pathogenesis of white matter changes in vascular dementia development, but alternative hypotheses are also emerging. Further fundamental morphological and clinical studies will help to determine the leading mechanisms of white matter damage in patients with vascular and other age-related forms of dementia. This is necessary for the development of effective methods of treatment and prevention.

Specific mechanisms underlying the therapeutic effects of neurostimulation in Parkinson's disease remain a topic of discussion and intense study. Understanding these mechanisms can serve as the foundation for developing and selecting more effective parameters to relieve the symptoms of Parkinson's disease, maximize the advantages, and reduce the adverse effects and need for surgical intervention. The article discusses existing models of motor control in the basal ganglia in healthy individuals and in PD from the point of view of neuromodulation (changes in the impulse flow model, oscillatory model), as well as the current understanding of the mechanisms of action of deep brain stimulation (DBS): the block depolarization hypothesis, neural interference hypothesis, synaptic depression hypothesis, synaptic modulation hypothesis, and the DBS astrocytes hypothesis. Factors such as DBS location and neurostimulation parameters, affecting the clinical outcome, are considered in detail. The neuroprotective effect of DBS is also touched on.

We present a description of internal carotid artery restenosis five years after eversion carotid endarterectomy, progression of contralateral internal carotid artery stenosis and coronary atherosclerosis with imaging of haemodynamically significant stenosis of the anterior descending artery. The efficacy of hybrid revascularization is demonstrated: carotid angioplasty with stenting of the left internal carotid artery stenosis + percutaneous coronary intervention for the anterior descending artery + left carotid endarterectomy. We explain the choice of these types of reconstruction and staging of the intervention. We make a conclusion regarding the effectiveness and safety of the implemented treatment strategy.