Rheoencephalography Research Articles

Cerebral hemodynamic disorders in patients with schizophrenia with concomitant metabolic syndrome

To identify the differences or comparability of parameters of cerebral hemodynamics between patients with schizophrenia with or without concomitant metabolic syndrome (MS). The study included 94 patients with schizophrenia (48 men and 46 women). A control group consisted of 40 mentally and somatically healthy individuals (17 men and 23 women) comparable in sex and age to the main group of patients. The diagnosis of metabolic syndrome was carried out according to the criteria of the International Diabetes Federation (IDF). Assessment of cerebral hemodynamics was carried out by 4 - channel rheoencephalography (REG) at rest with closed eyes. Data analysis was carried out using the Kraskel-Wallis ANOVA criterion with the procedure of automatic a posteriori pairwise comparison, the χ2 criterion and Spearman correlation analysis. According to the IDF criteria, 37 (39.4%) patients were diagnosed with MS. REG results revealed significantly (p<0.05) lower indicators of blood filling in the carotid basin, elasticity of the wall of the main arteries, the tone of small-caliber arteries and arterioles, as well as higher values of the tone of medium-caliber arteries in the carotid and vertebrobasilar basins, in both groups of patients with schizophrenia compared with the control group. In patients with schizophrenia with MS, compared with patients without MS, there were lower indicators of blood filling (p=0.044 and p=0.016) and elasticity of the wall of the main arteries (p=0.044 and p=0.028) in the carotid basin on the left and right sides. The presence of MS in patients with schizophrenia was accompanied by more pronounced disorders of cerebral blood flow in the form of a decrease in blood filling and elasticity of the wall of the main arteries in the carotid basin. The results indicate that patients with schizophrenia with MS should be considered as a group at increased risk of cerebrovascular diseases.

Stimulation of Cerebral Angiogenesis and Neurogenesis with Transcatheter Intracerebral Laser Photobiomodulation Therapy in Alzheimer’s Disease and Vascular Parkinsonism Aggravated by Dementia

AbstractBackgroundThe research is focused on the stimulation of cerebral angiogenesis and neurogenesis using Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT) in patients with dementia in Alzheimer’s disease (AD) and patients with vascular parkinsonism (VP).MethodThe examination of 155 patients included assessment of CDR, The Tomography Dementia Rating scale (TDR), MMSE, cerebral CT, MRI, SG, rheoencephalography (REG) and cerebral MUGA.85 patients were selected, of whom:• 48 (30.97%) people suffering from AD, aged 34‐80 (mean age 67.5), men ‐ 17 (35.42%), women ‐ 31 (54.58%). According to dementia severity, patients were subdivided: preclinical stage (TDR‐0) ‐ 4, mild stage (TDR‐1) ‐ 16, moderately severe stage (TDR‐2) ‐ 21, severe stage (TDR‐3) ‐ 7 patients.• 37 (23.87%) people suffering from VP, aged 58‐80 (mean age 77), men 28 (75.68%), women ‐ 9 (24.32%). 19 (51.35%) had a mild dementia stage (CDR‐1).In hospital conditions, in a specialized cath lab, all patients underwent Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT) (wavelength 632.8 nanometers).ResultAll 48 (100%) patients with AD underwent angiogenesis stimulation resulting in cerebral collateral capillary revascularization and closure of atreriovenous shunts.Simultaneously, patients showed a 10‐20% increase in cerebral temporal lobes volume, which indicates cerebral neurogenesis development and tissue regeneration. The process was accompanied by dementia level decrease and cognitive functions restoration. Consequently, patients were transferred to a milder TDR group. Depending on the initial dementia severity, the resulting positive effect was observed from 2 to 15 years.All 37 (100%) patients with VP underwent angiogenesis stimulation resulting in cerebral microcirculation improvement and cerebral involutive changes decrease, which indicates the neurogenesis development and tissue regeneration. The process was accompanied by decreased dementia and cognitive functions restoration. The resulting positive effect was observed over 10 years.ConclusionDespite the differences in AD and VP etiology, Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT) is an effective treatment for dementia in these diseases. The method stimulates angiogenesis and improves blood supply to the brain, it stimulates neurogenesis and the restoration of normal tissue structures, which leads to improved mental and cognitive functions. The resulting effect persists for a long time.

Cerebrovascular Changes in Dementia Patients with Alzheimer’s Disease and Vascular Parkinsonism

AbstractBackgroundWhen examining patients with dementia, it is necessary to clearly differentiate the developed cerebrovascular and microcirculatory changes. We present the features of cerebral angioarchitectonics and microcirculation in Alzheimer’s disease (AD) and vascular parkinsonism (VP).MethodsThe research included 155 patients. The examination included assessment of CDR, TDR, MMSE, cerebral MRI, CT, scintigraphy (SG), rheoencephalography (REG), cerebral multi‐gated angiography (MUGA).Patients were divided into:• 93 people aged 34‐80 (mean age 67.5): men ‐ 32 (34.40%), women ‐ 61 (65.59%), suffering from AD. According to dementia severity, patients were subdivided: (TDR‐0) ‐ 10, (TDR‐1) ‐ 29, (TDR‐2) ‐ 36, (TDR‐3) ‐ 18 people;• 62 people aged 52‐80 (mean age 77): men ‐ 48 (77.42%), women ‐ 14 (22.58%), suffering from VP. According to dementia severity, patients were subdivided: no dementia ‐ 30 people, dementia at level (CDR‐1) ‐ 32 people.ResultsIn AD patients, changes in angioarchitectonics and microcirculation are manifested in:• Absence of calcium salts deposits and atherosclerotic changes in intracerebral vessels;• Increased tortuosity of distal intracranial arteries;• Reduction of the capillary bed in the temporal and frontoparietal regions;• Development of multiple, large arteriovenous shunts with early venous discharge of arterial blood in the same regions;• Development of abnormal, intracerebral venous trunks;• Development of intracerebral stagnation of venous blood.These changes are called “Discirculatory angiopathy of Alzheimer’s type” (DAAT).In patients with VP, changes in angioarchitectonics and microcirculation are manifested in:• Multiple calcium salts deposits with atherosclerotic changes in intracranial vessels, mainly in the thalamus, basal ganglia, and pons;• Local decrease in subcortical cerebral capillary blood flow in the same regions;• Development of local subcortical small intracerebral arteriovenous shunts;• Absence of expressed intracerebral venous blood stagnation.ConclusionsDiscirculatory angiopathy of Alzheimer’s type (DAAT), regardless of dementia severity, is an AD‐specific cerebrovascular and microcirculatory lesion of the brain, unconnected with atherosclerotic process.In patients with VP, regardless of dementia, vascular and microcirculatory changes are atherosclerotic in nature. Capillary bed lesions, presence of arteriovenous shunts are subcortical in nature, mainly in the region of the thalamus, basal ganglia, and bridge. Marked venous stasis does not occur in this case.

Particularities of Cerebrovascular Changes in Patients with Dementia during Alzheimer’s Disease in Comparison with Distal Cerebral Atherosclerosis

AbstractBackgroundWhen studying the causes of dementia, there are certain difficulties in differentiating existing cerebrovascular changes. We present the features of cerebrovascular changes in Alzheimer’s disease (AD) and in distal forms of cerebral atherosclerosis.MethodsThe research included 935 patients, of whom: 93 people aged 34‐80 (mean age 67.5), 32 men (34.40%), 61 women (65.59%), suffered from AD. According to their dementia severity, the patients were subdivided: (TDR‐0) ‐ 10, (TDR‐1) ‐ 29, (TDR‐2) ‐ 36, (TDR‐3) ‐ 18;• 842 people aged 29‐81 (mean age 74.5), 622 men (73.87%), 220 women (26.13%), with distal cerebral atherosclerosis and chronic cerebrovascular insufficiency. According to their dementia severity, the patients were subdivided: (CDR‐1) ‐ 284, (CDR‐2) ‐ 18.• The examination plan included cerebral MRI, CT, scitrigraphy (SG), rheoencephalography (REG), cerebral multi‐gated angiography (MUGA).ResultsIn patients with AD, changes in angioarchitectonics and microcirculation are manifested in:• Absence of calcium salts deposits and atherosclerotic changes in intracerebral arteries;• Increased tortuosity of the distal parts of the intracerebral arteries;• Reduction of the capillary bed in the temporal and frontoparietal regions;• Development of multiple large arteriovenous shunts with early venous discharge of arterialblood in the same regions;• Development of abnormal venous trunks in the same regions;• Development of intracerebral stagnation of venous blood;These changes are called “Dyscirculatory angiopathy of Alzheimer’s type” (DAAT).In patients with distal cerebral atherosclerosis, changes in angioarchitectonics and microcirculation are manifested in:• Multiple calcium salts deposition and atherosclerotic changes in the intracerebral arteries;• Multiple disseminated contraction of the intracerebral capillary bed;• Development of multiple small disseminated intracerebral arteriovenous shunts;• Lack of pronounced intracerebral venous congestion.ConclusionsDyscirculatory angiopathy of Alzheimer’s type (DAAT), regardless of the severity of dementia, is an AD‐specific cerebrovascular and microcirculatory lesion of the brain not associated with atherosclerotic processes.In patients with distal cerebral atherosclerosis, regardless of the severity of dementia, vascular disorders are of disseminated atherosclerotic character. Anatomically, the lesion of the capillary bed and the presence of arteriovenous shunts are of disseminated character, and there is no pronounced venous stasis. Timely detection of these changes is very important for diagnosis.

Possibility of stimulation of cerebral angiogenesis and neurogenesis with transcatheter intracerebral laser photobiomodulation therapy during dementia in patients with Alzheimer’s disease and in patients with distal cerebral atherosclerosis

AbstractBackgroundThe research is dedicated to stimulation of cerebral angiogenesis and neurogenesis with Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT) in patients with dementia during Alzheimer’s disease (AD) and patients with distal forms of cerebral atherosclerosis.Materials &amp; Methods350 patients with dementia were examined.We carried out determination of CDR, Tomography Dementia Rating scale (TDR), MMSE, cerebral CT, MRI, SG, rheoencephalography (REG), cerebral MUGA.48 (13.71%) patients with AD aged 34‐80 (mean age 67.5) were selected: 17 men (35.42%), 31 women (54.58%). According to their dementia severity, the patients were subdivided: preclinical stage (TDR‐0) ‐ 4, mild stage (TDR‐1) ‐ 16, moderately severe stage (TDR‐2) ‐ 21, severe stage (TDR‐3) ‐ 7.302 (86.29%) patients with distal cerebral atherosclerosis aged 58‐81 (mean age 78) were selected: 226 men (74.83%), 76 women (25.17%). According to their dementia severity, the patients were subdivided: mild stage (СDR‐1) ‐ 284 (94.04%), moderately severe stage (СDR‐2) ‐ 18 (5.96%).At hospital, all the patients underwent PBMT.ResultsAll 48 (100%) patients with AD showed improved cerebral microcirculation and 10‐20% increase in the volume of cerebral temporal lobes, which indicates cerebral neurogenesis development and tissue regeneration. The process was accompanied by a decreased level of dementia and restoration of cognitive functions. Consequently, the patients were transferred to milder TDR groups. Depending on the initial dementia severity, the resulting positive effect was observed during 2‐10 years.All 302 (100%) patients with distal cerebral atherosclerosis showed improved cerebral microcirculation and declining cerebral involutional changes, which indicates neurogenesis development and tissue regeneration. The process was accompanied by a decreased dementia level and cognitive functions restoration. The resulting positive effect was observed for over 10 years.ConclusionsDespite differences in the etiology of AD and distal cerebral atherosclerosis, PBMT is an effective treatment for dementia in these diseases. The method improves the blood supply of the brain; it stimulates neurogenesis and tissue structures restoration, which leads to an improvement in mental and cognitive functions. The resulting effect persists for a long time.

Реґіонарна гемодинаміка ока при невриті зорового нерва

Background: Optic nerve disease accounts for up to 28% of all cases of visual disability. Although recent studies have demonstrated abnormal hemodynamics in optic neuritis (ON), results of different studies as well as data on the pathophysiology of vascular abnormalities are contradictory. Purpose: To assess regional hemodynamics on the basis of ophthalmic rheography (ORG) and rheoencephalography (REG) in patients with optic neuritis and those with complications of the disease. Material and Methods: Fifty-seven patients (82 affected eyes; 27 women and 30 men) who were examined for idiopathic ON at the Department of Ocular Inflammatory Disease, Filatov Institute of Eye Disease and Tissue Therapy, were included in the study and divided into four groups. They underwent a clinical ophthalmological examination as well as ORG and REG studies with the computerized rheography apparatus Reocom (Kharkiv). Results: Best-corrected visual acuity (BCVA) values were twofold to threefold lower for the eyes with partial optic atrophy (POA) after ON or those with macular involvement in ON than for the eyes with acute ON or prolonged ON. BCVA showed mild direct correlation with ocular pulse blood filling (OPBF) expressed as RQ (r = 0.24; р &lt; 0.05), and negative correlation with the presence of complications following ON (r = -0.35; р &lt; 0.05). RQ values in patients with acute ON were 15.5% higher than in controls (р &lt; 0.05) and 35% and 31% higher than in patients with POA following ON and patients developing macular lesion following ON, respectively (р &lt; 0.05). RQ values in patients with partial optic atrophy (POA) were 23.6% lower than in controls (р &lt; 0.05), which reflected regional ischemic process. The odds ratio (OR) for the presence of a reduced RQ value (a) in the eye with POA following ON compared to the eye with acute ON was 9.2 (P &lt; 0.05, 95% confidence interval 2.0–42.4), and (b) in the eye developing macular lesion following ON compared to the eye with acute ON was 4.3 (P &lt; 0.05, 95% CI, 1.2–14.7). Pulse blood filling as assessed by rheography index (RI) in the internal carotid artery (ICS) was actually normal in patients with acute ON and 44% increased in patients with prolonged ON or outcome of ON compared to controls (р &lt; 0.05). In addition, tonicity of large vessels in the ICS and VBS as assessed by alpha/Т (%) was normal in patients with acute ON and at average 15% higher in patients with complications following ON. Moreover, tonicity of small-caliber vessels as assessed by the dicrotic index (DCI) and diastolic index (DSI) values was at average 32.2% and 55%, respectively, higher in patients than in controls. Conclusion: We revealed features of ocular and brain hemodynamics in patients with acute ON, prolonged ON and those with complications of the disease.

Noninvasive neuromonitoring with rheoencephalography: a case report.

Cerebral blood flow (CBF) autoregulation (AR) can be monitored using invasive modalities, such as intracranial pressure (ICP) and arterial blood pressure (ABP) to calculate the CBF AR index (PRx). Monitoring PRx can reduce the extent of secondary brain damage in patients. Rheoencephalography (REG) is an FDA-approved non-invasive method to measure CBF. REGx, a CBF AR index, is calculated from REG and arm bioimpedance pulse waves. Our goal was to test REG for neuromonitoring. 28 measurement sessions were performed on 13 neurocritical care patients. REG/arm bioimpedance waveforms were recorded on a laptop using a bioimpedance amplifier and custom-built software. The same program was used for offline data processing. Case #1: The patient's mean REGx increased from - 0.08 on the first day to 0.44 on the second day, indicating worsening intracranial compliance (ICC) (P < 0.0001, CI 0.46-0.58). Glasgow Coma Scale (GCS) was 5 on both days. Case #2: REGx decreased from 0.32 on the first recording to 0.07 on the last (P = 0.0003, CI - 0.38 to - 0.12). GCS was 7 and 14, respectively. Case #3: Within a 36-minute recording, REGx decreased from 0.56 to - 0.37 (P < 0.0001, 95%, CI - 1.10 to - 0.76). Central venous pressure changed from 14 to 9 mmHg. REG pulse wave morphology changed from poor ICC to good ICC morphology. Bioimpedance recording made it possible to quantify the active/passive status of CBF AR, indicate the worsening of ICC, and present it in real time. REGx can be a suitable, non-invasive alternative to PRx for use in head-injured patients.

Characteristics of Rheoencephalography and some Associated Factors on Menopausal Women.

The significant drop in estrogen levels during menopause increases the cardiovascular risks, one of which is cerebrovascular atherosclerosis. Research on rheoencephalography (REG) parameters for the early diagnosis of cerebrovascular atherosclerotic lesions is of great interest to scientists because of its ease of implementation, low cost, and non-invasiveness. The objectives of study are to evaluate the vascular tone, cerebral circulation flow in each hemisphere of the brain of menopausal women, and some associated factors through waveform characteristics and parameters in REG. A controlled cross-sectional descriptive study was conducted on a group of patients including 80 menopausal women and a control group of 46 menstruating women. All patients were measured REG in the frontal-occipital leads by VasoScreen 5000 impedance REG meter. In menopausal women, the percentage of sharp waves, the percentage of clear side waves, and the average REG were all lower than in the control group (p<0.01). The mean conduction time and mean slope ratio was lower than the control group (p<0.001). The mean peak time was higher than the control group (p<0.01). The mean elasticity index (alpha/T) was higher than the control group (p<0.001). Menopausal women have increased vascular tone, the highest in the group of women 50-60 years old, menopause <5 years, having a habit of eating red meat; and decreased blood flow intensity, the highest in the group of women <50 years old. However, the difference was statistically significant only in the left hemisphere (p<0.05). Vascular hypertonia in menopausal women with central obesity was higher than in the non-obese group in both hemispheres (p<0.05). In conclusion, menopausal women had atherosclerosis in both hemispheres of the brain, which was clearly shown in the rate of increased vascular tone. Central obesity may increase the risk of vascular hypertonia 3.75 times in the right and 5.44 times in the left hemisphere.

Assessing rheoencephalography dynamics through analysis of the interactions among brain and cardiac networks during general anesthesia.

Cerebral blood flow (CBF) reflects the rate of delivery of arterial blood to the brain. Since no nutrients, oxygen or water can be stored in the cranial cavity due to space and pressure restrictions, a continuous perfusion of the brain is critical for survival. Anesthetic procedures are known to affect cerebral hemodynamics, but CBF is only monitored in critical patients due, among others, to the lack of a continuous and affordable bedside monitor for this purpose. A potential solution through bioelectrical impedance technology, also known as rheoencephalography (REG), is proposed, that could fill the existing gap for a low-cost and effective CBF monitoring tool. The underlying hypothesis is that REG signals carry information on CBF that might be recovered by means of the application of advanced signal processing techniques, allowing to track CBF alterations during anesthetic procedures. The analysis of REG signals was based on geometric features extracted from the time domain in the first place, since this is the standard processing strategy for this type of physiological data. Geometric features were tested to distinguish between different anesthetic depths, and they proved to be capable of tracking cerebral hemodynamic changes during anesthesia. Furthermore, an approach based on Poincaré plot features was proposed, where the reconstructed attractors form REG signals showed significant differences between different anesthetic states. This was a key finding, providing an alternative to standard processing of REG signals and supporting the hypothesis that REG signals do carry CBF information. Furthermore, the analysis of cerebral hemodynamics during anesthetic procedures was performed by means of studying causal relationships between global hemodynamics, cerebral hemodynamics and electroencephalogram (EEG) based-parameters. Interactions were detected during anesthetic drug infusion and patient positioning (Trendelenburg positioning and passive leg raise), providing evidence of the causal coupling between hemodynamics and brain activity. The provided alternative of REG signal processing confirmed the hypothesis that REG signals carry information on CBF. The simplicity of the technology, together with its low cost and easily interpretable outcomes, should provide a new opportunity for REG to reach standard clinical practice. Moreover, causal relationships among the hemodynamic physiological signals and brain activity were assessed, suggesting that the inclusion of REG information in depth of anesthesia monitors could be of valuable use to prevent unwanted CBF alterations during anesthetic procedures.

Scalp-Mounted Electrical Impedance Tomography of Cerebral Hemodynamics.

An Electrical Impedance Tomography (EIT) system has been developed for dynamic three-dimensional imaging of changes in conductivity distribution in the human head, using scalp-mounted electrodes. We attribute these images to changes in cerebral perfusion. At 100 frames per second (fps), voltage measurement is achieved with full-scale signal-to-noise ratio of 105 dB and common-mode rejection ratio > 90 dB. A novel nonlinear method is presented for 3-D imaging of the difference in conductivity distribution in the head, relative to a reference time. The method achieves much reduced modelling error. It successfully localizes conductivity inclusions in experimental and simulation tests, where previous methods fail. For > 50 human volunteers, the rheoencephalography (REG) waveform is observed in EIT voltage measurements for every volunteer, with peak-to-peak amplitudes up to approx. 50 μVrms. Images are presented of the change in conductivity distribution during the REG/cardiac cycle, at 50 fps, showing maximum local conductivity change of approx. 1% in grey/white matter. A total of 17 tests were performed during short (typically 5s) carotid artery occlusions on 5 volunteers, monitored by Transcranial Doppler ultrasound. From EIT measurements averaged over complete REG/cardiac cycles, 13 occlusion tests showed consistently decreased conductivity of cerebral regions on the occluded side, and increased conductivity on the opposite side. The maximum local conductivity change during occlusion was approx. 20%. The simplicity of the carotid artery intervention provides a striking validation of the scalp-mounted measurement system in imaging cerebral hemodynamics, and the REG images indicate its unique combination of sensitivity and temporal resolution.

Differences between vascular and microcirculatory disorders of the brain in patients with dementia suffering from Alzheimer's disease and Binswanger's disease.

During differential diagnosis of various types of dementia, there are certain difficulties in determining disorders of cerebral angioarchitectonics and microcirculation. We present the features of cerebrovascular and microcirculatory disorders in Alzheimer's disease (AD) and Binswanger's disease (BD). The research included 120 patients, of whom: (1) 93 aged 34-80 (average age 67.5), 32 (34.40%) men and 61 (65.59%) women, suffering from AD. According to dementia severity, the patients were subdivided: (TDR-0) - 10, (TDR-1) - 29, (TDR-2) - 36, (TDR-3) - 18 people; (2) 27 aged 58-81 (average age 78), 17 (62.96%) men and 10 (27.04%) women, suffering from BD. The patients were subdivided according to dementia severity: (CDR-1) - 17, (CDR-2) - 10 people. The examination plan included cerebral MRI, CT, scitrigraphy (SG), rheoencephalography (REG), cerebral multi-gated angiography (MUGA). Patients with AD show the following changes in angioarchitectonics and microcirculation: (1) No calcium salts deposits in intracerebral vessels; (2) Increased tortuosity of distal intracranial arteries; (3) Capillary bed reduction in the temporal and fronto-parietal regions; (4) Development of multiple arteriovenous shunts in the same regions; (5) Development of abnormal venous trunks with early venous discharge of arterial blood in the same regions; (6) Development of intracerebral stasis of venous blood. These vascular changes are called dyscirculatory angiopathy of Alzheimer's type (DAAT). Patients with BD show the following changes in angioarchitectonics and microcirculation: (1) Multiple calcium salts deposition in intracerebral vessels; (2) Disseminated reduction of the capillary bed in the subcortical regions; (3) Development of multiple disseminated arteriovenous shunts in the subcortical regions; (4) No pronounced intracerebral venous stasis. Dyscirculatory angiopathy of Alzhemer's type, regardless of dementia severity, is a cerebrovascular and microcirculatory brain lesion specific for AD and not associated with atherosclerotic process. BD patients, irrespective of dementia severity, have vascular disorders of atherosclerotic nature. Anatomically, capillary bed reduction and arteriovenous shunts are located exclusively in the white matter of the brain. Due to the disseminated development of arteriovenous shunts, pronounced venous stasis does not occur. Timely identification of these changes is of an important diagnostic nature.

Stimulation of cerebral angiogenesis and neurogenesis with transcatheter intracerebral laser photobiomodulation therapy during dementia in patients with Alzheimer's and Binswanger's disease

AbstractBackgroundThe research investigates stimulation of cerebral angiogenesis and neurogenesis with Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT) in patients with dementia with Alzheimer's disease (AD) and Binswanger's disease (BD).Materials &amp; MethodsExamined 120 patients suffering from dementia. Accomplished: CDR assessment, Tomography Dementia Rating scale (TDR), MMSE, cerebral CT, MRI, SG, rheoencephalography (REG), cerebral MUGA. We chose 48 patients suffering from AD aged 34‐80 (mean age 67.5), 17 men (35.42%) and 31 women (54.58%). The patients were subdivided according to dementia severity: preclinical stage (TDR‐0 dementia level) ‐ 4, mild stage (TDR‐1 dementia level) ‐ 16, moderately severe stage (TDR‐2 dementia level) ‐ 21, severe stage (TDR‐3 dementia level) ‐ 7 patients. 17 patients with BD aged 58‐81 (mean age 78) were selected, 11 men (64.71%) and 6 women (35.29%). According to dementia severity, the patients were subdivided: mild stage (dementia level CDR‐1) ‐ 9, moderately severe stage (dementia level CDR‐2) ‐ 5 patients. In hospital setting, all patients underwent Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT).ResultsAll 48 (100%) patients with AD showed cerebral microcirculation improvement, as well as a 10‐20% increase in cerebral temporal lobes volume, which indicates cerebral neurogenesis development and tissue regeneration. The process was accompanied by dementia level decline and cognitive functions restoration. As a result, patients were transferred to the milder TDR stage group. Depending on the initial dementia severity, the obtained positive effect has been observed for 2‐10 years. All 17 (100%) patients with BD showed cerebral microcirculation improvement and cerebral involutional changes decline, which indicates neurogenesis development and tissue regeneration. The process was accompanied by dementia level decline and cognitive functions restoration. The resulting positive effect has been observed for over 10 years.ConclusionsDespite the differences in the etiology of AD and BD, Transcatheter Intracerebral Laser Photobiomodulation Therapy (PBMT) is an effective treatment for dementia during these diseases. The method improves cerebral blood flow; it stimulates neurogenesis and tissue structure restoration, which lead to dementia decline and cognitive functions improvement. The resulting effect lasts for a long time.

Exposure to low output power laser with transcatheter intracerebral photobiomodulation therapy reduces mental and cognitive disorders and dementia in Alzheimer's disease

AbstractBackgroundTranscatheter Intracerebral Photobiomodulation Therapy (PBMT) using low output power laser is a promising area in AD treatment. The method is aimed at stimulating angiogenesis, restoring cerebral microcirculation, stimulating metabolic processes and ATP metabolism in neuronal mitochondria, stimulating neurogenesis and regenerating cerebral tissues.MethodThe treatment was performed for 93 patients suffering from various AD stages with dementia, cognitive and mental disorders aged 34‐80 (average age 67.5), men ‐ 32 (34.40%), women ‐ 61 (65.59%). The examination included: CDR determination, MMSE testing, CT, MRI with calculation of temporal lobe atrophy degree and determination of dementia stage using the Tomography Dementia Rating scale (TDR), cerebral scintigraphy (SG), rheoencephalography (REG), cerebral MUGA. Test Group: 48 (51.61%) patients underwent transcatheter intracerebral Photobiomodulation Therapy (PBMT) using a helium‐neon laser. According to atrophy and dementia degree, cognitive and mental disorders severity, the patients were divided: preclinical AD stage (TDR‐0) ‐ 4 (8.33%); early AD stage (TDR‐1) ‐ 16 (33.33%); medium AD stage (TDR‐2) ‐ 21 (43.76%); severe AD stage (TDR‐3) ‐ 7 (14.58%) patients. Control Group: 45 (48.39%) patients underwent conservative treatment (Memantine 5‐20mg or Rivastigmine 3‐12 mg daily). According to atrophy degree, the severity of dementia, cognitive and mental disorders, the patients were divided: preclinical AD stage (TDR‐0) ‐ 6 (13.33%); early AD stage (TDR‐1) ‐ 13 (28.89%); medium AD stage (TDR‐2) ‐ 15 (33.34%); severe AD stage (TDR‐3) ‐ 11 (24.44%) patients.ResultAn early follow‐up period of 6‐12 months. Test Group: all 48 (100%) patients showed improvement in cerebral microcirculation and signs of cerebral temporal lobes volume increase, which indicates neurogenesis and cerebral regenerative changes. The process was accompanied by clinical condition improvement, dementia decline, cognitive and mental functions restoration. Control Group: during the treatment, there was no stable improvement in the patients’ condition but a tendency to further increase in cerebral involutive changes, which was accompanied by dementia growth, cognitive and mental impairment.ConclusionTranscatheter intracerebral PBMT is a promising, effective AD treatment. It diminishes dementia, cognitive and mental disorders, and allows improving the quality of patients’ life and restoring their daily activity.

A noninvasive, continuous brain monitoring method: rheoencephalography (REG)

This paper deals with the sustainability under anoxic conditions of human beings, both when healthy, and diseased. As our attention is focused these days on the environment, sustainability, and green energy, a similar effort is being made in neuromonitoring to switch from invasive to noninvasive monitoring methods. Keys to these changes are computerization and shrinking size of electronic hardware. Computerization is going on in all areas of biomedical engineering, both in research and in clinical fields of medicine. In neurology, brain imaging is the most characteristic change in recent decades. These modalities of imaging (MRI, CT, PET scan, etc.) are predominantly utilized for localizing brain pathology. Brain imaging offers great spatial resolution, but poor time resolution. Therefore, for continuous monitoring, neurocritical care departments require an additional tool with good time resolution. There are invasive and noninvasive neuromonitoring methods. The standard method to monitor intracranial pressure (ICP) is an invasive method. Computerization allows for calculating the cerebral blood flow autoregulation (CBF AR) index (pressure reactivity index - PRx) from ICP and systemic arterial pressure (SAP) in real time, continuously, but invasively. The new development, discussed in this paper, is to calculate this index noninvasively by using rheoencephalography (REG), called REGx. We present the road to this invention and summarize multifold REG related results, such as using REG for primary stroke prevention screening, comparison incidence of arteriosclerotic risk factors, various studies by using CBF manipulations, and correlations with other neuromonitoring methods, and validation with in vitro and in vivo methods. REG by using different algorithms allow for real time calculation of autoregulated blood flow. This paper presents results of validation of CBF algorithms as an effective, noninvasive method. The author’s intent is to supply sufficient physiological background information. This review covers the author’s research efforts over several decades; it pertains multiple studies and has an updated addition to human sustainability by considering that Covid-19 is increasing stroke and cardiovascular disease (CVD) morbidity and mortality.

PROTECTIVE MECHANISMS AGAINST HYPOXIA IN DIVING SIMULATION IN SWIMMERS

Aim. The article deals with studying the systemic protective mechanisms of the brain against hypoxia during water immersion in highly skilled swimmers. Material and methods. 25 males aged 18–20 years were examined: 9 masters of sports, one master of sports of international class and 15 people not involved in sports. The study of cerebral blood flow was carried out by rheoencephalography (REG). REG was recorded at rest, when the face was immersed in water and during recovery. Examination was carried out 2 hours after the morning training session. In addition to cerebral blood flow, ECG and blood pressure were recorded at rest, during water immersion and recovery. Statistical data processing was performed using nonparametric Mann–Whitney and Wilcoxon criteria. Results. It was revealed that athletes at rest demonstrated more pronounced asymmetry of blood circulation and higher blood flow in the right hemisphere than people not involved in sports. However, during water immersion, the asymmetry disappears, blood flow improves, especially in the left hemisphere in the carotid artery territory as a result of a decrease in the tone of small vessels. In people not involved in sports, protective mechanisms are less pronounced. Conclusion. Vast experience in sports activities related to exercises performed in water and to training hypoxic exercises contributed to effective protective mechanisms against hypoxia based on the diving reflex.

Features of rheoencephalography in children with primary mitral valve prolapse

Annotation. Mitral valve prolapse (MVP), as a manifestation of connective tissue dysplasia, is of great interest in the field of medicine. It occupies an important place in the structure of diseases of the cardiovascular system, which is mainly due to its high incidence and possible complications. MVP is detected in almost 2–3% of the population. In addition, this pathology with a genetic predisposition is a manifestation of a connective tissue defect and is rare in newborns and at an early age, which characterizes it as a progressive disease. At the moment, the features of cerebral hemodynamics in children with MVP are not well understood. The aim of our study was to study cerebral hemodynamics in children with primary mitral valve prolapse using quantitative indicators of rheoencephalography (REG). The study included patients with primary MVP. Under our supervision, there were 106 children aged 13 to 17 years. The control group included 23 healthy children at the same age. All children underwent a REG with quantitative indicators. In children with MVP, there is a variability in the results of REG in the cerebral hemispheres. Vascular elasticity is significantly reduced due to anacrot time increase (p&lt;0.001), which, in fact, is characteristic of the hypertonic type of blood flow (57.5%). It can be argued that in children there is a hypovolemic type of blood flow in the form of a decrease in the rheographic index relative to the control group (p&lt;0.05). There is a tendency to vascular tone tension of all calibers according to the absence of statistically significant deviations of the corresponding indicators (dictrotic index and the ratio of the duration of the ascending phase to the duration of the entire pulse wave). The same picture is observed with venous blood flow, according to the values of the dystolic index in the carotid artery basin. In the basin of the vertebral artery there is a tendency to increase the tone of small vessels and venous vessels. Thus, in children with mitral valve prolapse, cerebral blood flow changes in the form of hypovolemia in the carotid artery basin and normovolemia in the vertebral artery basin according to REG parameters; in this group of children with MVP, there is a tendency to tension in the tone of blood vessels of all calibers according to the absence of statistically significant deviations of the corresponding indicators (dictrotic index and the ratio of the duration of the ascending phase to the duration of the entire pulse wave). Also, patients with MVP should be constantly monitored by narrow specialists (cardiologists, neurologists) for timely and adequate recovery.

P3‐036: LONG‐TERM RESULTS OF CEREBRAL NEUROGENESIS STIMULATION WITH TRANSCATHETER INTRACEREBRAL LOW‐LEVEL LASER (LIGHT) THERAPY FOR ALZHEIMER'S DISEASE

The research is devoted to long-term results of cerebral neurogenesis after trans-catheteric intracerebral Low-level Laser Therapy (LLLT) in Alzheimer's disease (AD) patients. 220 patients with AD were examined. The examination included CDR definition, Tomography Dementia Rating scale (TDR), MMSE, cerebral CT, MRI, SG, rheoencephalography (REG), cerebral MUGA. We selected 93 patients aged 34–80 (average age 67.5), 32 (34.40%) male, 61 (65.59%) female. - Test Group, 48 (51.61%) patients: preclinical stage (TDR-0 dementia level) - 4 patients, early stage (TDR-1) - 16, middle stage (TDR-2) - 21, severe stage (TDR-3) - 7 patients. They all underwent transcatheter intracerebral LLLT (helium-neon laser). - Control Group, 45 (48.39%) patients: preclinical stage (TDR-0 dementia level) - 6 patients, early stage (TDR-1) - 13, middle stage (TDR-2) - 15, severe stage (TDR-3) - 11 patients. These patients received conservative treatment (Memantine or Rivastigmine). All 48 (100%) Test Group patients demonstrated improved microcirculation along with improved metabolism in neurons, neurogenesis and cerebral regenerative processes with 10–20% increase in cerebral temporal regions volume. The process was accompanied by decrease in dementia level and cognitive functions restoration, which made it possible to transfer the treated patients to a lighter stage TDR group. The resulting positive effect in TDR-0 and TDR-1 patients was observed for 10 years; in TDR-2 patients - 4–5 years; in TDR-3 patients - 2−2.5 years. Control Group treatment resulted in a lack of neurogenesis, as well as in further increase in cerebral involutive changes and decrease in the volume of temporal lobes. In patients with early stages of AD (TDR-0, TDR-1), temporary stabilization of the condition was noted for 0.5 - 2 years followed by growing dementia and cognitive impairment. In patients with more severe stages of AD (TDR-2, TDR-3), further dementia and cognitive impairment growth was noted.

P1‐338: FEATURES OF CEREBRAL MICROCIRCULATION IN ALZHEIMER'S DISEASE

The research is devoted to specific features of cerebral microcirculation disorders in AD in comparison with other neurodegenerative and ischemic lesions. 1129 examined patients aged 34–81 (mean age 75.5), 801 male (70.95%), 328 female (29.05%), with various types of cerebral neurodegenerative and ischemic lesions. The examination included CDR identification, Tomography Dementia Rating scale (TDR), MMSE, cerebral CT, MRI, SG, rheoencephalography (REG), cerebral MUGA. - Test Group: 93 (8.24%) patients with AD. - Control Group: 605 (53.59%) patients with mild and moderate level of chronic cerebrovascular insufficiency of atherosclerotic genesis, 342 (30.29%) with severe chronic cerebrovascular insufficiency, 27 (2.39%) with Binswanger's disease, 62 (5.49%) with vascular parkinsonism. All 93 (100%) Test Group patients showed specific CSVDs called dyscirculatory angiopathy of Alzheimer's type (DAAT): absence of atherosclerotic changes of extra and intracerebral arteries; local decrease in the number of capillaries in the temporal and frontoparietal regions; local development of multiple arteriovenous shunts in the temporal and frontoparietal regions; local development of dilated venous trunks receiving blood from arteriovenous shunts of the temporal and frontoparietal regions; venous blood stagnation on the border of the frontal and parietal region; increased looping of distal intracerebral arteries. All 1036 (100%) Control Group patients demonstrated CSVD which were completely different from CSVD detected in patients with AD: 1004 (96.91%) patients had atherosclerotic changes of intracerebral arteries and arterioles; 932 (89.96%) - areas of lowered capillary blood supply disseminated in different cerebral parts; 893 (86.20%) - arteriovenous shunts disseminated in various cerebral parts-; no patients showed AD-specific local decrease in the number of capillaries, as well as no arteriovenous shunts in the temporal and frontoparietal parts; no AD-specific abnormally dilated venous trunks or blood stagnation at the level of the frontoparietal regions.

Entropy Measures as Descriptors to Identify Apneas in Rheoencephalographic Signals.

Rheoencephalography (REG) is a simple and inexpensive technique that intends to monitor cerebral blood flow (CBF), but its ability to reflect CBF changes has not been extensively proved. Based on the hypothesis that alterations in CBF during apnea should be reflected in REG signals under the form of increased complexity, several entropy metrics were assessed for REG analysis during apnea and resting periods in 16 healthy subjects: approximate entropy (ApEn), sample entropy (SampEn), fuzzy entropy (FuzzyEn), corrected conditional entropy (CCE) and Shannon entropy (SE). To compute these entropy metrics, a set of parameters must be defined a priori, such as, for example, the embedding dimension m, and the tolerance threshold r. A thorough analysis of the effects of parameter selection in the entropy metrics was performed, looking for the values optimizing differences between apnea and baseline signals. All entropy metrics, except SE, provided higher values for apnea periods (p-values < 0.025). FuzzyEn outperformed all other metrics, providing the lowest p-value (p = 0.0001), allowing to conclude that REG signals during apnea have higher complexity than in resting periods. Those findings suggest that REG signals reflect CBF changes provoked by apneas, even though further studies are needed to confirm this hypothesis.

Transcranial Impedance Changes during Sleep: A Rheoencephalography Study.

Objective: To demonstrate the utility of rheoencephalography (REG) for measuring cerebral blood flow and fluid dynamics during different stages of sleep. Methods: Anteroposterior cranial electrical impedance was measured with concurrent polysomnography in a group of healthy subjects during sleep. Transcranial electrical impedance was characterized by measuring the peak-to-trough and envelope of the filtered pulsative REG signal as well as its frequency. The sensitivity of the REG amplitude to changes in cerebral blood flow (CBF) was confirmed by the analysis of the signal during breathing maneuvers with known effects on CBF. The mean amplitude and variability of the REG characteristic parameters were averaged across all participants and were compared between different stages of sleep. Results: Average transcranial impedance was significantly lower during non-REM stages N1 and N2, compared to other sleep stages, suggesting a decrease in CBF volume. Stage N3 showed the slowest frequency indicating a slow heart rate during this stage. N3 also had the lowest variability in frequency and peak-to-trough amplitude. Conclusion: Measurement of transcranial electrical conductivity may be a viable non-invasive method for monitoring any potential changes in intracranial fluid homeostasis. Clinical Impact: In the absence of other convenient non-invasive methods, using REG to track intracranial fluid dynamics during sleep can facilitate an improved understanding of pathogenesis in Alzheimer’s disease.