[A modern concept of mixed dementia]

Beneath the Top of the Iceberg: Financial Capacity Deficits in Mixed Dementia with and without Depression

Nowadays, controversy exists regarding the influence of comorbid depression on cognition in old age. Additionally, we still know little about the influence of depression in mixed dementia (MD), that is, in cases where there is the co-existence of Alzheimer's disease and vascular dementia (VaD). Given that the assessment of financial capacity is pivotal for independent living as well as in the prevention of financial exploitation and abuse in old age, in this pilot study, we aimed to examine whether comorbid depression in MD patients can influence financial capacity performance. A total of 115 participants were recruited. They were divided into four groups: MD patients with and without depressive symptoms and healthy elderly without depression as well as older adults suffering from depression. Participants were examined with a number of neuropsychological tests, including the Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS-15), and Legal Capacity for Property Law Transactions Assessment Scale (LCPLTAS). The results of this study suggested that financial capacity as measured with LCPLTAS in MD patients was severely impaired when depression co-existed compared to patients suffering only from depression and healthy controls. Deficits in financial capacity in MD and comorbid depression should be a point on which healthcare professionals should focus during neuropsychological assessment in order to prevent financial exploitation.

[Cerebrovascular disease with neurocognitive impairment]

In the International Classification of Diseases 11th revision in the section «Diseases of the nervous system», it is proposed to distinguish «Cerebrovascular disorder with neurocognitive impairment», which corresponds to both discirculatory encephalopathy (DEP) or chronic cerebral ischemia (CCI) accepted in our country, and also vascular cognitive impairments. The terminology, prevalence, risk factors and pathological basis of the disease are discussed, in particular multiple infarctions, strategic infarctions, cerebral small vessel disease, specific microangiopathies, intracerebral hemorrhage and global hypoperfusion. Post-stroke cognitive impairments are discussed in detail. The article presents relevant data on the pathogenesis of the disease, highlights the issues of clinical and neuroimaging diagnostics. Based on the data presented in the article, we can conclude that the diagnosis of DEP, CCI should be based on the presence of cerebrovascular disease with neurocognitive impairment, which implies the verification of vascular cognitive impairments and reliable neuroimaging signs of cerebrovascular pathology while excluding other causes. Early diagnosis and effective treatment of cerebrovascular disease with neurocognitive impairment (DEP, CCI) is becoming increasingly important, since treatment can slow the progression of the disease and lead to a decrease in the incidence of stroke and dementia.

[Results of the round table: modern approaches to drug therapy of cognitive impairment in cerebrovascular pathology]

On June 25-26, 2021, a round table was held in Kazan with the participation of leading neurologists of Russia, where the issues of treatment of patients with cognitive impairment due to cerebrovascular diseases were discussed. Cognitive disorders of vascular genesis (VCD) are widespread in the population, are a common cause of a decrease in the quality of life and restriction of daily activity. The cause of VCD is both acute and chronic cerebrovascular diseases. An effective way to prevent VCD is to control cardiovascular risk factors, ensure a sufficient level of cognitive and physical activity throughout life. The role of drug therapy, aimed, among other things, at normalizing metabolic processes in the brain, is extremely important. The data on the mechanisms of action of the new domestic drug prospecta, the results of its clinical trials in patients with VCD are presented.

[Neurophysiological correlates of postoperative cognitive disorders]

OBJECTIVE

A special place among cognitive disorders in patients with cardiovascular diseases is given to postoperative cognitive dysfunction (POCD). The study aimed at investigating the patterns of beta-2 activity associated with postoperative cognitive dysfunction (POCD) in patients after coronary artery bypass grafting (CABG).

MATERIAL AND METHODS

The study included 60 patients who underwent neuropsychological testing 3-5 days before surgery and on the 7-10^th day of CABG. A multichannel electroencephalogram of resting state with eyes closed in 62 standard leads was recorded. Statistical processing of the results was carried out using Statistica 10 (StatSoft Inc, USA) and the developed method of data clustering with a minimax criterion, a software implementation of the binary clipping and branching algorithm was used to find optimal solutions.

RESULTS

Patients with POCD had higher pre- and postoperative high-frequency beta-2 rhythm power (20-30 Hz) compared with patients without cognitive impairment. The regression model demonstrated that POCD was associated with high values of preoperative beta-2 activity in the right frontal cortex and with low values in the left parietal areas after CABG. The clustering of beta-2 rhythm power before and after CABG revealed that the best cognitive status corresponded to a stable affiliation of patients with the selected clusters.

CONCLUSION

The specific POCD correlates were established in patients after CABG. Low cognitive status was characterized by the preoperative beta-2 power increase in the right frontal areas and postoperative decrease in the left parietal cortex. The developed method for classifying patients according to the level of pre- and postoperative beta-2 rhythm power has a good discriminant ability. Stable patient affiliation with the selected clusters was associated with a higher level of cognitive status.

The Role of NADPH Oxidases and Oxidative Stress in Neurodegenerative Disorders

For a number of years, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOX) was synonymous with NOX2/gp91^phox and was considered to be a peculiarity of professional phagocytic cells. Over the last decade, several more homologs have been identified and based on current research, the NOX family consists of NOX1, NOX2, NOX3, NOX4, NOX5, DUOX1 and DUOX2 enzymes. NOXs are electron transporting membrane proteins that are responsible for reactive oxygen species (ROS) generation-primarily superoxide anion (O₂^●-), although hydrogen peroxide (H₂O₂) can also be generated. Elevated ROS leads to oxidative stress (OS), which has been associated with a myriad of inflammatory and degenerative pathologies. Interestingly, OS is also the commonality in the pathophysiology of neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). NOX enzymes are expressed in neurons, glial cells and cerebrovascular endothelial cells. NOX-mediated OS is identified as one of the main causes of cerebrovascular damage in neurodegenerative diseases. In this review, we will discuss recent developments in our understanding of the mechanisms linking NOX activity, OS and neurodegenerative diseases, with particular focus on the neurovascular component of these conditions. We conclude highlighting current challenges and future opportunities to combat age-related neurodegenerative disorders by targeting NOXs.

[Mixed dementia: the role of cerebrovascular pathology]

Alzheimer's disease and vascular dementia are two most common causes of dementia in late life. The combination of Alzheimer's type dementia and vascular dementia is the third most common form of dementia, especially in the elderly. Most clinical forms of dementia are characterized by the presence of 'overlap' symptoms of both neurodegenerative and vascular pathology, which makes it expedient to consider mixed dementia as a separate entity characterized by clinical presentations, course and the rate of progression of cognitive decline. Despite the lack of clinical guidelines for management of patients with mixed dementia, it seems appropriate to use strategies that have shown their effectiveness in various types of cognitive impairment.

An Overview of Systematic Reviews of Ginkgo biloba Extracts for Mild Cognitive Impairment and Dementia

Ginkgo biloba extracts (GBEs) have been recommended to improve cognitive function and to prevent cognitive decline, but earlier evidence was inconclusive. Here, we evaluated all systematic reviews of GBEs for prevention of cognitive decline, and intervention of mild cognitive impairment (MCI) and dementia. Six databases from their inception to September 2015 were searched. Ten systematic reviews were identified, including reviews about Alzheimer's disease (n = 3), about vascular dementia (n = 1), about both Alzheimer's disease and vascular dementia (n = 2), about Alzheimer's disease, vascular dementia and mixed dementia (n = 3), and a review about MCI (n = 1). Based on the overview quality assessment questionnaire, eight studies were scored with at least 5 points, while the other two scored 4 points and 3 points, respectively. Medication with GBEs showed improvement in cognition, neuropsychiatric symptoms, and daily activities, and the effect was dose-dependent. Efficacy was convincingly demonstrated only when high daily dose (240 mg) was applied. Compared with placebo, overall adverse events and serious adverse events were at the same level as placebo, with less adverse events in favor of GBE in the subgroup of Alzheimer's disease patients, and fewer incidences in vertigo, tinnitus, angina pectoris, and headache. In conclusion, there is clear evidence to support the efficacy of GBEs for MCI and dementia, whereas the question on efficacy to prevent cognitive decline is still open. In addition, GBEs seem to be generally safe.