Quantitative EEG and cognitive evoked potentials in anemia

Tooth loss and the risk of cognitive decline and dementia: A meta-analysis of cohort studies

Introduction

Epidemiological studies have shown that tooth loss may be associated with an increased risk of cognitive decline and dementia. However, some results do not show a significant association. Therefore, we performed a meta-analysis to evaluate this association.

Methods

Relevant cohort studies were searched in PubMed, Embase, Web of Science (up to May 2022), and the reference lists of retrieved articles. The pooled relative risk (RR) and 95% confidence intervals were computed using a random-effects model (CI). Heterogeneity was evaluated using the I 2 statistic. Publication bias was evaluated using the Begg's and Egger's tests.

Results

Eighteen cohort studies met the inclusion criteria. Original studies with 356,297 participants with an average follow-up of 8.6 years (ranging from 2 to 20 years) were included in this study. The pooled RRs of tooth loss on dementia and cognitive decline were 1.15 (95% CI: 1.10-1.20; P < 0.01, I 2 = 67.4%) and 1.20 (95% CI: 1.14-1.26; P = 0.04, I 2 = 42.3%), respectively. The results of the subgroup analysis showed an increased association between tooth loss and Alzheimer's disease (AD) (RR = 1.12, 95% CI: 1.02-1.23) and vascular dementia (VaD) (RR = 1.25, 95% CI: 1.06-1.47). The results of the subgroup analysis also showed that pooled RRs varied by geographic location, sex, use of dentures, number of teeth or edentulous status, dental assessment, and follow-up duration. None of the Begg's and Egger's tests or funnel plots showed evidence of publication bias.

Discussion

Tooth loss is associated with a significantly increased risk of cognitive decline and dementia, suggesting that adequate natural teeth are important for cognitive function in older adults. The likely mechanisms mostly suggested include nutrition, inflammation, and neural feedback, especially deficiency of several nutrients like vitamin D.

Associations between red blood cell indices and iron status and neurocognitive function in young adults: Evidence from memory and executive function tests and event-related potentials

Cognitive impairment has been associated with anemia and iron deficiency; however, brain electrophysiological studies correlating red blood cell (RBC) indices and iron status to cognition in adulthood are scarce. We aimed to assess neurocognitive function in young adults of the general population and its correlation with RBC indices and iron status. Neurocognitive function was investigated using scalp-recorded event-related potentials (ERPs) within the context of a task-switching paradigm. ERPs and test performance were also compared across groups of "high"/"low" RBC and iron indices. Working memory was examined using the digit span test, in which mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), and ferritin were found to be significant predictors of test performance, with higher MCH/MCV/ferritin being associated with better test scores. In the switching task, MCH, MCV, and ferritin were found to be significant predictors of task performance, with higher MCH/MCV/ferritin levels associated with a lower percentage of errors. Electrophysiological results showed that MCH and MCV were significant predictors of ERPs amplitude, with lower MCH/MCV levels associated with greater amplitude, which may reflect compensatory processes. P1, N1, P2, and P3 were greater for the low MCH/MCV groups. This is the first evidence of association between levels of MCH/MCV and brain function while engaged in an executive function task; possibly reflecting brain iron availability.

New Histophatological Finding About Data Destroying Amyloid Black Holes in Hippocampus Following Olfactory Bulb Lesion Like as the Universe

Background: Many infinite theories have been suggested to explain memory loss in neurodegenerative diseases. However, there are clear data that iron-containing neurofibrillary networks can cause neuron death and erase the memory of neurons, just like black holes in space. Objectives: Ths study aimed to investigate the electromagnetic properties of iron-loaded neurofibrillary networks formed in the hippocampus as a result of damage to the olfactory nerves, just like black holes in space, as well as whether they cause neuron death and memory loss. Methods: All rats were tested with star maze performance before, 3 weeks, and 3 months after surgery. The data used in the study were obtained from the subjects in the experimental groups who had been followed up for 3 months with control (GI; n = 5), SHAM (GII; n = 5) with only frontal burr hole, and study (GIII; n = 15) animals with olfactory bulb lesion. All rats were tested with star maze performance before, 3 weeks, and 3 months after surgery. The olfactory bulbs and hippocampus of subjects were examined by stereological methods. Olfactory bulb volumes, degenerated neuron densities of the hippocampus, and numbers of hippocampal black holes were estimated quantitatively, and results were statistically analyzed by a 1-way analysis of variance (ANOVA). The properties of black holes in the brains and the universe were compared theoretically. Results: The mean olfactory bulb volumes, degenerated neuron density, and black holes of the hippocampus were estimated as 4.43 ± 0.22 mm3, 42 ± 9 mm3, and 3 ± 1 mm3 in GI, 4.01 ± 0.19 mm3, 257 ± 78 mm3, and 11 ± 3 mm3 in GII, and 2.4 ± 0.8 mm3, 1675 ± 119 mm3, and 34 ± 7 mm3 in GIII. All animals were tested with star maze performance before, 3 weeks, and 3 months after surgery. Latency, distance, speed, and path efficiency values of all animals were detected. The more diminished olfactory bulb volume (P < 0.00001) causes more apoptotic neurons and black holes in the hippocampus (P < 0.0001) and more memory loss in olfactory bulb lesion (OBL)-applied animals (P < 0.005). Conclusions: Hippocampal black holes, which are similar to black holes in terms of their formation processes, may be responsible for neuronal losses and memory erasures in the brain by acting like black holes in space. These amyloid plaques, which cause neuron death and memory loss, will be called data-deleting amyloid black holes (DADA-Black Holes) in the paper.

P300, a tool for cognitive assessment in women with iron deficiency anemia: A systematic review

Iron-deficiency anemia (IDA) is a common nutritional disorder and an important risk factor for the development of mild cognitive impairment that may progress to dementia, if untreated. The anemic status due to iron deficiency (ID) alters the electrogenesis in the central nervous system. P300 is a cognitive evoked potential (CEP) used as an objective tool to assess cognitive function. Mild cognitive impairment is indicated by prolonged P300 wave latency and reduced amplitude. IDA is highly prevalent among women particularly in the reproductive phase and data on cognitive assessment using P300 in them are sparse. This review aims to analyze the evidence from recent literature regarding the effect of IDA on evoked potentials like P300 in women. A systematic literature review was conducted and databases, like PubMed, Medline, Scopus, and Google Scholar, were searched for studies from the last 20 years. We selected research papers that compared P300 between anemic women and controls of the same age, and evaluated the effects of iron supplementation on P300 in anemic women. Based on the inclusion criteria, three studies were found. The studies demonstrated impaired P300 potentials in anemic women that improved following iron supplementation. Promoting screening of anemic women with P300 aids in the early detection of subclinical cognitive decline. Ensuring adequate iron treatment can prevent mild cognitive impairment from progressing to severe forms like dementia and other neuropsychological disorders. Further studies utilizing P300 as a cognitive tool need to be encouraged to establish definite conclusions regarding its efficacy in detecting cognitive dysfunctions in anemia.

Impact of Beef and Beef Product Intake on Cognition in Children and Young Adults: A Systematic Review

(1) Background: Undernutrition and micronutrient deficiency have been consistently linked to cognitive impairment among children and young adults. As a primary source of dietary animal protein, beef consumption holds the potential to improve diet quality and positively influence cognitive function. This study systematically reviewed evidence linking beef intake to cognition among children and young adults. (2) Methods: A literature search was conducted in seven electronic bibliographic databases for studies assessing the impact of beef consumption on cognition. (3) Results: We identified eight studies reporting results from five unique interventions. Two interventions were conducted in Kenya, two in the U.S. and one in four countries including Guatemala, Pakistan, Democratic Republic of the Congo and Zambia. Only one intervention employed a non-feeding control arm and found beef consumption to improve cognitive abilities compared to the control. However, the other interventions comparing beef consumption to other food types found no consistent result. (4) Conclusions: Evidence pertaining to the impact of beef consumption on cognition remains limited due to the small and heterogeneous set of studies. Future research should adopt a population representative sample and longer follow-up period, employ a non-feeding control arm and comprehensively measure nutrient intakes among study participants.

Mild iron deficiency may affect female endurance and behavior

The function of central nervous system (CNS) processes is highly dependent on iron containing enzymes and proteins. Therefore, even mild iron deficiency (ID) may result in decreased endurance, increased irritability and withdrawal behavior among women. The current study was designed to assess the effects of iron status on perceived energy level along with its electroencephalographical (EEG) correlates and cognitive capacity of young women, since this group is at particular risk of experiencing depleted iron stores and iron deficiency anemia. The study group consisted of 23 non-anemic women of reproductive age (20-32 years) during their follicular phase of menstrual cycle. All participants were moderately physically active with a mean weekly energy expenditure of 1110 ± 450 Metabolic Equivalent of Task per minute-(MET/min). The group's electroencephalographic (EEG) alpha asymmetry and psychometric data - intelligence, anxiety level and temperamental traits (activity, briskness, sensory sensitivity, emotional reactivity, perseveration and endurance) were assessed and compared between iron deficient (serum ferritin <12 μg/l) and iron sufficient (serum ferritin ≥12 μg/l) females. Participants with depleted iron stores reported lower levels of activity (p = .004; partial η² = 0.34) and endurance (p = .038, partial η² = 0.25), temperamental traits, and presented increased relative left EEG alpha activity in prefrontal regions (p = .004; partial η² = 0.63), which is a characteristic EEG pattern for withdrawal tendencies. Iron-depleted females did not differ in anxiety and general intelligence scores from those which were iron sufficient, however needed more time (median difference: 3 min, p = .004; partial η² = 0.53) to complete an administered intelligence test, which may reflect lowered endurance during a cognitive-demanding task. These data provide proof that that even mild iron deficiency may be connected with CNS function and lead to decreased endurance, or at least cognitive endurance, which may be a risk-factor for mood disorders. Therefore, more attention should be paid to preventing even mild iron deficiency, particularly among young women.

Iron therapy substantially restores qEEG maturational lag among iron-deficient anemic infants

OBJECTIVE

To use quantitative electroencephalography (qEEG) to assess the impact of iron-deficiency anemia on central nervous system maturation in the first year of life.

METHOD

Twenty-five infants (3-12 months old) presenting ferropenic anemia (IDA) and 25 healthy controls (CTL1), matched by age/gender with the former, were studied in two stages. Electroencephalogram during spontaneous sleep was recorded from all participants; the fast Fourier transform was calculated to obtain absolute power (AP) and relative power (RP) qEEG measures. In the first stage, a qEEG comparison between CTL1 and IDA was performed. Second stage consisted in comparing qEEG of the IDA infants before and after supplementation with iron (IDA-IS group), and comparing qEEG of the IDA-IS group with another control age-matched group (CTL2). Non-parametric multivariate permutation tests (NPT) were applied to assess differences between CTL1 and IDA groups, as well as IDA vs. IDA-IS, and IDA-IS vs. CTL2.

RESULTS

More power in slow frequency bands and less power in fast frequency bands in 64% of IDA babies were observed. NPT evinced higher alpha AP and RP (P < 0.001), less theta AP, and less delta and theta RP in CTL1 than in IDA. After iron-restoration therapy, alpha AP and RP increased while theta AP and theta and delta RP decreased, reaching almost normal values.

DISCUSSION

This work reveals CNS developmental delay through the study of qEEG (less rapid and more slow frequencies) which recovered significantly with iron supplementation. It is concluded that IDA constitutes a high risk factor for a lag of CNS maturation.

Improvements in iron status and cognitive function in young women consuming beef or non-beef lunches

Iron status is associated with cognitive performance and intervention trials show that iron supplementation improves mental function in iron-deficient adults. However, no studies have tested the efficacy of naturally iron-rich food in this context. This investigation measured the hematologic and cognitive responses to moderate beef consumption in young women. Participants (n=43; age 21.1±0.4 years) were randomly assigned to a beef or non-beef protein lunch group [3-oz (85 g), 3 times weekly] for 16 weeks. Blood was sampled at baseline, and weeks 8 and 16, and cognitive performance was measured at baseline and week 16. Body iron increased in both lunch groups (p<0.0001), with greater improvement demonstrated in women with lower baseline body iron (p<0.0001). Body iron had significant beneficial effects on spatial working memory and planning speed (p<0.05), and ferritin responders (n=17) vs. non-responders (n=26) showed significantly greater improvements in planning speed, spatial working memory strategy, and attention (p<0.05). Lunch group had neither significant interactions with iron status nor consistent main effects on test performance. These findings support a relationship between iron status and cognition, but do not show a particular benefit of beef over non-beef protein consumption on either measure in young women.

Iron status and neuropsychological consequences in women of reproductive age: what do we know and where are we headed?

Iron deficiency disproportionately affects infants, children, and women of reproductive age. It is more prevalent in developing countries but continues to be a problem in developed countries. Included among the consequences of iron deficiency are changes in cognitive performance, emotions, and behavior. Although the behavioral and developmental sequelae of iron deficiency in young children have received much interest, data on the consequences of iron deficiency in women of reproductive age are just beginning to emerge. Interest in this area increased as a result of the findings that brain iron is much more fluid than previously thought and iron-deficient animals experience nondevelopment-dependent brain alterations. These findings, coupled with the symptoms often reported by iron-deficient women (lethargy, inability to concentrate, difficulty with memory, etc.), have led researchers to begin to explore the relation between iron and neuropsychological outcomes in this population. This paper reviews findings from studies that have examined the brain functional consequences of iron deficiency in women of reproductive age. Additional consideration is given to the fact that detriments to cognition and behavior in a woman of reproductive age may have negative implications beyond the woman's health; specifically, they may negatively influence her children. Therefore, the roles that cognitive and behavioral changes in these women have on their children's development is also reviewed. The paper concludes with a discussion on ways to use technological advances (especially in neuroimaging techniques) to help us elucidate the role of iron in the brains of women of reproductive age.

[Contribution of central venous oxygen saturation in postoperative blood transfusion decision]

OBJECTIVE

The aim of this study was to assess the value of central venous oxygen saturation (ScvO(2)) for the decision of blood transfusion in comparison with the criteria of the French guidelines for blood transfusion (2003).

STUDY DESIGN

Prospective, observational.

PATIENTS AND METHODS

Sixty patients, haemodynamically stable, for whom a blood transfusion (BT) was discussed in the postoperative course of general surgery, were included. ScvO(2) (%) and haemoglobin (g/dl) were measured before and after BT. Patients were retrospectively divided into two groups according to ScvO(2) measured before BT (< or >or=70%). Results are expressed as median.

RESULTS

The ScvO(2) before transfusion was greater or equal to 70% in 25 (47.2%) patients. Following BT, the ScvO(2) increased significantly (from 57.8 to 68.5%) in the group with initial ScvO(2) less than 70% whereas it was unchanged in patients with initial ScvO(2) greater or equal 70% (from 76.8 to 76.5%). Twenty patients (37.7%) did not meet the French guidelines for BT criteria. Eighteen patients out of 33 that met the criteria had ScvO(2) greater or equal 70% before BT while 13 patients with ScvO(2) less than 70% were not detected by these same criteria.

CONCLUSION

ScvO(2) could be a relevant biological parameter to complete the current guidelines for BT in stable patient with a central venous catheter during the postoperative period.