Digit Symbol Scores Research Articles

Association between fibrosis-4 index and cognitive impairment in elderly patients with hypertension: A cross-sectional study.

The fibrosis-4 index (FIB-4) is a noninvasive fibrosis test that is recommended for patients who are at risk of developing hepatic fibrosis. The aim of the study was to explore the correlation between FIB-4 index and the decline of cognitive function among older patients with hypertension. The study used a cross-sectional design to analyze data obtained from the NHANES 2011-2014. The significance of the FIB-4 index correlation with cognitive function in individuals over the age of 60 was evaluated via multivariate regression models. The nonlinear link was described and fitted smoothed curves. There were a total of 2039 participants in the study, and those with a higher FIB-4 index were more susceptible to developing cognitive decline. In the completely adjusted model, the association remained statistically significant between the FIB-4 index and poor cognitive function as measured by CERAD: Total Score (OR=0.72, 0.57-0.91), Animal Fluency Score (OR=0.66, 0.48-0.91), and Digit Symbol Score (OR=0.36, 0.17-0.77). A nonlinear association was found between the FIB-4 and poor cognitive ability: Total Score, CERAD: Score Delayed Recall, Digit Symbol Score, and Animal Fluency Score. In elderly patients with hypertension, a high FIB-4 index is correlated with an increased prevalence of cognitive decline. Hence, the FIB-4 index could potentially serve as a valuable tool for determining individuals with hypertension who are susceptible to both liver-related complications and cognitive impairment.

An unexpected interaction between diabetes and cardiovascular diseases on cognitive function: A cross-sectional study

ObjectiveImpaired cognitive function in older individuals significantly affects quality of life. The interaction between comorbid diabetes and cardiovascular disease (CVD) and its impact on cognitive impairment remains unclear. MethodsThis study analyzed 2564 subjects from the National Health and Nutrition Examination Survey dataset. Cognitive function was measured using various scores, including CERAD Total Score, CERAD Delayed Recall Score (CDRS), Animal Fluency Total Score, and Digit Symbol Score. Multiple regression models were constructed to explore the relationship between different diseases and cognitive function, considering covariates such as age, sex, education, body mass index, alcohol intake, smoking, physical activity, kidney function, and hypertension. ResultsAfter adjusting for multiple factors, the presence of CVD, diabetes, or both showed a significant negative association with the total cognitive score. The CDRS was associated with both CVD and diabetes. The Digit Symbol score was associated with the presence of CVD, diabetes, or both. No significant differences were found between patients with diabetes and CVD in cognitive test results. An interaction between CVD and diabetes was observed in relation to the CDRS but not in other test scores or the total score. ConclusionThe individual impact of each disease on cognitive function was not significant. However, an interaction between CVD and diabetes was found when both diseases coexisted, specifically in relation to delayed learning ability.

Circadian rhythms in older adults are associated with sleep quality, cognitive function, and ß‐amyloid burden: an accelerometry analysis of the Lifestyle Enriching Activities for Research in Neuroscience Intervention Trial ‐ LEARNit

AbstractBackgroundSeveral studies demonstrate circadian rhythm disturbances in patients with Alzheimer’s disease. However, less is known about circadian rhythms in older adults with early mild cognitive impairment. Wrist‐worn accelerometers provide continuous, objective, high resolution quantification of 24‐hour rest activity rhythms. This study examines the relationship between circadian rhythms and sleep, cognition, and ß‐amyloid (Aß) burden.MethodThis study examines baseline data from the “Lifestyle Enriching Activities for Research in Neuroscience Intervention Trial” (LEARNit). Sixty‐six older adults ages 55‐80 experiencing early cognitive changes wore a GENEActiv accelerometer for approximately 30 consecutive days. Accelerometer data was analyzed using the R package GGIR (version 2.8‐1), and circadian rhythm measures were extracted using the GGIR secondary package ActCR (version 0.3.0). Circadian rhythm variables include intradaily variability (fragmentation), interdaily stability (rhythm synchronization to light‐dark cycle), acrotime (peak activity time), and Midline Estimated Statistics of Rhythm or MESOR (mean activity level). Up‐MESOR and Down‐MESOR represent the timing of activity increasing above or decreasing below MESOR, respectively—lower values of each indicate a phase advance (shift towards morning), whereas higher values indicate a phase delay (shift towards evening). Sleep was assessed as mean sleep efficiency and Wake After Sleep Onset, or WASO (accumulated wakefulness after sleep onset). Cognitive tests include the Montreal Cognitive Assessment (MoCA) for global cognition and attention/processing speed (Digit Symbol Task). Aß burden was measured by positron emission tomography standard uptake value ratio for fifty‐six participants. Age‐adjusted linear regression models were used to test associations between circadian rhythms and sleep, cognition, and Aß.ResultParticipant characteristics are summarized in Table 1 and results are summarized in Figure 1. Intradaily variability (b = ‐0.095, p = 0.03) and interdaily stability (b = 0.34, p = 0.01) were both associated with mean sleep efficiency. Intradaily variability (b = 1.41, p<0.001) and interdaily stability (b = ‐4.45, p<0.001) were associated with WASO. Up‐MESOR was associated with MoCA total score (b = ‐0.41, p = 0.03). Up‐MESOR (b = ‐2.12, p = 0.006), Down‐MESOR (b = ‐1.99, p = 0.02), and acrotime (b = ‐4.20, p<0.001) were associated with Digit Symbol score. Down‐MESOR was significantly associated with Aß (b = ‐0.029, p = 0.02).ConclusionCircadian rhythm robustness is positively associated with better sleep quality. Participants with dynamic circadian rhythm phases demonstrated poorer cognition and higher Aß burden.

Vigor to Frailty As a Continuum-A New Approach in the Study of Muscle, Mobility, and Aging Cohort.

Frailty can occur in older adults without disability or multimorbidity. Current methods focus on the most frail, but poorly discriminate among those "not frail." The Study of Muscle, Mobility, and Aging (SOMMA) included 879 adults aged 70 years and older without mobility disability. We operationalized frailty domains using: peak oxygen consumption (endurance), digit symbol substitution test (speed), leg power (strength), perceived fatigability, D3 creatine dilution (sarcopenia), and accelerometry (sedentary behavior) to construct a frailty score of 0-12 summing tertiles (0-2) of each component. We used linear or logistic regression with and without adjustment for confounders to examine associations with age, reported, and performance function. The SOMMA frailty score distribution was broad and strongly associated with age (r = 0.33, p < .0001). Each point was associated with a 30%-50% higher odds of having reported difficulty with activities of daily living or mobility. After grouping the total score (0-3, 4-7, and 8-12) those in the highest group were 9-31 times more likely to have functional limitation, and at least 8 times more likely to have poorer function after full adjustment. Higher scores identified those less likely to report ease of walking or higher physical activity. Peak oxygen consumption, leg power, fatigability, and digit symbol score contributed most to these associations. The SOMMA frailty score characterizes frailty as a continuum from frail to vigorous with assessments that are amenable to change. Associations with age and function suggest utility for distinguishing a wide range of vigor and vulnerability in relatively well-functioning older adults.

Effect of Metabolic Syndrome Risk Factors on Processing Speed and Executive Function in Three Racialized Groups.

Metabolic syndrome (MetS) has been associated with increased risk for Alzheimer's disease and related dementias (ADRD). Understanding the association of MetS risk factors to processing speed and executive function in the pre-clinical stages of ADRD in under-represented groups would offer insight on potential mechanisms through which MetS associates with ADRD risk. Examine association of MetS features and processing speed and executive function across three racial groups. Cognitively unimpaired adults from the Wisconsin Alzheimer's Disease Research Center and the Wisconsin Registry for Alzheimer's Disease Prevention completed blood-draws and neuropsychological testing. Six cognitive outcomes were assessed in association to MetS risk factors: Trailmaking Tests A and B, Animal Fluency, Digit Symbol, and composite scores for Processing Speed and Executive Function. Linear mixed effect models were used to assess the relationship between MetS risk factor count and longitudinal cognitive performance across three racialized groups. Participant sample sizes varied by outcome analyzed (N = 714-1,088). African American and Native American groups exhibited higher rates of MetS than non-Hispanic Whites. MetS was associated with processing speed and executive function across all racialized groups. Three-way interaction by racialized group was limited to one cognitive outcome: Trailmaking Test A. Metabolic dysfunction incrementally affects cognitive trajectory, with generally similar associations across racial groups. Since racialized groups exhibit higher levels of both MetS and ADRD, MetS may represent a driving factor for increased ADRD risk experience by racialized group and an important and modifiable target through which to reduce risk of ADRD.

Abstract TP16: Association Between Sleep Duration And Cognition Among Us Stroke Survivors.

Rationale: Sleep duration has been associated with an increased risk of stroke. Cognitive impairments are frequent complications of stroke, particularly among elderly stroke survivors; However, there is a dearth of information on the link between sleep duration and cognitive impairment among stroke survivors. The current analysis aims at filling this gap. Methods: We used the National Health and Nutrition Examination Survey (NHANES) 2011-2012 to examine the association between sleep duration and cognitive impairment among elderly (60 years and above) stroke survivors. Sleep duration was divided into short (&lt;7 hours), normal (7-8 hours), and long (&gt;8 hours). We applied linear regression models to compare mean scores of pre-specified cognitive test scores, including the Consortium to Establish a Registry for Alzheimer’s Disease total score (CERAD total); CERAD: Score Trial 1 Recall; CERAD: Score Trial 2 Recall; CERAD: Score Trial 3 Recall; CERAD: Score Delayed Recall; Animal Fluency: Score Total, and Digit Symbol Score across sleep duration, accounting for complex survey design, including weighting, clustering and stratification, and adjusting for age, sex, race/ethnicity, income, BMI, diabetes and hypertension. Results: Out of a total of 240 (unweighted) stroke participants, 58% were women. Stroke survivors with short sleep duration were more likely to be non-white compared to those with normal sleep duration (p-value &lt;0.0001). Compared to normal sleep duration, long sleep duration was associated with lower mean CERAD total score (22.3 vs. 18.3, p = 0.014) and Digit Symbol score (35.8 vs. 29.4, p = 0.024). Compared to short sleep duration, long sleep duration was associated with smaller mean CERAD total score (22.761 vs. 18.331, p = 0.009) and Digit Symbol score (36.530 vs. 29.424, p = 0.041). There were no associations between short sleep duration and cognitive scores. Conclusion: In this retrospective analysis of elderly stroke survivors, long sleep duration (vs normal and short) were independently associated with poor cognitive scores. There was no association between short sleep duration and cognitive scores

Association between vision and cognitive function among community-dwelling older adults in Selangor, Malaysia.

To determine the association between distance and near visual acuity (VA) and cognitive function among older adults in Selangor, Malaysia. A total of 230 older adults (age ≥60y) participated in this study. Habitual distance and near VA were measured using the Early Treatment Diabetic Retinopathy Study Chart and Lighthouse Near Visual Acuity Chart, respectively. Global cognitive function was assessed using the Mini-Mental State Examination (M-MSE) and the Malay language version of the Montreal Cognitive Assessment (M-MoCA). Digit Symbol (DS) subtest was used to measure information processing. No significant association was observed between vision and M-MSE and M-MoCA scores. However, poor distance and near VA were found to be significantly associated with low DS scores [distance VA: β=-0.01, R 2=0.1, P=0.02; odds ratio (OR)=2.84, 95% confidence interval (CI), 1.10-7.33, P=0.03; near VA: β=-0.05, R 2=0.08, P=0.00; OR=3.32, 95%CI, 1.28-8.59, P=0.01]. Poor vision is associated with a decline in information processing in older adults and substantiates the importance of preserving good vision in maintaining cognitive function.

BDNF‐mediated improvements in cognition after computerized cognitive training

AbstractBackgroundEvidence suggests that engagement in cognitively stimulating activities may reduce risk of cognitive deterioration and dementia. Mechanisms underlying these observations remain to be determined. Animal research indicates that brain‐derived neurotrophic factor (BDNF) plays an important role in neural plasticity, neurogenesis, synaptic growth, and cognitive performance. Working under the assumption that augmented BDNF levels benefit brain function, investigations of human subjects have focused on determining whether physical or mental activities can increase BDNF levels. Surprisingly little research has been devoted to linking alterations in BDNF to changes in cognition. This study aimed to determine whether changes in BDNF contribute to the enhancement of cognitive performance after computerized cognitive training (CCT). We have demonstrated that five weeks of CCT emphasizing working memory (WM) was associated with improvement on an untrained test of WM/processing speed, the Digit Symbol Test. Here, we investigated whether this improvement was mediated by changes in BDNF levels.MethodSeventy‐five older adults, ages 65‐86, at two sites (USA and Sweden) were randomized to either Cogmed Adaptive (n=37) or Non‐Adaptive (active control) (n=38) CCT. Under the adaptive CCT, task difficulty was revised on a trial‐by‐trial basis to create a consistently high level of challenge. Under the active control condition, task load remained at a constant, relatively low level. CCT was performed in the homes of participants, five days per week, over five weeks. Serum BDNF levels and performance on Digit Symbol were measured pre‐ and post‐intervention.ResultAnalysis using linear mixed models demonstrated an interaction between time and intervention group for Digit Symbol score (p=.036) and BDNF level (p=.013) Only the adaptive CCT group demonstrated an augmentation of BDNF level (p=.014) and improvement in Digit Symbol scores (p&lt;.001) after training. Mediation analysis revealed that changes in BDNF level accounted for the intervention‐related improvement in performance on Digit Symbol. Regression analysis indicated that changes in BDNF level predicted changes in Digit Symbol score (p=.010).ConclusionThe results of this investigation suggest that increases in BDNF linked to cognitive training mediate improvement in cognitive performance. Additional research is needed to determine if these findings are specific to WM or are observed in other cognitive domains.

The Comparison Between Neuropsychological Features of Psychogenic Non-epileptic Seizures and Epileptic Seizures

Background: Both epileptic seizures (ES) and psychogenic non-epileptic seizures (PNES) are often associated with some degree of cognitive impairment. Video electroencephalography (EEG) monitoring is the gold standard for diagnosing PNES. This diagnostic procedure is costly and available in specific tertiary centers. Neuropsychological assessment can provide clues for the differential diagnosis of PNES and ES and help clarify the nature and etiology of these two disorders. Objectives: Therefore, this study aimed to compare the neuropsychological profiles of PNES and ES patients. Methods: In this analytical cross-sectional study, 30 patients with ES and 31 patients with PNES were compared by neuropsychiatric tests, such as the Wechsler Adult Intelligence scale (WAIS), Addenbrooke’s Cognitive examination (ACE), and California Verbal Learning test (CVLT). Results: There was a female predominance in the PNES group (female-to-male ratio = 4.16/1, P = 0.003). In the PNES group, 77.4% of the patients had a psychiatric disorder versus 66.7% of the patients in the ES group; however, the difference was not statistically significant (P = 0.34). The mean score of total intelligence was higher in the PNES group (84.77 ± 16.94), compared to the ES group (83.63 ± 10.04); however, the difference was not significant (P = 0.75). Based on the mean subscale scores, the digit symbol score (WAIS-IV subscale) and memory score (ACE subscale) were significantly higher in the PNES group compared to the ES group (P = 0.037 and 0.032, respectively). Conclusions: This study showed that neuropsychological assessments might not differentiate ES from non-epileptic seizures.

All-cause Dementia Prediction by Machine Learning: The Health, Aging, and Body Composition Study

There are several shortcomings of the currently available risk prediction models for dementia. We developed a risk prediction model for dementia using machine-learning approach and compared its performance with traditional approaches. Data were from the Health, Aging, and Body Composition Study, comprising 3,075 older adults (at least 70 years). Dementia was defined as (1) use of a prescribed dementia medication, (2) adjudicated dementia diagnosis, or (3) a race-stratified cognitive decline>1.5 SDs from the baseline mean. We selected 275 predictors collected from questionnaires, imaging data, performance testing, and biospecimen. We used random survival forest (RSF) to build the full model and rank the importance of predictors. Subsequently, we built parsimonious models with top-20 predictors using RSF and Cox regression. A dementia risk score was developed using top-ranked variables. We used the C-statistic for performance evaluation. Over a median of 11.4 years of follow-up, 659 dementias (21.4%) occurred. The RSF model (both including all and top-20 variables) showed a higher C-statistic than the regression model. Digit symbol score, physical performance battery, finger tapping score, weight change since age 50, serum adiponectin, and APOE genotype were the top-6 variables. We created a dementia risk score (0-10) using the top-6 variables. A 1-unit increase in the risk score was associated with an 8% higher risk of dementia. The risk score demonstrated good discrimination (C-statistic=0.75). Machine learning methods offered improvement over traditional approaches in predicting dementia. The risk prediction score derived from a parsimonious model had good prediction performance.

Cognitive impairment in elderly people with prediabetes or diabetes: A cross-sectional study of the NHANES population

AimTo investigate the cognitive function in people without diabetes, with prediabetes and with diabetes. Methods/DesignThe study design used was a cross-sectional analysis of data in people above 60 years registered in NHANES from 2011 to 2014.Three assessments were used to characterize cognitive function: (a) CERAD Word Learning subtest assessing immediate and delayed learning ability, (b) The Animal Fluency test assesing categorical verbal fluency, and (c) The Digit Symbol Substitution test assessing processing speed, sustained attention, and working memory. Results(A) Memory recall (−0.19, [−0.34; −0.039], p = 0.014) and Delayed memory recall decline was associated with diabetes (−0.285, [−0.503; −0.067], p = 0.01), but not in an adjusted analysis. (B) Animal Fluency score decline was associated with diabetes (−1.185, [−1.688; −0.682], p < 0.001). (C) Digit Symbol score decline was associated with diabetes (−6.897, [−8.491; −5.302], p < 0.001). Prediabetes was not associated with cognitive function. ConclusionsThis study demonstrates an association between cognitive dysfunction and diabetes. Results may also indicate that cognitive decline is not yet present in people with mild impairments of glucose homeostasis.

Relationships between dietary nutrients intake and lipid levels with functional MRI dorsolateral prefrontal cortex activation.

BackgroundDorsolateral prefrontal cortex (DLPFC) is a key node in the cognitive control network that supports working memory. DLPFC dysfunction is related to cognitive impairment. It has been suggested that dietary components and high-density lipoprotein cholesterol (HDL-C) play a vital role in brain health and cognitive function.PurposeThis study aimed to investigate the relationships between dietary nutrient intake and lipid levels with functional MRI (fMRI) brain activation in DLPFC among older adults with mild cognitive impairment.Participants and methodsA total of 15 community-dwelling older adults with mild cognitive impairment, aged ≥60 years, participated in this cross-sectional study at selected senior citizen clubs in Klang Valley, Malaysia. The 7-day recall Diet History Questionnaire was used to assess participants’ dietary nutrient intake. Fasting blood samples were also collected for lipid profile assessment. All participants performed N-back (0- and 1-back) working memory tasks during fMRI scanning. DLPFC (Brodmann’s areas 9 and 46, and inferior, middle, and superior frontal gyrus) was identified as a region of interest for analysis.ResultsPositive associations were observed between dietary intake of energy, protein, cholesterol, vitamins B6 and B12, potassium, iron, phosphorus, magnesium, and HDL-C with DLPFC activation (P<0.05). Multivariate analysis showed that vitamin B6 intake, β=0.505, t (14)=3.29, P=0.023, and Digit Symbol score, β=0.413, t (14)=2.89, P=0.045; R2=0.748, were positively related to DLPFC activation.ConclusionIncreased vitamin B6 intake and cognitive processing speed were related to greater activation in the DLPFC region, which was responsible for working memory, executive function, attention, planning, and decision making. Further studies are needed to elucidate the mechanisms underlying the association.

Dietary carotenoids and cognitive function among US adults, NHANES 2011–2014

Objectives: Dietary carotenoids may limit neuronal damage from free radicals, potentially serving as a modifiable risk factor for cognitive decline. We examined intake of lutein and zeaxanthin (L and Z) in relation to cognitive performance among 2011–2014 National Health and Nutrition Examination Survey participants aged ≥60 years. Methods: L and Z intake from foods and supplements was estimated from two non-consecutive 24-hour diet recalls. Outcomes included the CERAD Word Learning sub-test score, Animal Fluency test score, and Digit Symbol Substitution test score. Regression models were adjusted for survey design variables, year, sex, age, race/ethnicity, body mass index, family income, education, alcohol, and smoking. Results: Among the 2796 participants, higher dietary intake of L and Z was associated with higher score on each test. For example, the highest quartile of L and Z intake was associated with a 2.52 point increase (SE=0.86 points, P=0.01) on the digit symbol score test, compared with the lowest quartile. There were differences by race/ethnicity, with positive associations generally stronger for Black compared to white participants. Discussion: Further research from longitudinal studies is needed, but increasing L and Z intake may help to prevent or slow cognitive decline.

Clinical comparative study of sodium valproate separately combined with ziprasidone and olanzapine in the treatment of bipolar disorder type I

Objective To compare the clinical effects of sodium valproate separately combined with ziprasidone and olanzapine in the treatment of bipolar disorder type I. Methods 100 patients with bipolar disorder type I were chosen.According to the digital table, the patients were randomly divided into two groups, including A group (50 children) with olanzapine and B group (50 children) with ziprasidone on the basis of sodium valproate.The clinical effects, the BRMS score, digit symbol scores, TMT A/B scores, WCST score and TOH cognitive function scores before and after treatment of the two groups were compared. Results The total effective rates of A group and B group were 88.00%, 92.00%, respectively.There was no statistically significant difference in clinical effects between the two groups(χ2=8.14, P 0.05). The digit symbol scores, WCST score and TOH cognitive function scores of B group after treatment were significantly higher than those of A group and before treatment(t=3.17, 4.03, 3.96, 3.54, 2.86, 3.81, 4.66, 4.29, 3.81, 3.43, all P<0.05). The TMT A/B scores of B group after treatment were significantly lower than those of A group and before treatment(t=3.82, 4.82, 4.55, 4.09, 3.83, all P<0.05). Conclusion Sodium valproate separately combined with ziprasidone and olanzapine in the treatment of bipolar disorder type I possess the same clinical effects in manic symptoms relief, and sodium valproate combined with ziprasidone can effectively promote the recovery process of cognitive function damage and improve the clinical prognosis for long-term. Key words: Bipolar disorder; Sodium valproate; Ziprasidone; Olanzapine

Predictors of Cognitive Decline in Older Adult Type 2 Diabetes from the Veterans Affairs Diabetes Trial.

Cognitive decline disproportionately affects older adult type 2 diabetes. We tested whether randomized intensive (INT) glucose-lowering reduces the rate(s) of cognitive decline in adults with advanced type 2 diabetes (mean: age, 60 years; diabetes duration, 11 years) from the Veterans Affairs Diabetes Trial. A battery of neuropsychological tests [digit span, digit symbol substitution (DSym), and Trails-making Test-Part B (TMT-B)] was administered at baseline in ~1700 participants and repeated at year 5. Thirty-seven risk factors were evaluated as predictors of cognitive decline in multivariable regression analyses. The mean age-adjusted DSym or TMT-B declined significantly in all study participants (P < 0.001). Randomized INT glucose-lowering did not significantly alter the rate of cognitive decline. The final model of risk factors associated with 5-year decline in age-adjusted TMT-B included as significant predictors: longer baseline diabetes duration (beta = -0.028; P = 0.0057), lower baseline diastolic blood pressure (BP; beta = 0.028; P = 0.002), and baseline calcium channel blocker medication use (beta = -0.639; P < 0.001). Higher baseline pulse pressure was significantly associated with decline in age-adjusted TMT-B suggesting a role for both higher systolic and lower diastolic BPs. Baseline thiazide diuretic use (beta = -0.549; P = 0.015) was an additional significant predictor of 5-year decline in age-adjusted digit symbol score. Post-baseline systolic BP-lowering was significantly associated (P < 0.001) with decline in TMT-B performance. There was a significant inverse association between post-baseline plasma triglyceride-lowering (P = 0.045) and decline in digit symbol substitution task performance. A 5-year period of randomized INT glucose-lowering did not significantly reduce the rate of cognitive decline in older-aged adults with type 2 diabetes. Systolic and diastolic BPs as well as plasma triglycerides appeared as modifiable risk factors of the rate of cognitive decline in older adult type 2 diabetes.

DISRUPTION OF WHITE MATTER STRUCTURAL NETWORKS AND COGNITIVE DECLINE IN MILD COGNITIVE IMPAIRMENT

global efficiency and microstructure of cingulum portions predict aspects of cognitive control. Results: When global efficiency was used as a sole predictor, significant relationships were found with Category Fluency (t 1⁄43.25, p 1⁄4.004), Digit Symbol Substitution (t 1⁄42.43, p 1⁄4.025), and Stroop suppression score (t 1⁄42.26, p 1⁄4.035). Category Fluency correlated most strongly with mean diffusivity (MD) of the left posterior cingulum in MCI, while MD of the left parahippocampal and right middle cingulum were the main correlates of Digit Symbol and Stroop suppression scores, respectively. When the relevant microstructural measure from a portion of the cingulum was added to any of the individual regression models for the relevant task, the relationship with global efficiency was no longer significant. In contrast, independent relationship between left posterior cingulum and Category Fluency (t 1⁄4-2.25, p 1⁄4.037) and left parahippocampal cingulum and Digit Symbol Substitution (t 1⁄4-3.30, p 1⁄4.004) remained. Conclusions:Global efficiency of white matter network structure correlates with cognitive control inMCI. Multivariate analyses suggest that alterations in global efficiency potentially mediate the effect of microstructural variation in specific components of the cingulum. However, for some tasks there was also an association between performance and microstructure of cingulum segments that was independent of global network efficiency. Both global and local network properties are likely to play a role in the status of cognitive control in MCI.

Clinical and radiological impact of liver transplantation for brain in cirrhosis patients without hepatic encephalopathy

ObjectiveTo elucidate the effect of liver transplantation (LT) on brain dysfunctions in cirrhotic patients who had no clinical evidence of hepatic encephalopathy (HE), we performed a prospective study of voxel-based diffusion tensor imaging (DTI) and detailed cognitive examination. MethodsWe assessed 12 consecutive patients as transplant candidates by DTI, with neurological and cognitive examinations just before and at 6 months after LT. ResultsAfter LT, cirrhotic patients showed significant improvement in visual reproduction, digit symbol, digit span, Stroop test, and Trail-making test scores, suggesting recovery of frontal-temporal function. As for voxel-based DTI, increased mean diffusivity (MD) and reduced fractional anisotropy (FA) values were found before LT in the frontal and temporal lobes of cirrhotic patients. After LT, the unusual FA and MD values observed in the frontal and temporal lobes preoperatively were significantly reduced. ConclusionEnd-stage cirrhotic patients without clinical evidence of HE showed increased MD and decreased FA values in both frontal and temporal lobes. These parameters improved after LT, in line with cognitive function. MD and FA values might be of value as a biomarker in end-stage cirrhotic patients for investigating brain tissue dysfunctions and evaluating the efficacy of LT.

Cognitive Effects of Subthalamic Nucleus Stimulation in Parkinson’s Disease: A Controlled Study

Background: Subthalamic nucleus deep brain stimulation (STN-DBS) improves motor function in selected patients with Parkinson’s disease (PD) but can be associated with variable changes in cognitive functions. Methods: We studied 21 patients selected for STN-DBS and compared 6-month clinical and neuropsychological outcomes between those who underwent surgery (n = 9) and those who voluntarily refused it (n = 12). Results: Motor and quality of life outcomes were markedly superior in the STN-DBS group versus controls. A wide neuropsychological battery was administered, and the whole sample showed a statistically significant worsening in phonemic verbal fluency, time to perform the Trail Making Test part B, Digit Symbol score of WAIS-III and color-naming score of the Stroop Test. In comparison to controls, a trend to a slightly worse deterioration in phonemic verbal fluency was observed in the STN-DBS patients and was significantly correlated with reductions in the <smlcap>l</smlcap>-dopa-equivalent daily dose (r = 0.850, p = 0.007). Conclusion: Our study confirms the safety of STN-DBS from a cognitive standpoint; a reduction in verbal fluency at 6 months after surgery can also be related to PD progression and medication reduction.

Training-dependent cognitive advantage is suppressed at high altitude

Ascent to high altitude is associated with decreases in cognitive function and work performance as a result of hypoxia. Some workers with special jobs typically undergo intensive mental training because they are expected to be agile, stable and error-free in their job performance. The purpose of this study was to determine the risk to cognitive function acquired from training following hypoxic exposure. The results of WHO neurobehavioral core tests battery (WHO-NCTB) and Raven's standard progressive matrices (RSPM) tests of a group of 54 highly trained military operators were compared with those of 51 non-trained ordinary people and were investigated at sea level and on the fifth day after arrival at high altitudes (3900m). Meanwhile, the plasma levels of brain-derived neurotrophic factor (BDNF), interleukin 1β (IL-1β) and vascular endothelial growth factor (VEGF) were examined. The result showed that at sea level, the trained group exhibited significantly better performance on neurobehavioral and RSPM tests. At high altitude, both groups had decreased accuracy in most cognitive tests and took longer to finish them. More importantly, the highly trained subjects showed more substantial declines than the non-trained subjects in visual reaction accuracy, auditory reaction speed, digit symbol scores, ability to report correct dots in a pursuit aiming test and total RSPM scores. This means that the training-dependent cognitive advantages in these areas were suppressed at high altitudes. The above phenomenon maybe associated with decreased BDNF and elevated inflammatory factor during hypoxia, and other mechanisms could not be excluded.

Poor Sleep Quality Predicts Decreased Cognitive Function Independently of Chronic Mountain Sickness Score in Young Soldiers with Polycythemia Stationed in Tibet

Little is known about the association between poor sleep and cognitive function in people with polycythemia at high altitude. The aim of this study was to survey the sleep quality of individuals with polycythemia at high altitude and determine its association with cognitive abilities. We surveyed 230 soldiers stationed in Tibet (all men; mean age 21-52±4.30 yr) at altitudes ranging from 3658 to 3996 m. All participants were given a blood tests for hemoglobin level and a questionnaire survey of cognitive function. Polycythemia was defined as excessive erythrocytosis (Hb≥21 g/dL in men or ≥19 g/dL in women). Poor sleepers were defined as having a global Pittsburgh Sleep Quality Index score (PSQI)>5. Cognitive abilities were determined by the Chinese revision of the Wechsler Adult Intelligence Scale and the Benton Visual Retention Test. Multiple linear regression analysis was used to determine the association between the PSQI and cognitive function. Logistic regression analysis was performed to determine the independent effect of sleep quality on cognitive function. The global PSQI score of enrolled participants was 8.14±3.79. Seventy-five (32.6%) soldiers were diagnosed with polycythemia. The proportion of poor sleepers was 1.45 times greater in those with polycythemia compared with those without polycythemia [95% (confidence interval) CI 1.82-2.56], and they had a statistically significant lower score for cognitive function. Multiple linear regression analysis showed that the global PSQI score was negatively associated with IQ (β=0.11, 95% CI -0.16 to -0.05) and digit symbol scores (β=0.66, 95% CI -0.86 to -0.44). Poor sleep quality was determined to be an independent predictor of impaired IQ [odds ratio (OR) 1.59, 95% CI 1.30-1.95] and digit symbol score (OR 1.18, 95% CI 1.07-1.31) in logistic regression analysis. The present study showed that for young soldiers with polycythemia at high altitude impaired subjective sleep quality was an independent predictor of decreased cognitive function, especially IQ and verbal short-term memory.