Discriminating subcortical ischemic vascular disease and Alzheimer's disease by diffusion kurtosis imaging in segregated thalamic regions.

Differentiating between subcortical ischemic vascular disease (SIVD), Alzheimer's disease (AD), and normal cognition (NC) remains a challenge, and reliable neuroimaging biomarkers are needed. The current study, therefore, investigated the discriminative ability of diffusion kurtosis imaging (DKI) metrics in segregated thalamic regions and compare with diffusion tensor imaging (DTI) metrics. Twenty-three SIVD patients, 30 AD patients, and 24 NC participants underwent brain magnetic resonance imaging. The DKI metrics including mean kurtosis (MK), axial kurtosis (Kaxial ) and radial kurtosis (Kradial ) and the DTI metrics including diffusivity and fractional anisotropy (FA) were measured within the whole thalamus and segregated thalamic subregions. Strategic correlations by group, thalamo-frontal connectivity, and canonical discriminant analysis (CDA) were used to demonstrate the discriminative ability of DKI for SIVD, AD, and NC. Whole and segregated thalamus analysis suggested that DKI metrics are less affected by white matter hyperintensities compared to DTI metrics. Segregated thalamic analysis showed that MK and Kradial were notably different between SIVD and AD/NC. The correlation analysis between Kaxial and MK showed a nonsignificant relationship in SIVD group, a trend of negative relationship in AD group, and a significant positive relationship in NC group. A wider spatial distribution of thalamo-frontal connectivity differences across groups was shown by MK compared to FA. CDA showed a discriminant power of 97.4% correct classification using all DKI metrics. Our findings support that DKI metrics could be more sensitive than DTI metrics to reflect microstructural changes within the gray matter, hence providing complementary information for currently outlined pathogenesis of SIVD and AD.

Effects of Mental Imagery on Prospective Memory: A Process Analysis in Individuals with Amnestic Mild Cognitive Impairment.

INTRODUCTION: Prospective memory (PM) is a multiphasic cognitive function important for autonomy and functional independence but is easily disrupted by pathological aging processes. Through cognitive simulation of perceptual experiences, mental imagery could be an effective compensatory strategy to enhance PM performance. Nevertheless, relevant research in individuals with amnestic mild cognitive impairment (MCI) has been limited, and the underlying mechanism of the therapeutic effect has not been sufficiently elucidated. The present study aimed to examine complex PM performances and the effect of mental imagery on each phase in older adults with MCI and to investigate the underlying cognitive mechanism from a process perspective. METHODS: Twenty-eight MCI and 32 normal aging controls completed a seminaturalistic PM task, in addition to a series of neuropsychological tests. Participants from each group were randomly assigned to a mental imagery condition or a standard repeated encoding condition before performing the PM task. Four indices were used to measure performance in the intention formation, intention retention, intention initiation, and intention execution phases of PM. Performances in each phase was compared between the 2 diagnostic groups and the 2 instruction conditions. RESULTS: The MCI group performed worse than the normal aging group in the intention formation and intention retention phases. The participants in the mental imagery condition performed significantly better than those in the standard condition during the intention formation, intention retention, and intention execution phases, regardless of the diagnostic group. Moreover, there was a significant interaction between the group and condition during intention retention, showing that people with MCI benefited even more from mental imagery than normal aging in this phase. Performance in the intention retention phase predicted performance in the intention initiation and intention execution phases. DISCUSSION: PM deficits in MCI mainly manifest during planning and retaining intentions. Mental imagery was able to promote performance in all but the initiation phase, although a trend for improvement was observed in this phase. The effects of mental imagery may be exerted in the intention retention phase by strengthening the PM cue-action bond, thereby facilitating the probability of intention initiation and bolstering fidelity to the original plan during intention execution.

Postoperative change of neuropsychological function after indirect revascularization in childhood moyamoya disease: a correlation with cerebral perfusion study.

PURPOSE: The relationships between postoperative functional improvement in various cognitive domains and regional hemodynamic change have not been sufficiently studied in childhood moyamoya disease (MMD). The present study aimed to examine the cognitive benefit of indirect revascularization, the underlying biological mechanism, and factors affecting surgical outcome in childhood MMD. METHODS: Twenty-three patients with MMD aged under 20 years received neuropsychological examinations before and after indirect revascularization surgery, evaluating intellectual function, verbal and visual memory, and executive function. Among them, 13 patients had magnetic resonance perfusion (MRP) studies, in which regional cerebral perfusion was rated. RESULTS: Postoperative improvement was observed in verbal memory performances (p = 0.02-0.03) and in cerebral perfusion at all 26 cerebral hemispheres (p = 0.003-0.005), especially in the middle cerebral artery (MCA) territories (p = 0.001-0.003). Hemodynamic improvement in the left MCA territories was significantly correlated with improvement of both verbal new learning (p = 0.01) and intellectual function (p = 0.004). Postoperative cognitive improvement of immediate recall and verbal intellectual function was associated with female sex (r = - 0.42) and symptom duration (p = - 0.03), respectively. Hemodynamic improvement in the MCA territories was related to longer follow-up intervals (p = 0.02). CONCLUSION: The findings revealed that the selective postoperative cognitive improvement was associated with increased regional perfusion in the MCA territories, and indicate the importance of early intervention and the potential of indirect revascularization regarding long-term outcome.

Microstructural Correlates and Laterality Effect of Prospective Memory in Non-Demented Adults with Memory Complaints.

BACKGROUND: An increasing number of studies suggest the importance of prospective memory (ProM) due to its functional relevance and sensitivity to neuropathology. However, its relevant neural substrates have not been sufficiently explored. OBJECTIVES: The present study aimed to investigate the relationship between structural connectivity and both objective and subjective ProM measures in a group of non-demented people with subjective memory complaints, and to examine the potential of ProM measures to detect the difference between subjective cognitive decline (SCD) and mild cognitive impairment (MCI) in the pre-dementia stage. METHOD: Thirty-sevennon-dementedparticipants aged above 50 years were recruited from an outpatient Neurology Clinic; 13 of them fulfilled the criteria of MCI and 24 of SCD. All subjects received comprehensive neuropsychological tests, including the adapted version of the Cambridge Prospective Memory Test, as well as the Taiwan version of the Prospective and Retrospective Memory Questionnaire. The diffusion tensor imaging technique with tract-based spatial statistics was applied to measure cerebral microstructural changes. RESULTS: Time-based ProM performance was significantly correlated with microstructural integrity of the right superior longitudinal fasciculus, while the event-based one was associated with that of the left superior longitudinal fasciculus and the genu of the corpus callosum among all participants and in the SCD group. After controlling for age, the correlation remained significant between event-based ProM performance and the left superior longitudinal fasciculus among all participants and in the MCI group, as well as between event-based ProM performance and the genu among all participants. Although self-reported ProM failures in real life was associated with fiber disruption of the left superior longitudinal fasciculus among all participants and within the MCI group, an inverse relationship was also observed with that of the corpus callosum in the SCD group even after controlling for age. As compared to the SCD group, people with MCI performed significantly worse on time-based ProM tasks and reported more ProM failures in daily life. CONCLUSIONS: ProM was related to the integrity of interhemispheric commissural fibers and association fibers that connect the frontal lobe with posterior regions, with a task-specific laterality effect. Time-based ProM tasks and self-reported ProM questionnaire may be sensitive to early pathological cognitive deterioration, while the concomitant aging process and individual awareness level may respectively confound the results of evaluation.

Comparison of neuropsychiatric symptoms and diffusion tensor imaging correlates among patients with subcortical ischemic vascular disease and Alzheimer's disease.

BACKGROUND: The causes of behavioral and psychological symptoms of dementia (BPSD) vary according to the dementia subtype and associated neuropathology. The present study aimed to (i) compare BPSD between patients with subcortical ischemic vascular disease (SIVD) and Alzheimer's disease (AD) across stages, and (ii) explore the associations with diffusion tensor imaging (DTI) in the corpus callosum (CC) and other major fibers. METHODS: Twenty-four patients with SIVD and 32 with AD were recruited. Four domains of the Neuropsychiatric Inventory (NPI) (hyperactivity, psychosis, affective, and apathy) and two DTI parameters [fractional anisotropy (FA) and mean diffusivity (MD)] within the genu, body (BCC), and splenium (SCC) of the CC and other major fibers were assessed. RESULTS: Overall, the patients with clinical dementia rating (CDR) 1 ~ 2 had higher scores in apathy domain than those with CDR0.5. Among those with CDR1 ~ 2, SIVD had higher scores in apathy domain than AD. MD values in the BCC/SCC were positively correlated with total NPI score and psychosis, hyperactivity, and apathy domains. FA values in the SCC were inversely correlated with total NPI score and psychosis domain. The correlations were modified by age, the CASI, and CDR scores. Stepwise linear regression models suggested that FA value within the left superior longitudinal fasciculus predicted the hyperactivity domain. MD value within the SCC/left uncinate fasciculus and FA value within the GCC/left forceps major predicted the psychosis domain. MD value within the right superior longitudinal fasciculus and CDR predicted the apathy domain. Further analysis suggested distinct patterns of regression models between SIVD and AD patients. CONCLUSION: White matter integrity within the BCC/SCC had associations with multi-domains of BPSD. Our study also identified important roles of regions other than the CC to individual domain of BPSD, including the left superior longitudinal fasciculus to the hyperactivity domain, the left uncinate fasciculus/forceps major to the psychosis domain, and the right superior longitudinal fasciculus to the apathy domain. The neuronal substrates in predicting BPSD were different between SIVD and AD patients. Of note, apathy, which was more profound in SIVD, was associated with corresponding fiber disconnection in line with dementia severity and global cognition decline.

Frontal Assessment Battery as a Useful Tool to Differentiate Mild Cognitive Impairment due to Subcortical Ischemic Vascular Disease from Alzheimer Disease.

BACKGROUND: Prominent executive dysfunction can differentiate vascular dementia from Alzheimer disease (AD). However, it is unclear whether the Frontal Assessment Battery (FAB) screening tool can differentiate subcortical ischemic vascular disease (SIVD) from AD at the pre-dementia stage. In addition, the neural correlates of FAB performance have yet to be clarified. METHODS: Patients with mild cognitive impairment (MCI) due to SIVD (MCI-V), MCI due to AD (MCI-A), and demographically matched controls completed the Mini-Mental State Examination, Taiwanese FAB (TFAB), Category Fluency, and Chinese Version of the Verbal Learning Test, and underwent magnetic resonance imaging. White matter hyperintensities were rated according to the Scheltens scale. RESULTS: TFAB total scale and its Orthographical Fluency subtest were the only measures that could differentiate MCI-V from MCI-A. Discriminative analysis showed that Orthographical Fluency scores successfully identified 73.2% of the cases with MCI-V, with 85.0% sensitivity. Orthographical Fluency scores were specifically associated with lesion load within frontal periventricular, frontal deep white matter, and basal ganglia regions. CONCLUSION: The TFAB, and especially its 1-min Orthographical Fluency subtest, is a useful screening procedure to differentiate MCI due to SIVD from MCI due to AD. The discriminative ability is probably due to frontosubcortical white matter pathologies disproportionately involved in the two disease entities.

Vitamin B12 deficiency: Characterization of psychometrics and MRI morphometrics.

OBJECTIVES: Vitamin B12 is essential for the integrity of the central nervous system. However, performances in different cognitive domains relevant to vitamin B12 deficiency remain to be detailed. To date, there have been limited studies that examined the relationships between cognitions and structural neuroimaging in a single cohort of low-vitamin B12 status. The present study aimed to depict psychometrics and magnetic resonance imaging (MRI) morphometrics among patients with vitamin B12 deficiency, and to examine their inter-relations. METHODS: We compared 34 consecutive patients with vitamin B12 deficiency (serum level ≤ 250 pg/ml) to 34 demographically matched controls by their cognitive performances and morphometric indices of brain MRI. The correlations between psychometrics and morphometrics were analyzed. RESULTS: The vitamin B12 deficiency group had lower scores than the controls on total scores of Mini-Mental Status Examination (MMSE) and Cognitive Abilities Screening Instrument (CASI) (both P < 0.05), language (P < 0.01), orientation (P < 0.01), and mental manipulation (P < 0.05). The patients also showed a greater frontal horn ratio than the controls (P < 0.05). Bicaudate ratio, fronto-occipital ratio, uncotemporal index, and normalized interuncal distance all showed a strong correlation with the total score of MMSE and CASI (all P < 0.01). Among these psychometric and morphometric indices, pronounced correlations between bicaudate ratio and long-term memory, mental manipulation, orientation, language, and verbal fluency were noted (all P < 0.01). DISCUSSION: Vitamin B12 deficiency is associated with a global cognition decline with language, orientation, and mental manipulation selectively impaired. Preferential atrophy in frontal regions is the main neuroimaging feature. Although the frontal ratio highlights the relevant atrophy among patients, the bicaudate ratio might be the best index on the basis of its strong association with global cognition and related cognitive domains, implying dysfunction of fronto-subcortical circuits as the fundamental pathogenesis related to vitamin B12 deficiency.

Prospective memory in subjective cognitive decline: a preliminary study on the role of early cognitive marker in dementia.

Accumulating evidence shows that subjective cognitive decline (SCD) without impairment on conventional neuropsychological tests may indicate increased risk for Alzheimer disease. Previous studies of mild cognitive impairment have demonstrated the potential role of prospective memory (PM) in the early detection of cognitive decline. We thus aimed to investigate the performance of people with SCD on PM tasks relative to their healthy controls (HCs). Forty-one participants with SCD and demographically matched HCs received regular cognitive testing as well as 2 single-trial naturalistic time-based and event-based PM tasks. Statistical analyses showed that the individuals with SCD performed worse on the time-based PM task, especially on the prospective component, when compared with their HCs. Our findings suggest that PM, especially the time-based one on the prospective component, may be an early cognitive marker of dementia. This implies an underlying difficulty among subjects with SCD in self-initiation that exacerbates their memory difficulties. Further investigation on a large scale is needed.

Evident cognitive impairments in seemingly recovered patients after midazolam-based light sedation during diagnostic endoscopy.

BACKGROUND/PURPOSE: Midazolam is a widely used sedative agent during colonoscopy, with cognitive toxicity. However, the potential cognitive hazard of midazolam-based light sedation has not been sufficiently examined. We aimed to examine the cognitive safety and vulnerability profile under midazolam light sedation, with a particular focus on individual variations. METHODS: We conducted a prospective case-controlled study in an academic hospital. In total, 30 patients undergoing sedative colonoscopy as part of a health check-up were recruited. Neuropsychological testing on the full cognitive spectrum was evaluated at 15 minutes and 120 minutes after low-dose midazolam administration. The modified reliable change index (RCI) was used for intrapersonal comparisons and controlling for practice effects. RESULTS: Midazolam affected psychomotor speed (48%), memory (40%), learning (32%), working memory (17%), and sustained attention (11%), while sparing orientation and the fluency aspect of executive function at the acute stage. Residual memory (10%) and learning (10%) impairments at 2 hours after administration were evidenced in some patients. The three object recall and digit symbol coding tests can serve as useful screening tools. CONCLUSION: Midazolam-based light sedation induced selective cognitive impairments and prolonged cognitive impairments occurred in patients with advanced age. A longer observation time and further screening were recommended for patients due to their at risk state.

Selective neuropsychological impairments and related clinical factors in children with moyamoya disease of the transient ischemic attack type.

PURPOSE: Moyamoya disease is characterized by progressive narrowing of bilateral internal carotid arteries. Neuropsychological impairments are suspected due to frequent involvement of the frontotemporal areas. The present study thus aimed to investigate the pattern of neuropsychological function in children diagnosed with moyamoya disease. METHODS: Thirteen children with moyamoya disease of the transient ischemic attack type received standardized neuropsychological tests that evaluate general intellectual function, verbal comprehension, perceptual organization, working memory, processing speed, episodic memory, category fluency and visuospatial function. Related clinical factors were also analyzed. RESULTS: The results showed single-domain cognitive impairment in around 15 % of patients and multiple-domain cognitive impairments in 23 % of patients. Selective impairments of episodic memory and processing speed were especially noted in those with younger age of onset and prolonged symptom duration. CONCLUSIONS: Neuropsychological impairments are not infrequent in children with moyamoya disease despite normal general intellectual functioning. The pattern of cognitive dysfunction is often associated with lesions in frontotemporal areas. Early detection and intervention shall be considered regarding cognitive outcome in pediatric group.

Joint diffusional kurtosis magnetic resonance imaging analysis of white matter and the thalamus to identify subcortical ischemic vascular disease.

Identifying subcortical ischemic vascular disease (SIVD) in older adults is important but challenging. Growing evidence suggests that diffusional kurtosis imaging (DKI) can detect SIVD-relevant microstructural pathology, and a systematic assessment of the discriminant power of DKI metrics in various brain tissue microstructures is urgently needed. Therefore, the current study aimed to explore the value of DKI and diffusion tensor imaging (DTI) metrics in detecting early-stage SIVD by combining multiple diffusion metrics, analysis strategies, and clinical-radiological constraints. This prospective study compared DKI with diffusivity and macroscopic imaging evaluations across the aging spectrum including SIVD, Alzheimer's disease (AD), and cognitively normal (NC) groups. Using a white matter atlas and segregated thalamus analysis with considerations of the pre-identified macroscopic pathology, the most effective diffusion metrics were selected and then examined using multiple clinical-radiological constraints in a two-group or three-group paradigm. A total of 122 participants (mean age, 74.6 ± 7.38 years, 72 women) including 42 with SIVD, 50 with AD, and 30 NC were evaluated. Fractional anisotropy, mean kurtosis, and radial kurtosis were critical metrics in detecting early-stage SIVD. The optimal selection of diffusion metrics showed 84.4-100% correct classification of the results in a three-group paradigm, with an area under the curve of .909-.987 in a two-group paradigm related to SIVD detection (all P < .001). We therefore concluded that greatly resilient to the effect of pre-identified macroscopic pathology, the combination of DKI/DTI metrics showed preferable performance in identifying early-stage SIVD among adults across the aging spectrum.

Investigating the effect of hypertension on vascular cognitive impairment by using the resting-state functional connectome.

Hypertension (HTN) affects over 1.2 billion individuals worldwide and is defined as systolic blood pressure (BP) ≥ 140 mmHg and diastolic BP ≥ 90 mmHg. Hypertension is also considered a high risk factor for cerebrovascular diseases, which may lead to vascular cognitive impairment (VCI). VCI is associated with executive dysfunction and is also a transitional stage between hypertension and vascular dementia. Hence, it is essential to establish a reliable approach to diagnosing the severity of VCI. In 28 HTN (51-83 yrs; 18 males, 10 females) and 28 healthy controls (HC) (51-75 yrs; 7 males, 21 females), we investigated which regions demonstrate alterations in the resting-state functional connectome due to vascular cognitive impairment in HTN by using the amplitude of the low-frequency fluctuations (ALFF), regional homogeneity (ReHo), graph theoretical analysis (GTA), and network-based statistic (NBS) methods. In the group comparison between ALFF/ReHo, HTN showed reduced spontaneous activity in the regions corresponding to vascular or metabolic dysfunction and enhanced brain activity, mainly in the primary somatosensory cortex and prefrontal areas. We also observed cognitive dysfunction in HTN, such as executive function, processing speed, and memory. Both the GTA and NBS analyses indicated that the HTN demonstrated complex local segregation, worse global integration, and weak functional connectivity. Our findings show that resting-state functional connectivity was altered, particularly in the frontal and parietal regions, by hypertensive individuals with potential vascular cognitive impairment.

Neurovascular Correlates of Cobalamin, Folate, and Homocysteine in Dementia.

BACKGROUND: Cobalamin (Cbl) and folate are common supplements clinicians prescribe as an adjuvant therapy for dementia patients, on the presumption of their neurotrophic and/or homocysteine (Hcy) lowering effect. However, the treatment efficacy has been found mixed and the effects of Cbl/folate/Hcy on the human brain remain to be elucidated. OBJECTIVE: To explore the neurovascular correlates of Cbl/folate/Hcy in Alzheimer's disease (AD) and subcortical ischemic vascular dementia (SIVD). METHODS: Sixty-seven AD patients and 57 SIVD patients were prospectively and consecutively recruited from an outpatient clinic. Multimodal 3-Tesla magnetic resonance imaging was performed to quantitatively evaluate cerebral blood flow (CBF) and white matter integrity. The relationship between neuroimaging metrics and the serum levels of Cbl/folate/Hcy was examined by using the Kruskal-Wallis test, partial correlation analysis, and moderation analysis, at a significance level of 0.05. RESULTS: As a whole, CBF mainly associated with Cbl/folate while white matter hyperintensities exclusively associated with Hcy. As compared with AD, SIVD exhibited more noticeable CBF correlates (spatially widespread with Cbl and focal with folate). In SIVD, a bilateral Cbl-moderated CBF coupling was found between medial prefrontal cortex and ipsilateral basal ganglia, while in the fronto-subcortical white matter tracts, elevated Hcy was associated with imaging metrics indicative of increased injury in both axon and myelin sheath. CONCLUSIONS: We identified the neurovascular correlates of previously reported neurotrophic effect of Cbl/folate and neurotoxic effect of Hcy in dementia. The correlates exhibited distinct patterns in AD and SIVD. The findings may help improving the formulation of supplemental Cbl/folate treatment for dementia.

Cognitive function and breast cancer molecular subtype before and after chemotherapy.

Chemotherapy-related cognitive impairment has been reported in patients with breast cancer and received growing attention due to increased survival rate. However, cognitive outcome according to pathological tumor features, especially human epidermal growth factor receptor (HER2) status, has not been clearly elucidated. Despite its potential link with cognitive status through neuroinflammatory response, existing research is sparse and limited to cross-sectional studies. In this observational cohort study, 52 breast cancer patients received a series of neuropsychological examinations before and after chemotherapy. Patients' performances were compared with normative data, and analyzed with Reliable Change Indices and mixed-model analysis of covariance. Results showed that there was a higher percentage of HER2+ patients than HER2- patients who showed defective attention and processing speed before chemotherapy, and that there were more patients with HER2+ status showing cognitive decline on tests of attention and executive functions following chemotherapy. Group-wise analyses confirmed the foregoing pattern and further revealed that patients with HER2+ status also tended to deteriorate more in verbal memory after chemotherapy. These findings indicate that HER2 overexpression may serve as prognostic factors that help explain the heterogeneous cognitive outcome in breast cancer survivors. Further studies are needed to replicate this finding and delineate the underlying mechanisms.

Stage-Dependent Cerebral Blood Flow and Leukoaraiosis Couplings in Subcortical Ischemic Vascular Disease and Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) and subcortical ischemic vascular disease (SIVD) have both been associated with white matter hyperintensities (WMHs) and altered cerebral blood flow (CBF) although the etiology of AD is still unclear. OBJECTIVE: To test the hypothesis that CBF and WMHs have differential effects on cognition and that the relationship between CBF and WMHs changes with the subtypes and stages of dementia. METHODS: Forty-two patients with SIVD, 50 patients with clinically-diagnosed AD, and 30 cognitively-normal subjects were included. Based on the Clinical Dementia Rating (CDR), the patients were dichotomized into early-stage (CDR = 0.5) and late-stage (CDR = 1 or 2) groups. CBF and WMH metrics were derived from magnetic resonance imaging and correlated with cognition. RESULTS: Hierarchical linear regression revealed that CBF metrics had distinct contribution to global cognition, memory, and attention, whereas WMH metrics had distinct contribution to executive function (all p < 0.05). In SIVD, the WMHs in frontotemporal areas correlated with the CBF in bilateral thalami at the early stage; the correlation then became between the WMHs in basal ganglia and the CBF in frontotemporal areas at the late stage. A similar corticosubcortical coupling was observed in AD but involved fewer areas. CONCLUSION: A stage-dependent coupling between CBF and WMHs was identified in AD and SIVD, where the extent of cortical WMHs correlated with subcortical CBF for CDR = 0.5, whereas the extent of subcortical WMHs correlated with cortical CBF for CDR = 1-2.

Prospective Memory and Default Mode Network Functional Connectivity in Normal and Pathological Aging.

BACKGROUND: Prospective memory (PM), the ability to execute a previously formed intention given the proper circumstance, has been proven to be vulnerable to Alzheimer's disease. Previous studies have indicated the involvement of the frontoparietal networks; however, it is proposed that PM may also be associated with other neural substrates that support stimulus-dependent spontaneous cognition. OBJECTIVE: The present study aimed to examine the hypothesis that PM deficit in Alzheimer's disease is related to altered functional connectivity (FC) within the default mode network (DMN). METHODS: Thirty-four patients with very mild or mild dementia (17 with Alzheimer's disease and 17 with subcortical ischemic vascular disease) and 22 cognitively-normal participants aged above 60 received a computerized PM task and resting-state functional magnetic resonance imaging study. Seed-based functional connectivity analysis was performed at group level within the DMN. RESULTS: We found that the dementia groups showed worse PM performance and altered FC within the DMN as compared to the normal aging individuals. The FC between the medial prefrontal cortices and precuneus/posterior cingulate cortex was significantly correlated with PM in normal aging, while the FC between the right precuneus and bilateral inferior parietal lobules was correlated with PM in patients with Alzheimer's disease. CONCLUSION: These findings support a potential role for the DMN in PM, and corroborate that PM deficit in Alzheimer's disease was associated with altered FC within the posterior hubs of the DMN, with spatial patterning different from normal aging.

Development of the Subjective Cognitive Decline Scale for Mandarin-Speaking Population.

Subjective cognitive decline (SCD) has been considered a high-risk group preceding mild cognitive impairment (MCI). However, methods to quantify and track the complaints have not been well-established. The present study aimed to develop a questionnaire tailored for Mandarin-speaking individuals with SCD. A total of 175 adults aged above 55 years completed a comprehensive set of items evaluating cognitive problems and neuropsychological examinations. After item reduction, internal consistency, construct, and concurrent validity were examined. The 14-item Subjective Cognitive Decline Scale (SCDS) has acceptable internal consistency (Cronbach's α = .93) and construct validity with a three-factor structure. Individuals with SCD and MCI scored higher than the control group. The SCDS demonstrated significant but small correlations with multiple cognitive tests and emotional variables. The SCDS provides an alternative approach to measure cognitive complaints, while an influence of emotional status shall be taken into consideration when interpreting the results.

Prospective Memory and Regional Functional Connectivity in Subcortical Ischemic Vascular Disease.

Objectives: Patients with subcortical ischemic vascular disease (SIVD) often have prominent frontal dysfunction. However, it remains unclear how SIVD affects prospective memory (PM), which strongly relies on the frontoparietal network. The present study aimed to investigate PM performance in patients with early stage SIVD as compared to those with Alzheimer's disease (AD) and to older adults with normal cognition, and to explore the neural correlates of PM deficits. Method: Patients with very-mild to mild dementia due to SIVD or AD and normal controls (NC) aged above 60 years were recruited. Seventy-three participants (20 SIVD, 22 AD, and 31 NC) underwent structural magnetic resonance imaging (MRI), cognitive screening tests, and a computerized PM test. Sixty-five of these participants (19 SIVD, 20 AD, and 26 NC) also received resting-state functional MRI. Results: The group with SIVD had significantly fewer PM hits than the control group on both time-based and non-focal event-based PM tasks. Among patients in the very early stage, only those with SIVD but not AD performed significantly worse than the controls. Correlational analyses showed that non-focal event-based PM in SIVD was positively correlated with regional homogeneity in bilateral superior and middle frontal gyri, while time-based PM was not significantly associated with regional homogeneity in any of the regions of interest within the dorsal frontoparietal regions. Conclusions: The findings of this study highlight the vulnerability of non-focal event-based PM to the disruption of regional functional connectivity in bilateral superior and middle frontal gyri in patients with SIVD.

Neuropsychiatric and cognitive symptoms in people with hypertension: An examination with the NINDS-CSN consensus protocol.

Hypertension has been associated with risk of cognitive impairments. The American Heart Association recommended the use of the harmonized neuropsychological protocol suggested by the National Institute of Neurologic Disorders and Stroke and the Canadian Stroke Network (NINDS-CSN) for studying related cognitive impairments. Initially designed for vascular cognitive impairment, empirical data of results from NINDS-CSN protocol has not been well-established in hypertension. The present study recruited 58 adults diagnosed with hypertension and 44 normotensive controls. Tests from the NINDS-CSN protocol were given in three lengths, including neuropsychological tests and neuropsychiatric inventories. The results showed higher proportions of hypertensive adults with impairments on tests of memory and executive functions and that they performed worse as a group on several tests from the 30-minute protocol, but not on the other additional tests in the full-length version, nor on cognitive screening test in the 5-minute protocol such as the Mini-Mental State Examination or the Montreal Cognitive Assessment. There was no significant group difference on neuropsychiatric symptoms. These findings suggested that the 30-minute version of the NINDS-CSN protocol with the two supplemental tests was able to reveal selective cognitive deficits in hypertensive adults and provide a practical solution for related studies, balancing between the requirement of sensitivity, domain variety, and brevity.