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1.  Long Term Effects on Cognitive Function of Postmenopausal Hormone Therapy Prescribed to Women Aged 50–55 Years 
JAMA internal medicine  2013;173(15):10.1001/jamainternmed.2013.7727.
Background
Postmenopausal hormone therapy with conjugated equine estrogens (CEE) may adversely affect older women’s cognitive function. It is not known whether this extends to younger women.
Methods
1,326 postmenopausal women, who had begun treatment in two randomized placebo-controlled clinical trials of hormone therapy when aged 50–55 years, were assessed with an annual telephone-administered cognitive battery that included measures of global (primary outcome) and domain-specific cognitive functions (verbal memory, attention, executive function, verbal fluency, and working memory). The clinical trials in which they participated had compared 0.625 mg CEE with or without 2.5 mg medroxyprogesterone acetate (MPA) over an average of 7.0 years. Cognitive testing was conducted an average of 7.2 years following the end of the trials, when women had mean age 67.2 years, and repeated one year later.
Results
Global cognitive function scores from women who had been assigned to CEE-based therapies were similar to those from women assigned to placebo: mean [95% confidence interval] intervention effect of 0.02 [−0.08,0.12]standard deviation units (p=0.66). Similarly, no overall differences were found for any individual cognitive domain (all p>0.15). Pre-specified subgroup analyses found some evidence that CEE-based therapies may have adversely affected verbal fluency among women who had prior hysterectomy or prior use of hormone therapy: mean treatment effects of −0.17 [−0.33, −0.02] and −0.25 [−0.42, −0.08], respectively, however this may be a chance finding. We are not able to address whether initiating hormone therapy during the menopause and maintaining therapy until any symptoms are passed affects cognitive function, either in the short or longer term.
Conclusions
CEE-based therapies produced no overall sustained benefit or risk to cognitive function when administered to postmenopausal women aged 50–55 years.
doi:10.1001/jamainternmed.2013.7727
PMCID: PMC3844547  PMID: 23797469
2.  Relations of Depressive Symptoms and Antidepressant Use to Body Mass Index and Selected Biomarkers for Diabetes and Cardiovascular Disease 
American journal of public health  2013;103(8):e34-e43.
Objectives
We investigated whether depressive symptoms and antidepressant use are associated with biomarkers for glucose dysregulation and inflammation, body mass index (BMI), and waist circumference.
Methods
Postmenopausal women were recruited into the Women’s Health Initiative from 1993 to 1998, and data were collected at regular intervals through 2005. We used multiple linear regression models to examine whether depressive symptoms and antidepressant use are associated with BMI, waist circumference, and biomarkers.
Results
Analysis of data from 71 809 women who completed all relevant baseline and year 3 assessments showed that both elevated depressive symptoms and antidepressant use were significantly associated with higher BMI and waist circumference. Among 1950 women, elevated depressive symptoms were significantly associated with increased insulin levels and measures of insulin resistance. Analyses of baseline data from 2242 women showed that both elevated depressive symptoms and antidepressant use were associated with higher C-reactive protein levels.
Conclusions
Monitoring body habitus and other biomarkers among women with elevated depression symptoms or taking antidepressant medication may be prudent to prevent diabetes and cardiovascular disease.
doi:10.2105/AJPH.2013.301394
PMCID: PMC3791588  PMID: 23763394
3.  Influence of Type 2 Diabetes on Brain Volumes and Changes in Brain Volumes 
Diabetes Care  2012;36(1):90-97.
OBJECTIVE
To study how type 2 diabetes adversely affects brain volumes, changes in volume, and cognitive function.
RESEARCH DESIGN AND METHODS
Regional brain volumes and ischemic lesion volumes in 1,366 women, aged 72–89 years, were measured with structural brain magnetic resonance imaging (MRI). Repeat scans were collected an average of 4.7 years later in 698 women. Cross-sectional differences and changes with time between women with and without diabetes were compared. Relationships that cognitive function test scores had with these measures and diabetes were examined.
RESULTS
The 145 women with diabetes (10.6%) at the first MRI had smaller total brain volumes (0.6% less; P = 0.05) and smaller gray matter volumes (1.5% less; P = 0.01) but not white matter volumes, both overall and within major lobes. They also had larger ischemic lesion volumes (21.8% greater; P = 0.02), both overall and in gray matter (27.5% greater; P = 0.06), in white matter (18.8% greater; P = 0.02), and across major lobes. Overall, women with diabetes had slightly (nonsignificant) greater loss of total brain volumes (3.02 cc; P = 0.11) and significant increases in total ischemic lesion volumes (9.7% more; P = 0.05) with time relative to those without diabetes. Diabetes was associated with lower scores in global cognitive function and its subdomains. These relative deficits were only partially accounted for by brain volumes and risk factors for cognitive deficits.
CONCLUSIONS
Diabetes is associated with smaller brain volumes in gray but not white matter and increasing ischemic lesion volumes throughout the brain. These markers are associated with but do not fully account for diabetes-related deficits in cognitive function.
doi:10.2337/dc12-0555
PMCID: PMC3526228  PMID: 22933440
4.  Cardiovascular Disease and Cognitive Decline in Postmenopausal Women: Results From the Women's Health Initiative Memory Study 
Background
Data on cardiovascular diseases (CVD) and cognitive decline are conflicting. Our objective was to investigate if CVD is associated with an increased risk for cognitive decline and to examine whether hypertension, diabetes, or adiposity modify the effect of CVD on cognitive functioning.
Methods and Results
Prospective follow‐up of 6455 cognitively intact, postmenopausal women aged 65 to 79 years old enrolled in the Women's Health Initiative Memory Study (WHIMS). CVD was determined by self‐report. For cognitive decline, we assessed the incidence of mild cognitive impairment (MCI) or probable dementia (PD) via modified mini‐mental state examination (3 MS) score, neurocognitive, and neuropsychiatric examinations. The median follow‐up was 8.4 years. Women with CVD tended to be at increased risk for cognitive decline compared with those free of CVD (hazard ratio [HR], 1.29; 95% CI: 1.00, 1.67). Women with myocardial infarction or other vascular disease were at highest risk (HR, 2.10; 95% CI: 1.40, 3.15 or HR, 1.97; 95% CI: 1.34, 2.87). Angina pectoris was moderately associated with cognitive decline (HR 1.45; 95% CI: 1.05, 2.01) whereas no significant relationships were found for atrial fibrillation or heart failure. Hypertension and diabetes increased the risk for cognitive decline in women without CVD. Diabetes tended to elevate the risk for MCI/PD in women with CVD. No significant trend was seen for adiposity.
Conclusions
CVD is associated with cognitive decline in elderly postmenopausal women. Hypertension and diabetes, but not adiposity, are associated with a higher risk for cognitive decline. More research is warranted on the potential of CVD prevention for preserving cognitive functioning.
doi:10.1161/JAHA.113.000369
PMCID: PMC3886762  PMID: 24351701
cardiovascular diseases; cognitive decline; postmenopausal women
5.  Toward a Positive Aging Phenotype for Older Women: Observations From the Women’s Health Initiative 
Background.
To develop a positive aging phenotype, we undertook analyses to describe multiple dimensions of positive aging and their relationships to one another in women 65 years of age and older and evaluate the performance of individual indicators and composite factors of this phenotype as predictors of time to death, years of healthy living, and years of independent living.
Methods.
Data from Women’s Health Initiative clinical trial and observational study participants ages 65 years and older at baseline, including follow-up observations up to 8 years later, were analyzed using descriptive statistics and principal components analysis to identify the factor structure of a positive aging phenotype. The factors were used to predict time to death, years of healthy living (without hospitalization or diagnosis of a serious health condition), and years of independent living (without nursing home admission or use of special services).
Results.
We identified a multidimensional phenotype of positive aging that included two factors: Physical–Social Functioning and Emotional Functioning. Both factors were predictive of each of the outcomes, but Physical–Social Functioning was the strongest predictor. Each standard deviation of increase in Physical–Social Functioning was accompanied by a 23.7% reduction in mortality risk, a 19.4% reduction in risk of major health conditions or hospitalizations, and a 26.3% reduction in risk of dependent living.
Conclusions.
Physical–Social Functioning and Emotional Functioning constitute important components of a positive aging phenotype. Physical–Social Functioning was the strongest predictor of outcomes related to positive aging, including years of healthy living, years of independent living, and time to mortality.
doi:10.1093/gerona/gls117
PMCID: PMC3667695  PMID: 22518819
Positive aging; Phenotypes; Women's health; Healthy life span
6.  Late-life depression, mild cognitive impairment and hippocampal functional network architecture☆ 
NeuroImage : Clinical  2013;3:311-320.
Late-life depression (LLD) and amnestic mild cognitive impairment (aMCI) are associated with medial temporal lobe structural abnormalities. However, the hippocampal functional connectivity (HFC) similarities and differences related to these syndromes when they occur alone or coexist are unclear. Resting-state functional connectivity MRI (R-fMRI) technique was used to measure left and right HFC in 72 elderly participants (LLD [n = 18], aMCI [n = 17], LLD with comorbid aMCI [n = 12], and healthy controls [n = 25]). The main and interactive relationships of LLD and aMCI on the HFC networks were determined, after controlling for age, gender, education and gray matter volumes. The effects of depressive symptoms and episodic memory deficits on the hippocampal functional connections also were assessed. While increased and decreased left and right HFC with several cortical and subcortical structures involved in mood regulation were related to LLD, aMCI was associated with globally diminished connectivity. Significant LLD–aMCI interactions on the right HFC networks were seen in the brain regions critical for emotion processing and higher-order cognitive functions. In the interactive brain regions, LLD and aMCI were associated with diminished hippocampal functional connections, whereas the comorbid group demonstrated enhanced connectivity. Main and interactive effects of depressive symptoms and episodic memory performance were also associated with bilateral HFC network abnormalities. In conclusion, these findings indicate that discrete hippocampal functional network abnormalities are associated with LLD and aMCI when they occur alone. However, when these conditions coexist, more pronounced vulnerabilities of the hippocampal networks occur, which may be a marker of disease severity and impending cognitive decline. By utilizing R-fMRI technique, this study provides novel insights into the neural mechanisms underlying LLD and aMCI in the functional network level.
Highlights
•Effects of late-life depression and MCI on hippocampal memory network using R-fMRI•Distinct hippocampal functional network correlates in late-life depression and MCI.•Late-life depression and MCI interact on hippocampal functional network level.•Hippocampal functional network correlates with neuropsychological measures.•Novel insights into functional network vulnerability underlying depression and MCI
doi:10.1016/j.nicl.2013.09.002
PMCID: PMC3814948  PMID: 24273715
Depression; Mild cognitive impairment; Hippocampus; Functional connectivity; MRI; Episodic memory; Depressive symptoms; Elderly
7.  Neural Basis of the Association between Depressive Symptoms and Memory Deficits in Nondemented Subjects: Resting-State fMRI Study 
Human Brain Mapping  2011;33(6):1352-1363.
Depressive symptoms often coexist with memory deficits in older adults and also are associated with incident cognitive decline in the elderly. However, little is known about the neural correlates of the association between depressive symptoms and memory deficits in nondemented elderly. Fifteen amnestic mild cognitive impairment (aMCI) and 20 cognitively normal (CN) subjects completed resting-state functional magnetic resonance imaging (R-fMRI) scans. Multiple linear regression analysis was performed to test the main effects of the Geriatric Depression Scale (GDS) and Rey Auditory Verbal Learning Test delayed recall (RAVLT-DR) scores, and their interaction on the intrinsic amygdala functional connectivity (AFC) network activity. Severer depressive symptoms and memory deficits were found in the aMCI group than in the CN group. Partial correlation analysis identified that the RAVLT-DR scores were significantly correlated with the AFC network in the bilateral dorsolateral prefrontal cortex (DLPFC), dorsomedial and anterior prefrontal cortex, posterior cingulate cortex (PCC), middle occipital gyrus, right inferior parietal cortex, and left middle temporal gyrus (MTG). The GDS scores were positively correlated with the AFC network in the bilateral PCC and MTG, and left DLPFC. The interactive effects of the GDS and RAVLT-DR scores on the AFC network were seen in the bilateral PCC, MTG, and left DLPFC. These findings not only supported that there were interactive neural links between depressive symptoms and memory functions in nondemented elderly at the system level, but also demonstrated that R-fMRI has advantages in investigating the interactive nature of different neural networks involved in complex functions, such as emotion and cognition.
doi:10.1002/hbm.21291
PMCID: PMC3190573  PMID: 21618660
amnestic mild cognitive impairment; depressive symptom; memory deficits; resting-state functional connectivity MRI; amygdala
8.  A clustering-based method to detect functional connectivity differences 
Neuroimage  2012;61(1):56-61.
Recently, resting-state functional magnetic resonance imaging (R-fMRI) has emerged as a powerful tool for investigating functional brain organization changes in a variety of neurological and psychiatric disorders. However, the current techniques may need further development to better define the reference brain networks for quantifying the functional connectivity differences between normal and diseased subject groups. In this study, we introduced a new clustering-based method that can clearly define the reference clusters. By employing group difference information to guide the clustering, the voxels within the reference clusters will have homogeneous functional connectivity changes above predefined levels. This method identified functional clusters that were significantly different between the amnestic mild cognitively impaired (aMCI) and age-matched cognitively normal (CN) subjects. The results indicated that the distribution of the clusters and their functionally disconnected regions resembled the altered memory network regions previously identified in task fMRI studies. In conclusion, the new clustering method provides an advanced approach for studying functional brain organization changes associated with brain diseases.
doi:10.1016/j.neuroimage.2012.02.064
PMCID: PMC3342474  PMID: 22405733
clustering; resting-state fMRI; postprocessing; functional connectivity; amnestic mild cognitive impairment; human brain
9.  Changes in Regional Cerebral Blood Flow and Functional Connectivity in the Cholinergic Pathway Associated with Cognitive Performance in Subjects with Mild Alzheimer’s Disease after 12-week Donepezil Treatment 
Neuroimage  2012;60(2):1083-1091.
Acetylcholinesterase inhibitors (AChEIs), such as donepezil, have been shown to improve cognition in mild to moderate Alzheimer’s disease (AD) patients. In this paper, our goal is to determine the relationship between altered cerebral blood flow (CBF) and intrinsic functional network connectivity changes in mild AD patients before and after 12-week donepezil treatment. An integrative neuroimaging approach was employed by combining pseudocontinuous arterial spin labeling (pCASL) MRI and resting-state functional MRI (R-fMRI) methods to determine the changes in CBF and functional connectivity (FC) in the cholinergic pathway. Linear regression analyses determined the correlations of the regional CBF alterations and functional connectivity changes with cognitive responses. These were measured with the Mini-Mental Status Examination (MMSE) scores and Alzheimer’s disease Assessment Scale-Cognitive subscale (ADAS-cog) scores. Our results show that the regional CBF in mild AD subjects after donepezil treatment was significantly increased in the middle cingulate cortex (MCC) and posterior cingulate cortex (PCC), which are the neural substrates of the medial cholinergic pathway. In both brain regions, the baseline CBF and its changes after treatment were significantly correlated with the behavioral changes in ADAS-cog scores. The intrinsic FC was significantly enhanced in the medial cholinergic pathway network in the brain areas of the parahippocampal, temporal, parietal and prefrontal cortices. Finally, the FC changes in the medial prefrontal areas demonstrated an association with the CBF level in the MCC and the PCC, and also were correlated with ADAS-cog score changes. These findings indicate that regional CBF and FC network changes in the medial cholinergic pathway were associated with cognitive performance. It also is suggested that the combined pCASL-MRI and R-fMRI methods could be used to detect regional CBF and FC changes when using drug treatments in mild AD subjects.
doi:10.1016/j.neuroimage.2011.12.077
PMCID: PMC3324180  PMID: 22245641
acetylcholinesterase inhibitors; donepezil; cerebral blood flow; resting-state functional connectivity; Alzheimer’s disease
10.  Functional Network Endophenotypes Unravel the Effects of Apolipoprotein E Epsilon 4 in Middle-Aged Adults 
PLoS ONE  2013;8(2):e55902.
Apolipoprotein E-ε4 (APOE-ε4) accentuates memory decline, structural volume loss and cerebral amyloid deposition in cognitively healthy adults. We investigated whether APOE-ε4 carriers will show disruptions in the intrinsic cognitive networks, including the default mode (DMN), executive control (ECN) and salience (SN) networks, relative to noncarriers in middle-aged healthy adults; and the extent to which episodic-memory performance is related to the altered functional connectivity (Fc) in these networks. Resting-state functional connectivity MRI (R-fMRI) was used to measure the differences in the DMN, ECN and SN Fc between 20 APOE-ε4 carriers and 26 noncarriers. Multiple linear regression analyses were performed to determine the relationship between episodic-memory performance and Fc differences in the three resting-state networks across all subjects. There were no significant differences in the demographic and neuropsychological characteristics and the gray-matter volumes in the carriers and noncarriers. While mostly diminished DMN and ECN functional connectivities were seen, enhanced connections to the DMN structures were found in the SN in ε4 carriers. Altered DMN and ECN were associated with episodic memory performance. Significant Fc differences in the brain networks implicated in cognition were seen in middle-aged individuals with a genetic risk for AD, in the absence of cognitive decline and gray-matter atrophy. Prospective studies are essential to elucidate the potential of R-fMRI technique as a biomarker for predicting conversion from normal to early AD in healthy APOE-ε4 carriers.
doi:10.1371/journal.pone.0055902
PMCID: PMC3570545  PMID: 23424640
11.  The co-existence of geriatric depression and amnestic mild cognitive impairment detrimentally affect gray matter volumes: Voxel-based morphometry study 
Behavioural brain research  2012;235(2):244-250.
While late-life depression (LLD) and amnestic mild cognitive impairment (aMCI), alone and in combination, is associated with an increased risk of incident Alzheimer’s disease (AD), the neurobiological mechanisms of this link are unclear. We examined the main and interactive effects of LLD and aMCI on the gray matter (GM) volumes in seventy-two physically healthy participants aged 60 and older. Participants were separated into normal controls, cognitively normal depressed, non-depressed aMCI, and depressed aMCI groups. Optimized voxel-based morphometry estimated GM volumes. The main and interactive effects of LLD and aMCI, and of depressive symptoms and episodic memory deficits on the GM volumes were analyzed. While decreased GM volumes in the mood regulating circuitry structures were associated with depression, GM atrophy in regions essential for various cognitive performance were related to aMCI. LLD-aMCI interactions were associated with widespread subcortical and cortical GM volume loss of brain structures implicated in AD. The interactions between episodic memory deficits and depressive symptom severity are associated with volume loss in right inferior frontal gyrus/anterior insula and left medial frontal gyrus clusters. Our findings suggest that the co-existence of these clinical phenotypes is a potential marker for higher risk of AD.
doi:10.1016/j.bbr.2012.08.007
PMCID: PMC3561929  PMID: 22909988
late-life depression; mild cognitive impairment; voxel-based morphometry; elderly; Alzheimer’s disease; episodic memory; Geriatric depression; gray matter brain volumes
12.  Recovery of Hippocampal Network Connectivity Correlates with Cognitive Improvement in Mild Alzheimer's Disease Patients Treated with Donepezil Assessed by Resting-State fMRI 
Purpose
To identify the neural correlates of cognitive improvement in mild AD subjects, following 12 weeks of donepezil treatment.
Materials and Methods
Resting-state functional connectivity MRI (R-fMRI) was used to measure the hippocampal functional connectivity (HFC) in 14 mild AD and 18 age-matched normal (CN) subjects. AD subjects were scanned at baseline and after donepezil treatment. CN subjects were scanned only at baseline as a reference to identify regions correlated or anticorrelated to the hippocampus. Before each scan, participants underwent cognitive, behavioral and functional assessments.
Results
After donepezil treatment, neural correlates of cognitive improvement measured by Mini-Mental State Examination scores were identified in the left parahippocampus, dorsolateral prefrontal cortex (DLPFC) and inferior frontal gyrus. Improvement in AD Assessment Scale-cognitive subscale scores correlated with the HFC changes in the left DLPFC and middle frontal gyrus. Stronger recovery in the network connectivity was associated with cognitive improvement.
Conclusion
R-fMRI may provide novel insight into the brain's functional responses to AD treatment in clinical pharmacological trials, and also may predict clinical response.
doi:10.1002/jmri.22662
PMCID: PMC3177015  PMID: 21769962
Resting-state Functional MRI; Hippocampus; Alzheimer's disease; Donepezil
13.  Cognitive Function and Fine Motor Speed in Older Women with Diabetes Mellitus: Results from the Women's Health Initiative Study of Cognitive Aging 
Journal of Women's Health  2011;20(10):1435-1443.
Abstract
Background
We sought to determine if type 2 diabetes mellitus (T2DM) was associated with accelerated decline in domain-specific measures of cognitive function and fine motor speed.
Methods
Women aged 65–80 years who were enrolled in a clinical trial of postmenopausal hormone therapy were grouped as having T2DM (n=179) or not (n=1984) and followed for an average of 5 years with annual standardized assessments of domain-specific cognitive function. Mean patterns of cognitive measures over time were contrasted between groups using general linear models and Wald tests, with varying levels of covariate adjustment. The influences of age at onset, use of oral medications, and use of insulin were also examined.
Results
T2DM was associated with mean deficits of 0.2–0.4 standard deviations (SD) across follow-up in most cognitive domains. Consistent evidence that rates of decline were accelerated among women with T2DM was evident only for verbal knowledge and verbal memory (p<0.05). Decrements in fine motor speed, but no measure of cognitive function, were greater for women with earlier onset T2DM. Use of oral diabetes medications was associated with better relative cognitive function.
Conclusions
In these women, T2DM was associated with cognitive deficits in most domains. Relative deficits in verbal knowledge and verbal memory may continue to increase after deficits in other domains have stabilized. Relative deficits in fine motor speed may be greater among women with earlier onsets of T2DM. Use of insulin, which may reflect greater T2DM severity, was associated with relatively greater cognitive deficits.
doi:10.1089/jwh.2011.2812
PMCID: PMC3186442  PMID: 21819251
14.  Depressive Symptoms, Brain Volumes and Subclinical Cerebrovascular Disease in Postmenopausal Women: The Women’s Health Initiative MRI Study 
Journal of affective disorders  2011;132(1-2):275-284.
Objective
Late-life depressive symptoms (DS) increase the risk of incident mild cognitive impairment and probable dementia in the elderly. Our objectives were to examine the relationship between elevated DS and regional brain volumes including frontal lobe subregions, hippocampus and amygdala, and to determine whether elevated DS were associated with increased subclinical cerebrovascular disease in postmenopausal women.
Methods
DS were assessed an average of 8 years prior to structural brain MRI in 1372 women. The 8-item Burnam regression algorithm was used to define DS with a cut-point of 0.009. Adjusting for potential confounders, mean differences in total brain, frontal lobe subregions, hippocampus and amygdala volumes and total ischemic lesion volumes in the basal ganglia and the cerebral white and gray matter outside the basal ganglia were compared between women with and without DS.
Results
Depressed women had lower baseline global cognition and were more likely to have prior hormone therapy history. After full adjustment, DS at baseline were associated with smaller superior and middle frontal gyral volumes. Hippocampal and amygdala volumes, and ischemic lesion volumes were similar in depressed and non-depressed women.
Limitations
Depression was not assessed based on semi-structured interview, and we were unable to determine the temporal relationships between DS and frontal lobe volume differences due to the availability of only one MRI scan.
Conclusions
Elevated DS were associated with lower volumes in certain frontal lobe subregions but not in the medial temporal lobe structures. Our findings support the role of frontal lobe structures in late-life DS among women.
doi:10.1016/j.jad.2011.01.020
PMCID: PMC3109161  PMID: 21349587
Late-life Depression; regional brain volumes; subclinical cerebrovascular disease; structural magnetic resonance imaging
15.  Neural Correlates of the Interactive Relationship between Memory Deficits and Depressive Symptoms in Nondemented Elderly: Resting fMRI Study 
Behavioural brain research  2011;219(2):205-212.
Prospective studies have shown an association between depressive symptoms and cognitive impairment among older adults. However, the neural correlates of this relationship are poorly understood. Our aim was to examine whether interactive effects of memory deficits and depressive symptoms are present in the memory-associated functional networks, in nondemented elderly subjects. Fifteen subjects with amnestic mild cognitive impairment (aMCI) and 20 age-matched normal (CN) elderly subjects participated in this cross-sectional study. Resting-state functional connectivity MRI (R-fMRI) measured the hippocampal functional connectivity (HFC) alterations between the two groups. Voxelwise linear regression analysis was performed to correlate hippocampal network strength with the Rey Auditory Verbal Learning Test delayed recall and the Geriatric Depression Scale scores, after adjusting for age and group effects. Poorer memory performance was associated with decreased positively correlated HFC connectivity in the specific frontal lobe and default mode network (DMN) structures. Poorer memory performance also was associated with decreased anticorrelated HFC connectivity in the bilateral inferior parietal and right dorsolateral prefrontal cortices. In contrast, greater depressive symptom severity was associated with increased HFC connectivity in several frontal lobes and DMN regions. Depressive symptoms and memory functions had interactive effects on the HFC, in the frontal, temporal, and PCC structures. Our findings suggest that the R-fMRI technique can be used to examine the changes in functional neural networks where memory deficits and depressive symptoms coexist in the geriatric population.
doi:10.1016/j.bbr.2011.01.008
PMCID: PMC3062733  PMID: 21238490
Mild cognitive impairment; Alzheimer’s disease; late-life depressive symptoms; functional connectivity magnetic resonance imaging; hippocampus; elderly
16.  Application of machine learning methods to describe the effects of conjugated equine estrogens therapy on region-specific brain volumes 
Magnetic resonance imaging  2011;29(4):546-553.
Use of conjugated equine estrogens (CEE) has been linked to smaller regional brain volumes in women aged ≥65 years, however it is unknown whether this results in a broad-based characteristic pattern of effects. Structural MRI was used to assess regional volumes of normal tissue and ischemic lesions among 513 women who had been enrolled in a randomized clinical trial of CEE therapy for an average of 6.6 years, beginning at ages 65-80 years. A multivariate pattern analysis, based on a machine learning technique that combined Random Forest and logistic regression with L1 penalty, was applied to identify patterns among regional volumes associated with therapy and whether patterns discriminate between treatment groups. The multivariate pattern analysis detected smaller regional volumes of normal tissue within the limbic and temporal lobes among women that had been assigned to CEE therapy. Mean decrements ranged as high as 7% in the left entorhinal cortex and 5% in the left perirhinal cortex, which exceeded the effect sizes reported previously in frontal lobe and hippocampus. Overall accuracy of classification based on these patterns, however, was projected to be only 54.5%. Prescription of CEE therapy for an average of 6.6 years is associated with lower regional brain volumes, but it does not induce a characteristic spatial pattern of changes in brain volumes of sufficient magnitude to discriminate users and non-users.
doi:10.1016/j.mri.2010.12.001
PMCID: PMC3079024  PMID: 21292420
Hormone therapy; MRI; Random Forest; WHIMS
17.  Dopamine Agonist Use is Associated with Impulse Control Disorders in Parkinson’s Disease 
Archives of neurology  2006;63(7):969-973.
Objective
To determine the frequency and correlates of impulse control disorders (ICDs) in Parkinson’s disease (PD).
Design
An unstructured screening interview for ICDs (compulsive gambling, buying, and sexual behavior) followed by a telephone-administered structured interview for screen-positive patients.
Setting
Two university-affiliated movement disorders centers.
Participants
A convenience sample of 272 patients with idiopathic PD who were screened for psychiatric complications.
Main Outcome Measures
Presence of compulsive gambling, buying, or sexual behavior as assessed by the Minnesota Impulsive Disorders Interview.
Results
Eighteen (6.6%) PD patients met criteria for an ICD at some point during the course of PD, including 11 (4.0%) with an active ICD. Compulsive gambling and compulsive sexual behavior were equally common. In a multivariate model, treatment with a dopamine agonist (P = .01) and a history of ICD symptomatology prior to PD onset (P = .02) predicted current ICD. There were no differences between the dopamine agonists in their association with ICDs (P = .21), and daily doses of dopamine agonists were higher in patients with an ICD than in dopamine agonist-treated patients without an ICD (P < .001).
Conclusions
PD patients treated with a dopamine agonist should be made aware of the risk of developing an ICD and monitored clinically. As dopamine agonists are increasing being used for other indications, future research should assess the dopamine agonist-associated risk for ICDs in other populations.
doi:10.1001/archneur.63.7.969
PMCID: PMC1761054  PMID: 16831966

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