Prevalence and Patterns of Cognitive Impairment in a Sample of Community Dwelling Older People in Nigeria

Objective

Prevalence and patterns of cognitive impairment were studied in older people from Nigeria.

Method

Four hundred and forty one participants (263 females; age: 60-87) were recruited from community dwelling adults in Anambra state Nigeria. Five domains of cognition were tested using the Uniform Data Set Version 3 (UDS-3).

Result

Prevalence: 49.7% were classified as normal cognition, 34% as borderline, 12.9% as MCI (2.72% with amnesic MCI) and 3.4% as dementia. We showed in descending order in that 13% of the participants were impaired on visual-spatial index; 6.8% on memory index; 5.2% on attention/concentration index; 2.7% were impaired on executive function index and 34.80% (based on mean) of the participants were impaired on processing speed index. There were significant interaction effects for gender and education on visual spatial and attention domains respectively. Significant effects of education were seen on executive function and processing speed while interaction effect was found on executive function alone. 8% scored 1.5 SD below the mean on MoCA. There was a significant effect of education on MoCA with the pairwise comparison showing a significant difference between tertiary education and other two levels of education. The groups did differ significantly for hypertension on MoCA.

Conclusion

This study showed a high prevalence of cognitive impairment among older adult population from Nigeria. A significant proportion of the sample were impaired on the visual spatial domain and at least half of the participants were impaired on one cognitive domain. Hypertensive participants performed significantly poor on MoCA compared to non-hypertensive group.

The Effect of Surgical Weight Loss on Cognition in Individuals with Class II/III Obesity

BACKGROUND

Obesity is a global epidemic and is associated with cognitive impairment and dementia. It remains unknown whether weight loss interventions, such as bariatric surgery, can mitigate cognitive impairment.

OBJECTIVES

We aimed to determine the effect of surgical weight loss on cognition in individuals with class II/III obesity.

DESIGN

We performed a prospective cohort study of participants who underwent bariatric surgery. At baseline and two years following surgery, participants completed metabolic risk factor and neuropsychological assessments.

SETTING

Participants were enrolled from an academic suburban bariatric surgery clinic.

PARTICIPANTS

There were 113 participants who completed baseline assessments and 87 completed two-year follow-up assessments (66 in-person and 21 virtual) after bariatric surgery. The mean (SD) age was 46.8 (12.5) years and 64 (73.6%) were female.

INTERVENTION

Bariatric surgery. There were 77 (88.5%) participants that underwent sleeve gastrectomy and 10 (11.5%) that underwent gastric bypass surgery.

MEASUREMENTS

Cognition was assessed using the NIH toolbox cognitive battery (NIHTB-CB) and the Rey Auditory Verbal Learning Test (AVLT). The primary outcome was the change in NIHTB-CB fluid composite score before and after surgery.

RESULTS

The primary outcome, NIHTB-CB composite score, was stable following bariatric surgery (-0.4 (13.9), p=0.81,n=66). Among secondary outcomes, the NIHTB-CB dimensional card sorting test (executive function assessment), improved (+6.5 (19.9),p=0.01,n=66) while the Rey AVLT delayed recall test (memory assessment) declined (-0.24 (0.83),p=0.01,n=87) following surgery. Improvements to metabolic risk factors and diabetes complications were not associated with improvements to NIHTB-CB composite score. The other 4 NIHTB-CB subtests and Rey AVLT assessments of auditory learning and recognition were stable at follow-up.

CONCLUSIONS

Following bariatric surgery, the age-adjusted composite cognitive outcome did not change, but an executive subtest score improved. These results suggest that bariatric surgery may mitigate the natural history of cognitive decline in individuals with obesity, which is expected to be faster than normal aging, but confirmatory randomized controlled trials are needed. The decline in delayed recall also warrants further studies to determine potential differential effects on cognitive subtests.

Mucoadhesive and mucopenetrating chitosan nanoparticles for glycopeptide antibiotic administration

The use of nanoparticles (NPs) represents a useful strategy for peptide antibiotic delivery to mucosal membranes by either prolonging drug residence time at the target site (mucoadhesive NPs) or by enhancing diffusion across mucus layer to reach the underlying epithelium (mucopenetrating NPs). The purpose of this study was to design chitosan (CH) NPs and to evaluate their employment as mucoadhesive and/or mucopenetrating systems for vancomycin (VM) delivery. NPs were prepared by ionic gelation of CH with sodium carboxymethylcellulose (CMC), sodium alginate (ALG), sodium tripolyphosphate (TPP) or phytic acid (PA) and characterized in terms of size, zeta-potential, morphology, drug encapsulation efficiency, mucoadhesion and mucopenetrating ability. Moreover, in vitro tests were conducted to evaluate VM release and the antibacterial activity against Staphylococcus aureus and Bacillus subtilis. NPs showed sizes ranged from 150 nm to 350 nm with good polydispersity index and positive zeta-potential. The selection of the suitable crosslinker allowed to modulate the mucoadhesive/mucopenetrating properties: CH/TPP NPs showed the best mucoadhesive ability, while CH/PA and CH/CMC NPs were characterized by an improved diffusion across the mucus layer. Further, NPs allowed a fast and complete release of VM, maintaining the antibacterial activity against the tested bacteria species.

In utero and peripartum antiretroviral exposure as predictor of cognition in 6- to 10-year-old HIV-exposed Ugandan children - a prospective cohort study

OBJECTIVES

To quantify association between in utero/peripartum antiretroviral (IPA) exposure and cognition, i.e. executive function (EF) and socioemotional adjustment (SEA), in school-aged Ugandan children who were perinatally HIV-infected (CPHIV, n = 100) and children who were HIV-exposed but uninfected (CHEU, n = 101).

METHODS

Children were enrolled at age 6-10 years and followed for 12 months from March 2017 to December 2018. Caregiver-reported child EF and SEA competencies were assessed using validated questionnaires at baseline, 6 and 12 months. IPA type - combination antiretroviral therapy (cART), intrapartum single-dose nevirapine ± zidovudine (sdNVP ± ZDV), nevirapine + zidovudine + lamivudine (sdNVP + ZDV + 3TC) - or no IPA (reference) was verified via medical records. IPA-related standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) in cognitive competencies were estimated from regression models with adjustment for caregiver sociodemographic and contextual factors. Models were fitted separately for CPHIV and CHEU.

RESULTS

Among CPHIV children, cART (SMD = -0.82, 95% CI: -1.37 to -0.28) and sdNVP ± ZDV (SMD = -0.41, 95% CI: -0.81 to -0.00) vs. no IPA predicted lower executive dysfunction over 12 months. Intrapartum sdNVP + ZDV + 3TC vs. no IPA predicted executive dysfunction (SMD = 0.80, 95% CI: 0.30-1.31), SEA problems (SMD = 0.63-0.76, 95% CI: 0.00-1.24) and lower adaptive skills (SMD = -0.36, 95% CI: -0.75-0.02) over 12 months among CHEU. Further adjustment for contextual factors attenuated associations, although most remained of moderate clinical importance (|SMD| > 0.33).

CONCLUSIONS

Among CPHIV children, cART and sdNVP ± ZDV IPA exposure predicted, on average, lower executive dysfunction 6-10 years later. However, peripartum sdNVP + ZDV + 3TC predicted executive and SEA dysfunction among CHEU 6-10 years later. These data underscore the need for more research into long-term effects of in utero ART to inform development of appropriate interventions so as to mitigate cognitive sequelae.

Clinical and microbiological monitoring of Cystic Fibrosis patients, three years of follow-up via Tele-Medicine: an empirical research

OBJECTIVES

Evaluation of the effectiveness of home care through a telemonitoring system in reducing the incidence of new colonization by Pseudomonas Aeruginosa in a population of patients with Cystic Fibrosis (CF) followed by the CF clinic of the Bambino Gesù Hospital in Rome over a period of 36 months.

MATERIALS AND METHODS

Two groups of patients were recruited, homogeneous for age, sex, BMI, FEV1, prevalence of CF-related Diabetes and CF-related Hepatopathy, access to new therapies with modulators: a) an IN group (N = 44 ) followed through a home telemonitoring system, b) an OUT control group (N = 110) followed according to the standards of care. The following parameters were detected for all patients: pulmonary colonization of the lungs, number and type of hospital admissions, respiratory function, BMI.

RESULT

The OUT group had a statistically significant increase in the prevalence of Pseudomonas Aeruginosa infections during the observation period. Furthermore, a significant decrease in lung function assessed through FEV1 was also observed in the OUT group.

CONCLUSION

Adolescent and adult patients belonging to the CF center who are not followed through the dedicated home telemonitoring service show, in the three-year period 2017-19, an increase in Pseudomonas Aeruginosa infections and a greater decrease in respiratory function. The use of telemedicine in CF is therefore an effective system not only in monitoring the disease but also as a treatment strategy, in the context of an evolving multidisciplinary model. As advantages, telemedicine can reduce the number of Pseudomonas Aeruginosa lung infections and the greater stability of respiratory function over time.

Culture and Diagnosis of MCI in Hispanics: A Literature Review

Objective

Hispanics are a rapidly growing and aging segment of the US population. There is a critical need to accurately and efficiently detect those at risk for dementia, particularly those with Mild Cognitive Impairment (MCI). MCI diagnosis typically relies on neuropsychological tests, although cultural and linguistic factors impact neuropsychological test scores. The current study reviews neuropsychological studies on MCI in Hispanics to evaluate the factors in testing for MCI diagnosis.

Participants and Method

Studies were identified from a literature search utilizing Web of Science, PubMed, Google Scholar, and Scopus, using search terms “Hispanic OR Mexican American” and “Mild Cognitive Impairment,” and from the reference sections of studies identified through this search. Studies utilizing neuropsychological tests in the diagnosis of MCI for Hispanics living in the US were identified and reviewed. Approaches for sample characterization (e.g., country of origin and of education, literacy, language preference and proficiency), neuropsychological test methods (e.g., test selection and translation, normative data source), and method of MCI diagnosis were reviewed.

Results

Considerable variability was found across studies with regard to the incorporation – and the method of incorporation – of cultural factors and their consideration in the MCI diagnosis process for Hispanics. For example, several studies did not report their sample’s country of education, source of normative data used for determination of cognitive impairment, or method of test adaptation/translation.

Conclusions

Diagnosis of MCI in Hispanics has been complicated by a dearth of culturally appropriate neuropsychological assessment tools and normative data, which likely contributes to inconsistency across studies. Future studies are needed to further develop culturally appropriate neuropsychological methods to evaluate MCI in Hispanics in the US and to improve diagnostic accuracy in this population.

Survival After Lung Transplant for Cystic Fibrosis in Italy: A Single Center Experience With 20 Years of Follow-up

OBJECTIVES

Lung transplantation is currently the only treatment for end-stage respiratory failure in patients with cystic fibrosis (CF). In this study we retrospectively analyzed our experience since the start of the transplantation program in 1996 with focus on survival analysis.

METHODS

All patients with CF who underwent lung transplant at our center were included (1996-2016). Survival analysis after lung transplant was performed using the Kaplan-Meier estimate, comparing by sex and by 4 eras (1996-2000, 2001-2005, 2006-2010, and 2011-2016).

RESULTS

In a 20-year period, 243 patients with CF were listed for lung transplant; 123 patients (61 male, 62 female) underwent transplant, and 85 died while waiting for donor organs. The mean (SD) and median age at transplant was 27.7 (8.7) years and 26.9 years (range, 9.1 - 52.1 years), respectively. Mean (SD) forced expiratory volume in the first second was 27.6 (9.7)% predicted; 115 patients (92.0%) were pancreatic insufficient, and 43 patients (34.0%) had CF-related diabetes. Removing patients with CF who died within the first 3 postoperative months, the mean (SD) and median survival after transplant were 8.2 (5.7) years and 7.5 years (range, 3 months-20 years), respectively. Overall post-lung transplant 1-year survival was 93.6%, 5-year survival was 71.4%, 10-year survival was 53.6%, 15-year survival was 36.7%, and 20-year survival was 31.6%. We found no difference in survival between sex (P = .22) and among the 4 eras (P = .56).

CONCLUSIONS

Survival after lung transplant in our single center is similar to international data.

Interaction of vaginal Lactobacillus strains with HeLa cells plasma membrane

Vaginal lactobacilli offer protection against recurrent urinary and vaginal infections. The precise mechanisms underlying the interaction between lactobacilli and the host epithelium remain poorly understood at the molecular level. Deciphering such events can provide valuable information on the mode of action of commensal and probiotic bacteria in the vaginal environment. We investigated the effects exerted by five Lactobacillus strains of vaginal origin (Lactobacillus crispatus BC1 and BC2, Lactobacillus gasseri BC9 and BC11 and Lactobacillus vaginalis BC15) on the physical properties of the plasma membrane in a cervical cell line (HeLa). The interaction of the vaginal lactobacilli with the cervical cells determined two kinds of effects on plasma membrane: (1) modification of the membrane polar lipid organisation and the physical properties (L. crispatus BC1 and L. gasseri BC9); (2) modification of α5β1 integrin organisation (L. crispatus BC2, L. gasseri BC11 and L. vaginalis BC15). These two mechanisms can be at the basis of the protective role of lactobacilli against Candida albicans adhesion. Upon stimulation with all Lactobacillus strains, we observed a reduction of the basal oxidative stress in HeLa cells that could be related to modifications in physical properties and organisation of the plasma membrane. These results confirm the strictly strain-specific peculiarities of Lactobacillus and deepen the understanding of the mechanisms underlying the health-promoting role of this genus within the vaginal ecosystem.

Immunological correlates of behavioral problems in school-aged children living with HIV in Kayunga, Uganda

BACKGROUND

HIV can affect the neuropsychological function of children, including their behavior. We aim to identify immunological correlates of behavioral problems among children living with HIV in Uganda.

METHODS

Children participating in a parent randomized control trial in Kayunga, Uganda were assessed with the Behavior Rating Inventory of Executive Function (BRIEF) and the Child Behavior Checklist (CBCL). We constructed simple and multiple linear regression models to identify immunological correlates of behavioral problems.

RESULTS

A total of 144 children living with HIV (50% male) with a mean age of 8.9 years [Standard Deviation (s.d.) = 1.9] were included in the analysis. Eighty-two children were on antiretroviral therapy. Mean CD4 cell count % was 35.1 cells/μl (s.d. = 15.0), mean CD4 cell activation 5.7% (s.d. = 5.1), mean CD8 cell activation was 17.5% (s.d. = 11.2) and 60 children (41.7%) had a viral load of <4000 copies/ml. In the adjusted models for the BRIEF, higher scores were associated with higher viral loads (aβ = 16.7 × 10-6, 95% CI -5.00 × 10-6 to 28.4 × 10-6), specifically on the behavioral regulation index. Higher mean CD8 activation % was associated with higher scores on the Externalizing Problems  and Total Problems  scales of the CBCL (aβ = 0.17, 95% CI 0.04-0.31 and aβ = 0.15, 95% CI 0.00-0.28, respectively).

CONCLUSIONS

Poorer behavioral outcomes were associated with higher viral loads while higher CD8 activation was associated with poorer emotional and behavioral outcomes. Complete immunological assessments for children living with HIV could include commonly used viral and immunological parameters to identify those at higher risk of having negative behavior outcomes and who would benefit the most from behavioral interventions.

Designing and evaluating Brain Powered Games for cognitive training and rehabilitation in at-risk African children

BACKGROUND

Valid, reliable, accessible, and cost-effective computer-training approaches can be important components in scaling up educational support across resource-poor settings, such as sub-Saharan Africa. The goal of the current study was to develop a computer-based training platform, the Michigan State University Games for Entertainment and Learning laboratory's Brain Powered Games (BPG) package that would be suitable for use with at-risk children within a rural Ugandan context and then complete an initial field trial of that package.

METHODS

After game development was completed with the use of local stimuli and sounds to match the context of the games as closely as possible to the rural Ugandan setting, an initial field study was completed with 33 children (mean age = 8.55 ± 2.29 years, range 6-12 years of age) with HIV in rural Uganda. The Test of Variables of Attention (TOVA), CogState computer battery, and the Non-Verbal Index from the Kaufman Assessment Battery for Children, 2nd edition (KABC-II) were chosen as the outcome measures for pre- and post-intervention testing. The children received approximately 45 min of BPG training several days per week for 2 months (24 sessions).

RESULTS

Although some improvements in test scores were evident prior to BPG training, following training, children demonstrated clinically significant changes (significant repeated-measures outcomes with moderate to large effect sizes) on specific TOVA and CogState measures reflecting processing speed, attention, visual-motor coordination, maze learning, and problem solving.

CONCLUSIONS

Results provide preliminary support for the acceptability, feasibility, and neurocognitive benefit of BPG and its utility as a model platform for computerized cognitive training in cross-cultural low-resource settings.

Smoking history, and not depression, is related to deficits in detection of happy and sad faces

INTRODUCTION

Previous research has demonstrated that chronic cigarette smoking and major depressive disorder (MDD) are each associated with cognitive decrements. Further, these conditions co-occur commonly, though mechanisms in the comorbid condition are poorly understood. There may be distinct, additive, or overlapping factors underlying comorbid cigarette smoking and MDD. The present study investigated the impact of smoking and MDD on executive function and emotion processing.

METHODS

Participants (N=198) were grouped by diagnostic category (MDD and healthy controls, HC) and smoking status (ever-smokers, ES and never-smokers, NS). Participants completed the Facial Emotion Perception Test (FEPT), a measure of emotional processing, and the parametric Go/No-go task (PGNG), a measure of executive function.

RESULTS

FEPT performance was analyzed using ANCOVA with accuracy and reaction time as separate dependent variables. Repeated measures MANCOVA was conducted for PGNG with performance measure and task level as dependent variables. Analyses for each task included diagnostic and smoking group as independent variables, and gender was controlled for. Results for FEPT reveal that lower overall accuracy was found for ES relative to NS, though MDD did not differ from HC. Post-hoc analyses revealed that ES were poorer at identifying happy and sad, but not fearful or angry, faces. For PGNG, poorer performance was observed in MDD relative to HC in response time to Go targets, but there were no differences for ES and NS. Interaction of diagnosis and smoking group was not observed for performance on either task.

CONCLUSIONS

The results of this study provide preliminary evidence for distinctive cognitive decrements in smokers and individuals with depression.

Using pictures to evoke spiritual feelings in breast cancer patients: development of a new paradigm for neuroimaging studies

This study was designed to develop and validate a method for enhancing spiritual feelings, particularly in women who have received a diagnosis of breast cancer. The protocol specifically was developed to be used in functional magnetic resonance imaging (fMRI) studies. Eighteen breast cancer survivors rated pictures for their ability to enhance feelings of spirituality, happiness, and sadness. Results indicate that presenting carefully selected pictures with spiritual content (e.g., nature scenes, people engaged in contemplative behaviors) can effectively enhance spiritual feelings among breast cancer survivors. Future fMRI studies will explore the use of the protocol developed in this study for investigating neural activity during spiritual feelings and states.

Assessing falls in the elderly: should we use simple screening tests or a comprehensive fall risk evaluation?

The risk for falling increases in the older population, resulting in an increase in serious outcomes and associated health care costs. Incorporating a falls assessment measure into the routine clinical evaluation is important for early identification of elders who are at greater risk for falls and provide information that can guide interventions. This article reviews a sample of available falls assessment approaches that are targeted to community dwelling older adults, ranging from simple questionnaires to more functional-based assessments. Newer high-tech and laboratory-based procedures still under development also are discussed. Finally, additional factors related to older individuals, specifically cognition- and emotion-based features that can impact falls risk are discussed as related to their importance for consideration in routine falls assessments. This paper summarizes information to help guide the clinician in choosing the most appropriate currently available tool. As many of these measures are similar in their sensitivity and specificity, decisions on which approach to take in many cases may have to be informed also by the clinic setting and existing resources available to the clinician.

Cognition and behavior in children with benign epilepsy with centrotemporal spikes (BECTS)

Characteristics of cognitive deficits in benign childhood epilepsy with centrotemporal spikes (BECTS) remain unclear. The authors screened 200 BECTS children presenting for a clinical trial, finding relative weaknesses in fine motor control, visual learning, and attention in the presence of overall normal intellect, with simple partial seizures associated with more difficulty. Parental concerns for psychosomatic and learning problems were noted. Monitoring select cognitive and behavioral features in BECTS appears appropriate.

Chlorpyrifos exposure and biological monitoring among manufacturing workers

AIM

To use biological monitoring data to evaluate the soundness of job based exposure classifications.

METHODS

The authors studied 52 chlorpyrifos manufacturing workers and 60 referent workers to compare chlorpyrifos exposure estimations from job titles and work areas to urinary excretion of 3,5,6 trichloro-2-pyridinol (TCP), a metabolite of chlorpyrifos. Work history records and industrial hygiene monitoring data were used to establish cumulative interim exposure. Chlorpyrifos exposure during the study year was assessed biologically by urinary excretion of TCP.

RESULTS

Exposure as measured by three urinary TCP samples was significantly higher among the chlorpyrifos workers (188 microg/l) than it was for the referent subjects (7 microg/l). Urinary TCP also correlated well with specific exposure categories of negligible (0.73-1.98 mg/m3 days), low (1.99-4.91 mg/m3 days), and moderate (4.92-15.36 mg/m3 days). The weighted Kappa coefficient was 0.80 (95% CI 0.72 to 0.87) for the mean TCP over the study period.

CONCLUSIONS

The estimates of chlorpyrifos exposure based on job classifications and industrial hygiene measurements were significantly related to urinary TCP excretion, indicating that the ambient estimates are useful for providing exposure estimates among chlorpyrifos manufacturing workers.

Patterns of neuropsychological performance in multiple system atrophy compared to sporadic and hereditary olivopontocerebellar atrophy

Although neuropsychological symptoms are associated with multiple system atrophy (MSA), sporadic olivopontocerebellar atrophy (sOPCA), and dominantly inherited olivopontocerebellar atrophy (dOPCA), the differences between these groups have not been explored. We compared 28 MSA patients on psychiatric rating scales and neuropsychological measures to 67 sOPCA patients, 42 dOPCA patients, and 30 normal controls. Patients with dOPCA, sOPCA, and MSA all exhibited significant deficits on motor-related tasks, as well as relatively mild deficits in cognitive functioning. Patients with MSA had greater neuropsychological dysfunction, particularly in memory and other "higher order" cognitive processes, than patients with either sOPCA or dOPCA.

Long-term estrogen replacement is associated with improved nonverbal memory and attentional measures in postmenopausal women

OBJECTIVE

To determine the cognitive domains improved or preserved by long-term hormone replacement therapy (HRT).

DESIGN

A comprehensive neuropsychological test battery was administered to healthy postmenopausal women who had been treated or not treated with long-term HRT without interruption since menopause.

SETTING

Women were recruited by advertisement from a university town and surrounding areas.

PATIENT(S)

Women 60 years or older were studied who were treated (n = 16) or not treated (n = 13) with HRT.

INTERVENTION(S)

Neuropsychological testing included tests of memory, verbal fluency, executive functions, attention and concentration, and psychomotor function. Tests of intellectual function, depressive symptoms, and emotional functioning assessed general functions and comparability of the groups.

MAIN OUTCOME MEASURE(S)

Neuropsychological testing scores were compared between groups.

RESULT(S)

No statistically significant differences between the groups were found for general demographic, intellectual, and psychological measures. Scores from both the Weschler Memory Scale Visual Reproduction (delayed recall) and the Digit Vigilance Test (attention) showed statistically significant better performance and fewer errors in the group of women on HRT.

CONCLUSION(S)

Long-term postmenopausal HRT is associated with higher scores in tests of nonverbal memory and attention.

Elevated cortisol levels in Cushing's disease are associated with cognitive decrements

OBJECTIVE

The objective of this study was to use Cushing's disease as a unique human model to elucidate the cognitive deficits resulting from exposure to chronic stress-level elevations of endogenous cortisol.

METHODS

Forty-eight patients with a first episode of acute, untreated Cushing's disease and 38 healthy control subjects were studied.

RESULTS

Scores for four of five verbal IQ subtests were significantly lower in patients with Cushing's disease; their scores were significantly lower for only one nonverbal performance IQ subtest (block design). Verbal, but not visual, learning and delayed recall at 30 minutes were significantly decreased among patients with Cushing's disease. Although verbal delayed recall was significantly lower in these patients, the retention index (percentage), which compares the amount of initially learned material to that recalled after the delay, was not significantly decreased. There was no significant association between depression scores and cognitive performance. A higher degree of cortisol elevation was associated with poorer performance on several subtests of learning, delayed recall, and visual-spatial ability.

CONCLUSIONS

Chronically elevated levels of glucocorticoids have deleterious effects on particular domains of cognition. Verbal learning and other verbal functions seem more vulnerable than nonverbal functions. The results suggest that both the neocortex and hippocampus are affected.

Effectiveness of a formal post-baccalaureate pre-medicine program for underrepresented minority students

PURPOSE

To address the effectiveness of a formal postbaccalaureate (PB) experience for underrepresented minority (URM) students before medical school. The program provided an intense year-long experience of course work, research, and personal development.

METHOD

There were 516 participants from one medical school: 15 URM medical students had completed the formal PB program, 58 students had done independent PB work before matriculation, and 443 students were traditional matriculants. Cognitive and academic indicators [college science and non-science grade-point averages (GPAs); biology, physics, and verbal MCAT scores; and percentage scores from first-year medical school courses] were compared for the three groups.

RESULTS

Both groups of students with PB experience demonstrated competency in the first year of medical school consistent with traditional students even though the students who had completed the formal PB program had lower MCAT scores and lower college GPAs than did the traditional students. Traditional predictors of academic performance during the first year of medical school did not significantly contribute to actual academic performances of students from the formal PB program.

CONCLUSION

The results support the use of a formal PB program to provide academic readiness and support for URM students prior to medical school. Such a program may also improve retention. Noncognitive variables, however, may be important to understanding the success of such students in medical school.

Cognitive side effects of electroconvulsive therapy in adolescents

OBJECTIVE

The primary aim of this study was to determine the presence of cognitive impairments among adolescents treated with electroconvulsive therapy (ECT) and whether these deficits would persist several months following the treatment.

METHODS

Retrospective data resulting from standard clinical care of a convenience sample with naturalistic follow-up were used. Subjects were 16 adolescents (13 females, 3 males; mean age = 15.9 +/- 1.6 years) hospitalized with a mood disorder (unipolar depression = 14, bipolar depression = 2). Cognitive tests administered prior to ECT were compared with results at 7.0 +/- 10.3 days following the last treatment and with a second testing at 8.5 +/- 4.9 months after the last treatment.

RESULTS

Comparison of pre-ECT and the first post-ECT testing administered during the first 10 days of the treatment yielded significant impairments of concentration and attention, verbal- and visual-delayed recall, and verbal fluency. A complete recovery of these functions was noted at the second post-ECT testing. There was no deficit in the ability to problem solve during the initial or the subsequent testing.

CONCLUSION

Cognitive parameters found to be impaired during the first few days of ECT recovered over several months following the treatment. Therefore, there was no evidence of long-term damage to concentration, attention, verbal and visual memory, or verbal fluency. There were no impairments of motor strength and executive processing, even during the early (within 7-10 days) post-ECT period. These results should be regarded as preliminary, awaiting confirmation with larger samples.

Mild cognitive impairments predict dementia in nondemented elderly patients with memory loss

BACKGROUND

Some elderly individuals exhibit significant memory deficits but do not have dementia because their general intellect is preserved and they have no impairments in everyday activities. These symptoms are often a precursor to Alzheimer disease (AD), but sometimes dementia does not occur, even after many years of observation. There is currently no reliable way to distinguish between these 2 possible outcomes in an individual patient. We hypothesized that clear impairments in at least 1 cognitive domain in addition to memory would help identify those who will progress to AD.

OBJECTIVE

To determine whether nondemented patients with impairments in memory and other domains are more likely than those with memory impairment alone to develop AD.

DESIGN AND METHODS

In a retrospective study, we evaluated 48 nondemented, nondepressed patients with clinical and psychometric evidence of memory impairment who were followed up for 2 or more years. Age-adjusted normative criteria were used to identify whether additional impairments were present in language, attention, motor visuospatial function, and verbal fluency at this initial evaluation. The presence or absence of dementia after 2 years and at the most recent neurological evaluation was compared in subjects with normal scores in all 4 of these cognitive areas apart from memory (M-) and those with impairment in 1 or more of these areas (M+). Outcomes were adjusted for age, intelligence at initial evaluation, and years of education.

RESULTS

Of the 48 nondemented patients with memory loss, 17 met M- criteria, leaving 31 in the M+ group. Deficits in block design were the most frequent abnormality other than memory loss. At the 2-year follow-up, 1 M- subject (6%) had progressed to AD, whereas 15 (48%) of the M+ group had progressed to AD (P =.003). At the most recent follow-up (mean +/- SD, 4.0 +/- 2.0 years), 4 (24%) of the M- patients progressed to AD compared with 24 (77%) of the M+ patients (P<.001).

CONCLUSIONS

Among nondemented elderly patients, memory loss alone rarely progresses to dementia in the subsequent 2 years. However, the risk of dementia is significantly increased among patients with clear cognitive impairments beyond memory loss. Further study is needed to determine whether patients with impairments limited to memory loss have a distinctive clinical course or pathophysiology.

A comparison of subset selection and analysis of covariance for the adjustment of confounders

Two common methods for adjusting group comparisons for differences in the distribution of confounders, namely analysis of covariance (ANCOVA) and subset selection, are compared using real examples from neuropsychology, theory, and simulations. ANCOVA has potential pitfalls, but the blanket rejection of the method in some areas of empirical psychology is not justified. Assumptions of the methods are reviewed, with issues of selection bias, nonlinearity, and interaction emphasized. Advantages of ANCOVA include better power, improved ability to detect and estimate interactions, and the availability of extensions to deal with measurement error in the covariates. Forms of ANCOVA are advocated that relax the standard assumption of linearity between the outcome and covariates. Specifically, a version of ANCOVA that models the relationship between the covariate and the outcome through cubic spline with fixed knots outperforms other methods in simulations.

Self-reported walking ability predicts functional mobility performance in frail older adults

OBJECTIVE

To determine how self-reported physical function relates to performance in each of three mobility domains: walking, stance maintenance, and rising from chairs.

DESIGN

Cross-sectional analysis of older adults.

SETTING

University-based laboratory and community-based congregate housing facilities.

PARTICIPANTS

Two hundred twenty-one older adults (mean age, 79.9 years; range, 60-102 years) without clinical evidence of dementia (mean Folstein Mini-Mental State score, 28; range, 24-30).

INTERVENTION AND MAIN OUTCOME MEASURES

We compared the responses of these older adults on a questionnaire battery used by the Established Populations for the Epidemiologic Study of the Elderly (EPESE) project, to performance on mobility tasks of graded difficulty. Responses to the EPESE battery included: (1) whether assistance was required to perform seven Katz activities of daily living (ADL) items, specifically with walking and transferring; (2) three Rosow-Breslau items, including the ability to walk up stairs and walk a half mile; and (3) five Nagi items, including difficulty stooping, reaching, and lifting objects. The performance measures included the ability to perform, and time taken to perform, tasks in three summary score domains: (1) walking ("Walking," seven tasks, including walking with an assistive device, turning, stair climbing, tandem walking); (2) stance maintenance ("Stance," six tasks, including unipedal, bipedal, tandem, and maximum lean); and (3) chair rise ("Chair Rise," six tasks, including rising from a variety of seat heights with and without the use of hands for assistance). A total score combines scores in each Walking, Stance, and Chair Rise domain. We also analyzed how cognitive/ behavioral factors such as depression and self-efficacy related to the residuals from the self-report and performance-based ANOVA models.

RESULTS

Rosow-Breslau items have the strongest relationship with the three performance domains, Walking, Stance, and Chair Rise (eta-squared ranging from 0.21 to 0.44). These three performance domains are as strongly related to one Katz ADL item, walking (eta-squared ranging from 0.15 to 0.33) as all of the Katz ADL items combined (eta-squared ranging from 0.21 to 0.35). Tests of problem solving and psychomotor speed, the Trails A and Trails B tests, are significantly correlated with the residuals from the self-report and performance-based ANOVA models.

CONCLUSIONS

Compared with the rest of the EPESE self-report items, self-report items related to walking (such as Katz walking and Rosow-Breslau items) are better predictors of functional mobility performance on tasks involving walking, stance maintenance, and rising from chairs. Compared with other self-report items, self-reported walking ability may be the best predictor of overall functional mobility.

Comparison of central and peripheral pharmacologic effects of biperiden and trihexyphenidyl in human volunteers

In this double-blind, randomized study, indices of central (memory, sedation) and peripheral (salivation, ratio of R-R interval on electrocardiogram) muscarinic function were evaluated in 14 healthy volunteers who received trihexyphenidyl, biperiden, and placebo. Additionally, serum drug levels were obtained 2 hours after oral administration. All subjects participated in three study sessions. During each session, subjects received two doses of biperiden (4 mg), trihexyphenidyl (5 mg), or placebo, and four series of tests were administered. The tests included the determination of cardiac response to standing (R-R ratio), mouth salivation, finger-tapping speed, digit span (forward and backward), a selective reminding task, and visual analog scales (VAS). On the VAS, subjects rated biperiden as significantly more sedating than either trihexyphenidyl or placebo, and both biperiden and trihexyphenidyl were associated with more dizziness than was placebo. Saliva production was significantly reduced by both trihexyphenidyl and biperiden compared with placebo. Digit span performance was significantly decreased in only the backward direction. The selective reminding task revealed highly significant decrements in the number of words recalled and consistent long-term retrieval after both biperiden and trihexyphenidyl. Delayed recall was significantly decreased by both active drugs. Both trihexyphenidyl and biperiden caused a significant increase in the R-R ratio comparison with placebo. With the exception of the VAS measurement of sedation, the effects caused by biperiden and trihexyphenidyl did not differ. The results of this study do not support the hypothesis that the side effect profile of biperiden is significantly different from that of trihexyphenidyl.

Decrease in cortisol reverses human hippocampal atrophy following treatment of Cushing's disease

BACKGROUND

Decreased hippocampal volume is observed in patients with Cushing's syndrome and other conditions associated with elevated cortisol levels, stress, or both. Reversibility of hippocampal neuronal atrophy resulting from stress occurs in animals. Our study investigated the potential for reversibility of human hippocampal atrophy.

METHODS

The study included 22 patients with Cushing's disease. Magnetic resonance brain imaging was performed prior to transsphenoidal microadenomectomy and again after treatment.

RESULTS

Following treatment, hippocampal formation volume (HFV) increased by up to 10%. The mean percent change (3.2 +/- 2.5) was significantly greater (p < .04) than that of the comparison structure, caudate head volume (1.5 +/- 3.4). Increase in HFV was significantly associated with magnitude of decrease in urinary free cortisol (r = -.61, p < .01). This relationship strengthened after adjustments for age, duration of disease, and months elapsed since surgery (r = -.70, p < .001). There was no significant correlation between caudate head volume change and magnitude of cortisol decrease.

CONCLUSIONS

Changes in human HFV associated with sustained hypercortisolemia are reversible, at least in part, once cortisol levels decrease. While many brain regions are likely affected by hypercortisolemia, the human hippocampus exhibits increased sensitivity to cortisol, affecting both volume loss and recovery.

The Academic Support Program at the University of Michigan School of Medicine

The University of Michigan has a support program aimed at early identification, remedial plans, and appropriate academic accommodations for at-risk students in under-graduate colleges and graduate and professional schools. Since 1994, the medical school has formally taken part in this program. Medical students at risk for academic failure (e.g., repeated failure in academic course work, licensure examinations, clinical examinations) are automatically referred to their academic counselors in the Student Programs Office of the medical school. Once a referral is made, the student is evaluated at the Office of Services for Students with Disabilities to identify problem areas. The office makes appropriate recommendations for interventions or accommodation. Tutoring, academic assistance, and other services are available through the medical school, specific divisions of the medical center, and the community. The Student Programs Office acts as a liaison between community and university assistance programs and between the student and the medical school. During the first four years of the program, 28 medical students were identified through it; of these, 24 (86%) were underrepresented minorities. Most (21) were referred during the first and third years of the curriculum. After a range of services for a variety of problems, 26 (93%) of the 28 students either graduated or continued to progress in their studies; the other two left the medical school for academic reasons.

Motor correlates of occipital glucose hypometabolism in Parkinson's disease without dementia

OBJECTIVE

To determine whether occipital reduction in regional cerebral glucose metabolism in PD reflects retinal versus nigrostriatal dopaminergic degeneration. We hypothesized that occipital glucose metabolic reduction should be symmetric if parkinsonian retinopathy is responsible for the reduction.

METHODS

PD patients without dementia (n = 29; age 63 +/- 10 years) and normal controls (n = 27; age 60 +/- 12 years) underwent [18F]fluorodeoxyglucose PET imaging. Regional cerebral glucose metabolic rates were assessed quantitatively.

RESULTS

When compared with normal controls, PD patients showed most severe glucose metabolic reduction in the primary visual cortex (mean -15%, p < 0.001). Occipital glucose metabolic reduction was greater in the hemisphere contralateral to the side of the body affected initially or more severely in PD. There was an inverse correlation between side-to-side asymmetries in finger-tapping performance and occipital glucose metabolic reduction (r = -0.45, p < 0.05; n = 28). The correlation was strongest in patients with a relatively early stage of PD with more unilateral motor impairment (Hoehn and Yahr stage I, r = -0.74, p < 0.01; n = 10).

CONCLUSION

The results indicate a pathophysiologic association between nigrostriatal dysfunction and occipital glucose metabolic reduction in PD.

Neuropsychological function and cerebral glucose utilization in isolated memory impairment and Alzheimer's disease

We hypothesized that 20 patients with isolated memory impairment (IMI) would demonstrate [18F]-2-fluoro-2-deoxy-D-glucose utilization and a progression of neuropsychological symptoms consistent with Alzheimer's disease (AD). IMI subjects performed similarly to AD in recall and verbal fluency, but comparable to normal subjects in other areas of cognitive functioning. A positron emission tomography (PET) diagnostic index based on parietal Z-scores categorized IMI patients into normal and abnormal metabolic patterns. Ten of the original 20 IMI patients (50%) reflected PET AD abnormalities. Clinical information was available for IMI patients at three-year follow-up. Ten (50%) had converted to AD, three were found to have pseudodementia and the seven remained IMI. Of the 10 IMI patients with an originally normal PET index, three (30%) were diagnosed with AD at three years. Of the 10 with an abnormal index originally, seven (70%) converted to AD. The finding that memory deficit in IMI was as pronounced as that in AD patients is consistent with the notion that memory is an initial symptom of AD. A substantial number of the IMI patients reflected regional hypometabolism similar to AD, suggesting that IMI is likely an early stage in progressive dementia. A large percentage of IMI patients converted clinically to AD within three years of initial study, though we observed impaired memory functioning well before a clinical diagnosis of AD could be made. In addition to potential clinical utility, IMI and PET represent an opportunity to study dementia in relation to brain chemistry at a time when brain pathology is in the process of development.

Unmasking the heterogeneity of Alzheimer's disease: case studies of individuals from distinct neuropsychological subgroups

Case descriptions of patients with probable Alzheimer's disease (AD) who were reliably classified into three neuropsychological subgroups (global [GAD], right-hemisphere [RAD], and left-hemisphere [LAD]) in an earlier cluster analytic study (Fisher et al., 1996) are presented. Concordance between the neuropsychological patterns and clinical histories of randomly selected and hand-selected cases from within each subgroup was high. Longitudinal analysis revealed stable subgroup-specific neuropsychological progression patterns. Results are discussed in terms of future research avenues worth pursuing, in addition to the conceptual shift in research design necessary to uncover both quantitative and qualitative subgroup-specific ability differences.

Metabolic reduction in the posterior cingulate cortex in very early Alzheimer's disease

This study investigated cerebral glucose metabolism in very early Alzheimer's disease, before a clinical diagnosis of probable Alzheimer's disease is possible, using [18F]fluorodeoxyglucose positron emission tomography. First, 66 patients with probable Alzheimer's disease with a spectrum of dementia severity (Mini-Mental State Examination score, 0-23) were recruited and studied. Cortical metabolic activity was analyzed topographically using three-dimensional stereotactic surface projections. Regression analysis was performed for each brain pixel to predict metabolic patterns of very early disease. Predictions were tested prospectively in a group of 8 patients who complained only of memory impairment without general cognitive decline (Mini-Mental State Examination score, 25 +/- 1) at the time of scanning but whose condition later progressed to probable Alzheimer's disease. Both results were compared to cerebral metabolic activity in 22 age-similar normal control subjects. Prediction and analysis of actual patients consistently indicated marked metabolic reduction (21-22%) in the posterior cingulate cortex and cinguloparietal transitional area in patients with very early Alzheimer's disease. Mean metabolic reduction in the posterior cingulate cortex was significantly greater than that in the lateral neocortices or parahippocampal cortex. The result suggests a functional importance for the posterior cingulate cortex in impairment of learning and memory, which is a feature of very early Alzheimer's disease.

Cognitive, behavioral, and motor effects of the NMDA antagonist ketamine in Huntington's disease

BACKGROUND

Excitotoxicity may contribute to neuronal degeneration in Huntington's disease (HD). N-methyl-D-aspartate (NMDA) receptor antagonists can prevent neuronal degeneration caused by excitotoxicity, but their effects in HD patients are not known.

METHODS

We investigated the acute cognitive, behavioral, and motor effects of the NMDA-receptor antagonist ketamine in HD patients. Double-blind infusions of 0.10, 0.40, and 0.60 mg/kg/hr ketamine were given to 10 HD patients on one test day and compared with placebo infusions on a second, identical testing day. Linear mixed-effects models and randomization tests were used to identify whether, and at which dose, a significant change from baseline occurred in outcome variables.

RESULTS

We demonstrated that ketamine is well tolerated at low and intermediate subanesthetic doses. Intermediate ketamine doses produced specific decline in memory and verbal fluency. Higher subanesthetic doses caused a significant increase in psychiatric symptoms and impairment of eye movements.

CONCLUSIONS

These results describe the spectrum of clinical effects produced by increasing NMDA receptor blockade in HD patients. The clinical effects appearing with higher levels of NMDA receptor blockade can identify the range of doses used in clinical trials of NMDA receptor antagonists.

Cerebral metabolic differences in Parkinson's and Alzheimer's diseases matched for dementia severity

Despite controversial clinicopathological distinctions between Parkinson's disease with dementia (PDD) and Alzheimer's disease (AD), similar patterns of metabolic reduction in the posterior brain were reported previously using PET with [18F]fluorodeoxyglucose. The current study was designed to examine more specific regional differences in cerebral glucose metabolism between PDD and AD using accurate and objective brain mapping techniques.

METHODS

This study included nine normal subjects, nine PDD patients and nine AD patients. PDD and AD groups were matched carefully for age, sex and general dementia severity as measured by Mini-Mental State Examination and Clinical Dementia Rating scales. Each subject underwent [18F]fluorodeoxyglucose-PET and neuropsychological testing. After anatomic standardization of PET image sets and stereotactic data extraction, absolute and normalized cerebral metabolic rates were assessed by region of interest and pixel-by-pixel analyses.

RESULTS

PDD and AD showed global glucose metabolic reduction with similar regional accentuation involving the lateral parietal, lateral temporal and lateral frontal association cortices and posterior cingulate cortex in comparison to normal controls. When comparing between PDD and AD, however, PDD showed greater metabolic reduction in the visual cortex and relatively preserved metabolism in the medial temporal cortex.

CONCLUSION

Although a common feature of metabolic abnormalities in the posterior brain exists in PDD and AD, the presence of regional metabolic differences suggests different degrees and combinations of disease specific underlying pathological and neurochemical processes.

Adult attention deficit hyperactivity disorder: psychological test profiles in a clinical population

Compared to attention deficit hyperactivity disorder (ADHD) in children, relatively little is known about the clinical characteristics of adults with persistent ADHD. We elected to use established tests with age-corrected norms to compare the battery of psychological and neuropsychological tests conducted on outpatients admitted to our Adult ADHD clinic. ADHD patients scored significantly higher than norms on the TPQ novelty seeking and harm avoidance scales and MMPI-2 scales F, 2, 4, 7, and 8. Further, these patients were impaired on the California verbal learning test, the attentional capacity test, and the omissions and variability subtests of the test of variables of attention. Adult ADHD had high comorbidity with current depressive disorder, antisocial personality disorder, and alcohol and drug abuse/dependence. High correlations were found between patients' and independent observers' reports of ADHD symptom severity. Implications for further research are discussed.

Determination of regional rate constants from dynamic FDG-PET studies in Parkinson's disease

Dynamic [18F]fluorodeoxyglucose (FDG) PET was used in Parkinson's disease patients and normal controls to determine kinetic rate constants for FDG. The goal was to assess whether the metabolic decreases observed in Parkinson's disease are associated with transport or phosphorylation processes or both.

METHODS

Fluorine-18-FDG was administered to 18 Parkinson's disease and 15 normal control subjects. Dynamic PET scanning was performed for 1 h and rate constants were obtained by nonlinear, least-squares analysis. Regional glucose metabolic rate was calculated from the individually fitted rate constants and by two standard static scan analyses.

RESULTS

Global CMRglu was decreased in Parkinson's disease (mean reduction 22%), reaching statistical significance in all regions investigated. K1 was significantly reduced in parietal cortex, temporal cortex and striatum while k3 was significantly reduced only in parietal cortex. The rate constant k2 was unchanged.

CONCLUSION

K1, k3 and CMRglu all demonstrated greater deficits across the brain with progression of disease and development of dementia, particularly in the parietal an occipital cortex. This suggested that the metabolic disturbance may be a global dysfunction throughout the brain. Because altered rate constants are specifically taken into account, dynamic measurements has shown to provide higher sensitivity for detecting diminished glucose utilization in Parkinson's disease than static approaches.

Neuropsychological subgroups of patients with Alzheimer's disease

Neuropsychological data from 134 patients diagnosed with probable Alzheimer's disease (AD) were studied retrospectively to investigate whether subgroups of patients with qualitatively distinct profiles could be identified. Three empirical classification approaches were undertaken in this regard: Q-type factor analysis, hierarchical agglomerative cluster analysis, and iterative partitioning. Three subgroups were consistently identified across the clustering methods. Subgroup 1, the largest of the groups, was marked by moderate to severe anomia and constructional dyspraxia. Individuals in subgroup 2 displayed relatively spared visual-perceptual/constructional functioning but severe anomia. Members of subgroup 3 exhibited intact naming and nonverbal reasoning and moderate difficulty in copying overlapping figures. The three subgroups did not differ with respect to age, age at disease onset, duration of illness, educational level, or Hamilton depression rating. Detailed description of the data analyses are provided as a tutorial outlining subtyping methodology. Results are discussed in terms of the subgroup and the stage model approaches to the conceptualization of AD.

Stepping over obstacles: dividing attention impairs performance of old more than young adults

BACKGROUND

Tripping over an obstacle is a common cause of falls in the elderly. An earlier study of abilities to avoid stepping on suddenly appearing obstacles found that, although healthy old adults had a lower rate-of-success than young adults, the magnitude of that difference was not large. The present study inquired whether dividing attention during such a task would differentially affect young and old healthy adults.

METHODS

Rates-of-success were observed in 16 young and 16 old healthy adults (mean ages 24 and 72 years) in avoiding stepping on a band of light that was suddenly projected across their gait path while they walked at their comfortable gait speed. This virtual obstacle was placed at predicted next-footfall locations to give 350 or 450 msec available response times before footfall. During most of the trials the subjects were asked, in addition to trying not to step on the obstacle, simultaneously to respond vocally as quickly as possible when red lights near the end of the walkway turned on. These attention-dividing reaction time tests were of two types: synchronized, when only red lights lit at intervals synchronized with the appearance of the obstacle, and unsynchronized, when green or yellow lights lit in addition to the red lights, with lighting intervals not synchronized with the appearance of the obstacle.

RESULTS

When synchronized and unsynchronized reaction time tests were conducted concurrently with the obstacle avoidance tasks, mean rates-of-success in avoidance decreased significantly in both young and old adults. With available response times of 350 msec, mean success rates decreased from their no-division values in the young adults by 14.7% for synchronized reaction and by 19.9% for unsynchronized reaction, attention-dividing tests. Corresponding mean decreases for the old adults were 32.0 and 35.7%. This age difference in the effects of dividing attention was significant.

CONCLUSION

Both young and old adults had a significantly increased risk of obstacle contact while negotiating obstacles when their attention was divided, but dividing attention degraded obstacle avoidance abilities of the old significantly more than it did in the young. Diminished abilities to respond to physical hazards present in the environment when attention is directed elsewhere may partially account for high rates of falls among the elderly.