Validation of the Dépistage Cognitif de Québec: A New Cognitive Screening Tool for Atypical Dementias.

OBJECTIVE: This study aimed to validate and provide normative data for the Dépistage Cognitif de Québec (DCQ; www.dcqtest.org), a new cognitive screening tool for atypical dementias. METHOD: The DCQ was developed by expert behavioral neurologists and clinical neuropsychologists based on updated criteria for Alzheimer's disease, primary progressive aphasia, and behavioral variant frontotemporal dementia. It targets five relevant domains: Memory, Visuospatial, Executive, Language, and Behavior. Validation was performed in a population-based sample of 410 healthy French-speaking Canadians aged between 50 and 89 years old. Normative data were derived from a subsample of 285 participants. RESULTS: Mean DCQ total score (out of 100) was 89.17 (SD = 7.36). Pearson's correlation coefficient showed a strong and significant correlation (r = .71, p < .001) with the Montreal Cognitive Assessment. Internal consistency for the cognitive domains assessed by Cronbach's alpha was satisfactory (.74). Test-retest reliability was adequate (Pearson's coefficient = . 70, p < .001) and interrater reliability, excellent (intraclass correlation = .99, p < .001). Normative data shown in percentiles were stratified by age and education. CONCLUSIONS: This study suggests that the DCQ is a valid and reliable cognitive screening test. Application of the DCQ on populations with atypical dementias is underway to derive sensitivity and specificity values for various dementias.

Differences in Rate of Cognitive Decline and Caregiver Burden between Alzheimer's Disease and Vascular Dementia: a Retrospective Study.

Few studies have explored the rate of cognitive decline and caregiver burden within the context of a specialized memory clinic. When this was done, the focus was largely on functional decline related to Alzheimer's disease (AD). Our goal was to compare the longitudinal decline of AD patients to those with Vascular Dementia (VaD) on Mini-Mental State Examination (MMSE). We further explored the differential impact on caregiver burden. We retrospectively studied 237 charts from patients seen at our Memory Clinic between 2006 and 2012. The data was collected over 17 years. Cohorts were formed by excluding conditions other than AD and VaD, and including patients who had been assessed at least twice with the MMSE (AD: n = 83; mean age: 67.7 yo; VaD: n = 32; mean age: 73.3yo). A small group of 36 caregivers was surveyed by phone to explore caregiver burden. Results indicated that the natural history of MMSE changes in AD patients differed significantly from that of patients with VaD (F = 10.41, p<0.0014), with AD patients showing more cognitive decline over time. Sadness, stress/anxiety, fatigue, and sleep disorders were reported as the main preoccupations by caregivers and its impact was rated as 'severe' in 50% of cases. Altogether, this study provides further insight into the natural history of cognitive decline in AD and VaD. Future studies should explore the progression of dementing disorders in larger cohorts using prospective methodological designs.

Clinical Utility of Amyloid PET Imaging in the Differential Diagnosis of Atypical Dementias and Its Impact on Caregivers.

Recent studies have supported a role for amyloid positron emission tomography (PET) imaging in distinguishing Alzheimer's disease (AD) pathology from other pathological protein accumulations leading to dementia. We investigated the clinical utility of amyloid PET in the differential diagnosis of atypical dementia cases and its impact on caregivers. Using the amyloid tracer 18F-NAV4694, we prospectively scanned 28 patients (mean age 59.3 y, s.d. 5.8; mean MMSE 21.4, s.d. 6.0) with an atypical dementia syndrome. Following a comprehensive diagnostic workup (i.e., history taking, neurological examination, blood tests, neuropsychological evaluation, MRI, and FDG-PET), no certain diagnosis could be arrived at. Amyloid PET was then conducted and classified as positive or negative. Attending physicians were asked to evaluate whether this result led to a change in diagnosis or altered management. They also reported their degree of confidence in the diagnosis. Caregivers were met after disclosure of amyloid PET results and completed a questionnaire/interview to assess the impact of the scan. Our cohort was evenly divided between positive (14/28) and negative (14/28) 18F-NAV4694 cases. Amyloid PET resulted in a diagnostic change in 9/28 cases (32.1%: 17.8% changed from AD to non-AD, 14.3% from non-AD to AD). There was a 44% increase in diagnostic confidence. Altered management occurred in 71.4% (20/28) of cases. Knowledge of amyloid status improved caregivers' outcomes in all domains (anxiety, depression, disease perception, future anticipation, and quality of life). This study suggests a useful additive role for amyloid PET in atypical cases with an unclear diagnosis beyond the extensive workup of a tertiary memory clinic. Amyloid PET increased diagnostic confidence and led to clinically significant alterations in management. The information gained from that test was well received by caregivers and encouraged spending quality time with their loved ones.

Clinical Impact of a Second FDG-PET in Atypical/Unclear Dementia Syndromes.

Diagnosis of atypical/unclear dementia is often difficult and this delays treatment initiation. Several authors have shown that beyond standard dementia workup, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) reduces the number of unclear diagnoses, leads to earlier treatment, and has a beneficial impact on families. However, it is not uncommon that the FDG-PET findings are equivocal in this setting. For those cases, a repeat FDG-PET may clarify the diagnosis and prevent treatment delay. We retrospectively assessed the clinical impact of a repeat FDG-PET in 59 patients with atypical/unclear dementia syndromes and inconclusive initial FDG-PET. Changes in primary diagnosis, diagnostic confidence, and management following the second FDG-PET were examined. Conducting a second FDG-PET reduced the number of unclear diagnoses from 80% to 34% , led to diagnostic change in 24% of cases, and treatment modification in 22% of patients. Overall, the clinical impact was higher when initial diagnostic confidence was low and the second FDG-PET repeated ≥12 months after the first one. In tertiary care memory clinic settings, when diagnostic incertitude persists despite extensive evaluation and an equivocal FDG-PET, repeating the FDG-PET 12 months later can greatly clarify the diagnosis and improve management.

The Effect of Adequate Gestational Weight Gain among Adolescents Relative to Adults of Equivalent Body Mass Index and the Risk of Preterm Birth, Cesarean Delivery, and Low Birth Weight.

OBJECTIVE: To determine whether similar odds of cesarean delivery (C/S), preterm birth (PTB), and low birth weight (LBW) are observed among adolescents compared with body mass index (BMI)-equivalent adults in cases of adequate gestational weight gain. STUDY DESIGN: We conducted a retrospective, population-based, cohort study using the Center for Disease Control and Prevention's birth data files from the United States for 2012. We selected from the cohort all singleton, cephalic pregnancies and stratified them according to maternal age, prepregnancy BMI, and gestational weight gain following the 2009 Institute of Medicine (IOM) recommendations. The effect of adequate gestational weight gain among adolescents relative to adults of equivalent BMI on the risk of C/S, PTB, and LBW was estimated using logistic regression analysis, adjusting for relevant confounders. RESULTS: We analyzed a total of 3,960,796 births, of which 1,036,646 (26.1%) met the inclusion criteria. In adolescents and adults, likelihood of achieving ideal gestational weight gain decreased with greater prepregnancy BMI. Relative to adults, the overall odds of C/S in all adolescents were (adjusted odds ratio [95% confidence interval]) 0.61 (0.58 to 0.63). When comparing equivalent BMI categories, these odds were unchanged (P < .0001). The overall adjusted odds ratio of LBW was 1.15 (1.13 to 1.16). These odds were significantly higher when BMI stratification took place, decreasing with advancing BMI categories, from 1.23 (1.14 to 1.33) among the underweight, to nonsignificant differences in the obese classes (P < .05). Finally, when including only those achieving ideal weight gain, the overall odds of premature delivery (1.17 [1.14 to 1.20]) were higher among nonobese adolescents, while they were not found among the obese. CONCLUSION: When ideal gestational weight gain is attained, only nonobese adolescents exhibit a greater risk of LBW and preterm birth relative to adults of similar BMI, whereas the risk of C/S remains lower for all adolescents, independent of BMI. This information may be useful in the counseling of adolescent pregnancies.

The value of PET in mild cognitive impairment, typical and atypical/unclear dementias: A retrospective memory clinic study.

This retrospective study examined the role of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis of atypical/unclear dementias in a memory clinic setting. A total of 94 patients with a diagnosis of mild cognitive impairment (MCI) or dementia, who had a PET study within 2 months of their diagnosis, were reevaluated at 5 and 18 months. Results showed that PET was associated with a change in diagnosis in 29% of patients and a 64% increase in the use of cholinesterase inhibitors (ChEIs). PET significantly lowered the number of atypical/unclear diagnoses from 39.4% to 16% and nearly 30% of these were found to have a typical Alzheimer's disease (AD) pattern of hypometabolism. In conclusion, the addition of PET to the investigation of atypical/unclear cases of dementia helped generating a more accurate diagnosis and initiating earlier treatment. PET was of limited contribution to typical AD and frontotemporal dementia (FTD) cases. This study provides guiding evidence about the true value of PET imaging in the day-to-day challenge of dementia diagnosis.

A predictive depression pattern in mild cognitive impairment.

OBJECTIVE: To evaluate the prognostic utility of the presence, persistence, and patterns of depression in subjects with amnestic Mild Cognitive Impairment (MCI). METHOD: Sixty amnestic MCI patients were assessed cognitively and for presence of depression using the 30 item Geriatric Depression Scale (GDS). They were followed annually for an average period of 4.3 years. RESULTS: Simple presence or absence of depression at referral did not predict progression of MCI to AD. Positive answers to specific GDS questions referring to "melancholic" affect as well as the persistence of depression over two to three years significantly predicted cognitive deterioration leading to AD. CONCLUSION: The affective characteristics of depression at referral and the persistence of depression were better predictors of conversion to AD than the simple presence or absence of depression measured at referral time.