Executive Dysfunction in MCI: Subtype or Early Symptom

Mild cognitive impairment (MCI) may take several forms, and amnestic MCI (aMCI) has been recognized as an early stage of Alzheimer's Disease (AD). Impairment in executive functions including attention (eMCI) may be indicative of several neurodegenerative conditions. Executive impairment is frequently found in aMCI, it is significant for prognosis, and patients with eMCI may go on to develop AD. Recent studies have found changes in white matter integrity in patients with eMCI to be more sensitive than measures of cortical atrophy. Studies of genetic high-risk groups using sensitive cognitive neuroscience paradigms indicate that changes in executive function may be a cognitive marker useful for tracking development in an AD pathophysiological process

Self-reported cognitive and psychiatric symptoms at 3 months predict single-item measures of fatigue and daytime sleep 12 months after ischemic stroke

Introduction: Post-stroke fatigue and increased need for daytime sleep are multidimensional and insufficiently understood sequelae. Our aim was to study the relationships of self-reported cognitive and psychiatric symptoms at 3 months with fatigue and daytime sleep at 12 months post-stroke. Methods: Ischemic stroke patients without reported history of dementia or depression completed postal surveys 3- and 12-months post-stroke. At 3 months, psychiatric symptoms were assessed with the Hospital Anxiety and Depression Scale (HADS), and self-reported changes in cognitive symptoms (concentration and memory) compared to pre-stroke were assessed using single-item measures. At 12 months, single-item questions about changes in self-reported difficulties sleeping at night, fatigue and daytime sleep were included. First, we studied whether self-reported cognitive and/or psychiatric symptoms at 3 months were associated with daytime sleep and fatigue at 12 months using multiple logistic regression. Second, we fitted 2 structural equation models (SEMs) predicting fatigue and 2 models predicting daytime sleep. We compared a model where only age, sex, stroke severity (National Institutes of Health Stroke Scale; NIHSS), and difficulties sleeping at night predicted fatigue and daytime sleep at 12 months to a model where mental distress (i.e., a latent variable built of cognitive and psychiatric symptoms) was included as an additional predictor of fatigue and daytime sleep at 12 months. Results: Of 156 patients (NIHSS within 24 hours after admission (mean ± SD) = 3.6 ± 4.3, age = 73.0 ± 10.8, 41% female) 37.9% reported increased daytime sleep and 50.0% fatigue at 12 months. Increased psychiatric symptoms and worsened cognitive symptoms were associated with fatigue and daytime sleep at 12 months, after controlling for NIHSS, age, sex, and difficulties sleeping at night. SEM models including mental distress as predictor showed adequate model fit across 3 fit measures (highest RMSEA = 0.063, lowest CFI and TLI, both 0.975). Models without mental distress were not supported. Conclusion: Self-reported cognitive and psychiatric symptoms at 3 months predict increased daytime sleep and fatigue at 12 months. This highlights the relevance of monitoring cognitive and psychiatric symptoms in the subacute phase post-stroke. However, future research using validated measures of self-reported symptoms are needed to further explore these relationships.publishedVersio

Effects of cerebrovascular disease on amyloid precursor protein metabolites in cerebrospinal fluid

Background Alzheimer's disease (AD) and cerebrovascular disease (CVD) including chronic small vessel disease of the brain (SVD) are the most frequent causes of dementia. AD is associated with metabolism of amyloid precursor protein (APP) and low levels of amyloid-β peptide (Aβ) X-42 in the cerebrospinal fluid (CSF). CVD and SVD are established risk factors for AD, brain white matter lesions (WML) are established surrogate markers for SVD and are also associated with reduced CSF AβX-42. A cohort survey was performed to examine whether SVD or acute CVD affects APP metabolism and to explore a potential association between WML and APP metabolism in two groups; cognitively impaired patients, subjective and mild (SCI and MCI) and stroke patients. Through measurements of CSF APP metabolite levels in patients with a wide range of WML volumes, this study aimed to determine how SVD influences APP metabolism. Methods Sixty-three patients were included: 37 with subjective cognitive impairment (SCI) or mild cognitive impairment (MCI) without stroke, and 26 after acute stroke. Chronic and acute WML volume and infarct volume were determined by magnetic resonance imaging (MRI) post-scan processing, and CSF levels of α- and β-cleaved soluble APP (sAPP-α and sAPP-β, AβX-38, AβX-40 and AβX-42) were determined. The Mann-Whitney test was used to compare the patient groups. Chronic and acute WML volumes, infarct volume, age, and sex were used as predictors for CSF biomarker levels in linear regression analysis. Results CSF levels of sAPP-α and sAPP-β were strongly correlated (r = 0.95, p < 0.001) and lower levels of these biomarkers were found in the stroke group than in the SCI/MCI group; median sAPP-α 499.5 vs. 698.0 ng/mL (p < 0.001), sAPP-β 258.0 vs. 329.0 ng/mL (p < 0.005). CSF levels of sAPP-α, sAPP-β, AβX-38, AβX-40 and AβX-42 were inversely correlated with chronic WML volume (p ≤ 0.005; p ≤ 0.01; p ≤ 0.01; p ≤ 0.05; p ≤ 0.05 respectively), but not with acute WML or infarct volumes. Conclusions Lower CSF levels of sAPP-α and sAPP-β in the stroke group than in the SCI/MCI group and an inverse correlation with chronic WML indicate that ischemia lowers the levels of CSF sAPP metabolites and suggests that APP axonal transport or metabolism may be affected in SVD of the brain

Association between prescribed central nervous system depressant drugs, comorbidity and cognition among hospitalised older patients: a cross-sectional study

Objectives Central nervous system depressants (CNSDs) such as opioids, benzodiazepine and Z-hypnotics are commonly used. However, CNSDs may influence cognitive function, especially in older hospitalised patients with comorbidities. The aim was to examine the association between CNSD use and cognitive function in older patients. We assessed global and domain specific cognitive function, among hospitalised older patients, including covariates for comorbidity, anxiety and depression. Design Cross-sectional hospital-based study. Settings Data was collected consecutively from inpatients at somatic wards of a general university hospital. Participants Older patients between 65 and 90 years with/without CNSD use for ≥4 weeks. Outcome measures The main outcome was cognitive function assessed by Cognistat. Secondary outcomes were routine clinical tests in the wards (mini-mental state examination (MMSE), trail making test (TMT) A and B, and clock drawing tests). Analyses were bivariate and multiple linear regression, adjusted for age, gender, and education. Covariates were comorbidity, depression and anxiety scores. Results The main result indicated that CNSD users (n=100) had (β=–3.4, 95%CI 6.27 to –0.58, p=0.017) lower Cognistat score than non-users (n=146), adjusted for age, gender, education, anxiety and depression, but not significant when including covariate for comorbidity (β= –2.50 - 5.45; –0.46, p=0.097). Comorbidity was associated with cognitive function (β=−0.77, 95%CI −1.22 to −0.14, p=0.014). Cognistat subdimensions associated with CNSD use were language (p=0.017) and calculation (p=0.003). In clock drawing test, users had lower scores than non-users (β=−0.80, 95%CI 1.24 to −0.36, p=0.004), but no significant difference was found with MMSE and TMT A or B. Z-hypnotics were associated with reduced cognitive function. Conclusion Among older hospitalised patients, global cognition and specific cognitive functions were associated with long-term use of CNSD medication as well as with somatic comorbidit

Correlates of Subjective and Mild Cognitive Impairment: Depressive Symptoms and CSF Biomarkers

Aims: To improve early diagnosis of dementia disease, this study investigates correlates of cognitive complaints and cognitive test performance in patients with subjective (SCI) and mild (MCI) cognitive impairment. Methods: Seventy patients from a memory clinic, aged 45-79, with a score of 2 (n = 23) or 3 (n = 47) on the Global Deterioration Scale, were included. CSF biomarkers [Aβ42, total tau (T-tau) and phosphorylated tau (P-tau)], depressive symptoms, cognitive performance, and complaints were examined. Results: Correlation analysis showed that cognitive complaints increased with decreasing cognitive performance in SCI and decreased with decreasing performance in MCI. Linear regression models revealed that cognitive complaints were associated with depressive symptoms in both groups of patients, while cognitive performance was associated with CSF Aβ42 and P-tau in SCI and with T-tau and P-tau in MCI. Conclusion: These results suggest that depressive symptoms are associated with cognitive complaints, while degenerative changes are associated with objective cognitive decline in high-risk predementia states