Lexical retrieval in discourse: An early indicator of Alzheimer’s dementia

We examined the progression of lexical-retrieval deficits in individuals with neuropathologically determined Alzheimer’s disease (AD; n=23) and a comparison group without criteria for AD (n=24) to determine whether linguistic changes were a significant marker of the disease. Our participants underwent multiple administrations of a neuropsychological battery, with initial administration occurring on average 16 years prior to death. The battery included the Boston Naming Test (BNT), a letter fluency task (FAS) and written description of the Cookie Theft Picture (CTP). Repeated measures analysis revealed that the AD-group showed progressively greater decline in FAS and CTP lexical performance than the comparison group. Crosssectional time-specific group comparisons indicated that the CTP differentiated performance between the two groups at 7–9 years prior to death and FAS and BNT only at 2–4 years. These results suggest that lexical retrieval deficits in written discourse serve as an early indicator of AD

Polycatechol Nanoparticle MRI Contrast Agents

Amphiphilic triblock copolymers containing Fe III -catecholate complexes formulated as spherical- or cylindrical-shaped micellar nanoparticles ( SMN and CMN , respectively) are described as new T 1 -weighted agents with high relaxivity, low cytotoxicity, and long-term stability in biological fl uids. Relaxivities of both SMN and CMN exceed those of established gadolinium chelates across a wide range of magnetic fi eld strengths. Interestingly, shape-dependent behavior is observed in terms of the particles\u2019 interactions with HeLa cells, with CMN exhibiting enhanced uptake and contrast via magnetic resonance imaging (MRI) compared with SMN . These results suggest that control over soft nanoparticle shape will provide an avenue for optimization of particle-based contrast agents as biodiagnostics. The polycatechol nanoparticles are proposed as suitable for preclinical investigations into their viability as gadolinium-free, safe, and effective imaging agents for MRI contrast enhancement

The ‘affect tagging and consolidation’ (ATaC) model of depression vulnerability

Since the 1960’s polysomnographic sleep research has demonstrated that depressive episodes are associated with REM sleep alterations. Some of these alterations, such as increased REM sleep density, have also been observed in first-degree relatives of patients and remitted patients, suggesting that they may be vulnerability markers of major depressive disorder (MDD), rather than mere epiphenomena of the disorder. Neuroimaging studies have revealed that depression is also associated with heightened amygdala reactivity to negative emotional stimuli, which may also be a vulnerability marker for MDD. Several models have been developed to explain the respective roles of REM sleep alterations and negatively-biased amygdala activity in the pathology of MDD, however the possible interaction between these two potential risk-factors remains uncharted. This paper reviews the roles of the amygdala and REM sleep in the encoding and consolidation of negative emotional memories, respectively. We present our ‘affect tagging and consolidation’ (ATaC) model, which argues that increased REM sleep density and negatively-biased amygdala activity are two separate, genetically influenced risk-factors for depression which interact to promote the development of negative memory bias – a well-known cognitive vulnerability marker for depression. Predictions of the ATaC model may motivate research aimed at improving our understanding of sleep dependent memory consolidation in depression aetiology

Insomnia and epilepsy: a questionnaire-based study.

STUDY OBJECTIVES: Although disturbed sleep has been frequently reported in patients with seizures, little is known about insomnia and epilepsy. The aims of this study were (1) to analyze the prevalence and degree of insomnia in patients with epilepsy, (2) to examine the clinical features and correlates of insomnia in these patients, and (3) to evaluate the impact of poor sleep on their quality of life. METHODS: One hundred-fifty-two patients with epilepsy (mean age 46 years) completed the following questionnaires: Insomnia Severity Index, Pittsburgh Sleep Quality Index, Beck Depression Inventory-II, Quality of Life in Epilepsy Inventory-31. Patients with other known sleep disorders, including obstructive sleep apnea, were excluded from the study. Regression analysis was conducted for adjusting for age, years since epilepsy onset, number of antiepileptic drugs, comorbidities, and depression scores. RESULTS: More than half of the participants (55%) suffered from insomnia and more than 70% were poor sleepers. Insomnia and poor sleep quality were significantly correlated with the number of antiepileptic medications and scores of depressive symptoms. After controlling for covariates, insomnia and poor sleep quality were significant predictors of lower quality of life. CONCLUSION: These results suggest that insomnia and poor sleep are common in patients with epilepsy and may adversely impact quality of life. Further studies should examine whether improvements in sleep can improve seizure control and quality of life of these patients

Effect of continuous positive airway pressure treatment on seizure control in patients with obstructive sleep apnea and epilepsy.

In patients with epilepsy, improvement in seizure control with treatment of coexisting obstructive sleep apnea (OSA) has been reported, but there is lack of data on the effect of continuous positive airway pressure (CPAP) compliance on seizure control in these patients. We examined the variability in seizure frequency in patients who were CPAP compliant and those who were not CPAP compliant. We undertook a retrospective review of clinical and polysomnographic data of adult patients with OSA and epilepsy seen at the Boston University Medical Center Epilepsy and Sleep Clinics between 2000 and 2010. Data were reviewed for CPAP compliance and seizure frequency after at least 6 months of CPAP use. Only patients with no changes in antiepileptic drug regimens during CPAP trial were included. Of the 660 patients identified, 41 fulfilled inclusion criteria, of whom 28 were CPAP compliant and 13 were not CPAP compliant. In the compliant group, CPAP use led to decreased seizure frequency from 1.8 per month to 1 per month (p = 0.01). In the noncompliant group, no significant difference in seizure frequency was noted between baseline (2.1 per month) and at follow-up (1.8 per month, p = 0.36). Sixteen of 28 CPAP-compliant subjects were seizure free, whereas only 3 of 13 non-CPAP compliant subjects were seizure free [relative risk (RR) 1.54, p = 0.05]. Patients with epilepsy and OSA not compliant with CPAP treatment are at higher risk of seizures than are CPAP-compliant patients. To validate this observation, further prospective studies are warranted