Stephen T. Moelter

Comparative accuracies of two common screening instruments for classification of Alzheimer's disease, mild cognitive impairment, and healthy aging

The aim of this study was to compare the utility and diagnostic accuracy of the Montreal Cognitive Assessment (MoCA) and Mini‐Mental State Examination (MMSE) in the diagnosis of Alzheimers disease (AD) and mild cognitive impairment (MCI) in a clinical cohort.

Patterns of Change in Cognitive Function over Six Months in Adults with Chronic Heart Failure.

Few investigators have studied cognition over time in adults with heart failure (HF). A battery of neuropsychological tests was administered to 279 adults with chronic systolic or diastolic HF at baseline, three and six months. Growth mixture modeling (GMM) was used to model the measure anticipated to be most sensitive, the digit symbol substitution task (DSST). We describe how and why the DSST patterns change over time. Other measures of cognition were examined to identify consistency with the DSST patterns. The sample was predominantly male (63.2%), Caucasian (62.7%), mean age 62 years. The best fit GMM revealed two trajectories of DSST scores: Average processing speed group (40.5%) and Below Average processing speed (59.9%). Neither group changed significantly over the six month study. Other measures of cognition were consistent with the DSST patterns. Factors significantly associated with increased odds of being in the Below Average processing speed group included older age, male gender, Non-Caucasian race, less education, higher ejection fraction, high comorbid burden, excessive daytime sleepiness, and higher BMI. As some of the factors related to cognitive impairment are modifiable, research is needed to identify interventions to preserve and improve cognition in these patients.

Retrospective assessment of rehabilitation outcome after traumatic brain injury: development and utility of the functional independence level.

Objective:To develop a measure suitable for retrospective analysis of qualitative brain injury outcome data, the Functional Independence Level (FIL), and document its reliability, validity, and utility. Design:Retrospective analysis of existing records, with inclusion based on availability of records, and quantitative or qualitative documentation of functional status at a minimum of 1.5 years after injury. Setting:Statewide acute and postacute rehabilitation facilities, as part of a State Head Injury Program. Participants:A total of 338 individuals, with documented moderate to severe traumatic brain injury; primarily males ages 16 to 45. Main Outcome Measures:Disability Rating Scale (DRS) at discharge from primary rehabilitation, Living Situation and Functional Independence Level coded from information in postacute rehabilitation reports, at an average of approximately 6 years after injury. Results:Inter-rater reliability coefficients for FIL ratings extracted from rehabilitation records, and between retrospective and in vivo assessments were highly significant. DRS scores at discharge from primary rehabilitation predicted a significant amount of variance in FIL scores at an average of 5 years after injury, and DRS scores remained a stable and significant predictor of FIL scores as the time period between discharge from rehabilitation and outcome ratings increased to 10 years after injury. FIL ratings were significantly lower for individuals living in residential facilities than those living with their families, as compared to living alone. Conclusions:The FIL is a reliable and useful tool for retrospective and prospective assessments of rehabilitation outcome. Gains made during primary rehabilitation by people with severe traumatic brain injury are generally maintained at long-term follow up. Retrospective ratings using the DRS and FIL can help guide postacute rehabilitation planning within state or regional head injury programs.

Research consent capacity varies with executive function and memory in Parkinson's disease.

We examined the association between cognitive domains and research consent capacity in PD. Our hypothesis was that research consent capacity is best predicted by executive function.

The Dementia Severity Rating Scale predicts clinical dementia rating sum of boxes scores.

Functional assessment is an indispensable component of dementia evaluations. Functional evaluations are necessary to differentiate normal aging from mild cognitive impairment (MCI) and MCI from Alzheimer disease (AD), and to track AD progression. Although cognitive test performance is an equally important part of this process, functional measures have higher ecological validity, may be better at determining change from previous, higher levels of ability, and are less sensitive to the effects of education and premorbid intelligence.1 The Clinical Dementia Rating Scale (CDR), a commonly used dementia staging instrument, employs a semistructured interview format to collect detailed information from an informant regarding the patient’s ability to function in various domains. The CDR offers a global characterization of everyday functions that may be affected by neurodegenerative disease.2 However, the value of global characterizations has been questioned, especially during the assessment of MCI.3 The wider range of scores provided by the CDR sum of boxes (CDR-SB) score may enable a more refined analysis of subtle changes associated with very mild disease or between stages in later AD.4,5 The CDR is the most well-known, well-studied dementia staging instrument.6 The scale, however, is not without limitations. Primary concerns include a lengthy rater certification process, approximately 30-minute administration time, and clinical judgment required during administration and scoring.2 The Dementia Severity Rating Scale (DSRS) is a brief informant-rated, multiple-choice questionnaire made up of 12 items that measure functional abilities and parallel CDR content.7 The DSRS requires minimal staff training to administer, takes 5 minutes to complete, and can be completed by mail, internet, or phone. Similar to the CDR-SB, the DSRS incorporates a broad range of scores, making this instrument useful for quantifying all levels of functional impairment and permitting the detection of fine increments of change over time.8 Reliability and validation studies have shown that the DSRS has high reliability, as well as a constant linear rate of change throughout the entire course of AD. The original version demonstrated high concurrent validity with the CDR and the Mini Mental State Examination.7,8 To improve its utility, however, further analysis of the association between the DSRS and the CDR is required. With this in mind, the goal of the present study was to examine the ability of the DSRS to predict scores on the CDR-SB.

A mixed methods study of symptom perception in patients with chronic heart failure

Background Early heart failure (HF) symptoms are frequently unrecognized for reasons that are unclear. We explored symptom perception in patients with chronic HF. Methods We enrolled 36 HF out‐patients into a longitudinal sequential explanatory mixed methods study. We used objectively measured thoracic fluid accumulation and daily reports of signs and symptoms to evaluate accuracy of detected changes in fluid retention. Patterns of symptom interpretation and response were explored in telephone interviews conducted every 2 weeks for 3‐months. Results In this sample, 44% had a mismatch between objective and subjective fluid retention; younger persons were more likely to have mismatch. In interviews, two patterns were identified: those able to interpret and respond appropriately to symptoms were higher in decision‐making skill and the quality of social support received. Conclusion Many HF patients were poor at interpreting and managing their symptoms. These results suggest a subgroup of patients to target for intervention.

The content of lexical stimuli and self-reported physiological state modulate error-related negativity amplitude

The Error-Related Negativity (ERN) and Correct-Response Negativity (CRN) are brief event-related potential (ERP) components-elicited after the commission of a response-associated with motivation, emotion, and affect. The Error Positivity (Pe) typically appears after the ERN, and corresponds to awareness of having committed an error. Although motivation has long been established as an important factor in the expression and morphology of the ERN, physiological state has rarely been explored as a variable in these investigations. In the present study, we investigated whether self-reported physiological state (SRPS; wakefulness, hunger, or thirst) corresponds with ERN amplitude and type of lexical stimuli. Participants completed a SRPS questionnaire and then completed a speeded Lexical Decision Task with words and pseudowords that were either food-related or neutral. Though similar in frequency and length, food-related stimuli elicited increased accuracy, faster errors, and generated a larger ERN and smaller CRN than neutral words. Self-reported thirst correlated with improved accuracy and smaller ERN and CRN amplitudes. The Pe and Pc (correct positivity) were not impacted by physiological state or by stimulus content. The results indicate that physiological state and manipulations of lexical content may serve as important avenues for future research. Future studies that apply more sensitive measures of physiological and motivational state (e.g., biomarkers for satiety) or direct manipulations of satiety may be a useful technique for future research into response monitoring.

The Dementia Severity Rating Scale for dementia: Relationships with the CDR sum of boxes, clinical diagnosis and CSF biomarkers

that these changes in velocity and variability were not simply age-related. Conclusions: Cognitive impairment is characterized not only by memory loss, but also by functional impairment. Using quantitative gait analysis with dual task paradigms, we show that gait becomes slower and more variable as cognitive decline progresses. Particularly, gait cycle time variability increases during cognitive dual tasking compared to normal walking in thosewithMCI andmild AD. Early detection of these mobility impairments may be used as a tool to aid diagnosis of those in the earliest stages of cognitive impairment.

The time is “right:” Electrophysiology reveals right parietal electrode dominance in time perception

&NA; In the present study, healthy undergraduates were asked to identify if a visual stimulus appeared on screen for the same duration as a memorized target (2 s) while event‐related potentials (ERP) were recorded. Trials consisted of very short (1.25 s), short (1.6 s), target (2 s), long (2.5 s) or very long (3.125 s) durations, and a yes or no response was required on each trial. We examined behavioral response as signal detection (d′) and response bias via a Generalized Accuracy Coefficient (GAC). We examined the mean amplitude as well as the change in amplitude of the initial Contingent Negative Variation (iCNV) and overall CNV (oCNV) and P350 (a P300‐like component that follows stimulus extinction) potentials in paired, lateralized posterior electrodes. Results showed a bias to identifying shorter trials as the target more than longer trials via negative GAC scores. The slope and amplitudes of the iCNV and oCNV were consistently greater in right parietal electrodes. Also in right parietal electrodes, the iCNV correlated to d′ scores while greater P350 amplitudes in the short condition correlated with more negative GAC scores. The results indicate dominance in the right hemisphere in temporal processing for durations exceeding 1 s. The P350 should also be studied further.

Cognitive performance characteristics of individuals with normal or pathological CSF and MRI biomarkers of Alzheimer's disease

a symptomatic offset. Conclusions: A similar model structure can adequately describe data from the literature and within individual studies for mild-to-moderate AD. The model allows for ongoing inclusion of new patient-level and summary-study level data, hypothesis testing for new covariates as they arise, and appropriate clinical trial simulation and testing of trial performance characteristics for various trial designs used in patients with mild-to-moderate AD. The results suggest that 6 months may be an inadequate duration to assess whether average disease progression has changed over the past two decades.