Association rule learning in neuropsychological data analysis for Alzheimer's disease.

Efficient methods of analysis readily available for clinicians continue to be limited within neuropsychological assessment at the raw data level. Here, a novel approach for generating predictive response patterns and analysing neuropsychological raw data is offered. In order to assess the usefulness of association rule learning as an analysis tool for neuropsychological raw data, Frequent Pattern Growth (FP-Growth) was used to mine patterns from the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD-NB) database. Complete assessment data for 84 post-mortem confirmed Alzheimer's disease (AD) cases and 294 age, race, and education matched controls were analysed across baseline and one-year follow-up using FP-Growth, for the purpose of assessing the clinical utility of a finer analysis at the raw data level and the feasibility of predicting response patterns for clinical/control groups. Output from FP-Growth, in terms of the number of frequent itemsets retained across both evaluation timepoints, was discernable between controls, mild, and moderate to severe Alzheimer's disease cases (p < .001, and η2 = .488). Patterns within raw data scores, both in terms of frequent itemsets and predictive association rules, appear to be differentiable across groups within neuropsychological analysis, which indicates that FP-Growth is applicable as a supplementary analysis tool for neuropsychological assessment by means of offering an additional level of data analysis, predictive item response capabilities, and aiding in clinical decision making.

Ginkgo biloba: indications, mechanisms, and safety.

Ginkgo biloba special extract (EGb761) is used in most randomized control trials. Indications include cognition and memory in Alzheimer disease, age-associated dementia, cerebral insufficiency, intermittent claudication, schizophrenia, and multi-infarct dementia. Dosages range from 80 to 720 mg/d for durations of 2 weeks to 2 years. Mechanisms of action include increasing cerebral blood flow, antioxidant and antiinflammatory effects, with antiplatelet effects attributed to flavone and terpene lactones. Possible interactions with monoamine oxidase inhibitors, alprazolam, haloperidol, warfarin, and nifedipine have been reported. Optimal dosage/duration, dose-response characteristics, drug interactions, bioavailability, long-term effects, and optimal intervention timing should be the focus of future work.

Priming, recognition and autonomic discrimination in amnesia.

Six individuals with amnesia and matched healthy controls participated. There were two objectives. First, determine whether physiological activity at encoding relates to whether a word shows autonomic priming or is recognized. Second, propose a model for understanding relationships between recognition and autonomic priming. In amnesics, 'unrecognized' words were associated with better autonomic discrimination and lower levels of physiological activity at encoding. In healthy participants and amnesics, 'recognized' words were associated with poorer autonomic priming and higher levels of physiological activity at encoding. A state-dependent, activation-fractionation-inhibition model is proposed involving an orienting response elicited by preference and search and modulated by underlying memory strength.

Mindfulness meditation improves cognition: evidence of brief mental training.

Although research has found that long-term mindfulness meditation practice promotes executive functioning and the ability to sustain attention, the effects of brief mindfulness meditation training have not been fully explored. We examined whether brief meditation training affects cognition and mood when compared to an active control group. After four sessions of either meditation training or listening to a recorded book, participants with no prior meditation experience were assessed with measures of mood, verbal fluency, visual coding, and working memory. Both interventions were effective at improving mood but only brief meditation training reduced fatigue, anxiety, and increased mindfulness. Moreover, brief mindfulness training significantly improved visuo-spatial processing, working memory, and executive functioning. Our findings suggest that 4days of meditation training can enhance the ability to sustain attention; benefits that have previously been reported with long-term meditators.

Relationships between information processing, depression, fatigue and cognition in multiple sclerosis.

The neurobehavioral sequelae of multiple sclerosis (MS) consistently include fatigue, depression and cognitive dysfunction with slower processing figuring prominently. However, processing speed is often confounded with accuracy and the relative contributions of depressed mood and fatigue in influencing speed of processing are difficult to quantify. Therefore, there were three objectives in this study. First, compare processing speed in MS and healthy controls under conditions in which accuracy is not confounded with speed; second, determine the relationships between information processing speed and cognition; third, determine the contributions of clinical depression and fatigue in mediating these relationships. Forty-eight participants with confirmed MS participated. The findings suggested that slower processing was correlated with higher levels of depressed mood, fatigue, lower verbal fluency, fewer words and digits recalled and poorer recall of visual-spatial information. Depression and physical fatigue had the greatest influence on the association between processing speed and more effortful tasks (e.g., immediate word recall and word list learning). Current findings extend previous work by using a more sensitive measure of processing speed and by quantifying the relative contributions of depression and fatigue in mediating relationships between processing speed and cognition.

The effect of Ginkgo biloba on functional measures in multiple sclerosis: a pilot randomized controlled trial.

BACKGROUND: Multiple sclerosis (MS) is a chronic demyelinating neurological disease afflicting young and middle-aged adults, resulting in problems with coordination, strength, cognition, affect, and sensation. OBJECTIVE: The objective of this study was to determine whether a ginkgo extract (EGb 761) improved functional performance in individuals with MS. DESIGN: This study used a double-blind, placebo-controlled, parallel group design. The end point was change between baseline (ie, preintervention) and follow-up evaluation following a regimen of four tablets per day at 60 mg per tablet for four weeks. SETTING: The study was conducted in academic and clinical-based settings. PATIENTS/PARTICIPANTS: Twenty-two individuals with MS were randomly assigned to either the treatment or control condition. Groups did not differ with respect to age, IQ, and education. INTERVENTION: Half of the subjects received 240 mg per day of ginkgo special extract (EGb 761), and the other half received placebo. MAIN OUTCOME MEASURE: The main outcome measures assessed depression (Center for Epidemiologic Studies of Depression Scale [CES-D]), anxiety (State-Trait Anxiety Inventory [STAI]), fatigue (Modified Fatigue Impact Scale [MFIS]); symptom severity (Symptom Inventory [SI]) and functional performance (Functional Assessment of Multiple Sclerosis [FAMS]). RESULTS: The ginkgo group had significantly more individuals showing improvement on four or more measures with improvements associated with significantly larger effect sizes on measures of fatigue, symptom severity, and functionality. The ginkgo group also exhibited less fatigue at follow-up compared with the placebo group. CONCLUSIONS: This exploratory pilot study showed that no adverse events or side effects were reported and that ginkgo exerted modest beneficial effects on select functional measures (eg, fatigue) among some individuals with MS.

Processing speed interacts with working memory efficiency in multiple sclerosis.

Information processing speed was assessed using the visual threshold serial addition test (VT-SAT), a computerized modification of the PASAT designed to assess processing speed by controlling for performance accuracy. Persons with MS (N=43) and healthy individuals (N=32) were administered the VT-SAT varying working memory loads (1-back versus 2-back). Results indicated that at the lower working memory load (1-back) all individuals with MS were able to achieve a working memory performance level equivalent to healthy individuals, but required significantly more processing time to do so. In contrast, at the higher working memory load (2-back), about 70% of MS participants were able to achieve a performance level equivalent to healthy individuals, but again required significantly more processing time. The results are discussed in the context of the dynamic nature of the relationship between processing speed and working memory performance, emphasizing the dependence of this relationship on other cognitive and disease-related factors.

Working memory deficits in chronic fatigue syndrome: differentiating between speed and accuracy of information processing.

To examine the relative influence of speed of information processing versus working memory ability, CFS participants with psychiatric comorbidity (CFS-Psych) and CFS without a psychiatric history (CFS-noPsych) were examined on tests of visual and auditory processing speed and visual and auditory working memory. Compared to healthy controls (HC) and a group of participants with rheumatoid arthritis (RA), the CFS-noPsych group displayed significantly reduced performance on tests of information processing speed, but not on tests of working memory. No significant differences were observed between the CFS-Psych group and any other group in the study. The implications of group heterogeneity on the understanding of cognitive impairment in CFS are discussed.

Telerehabilitation, cognition and user-accessibility.

Survivors of traumatic brain injury (TBI) often experience cognitive and physical impairments. The aims of this study were to: 1) build an internet-based, "Virtual Rehabilitation Center" (VRC) that provides rehabilitation, education and support services to individuals with TBI; and 2) to determine the relationships between the nature and severity of the participants' cognitive impairments and their ability to use the VRC. Eight individuals with brain injuries (Age: M=43, SD=15.4; Years of Education: M=13.8, SD=3.15) participated. The Neurobehavioral Cognitive Status Exam (NBCSE) was used to assess intellectual functioning. The VRC modules consisted of reaction time, functional modules, and communication capabilities. All participants learned how to use the VRC. However, those requiring more "trials to acquisition" showed greater cognitive impairment than those requiring fewer trials in: Construction (p=0.02), Reasoning-Similarities (p=0.01) and in calculation and language repetition.(i.e., a non-significant trend). Importantly, all participants learned how to use the system although learning rates varied. Moreover, one case-study demonstrated that learning on the VRC generalized to the community. Overall, impairments on the NBCSE in visual-constructional integration and executive-type functions, as well as language processing appeared to be related to how effectively participants learned how to use the VRC.