Serum brain-derived neurotrophic factor levels are specifically associated with memory performance among Alzheimer's disease cases.

AIMS: Our purpose was to study the link between serum brain-derived neurotrophic factor (BDNF) levels and neuropsychological functioning through the Texas Alzheimer's Research Consortium cohort. METHODS: A total of 399 participants [probable Alzheimer's disease (AD) n = 198, controls n = 201] were available for analysis. The BDNF levels were assayed via multiplex immunoassay. Regression analyses were utilized to examine the relation between BDNF levels and neuropsychological functioning. RESULTS: There were no significant mean differences in BDNF levels between cases and controls. In the AD group, the BDNF levels were significantly negatively associated with the scores on immediate [B = -0.07 (0.02), t = -3.55, p = 0.001] and delayed [B = -0.05 (0.02), t = -2.79, p = 0.01] verbal memory and immediate [B = -0.12 (0.05), t = -2.70, p = 0.01] visual memory. No other neuropsychological variables were significantly related to the BDNF levels. The BDNF levels were not significantly related to the neuropsychological test scores in the control group. CONCLUSIONS: Increased serum BDNF levels were associated with poorer visual and verbal memory, but only among AD cases. The current findings point toward an upregulation of serum BDNF as one possible mechanism linked to memory disturbances in AD though it does not appear to be linked to disease severity.

An examination of the Boston Naming Test: calculation of "estimated" 60-item score from 30- and 15-item scores in a cognitively impaired population.

OBJECTIVE: Multiple versions of the Boston Naming Test (BNT) exist, which makes comparison of findings from different studies difficult. The current project sought to determine if estimated 60-item BNT scores could be reliably calculated from 30- and 15-item administrations with patients diagnosed with Alzheimer's disease (AD). METHODS: Estimated 60-item scores were created for 30-item (even and odd) and 15-item Consortium to Establish a Registry for Alzheimer's disease (CERAD) versions of the BNT from a database containing item-level responses for all BNT items. Correlations were conducted between all three estimated 60-item scores and full 60-item version scores administered to all participants in the sample. RESULTS: The estimated versions were all highly correlated with the standard 60-item version of the BNT across the sample and these findings held when the sample was separated out by case (AD) and control status. Mean difference scores were very small for scores estimated from 30-item administrations; however, difference scores for the 15-item CERAD were much larger. CONCLUSIONS: Estimated 60-item versions of the BNT can be created from 30-item BNT administrations, which will enable comparisons across studies and allow integration of data from various AD research groups for increased power in analytic protocols. Creation of an estimated score from the 15-item CERAD version is not warranted.

Identifying functional impairment with scores from the repeatable battery for the assessment of neuropsychological status (RBANS).

OBJECTIVE: To examine the link between RBANS scores and functional impairment. Functional status was evaluated through informant report using the clinical dementia rating (CDR) scale. METHODS: Archival data were reviewed from records of 99 patients in a memory disorder clinic (MDC) research database. Consensus-based diagnoses were Alzheimer's disease (AD; n = 48), mild cognitive impairment (MCI; n = 48), AD with vascular components; (n = 2) and dementia due to psychiatric conditions (n = 1). RESULTS: The RBANS language index score was significantly related to CDR domain scores of community affairs (p < .01), home and hobbies (p < .01), personal care (p < .05), memory (p < 0.01), and judgment (p < 0.01). RBANS immediate memory index scores were significantly related to (p < 0.05) the CDR Memory and judgment and problem solving domains. Based on these findings, follow-up regressions were conducted. Semantic fluency was significantly related to CDR memory (p < 0.01), judgment (p < 0.05), community affairs (p < 0.05), home/hobbies (p < 0.05), and personal care (p < 0.05) functional domains. Picture naming was significantly related to the CDR personal care domain (p < 0.05). List learning was significantly related to CDR memory functional domain (p < 0.01) and judgment (p < 0.05). Lastly, story memory was significantly related to the CDR judgment domain (p < 0.05). CONCLUSIONS: The RBANS may be an indicator of functional impairment as well as a neuropsychological testing tool. The use of the RBANS could reduce the amount of testing that is administered to the patient, or can provide a way to compare other measurements of functional impairment to assess accuracy of findings.

Appetitive nature of drug cues re-confirmed with physiological measures and the potential role of stage of change.

RATIONALE: Smokers report pleasant reactions to viewing cigarettes, suggesting that smoking cues may be appetitive in nature. Two studies have investigated this hypothesis through physiological assessment. The first study found that smoking cues were physiologically appetitive in nature, with dampened startle response to smoking pictures in comparison to neutral pictures. The second found that smoking pictures did not modulate the startle response, suggesting such cues may not be physiologically appetitive. OBJECTIVE: The goal of the present study was to further investigate how participants' motivation to quit smoking might modulate responses to smoking cues. MATERIALS AND METHODS: Twenty-two nicotine-dependent smokers viewed standardized pleasant, unpleasant, neutral, and smoking pictures. Eleven of the subjects reported no intent to quit (precontemplators) and 11 reported planning to quit within the next 6 months (contemplators). Acoustic startle probes were randomly administered while subjects viewed the pictures, and eyeblink startle magnitude was measured with electromyography (EMG). RESULTS: As a whole, participants exhibited dampened startle responses during smoking pictures, relative to unpleasant pictures. Precontemplators showed robust startle inhibition to smoking pictures, in comparison to both neutral and unpleasant pictures. Contemplators, however, showed blunted unpleasant picture augmentation and a lack of startle inhibition for pleasant pictures. CONCLUSION: These findings are consistent with the idea that smoking pictures are appetitive in nature. Furthermore, they suggest that smokers at a later stage of change may exhibit a lesser response.

Diagnostic accuracy of percent retention scores on RBANS verbal memory subtests for the diagnosis of Alzheimer's disease and mild cognitive impairment.

Previous research has supported the use of percent retention scores in the neuropsychological assessment of memory, and many widely used memory measures provide for the calculation and normative comparison of these scores. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), an increasingly utilized assessment tool for cognitive impairment, provides normative data on delayed memory total raw scores only. The current study was aimed at determining the diagnostic accuracy of a novel percent retention score calculated from RBANS verbal memory subtests (delayed recall minus last learning trial) when distinguishing between normal controls, individuals diagnosed with Mild Cognitive Impairment, and individuals diagnosed with Alzheimer's disease. Results revealed excellent diagnostic accuracy of the RBANS percent retention scores when discriminating between the three groups. Findings suggest that RBANS percent retention scores provide excellent diagnostic accuracy offering supplementary information to clinicians and researchers alike.

Diagnostic accuracy of the RBANS in mild cognitive impairment: limitations on assessing milder impairments.

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) has demonstrated adequate sensitivity in detecting cognitive impairment in a number of neuropsychiatric conditions, including Alzheimer's disease. However, its ability to detect milder cognitive deficits in the elderly has not been examined. The current study examined the clinical utility of the RBANS by comparing two groups: Patients with Mild Cognitive Impairment (MCI; n = 72) and cognitively intact peers (n = 71). Significant differences were observed on the RBANS Total score, 3 of the 5 Indexes, and 6 of the 12 subtests, with individuals with MCI performing worse than the comparison participants. Specificity was very good, but sensitivity ranged from poor to moderate. Areas under the receiver operating characteristic curves for the RBANS Immediate and Delayed Memory Indexes and the Total Scale score were adequate. Although significant differences were observed between groups and the areas under the curves were adequate, the lower sensitivity values of the RBANS suggests that caution should be used when diagnosing conditions such as MCI.