Martin J. Sliwinski

Classification of daily and near-daily headaches Field trial of revised IHS criteria

Primary chronic daily headache can be subdivided into transformed migraine, chronic tension-type headache, hemicrania continua, and new daily persistent headache. We proposed and tested criteria in 150 consecutive outpatients with chronic daily headache. Based on preliminary analysis, we revised the criteria for transformed migraine. Using the International Headache Society criteria, 43% of the patients could not be classified; using our old criteria, 25% could not be classified; however, using our new criteria, we were able to classify 100%. Seventy-eight percent had transformed migraine, 15.3% had chronic tension-type headache, and 6.7% had other headache disorders. NEUROLOGY 1996;47: 871-875

Screening for dementia with the Memory Impairment Screen

Objectives: To validate a sensitive and specific screening test for AD and other dementias, assess its reliability and discriminative validity, and present normative data for its use in various applied settings. Background: To improve discrimination in screening for AD and dementia, we developed the Memory Impairment Screen (MIS), a 4-minute, four-item, delayed free- and cued-recall test of memory impairment. The MIS uses controlled learning to ensure attention, induce specific semantic processing, and optimize encoding specificity to improve detection of dementia. Methods: Equivalent forms of the MIS were given at the beginning and end of the testing session to assess alternate forms reliability. Discriminative validity was assessed in a criterion sample of 483 aged individuals, 50 of whom had dementia according to Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised) criteria. Results: The MIS had good alternate forms reliability, high construct validity for memory impairment, and good discriminative validity in terms of sensitivity, specificity, and positive predictive value. We present normative data for use in settings with different base rates (prevalences) of AD and dementia. Conclusion: The MIS provides efficient, reliable, and valid screening for AD and other dementias.

Neuropsychological prediction of dementia and the absence of dementia in healthy elderly persons

Identification of elderly individuals with low and high risk for future dementia has emerged as an important clinical and public health issue. To address this issue, we assessed neuropsychological performance in 317 initially nondemented elderly persons between 75 and 85 years of age and followed them for at least 4 years as part of the Bronx Aging Study. Four measures of cognitive function from the baseline assessment (delayed recall from the Buschke Selective Reminding Test, recall from the Fuld Object Memory Evaluation, the Digit Symbol subtest from the Wechsler Adult Intelligence Scale, and a verbal fluency score) can identify one subgroup with an 85% probability of developing dementia over 4 years and another with a 95% probability of remaining free of dementia. The model achieved an overall positive predictive value of 68%, or three times the base rate, for prediction of the development of dementia in our sample. The overall negative predictive value for prediction of absence of dementia was 88%. Baseline measures of cognitive function, often performed many years before the actual diagnosis of dementia, can provide important information about dementia risk. The group likely to develop dementia becomes a target for preventive or early therapeutic interventions, and the group unlikely to develop dementia can be reassured.

Daily and momentary mood and stress are associated with binge eating and vomiting in bulimia nervosa patients in the natural environment.

The relation of mood and stress to binge eating and vomiting in the natural environments of patients with bulimia nervosa (BN) was examined using real-time data collection. Women (n = 131; mean age = 25.3 years) with BN carried a palmtop computer for 2 weeks and completed ratings of positive affect (PA), negative affect (NA), anger/hostility (AH), and stress (STRS); they also indicated binge or vomit episodes (BN-events) 6 times each day. Mixed models were used to compare mood and STRS between and within days when BN-events occurred. Between-days analyses indicated that binge and vomit days both showed less PA, higher NA, higher AH, and greater STRS than days with no BN-events. Within-day, decreasing PA, and increasing NA and AH, reliably preceded BN-events. Conversely, PA increased, and NA and AH decreased following BN-events. Demonstration of the temporal sequencing of affect, STRS, and BN-events with a large BN sample may help advance theory and clinical practice, and supports the view that binge and purge events hold negatively reinforcing properties for women with BN.

Aging and dual-task performance: A meta-analysis

The relations between dual-task effects and aging were examined through a meta-analysis of 33 studies (with 48 independent participant groups) using latency as the dependent measure and 30 studies (with 40 independent participant groups) focusing on accuracy. Brinley plots and state traces were derived, and a model to explicate different types of complexity (additive and multiplicative) was developed. The effects of dual-task processing on latency were additive, and this additive cost was larger in older adults than in younger adults and larger than predicted from general slowing. This cost was small and independent of task complexity. The effects of dual-task processing on logit-transformed accuracy were likewise additive, but no specific age deficit was associated with this dual-task cost.

Memory and mental status correlates of modified Braak staging

We assessed the relationships of performance on memory and mental status tests and neuropathologic stage of Alzheimers disease as defined by Braak and Braak in 29 patients from a prospective clinicopathologic series. We predicted that memory changes would occur at an earlier Braak stage than mental status changes. Staging was accomplished by matching the topographic distribution of neurofibrillary lesions detected with tau immunocytochemistry to the best fitting diagram published by Braak and Braak. Higher Braak stages were associated with decrements in performance on both memory and mental status tests. As predicted, memory performance declined from stages II to III and mental status did not decline until stages III to IV. The association between memory and Braak stage was unchanged after adjusting for neocortical senile plaques, whereas adjustments for Braak stage eliminated the association between cognitive functioning and amyloid burden. We conclude that Braak staging provides a useful summary of Alzheimers disease neuropathology, which is associated with both memory and mental status performance.

Understanding Ageing. An evaluation of research designs for assessing the interdependence of ageing-related changes.

Background: Cross-sectional studies of samples varying widely in age have found moderate to high levels of shared age-related variance among measures of cognitive and physiological capabilities, leading researchers to posit common factors or common causal influences for diverse age-related phenomenon. Objective: The influence of population average changes with age on cross-sectional estimates of association has not been widely appreciated in developmental and ageing research. Covariances among age-related variables in cross-sectional studies are highly confounded in regards to inferences about associations among rates of change within individuals since covariances can result from a number of sources including average population age-related differences (fixed age effects) in addition to initial individual differences and individual differences in rates of ageing (random age effects). Analysis of narrow age-cohort samples may provide a superior analytical basis for testing hypotheses regarding associations between rates of change in cross-sectional studies. Conclusions: The use of age-heterogeneous cross-sectional designs for evaluating interdependence of ageing-related processes is discouraged since associations will not necessarily reflect individual-level correlated rates of change. Typical cross-sectional studies do not provide sufficient evidence for the interdependence of ageing-related changes and should not serve as the basis for theories and hypotheses of ageing. Reanalyzing existing cross-sectional studies using a sequential narrow-age cohort approach provides a useful alternative for evaluating associations between ageing-related changes. Longitudinal designs, however, provide a much stronger basis for inference regarding associations between rates of ageing within individuals.

Diagnosis of early dementia by the Double Memory Test: Encoding specificity improves diagnostic sensitivity and specificity

Objective To compare the Double Memory Test (DMT) with standard memory tests in the diagnosis of early dementia. Background Diagnosis of dementia requires memory impairment, but few memory tests coordinate acquisition and retrieval to optimize encoding specificity for high sensitivity and specificity. The DMT was developed to improve early diagnosis. Design We compared the discriminative validity of the DMT, Paired Associates (PA), and Logical Memory (LM) memory tests in a nested case-control study of 30 cases of early dementia and 90 controls matched for age, education, and sex. Methods The DMT includes memory tests with (CCR) and without (ICR) encoding specificity. Both tests use category cues to elicit retrieval, but CCR optimizes encoding specificity because the same cues are used for acquisition and retrieval. ICR does not because category cues are used only for retrieval. We used conditional logistic regression to estimate diagnostic sensitivity and specificity. Results The median BIMC of dementia cases was 10, indicating mild dementia. CCR had much higher sensitivity (93%) and specificity (99%) than ICR (53%, 94%), PA (68%, 91%), and LM (48%, 92%). CCR had the greatest advantage in the mildest cases. Conclusions CCR has substantially higher sensitivity and specificity for diagnosis of early dementia than memory tests that do not coordinate acquisition and retrieval. Superior discrimination by CCR is due to an encoding specificity deficit in dementia that increases the difference in recall by cases and controls. CCR is an efficient test with excellent discriminative validity that should facilitate diagnosis of early dementia.

Neuropsychologic outcome after deep hypothermic circulatory arrest in adults

INTRODUCTION Pediatric patients undergoing prolonged periods of deep hypothermic circulatory arrest have been found to experience long-term deficits in cognitive function. However, there is limited information of this type in adult patients who are undergoing deep hypothermic circulatory arrest for thoracic aortic repairs. METHODS One hundred forty-nine patients undergoing elective cardiac or thoracic aortic operations were evaluated preoperatively; 106 patients were evaluated early in the postoperative period (EARLY), and 77 patients were evaluated late in the postoperative period (LATE) with a battery of neuropsychologic tests. Seventy-three patients had routine cardiac operations without deep hypothermic circulatory arrest, and 76 patients with deep hypothermic circulatory arrest were divided into 2 subgroups: those with 1 to 24 minutes of deep hypothermic circulatory arrest (n = 36 patients) and those with 25 minutes or more of deep hypothermic circulatory arrest (n = 40 patients). The neuropsychologic test battery consisted of 8 tests encompassing 5 domains: attention, processing speed, memory, executive function, and fine motor function. Data were normalized to baseline values, and changes from baseline were analyzed by analysis of covariance, multivariate logistic regression, and survival functions. RESULTS In all domains, poor performance or inability to be tested EARLY were significant predictors of poor performance LATE (odds ratio, 5.27; P <.01). Deep hypothermic circulatory arrest of 25 minutes or more and advanced age were significant predictors of poor performance LATE for the memory and fine motor domains. Deep hypothermic circulatory arrest of 25 minutes or more (odds ratio, 4. 0; P =.02) was a determinant of prolonged hospital stay (>21 days). CONCLUSION Deep hypothermic circulatory arrest of 25 minutes or more and advanced age were associated with memory and fine motor deficits and with prolonged hospital stay.

Cognitive activities delay onset of memory decline in persons who develop dementia

Background: Persons destined to develop dementia experience an accelerated rate of decline in cognitive ability, particularly in memory. Early life education and participation in cognitively stimulating leisure activities later in life are 2 factors thought to reflect cognitive reserve, which may delay the onset of the memory decline in the preclinical stages of dementia. Methods: We followed 488 initially cognitively intact community residing individuals with epidemiologic, clinical, and cognitive assessments every 12 to 18 months in the Bronx Aging Study. We assessed the influence of self-reported participation in cognitively stimulating leisure activities on the onset of accelerated memory decline as measured by the Buschke Selective Reminding Test in 101 individuals who developed incident dementia using a change point model. Results: Each additional self-reported day of cognitive activity at baseline delayed the onset of accelerated memory decline by 0.18 years. Higher baseline levels of cognitive activity were associated with more rapid memory decline after that onset. Inclusion of education did not significantly add to the fit of the model beyond the effect of cognitive activities. Conclusions: Our findings show that late life cognitive activities influence cognitive reserve independently of education. The effect of early life education on cognitive reserve may be mediated by cognitive activity later in life. Alternatively, early life education may be a determinant of cognitive reserve, and individuals with more education may choose to participate in cognitive activities without influencing reserve. Future studies should examine the efficacy of increasing participation in cognitive activities to prevent or delay dementia.