81 research outputs found

    Failure to Recover from Proactive Semantic Interference Differentiates Amnestic Mild Cognitive Impairment and PreMCI from Normal Aging after Adjusting for Initial Learning Ability

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    Background: There is increasing evidence that the failure to recover from proactive semantic interference (frPSI) may be an early cognitive marker of preclinical Alzheimer’s disease (AD). However, it is unclear whether frPSI effects reflect deficiencies in an individual’s initial learning capacity versus the actual inability to learn new semantically related targets. Objective: The current study was designed to adjust for learning capacity and then to examine the extent to which frPSI, proactive semantic interference (PSI) and retroactive semantic interference (RSI) effects could differentiate between older adults who were cognitively normal (CN), and those diagnosed with either Pre-Mild Cognitive Impairment (PreMCI) or amnestic MCI (aMCI). Methods: We employed the LASSI-L cognitive stress test to examine frPSI, PSI and RSI effects while simultaneously controlling for the participant’s initial learning capacity among 50 CN, 35 aMCI, and 16 PreMCI participants who received an extensive diagnostic work-up. Results: aMCI and PreMCI participants showed greater frPSI deficits (50% and 43.8% respectively) compared to only 14% of CNparticipants. PSI effects were observed for aMCI but not PreMCI participants relative to their CN counterparts. RSI failed to differentiate between any of the study groups. Conclusion: By using participants as their own controls and adjusting for overall learning and memory, it is clear that frPSI deficits occur with much greater frequency in individuals at higher risk for Alzheimer’s disease (AD), and likely reflect a failure of brain compensatory mechanisms.Fil: Curiel, Rosie E.. University of Miami; Estados UnidosFil: Crocco, Elizabeth A.. University of Miami; Estados UnidosFil: Raffo, Arlene. University of Miami; Estados UnidosFil: Guinjoan, Salvador Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Nemeroff, Charles B.. University of Miami; Estados UnidosFil: Penate, Ailyn. Mount Sinai Medical Center; Estados Unidos. University of Miami; Estados UnidosFil: Piña, Daema. University of Miami; Estados UnidosFil: Loewenstein, David A.. Mount Sinai Medical Center; Estados Unidos. University of Miami; Estados Unido

    Test anxiety in relation to measures of cognitive and intellectual functioning

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    The potential impact of test anxiety on cognitive testing was examined in a sample of 300 predominantly male veteran referrals who were administered a comprehensive neuropsychological test battery. Exclusionary criteria included failure on effort testing (n= 14). Level of test anxiety was significantly related to performance on the WAIS-III Working Memory Index (r = -.343, p < .001) but not to scores on the Processing Speed, Perceptual Organization, or Verbal Comprehension indexes. Test anxiety was not related to a global index of neuropsychological performance on the HRNES-R (Average Impairment Scale). Level of education had a collinear relationship with test anxiety in predicting cognitive test performance. Regression analyses revealed a more prominent role for education, indicating the possibility that test anxiety may be a reaction to, more than a cause of, deficient working memory performance. These results suggest that clinicians who use these particular tests should be reluctant to attribute poor test performance to anxiety that occurs during the testing process

    Salient Cognitive Paradigms to Assess Preclinical Alzheimer's Disease

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    Despite the growing emphasis to identify early biological markers that can detect the progressive accumulation of brain pathology in the complex pathophysiologic cascade that occurs in Alzheimer's disease (AD), we continue to employ the same neuropsychological paradigms that were developed to detect dementia or frank cognitive impairment. It has become increasingly clear that we cannot expect to measure clinically meaningful change in relationship to these emerging preclinical biomarkers using these traditional cognitive assessment paradigms, nor will we advance the efforts to identify the earliest cognitive changes that emerge in AD. Over the last decade, a few novel promising cognitive assessment paradigms have emerged that have shown promise in identifying subtle cognitive deficits in AD which aids in early detection and monitoring of meaningful cognitive change over time. Some of these cognitive assessment paradigms are reviewed here, including semantic interference, semantic intrusion errors, memory binding, and binding of face and name associations. These paradigms may be useful for AD clinical trials focused on secondary prevention if there is sufficient rigor to suggest that they correlate with AD biomarkers, having robust sensitivity, specificity, and predictive utility among culturally and linguistically diverse populations at-risk for AD

    Case study: A patient with agenesis of the corpus callosum with minimal associated neuropsychological impairment

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    This is a case study of an 88-year-old man who presented with agenesis of the corpus callosum and colpocephaly. Symptomatically, he reported a sudden onset of mild, intermittent left hand apraxia, but denied any previous manifestations consistent with this type of brain malformation. The patient underwent neuroimaging, evaluation by neurology, and comprehensive neuropsychological testing to determine the nature of any other associated impairments. Test results indicated that he was, with a few exceptions, neuropsychologically normal. He performed well on tests that are highly sensitive to acquired brain dysfunction. His most notable deficit was failed performance in the simultaneous and coordinated use of both hands in using tactile and proprioceptive feedback on the Tactual Performance Test. This case is discussed in terms of plasticity of the developing brain, including compensatory mechanisms, highlighting the variability in clinical outcome in the context of congenital brain malformation. This case study illustrates the strong influence of cerebral plasticity as well as a possible circumscribed manifestation of interhemispheric disconnection

    Bipolar Disorder in the Elderly

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    Bipolar disorder in older individuals is becoming more relevant to clinicians due to the advent of the aging of the population. Geriatric patients in general are more complex, and the disease process is not simply an extension of the symptomatology observed in the younger cohort. The information derived from study data of younger adults as applied to geriatric psychiatric management is never ideal. Additionally, research and guidelines for evidencebased management and treatment of the elderly bipolar is extremely limited. This chapter presents the most recent data describing the clinical features, diagnosis, comorbidities, and treatment strategies (including lithium and anticonvulsants, antipsychotics, antidepressants, benzodiazepines, and ECT) for this complex bipolar subgroup

    Novel Cognitive Paradigms for the Detection of Memory Impairment in Preclinical Alzheimer's Disease

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    In spite of advances in neuroimaging and other brain biomarkers to assess preclinical Alzheimer's disease (AD), cognitive assessment has relied on traditional memory paradigms developed well over six decades ago. This has led to a growing concern about their effectiveness in the early diagnosis of AD which is essential to develop preventive and early targeted interventions before the occurrence of multisystem brain degeneration. We describe the development of novel tests that are more cognitively challenging, minimize variability in learning strategies, enhance initial acquisition and retrieval using cues, and exploit vulnerabilities in persons with incipient AD such as the susceptibility to proactive semantic interference, and failure to recover from proactive semantic interference. The advantages of various novel memory assessment paradigms are examined as well as how they compare with traditional neuropsychological assessments of memory. Finally, future directions for the development of more effective assessment paradigms are suggested
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