Journal of clinical and experimental neuropsychology
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J Clin Exp Neuropsychol · Jan 2013
The adverse impact of type 2 diabetes on brain volume in heart failure.
Heart failure (HF) is associated with structural brain abnormalities, including atrophy in multiple brain regions. Type 2 diabetes mellitus (T2DM) is a prevalent comorbid condition in HF and is associated with abnormalities on neuroimaging in other medical and elderly samples. The current study examined whether comorbid T2DM exacerbates brain atrophy in older adults with HF. ⋯ T2DM is associated with smaller total and cortical lobar brain volumes in patients with HF, and these structural brain indices were associated with cognitive test performance. Prospective studies that directly monitor glucose levels are needed to confirm our findings and clarify the mechanisms by which T2DM adversely impacts brain atrophy in this population.
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J Clin Exp Neuropsychol · Jan 2013
Development of normative neuropsychological performance in Thailand for the assessment of HIV-associated neurocognitive disorders.
International studies of HIV-associated neurocognitive disorder (HAND) are needed to determine the viral and host factors associated with cognitive impairment particularly as more than 80% of HIV+ subjects reside in resource-limited settings. Recent diagnostic nomenclature of HAND requires comparison of cognitive performance specifically to local normative data. To evaluate this need for local norms, we compared normative data obtained locally in Thailand to Western norms. ⋯ Education was a more powerful predictor of performance in the Thai cohort than in the US group. These results highlight the continued need for the development of normative data within local populations. The use of Western norms as a comparison group could lead to inaccurate identification of HAND in culturally distinct groups.
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We examined the role of orbitofrontal (OF) cortex in regulating emotion-attention interaction and the balance between involuntary and voluntary attention allocation. We studied patients with OF lesion applying reaction time (RT) and event-related potential (ERP) measures in a lateralized visual discrimination task with novel task-irrelevant affective pictures (unpleasant, pleasant, or neutral) preceding a neutral target. This allowed for comparing the effects of automatic attention allocation to emotional versus neutral stimuli on subsequent voluntary attention allocation to target stimuli. ⋯ Specifically, OF patients responded faster to LVF targets subsequent to pleasant emotional distractors. We suggest that damage to the orbitofrontal circuitry leads to dysbalance between voluntary and involuntary attention allocation in the context of affective distractors with predisposition to posterior target-related processing over frontal novelty and affect-related processing. Furthermore, we suggest that orbitofrontal influence on emotion-attention interaction is valence and hemisphere dependent.
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J Clin Exp Neuropsychol · Jan 2012
Profiles of cognitive subtest impairment in the Montreal Cognitive Assessment (MoCA) in a research cohort with normal Mini-Mental State Examination (MMSE) scores.
The comparative ability of the Montreal Cognitive Assessment (MoCA) and MMSE to detect mild cognitive difficulties was investigated in 107 older adults. The sensitivity of the MoCA to detect cognitive impairment with a cutoff score of <26 was investigated, as compared to the MMSE across all scores, and at a cutoff of ≥27. ⋯ The MoCA detected cognitive impairment not detected by the MMSE in a high proportion of participants, and this impairment was evident across various subtests. The MoCA appears to be a sensitive screening test for detection of early cognitive impairment.
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J Clin Exp Neuropsychol · Jan 2012
Influence of poor effort on neuropsychological test performance in U.S. military personnel following mild traumatic brain injury.
The purpose of this study was to examine the influence of poor effort on neuropsychological test performance in military personnel following mild traumatic brain injury (MTBI). Participants were 143 U. S. service members who sustained a TBI, divided into three groups based on injury severity and performance on the Word Memory Test and four embedded markers of poor effort: MTBI-pass (n = 87), MTBI-fail (n = 21), and STBI-pass (n = 35; where STBI denotes severe TBI). ⋯ There were a greater number of elevated scales (e.g., 5 or more elevated mild or higher) in the MTBI-fail group (71.4%) than in the MTBI-pass group (32.2%) and Severe TBI-Pass group (17.1%). Effort testing is an important component of postacute neuropsychological evaluations following combat-related MTBI. Those who fail effort testing are likely to be misdiagnosed as having severe cognitive impairment, and their symptom reporting is likely to be inaccurate.