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Joel Eppig,
Denene Wambach,
Christine Nieves,
Catherine C Price,
Melissa Lamar,
Lisa Delano-Wood,
Tania Giovannetti,
Brianne M Bettcher, Dana L Penney,
Rod Swenson,
Carol Lippa,
Anahid Kabasakalian,
Mark W Bondi,
David J Libon
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ABSTRACT: Libon et al. (2010) provided evidence for three statistically determined clusters of patients with mild cognitive impairment (MCI): amnesic (aMCI), dysexecutive (dMCI), and mixed (mxMCI). The current study further examined dysexecutive impairment in MCI using the framework of Fuster's (1997) derailed temporal gradients, that is, declining performance on executive tests over time or test epoch. Temporal gradients were operationally defined by calculating the slope of aggregate letter fluency output across 15-s epochs and accuracy indices for initial, middle, and latter triads from the Wechsler Memory Scale-Mental Control subtest (Boston Revision). For letter fluency, slope was steeper for dMCI compared to aMCI and NC groups. Between-group Mental Control analyses for triad 1 revealed worse dMCI performance than NC participants. On triad 2, dMCI scored lower than aMCI and NCs; on triad 3, mxMCI performed worse versus NCs. Within-group Mental Control analyses yielded equal performance across all triads for aMCI and NC participants. mxMCI scored lower on triad 1 compared to triads 2 and 3. dMCI participants also performed worse on triad 1 compared to triads 2 and 3, but scored higher on triad 3 versus triad 2. These data suggest impaired temporal gradients may provide a useful heuristic for understanding dysexecutive impairment in MCI.
Journal of the International Neuropsychological Society 01/2012; 18(1):20-8. · 2.76 Impact Factor
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David J Libon,
Mark W Bondi,
Catherine C Price,
Melissa Lamar,
Joel Eppig,
Denene M Wambach,
Christine Nieves,
Lisa Delano-Wood,
Tania Giovannetti,
Carol Lippa,
Anahid Kabasakalian,
Stephanie Cosentino,
Rod Swenson, Dana L Penney
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ABSTRACT: Using cluster analysis Libon et al. (2010) found three verbal serial list-learning profiles involving delay memory test performance in patients with mild cognitive impairment (MCI). Amnesic MCI (aMCI) patients presented with low scores on delay free recall and recognition tests; mixed MCI (mxMCI) patients scored higher on recognition compared to delay free recall tests; and dysexecutive MCI (dMCI) patients generated relatively intact scores on both delay test conditions. The aim of the current research was to further characterize memory impairment in MCI by examining forgetting/savings, interference from a competing word list, intrusion errors/perseverations, intrusion word frequency, and recognition foils in these three statistically determined MCI groups compared to normal control (NC) participants. The aMCI patients exhibited little savings, generated more highly prototypic intrusion errors, and displayed indiscriminate responding to delayed recognition foils. The mxMCI patients exhibited higher saving scores, fewer and less prototypic intrusion errors, and selectively endorsed recognition foils from the interference list. dMCI patients also selectively endorsed recognition foils from the interference list but performed similarly compared to NC participants. These data suggest the existence of distinct memory impairments in MCI and caution against the routine use of a single memory test score to operationally define MCI.
Journal of the International Neuropsychological Society 09/2011; 17(5):905-14. · 2.76 Impact Factor
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ABSTRACT: Clock drawing is part of the Montreal Cognitive Assessment (MoCA) test but may have administration and scoring limitations. We assessed (1) the reliability of the MoCA clock criteria relative to a published error scoring approach, (2) whether command-only administration could distinguish dementia from cognitively intact individuals and (3) the value of adding a clock copy condition to the MoCA.
Three novice raters and clocks from dementia and control participants were used to assess the 3 aims.
MoCA interrater and intrarater reliability were low (i.e. intraclass correlation coefficient = 0.12-0.31) and required repeat training. Clocks drawn to command classified dementia at chance. Inclusion of a copy condition demonstrated expected dementia subgroup patterns.
Reliable clock scoring with MoCA criteria requires practice. Supplementing a clock copy to the standard MoCA test (takes <1 min) will improve dementia assessment.
Dementia and Geriatric Cognitive Disorders 03/2011; 31(3):179-87. · 2.14 Impact Factor
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ABSTRACT: Dementia research suggests executive dysfunction is best understood within the context of disease-specific neuropathology. Leukoaraiosis (LA) results in executive dysfunction yet little is known about its impact on specific aspects of working memory (WM). This study aimed to investigate the relationship between MRI LA severity and WM in dementia. A visual rating scale was used to assign patients with dementia into groups with minimal-mild LA (Low LA; n=34) and moderate-severe LA (High LA; n=32). A modified Digit Span Backward Task consisting of 3-, 4-, and 5-span trials measured specific components of WM. Short-term storage and rehearsal in WM were assessed by the total number of digits reported regardless of recall order (ANY-ORDER; e.g., 47981 recalled '18943', score=4). Mental manipulation in the form of disengagement and temporal re-ordering was assessed by the total number of digits recalled in correct position (SERIAL-ORDER; e.g., 47981 recalled '18943', score=3). There was no difference between LA groups on ANY-ORDER comparisons. The High LA group obtained lower SERIAL-ORDER scores than the Low LA group. Stepwise regression analyses were conducted that first entered MMSE scores then composite z-scores reflecting executive functioning, language and memory. ANY-ORDER performance variance was explained solely by dementia severity. SERIAL-ORDER performance variance was further explained by executive dysfunction. Results suggest that high degrees of LA do not interfere with immediate (digit) recall but do interfere with disengagement and temporal re-ordering. LA may disconnect the frontal lobes from subcortical and cortical structures that form the neuronal networks critical for these WM functions.
Neuropsychologia 02/2007; 45(2):245-54. · 3.64 Impact Factor
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ABSTRACT: Our orientation regarding the dementias has changed during the past 30 yr. For example, in the not too distant past, illnesses
such as Alzheimer’s disease (AD) and Pick’s disease were believed to be rare, if not obscure, illnesses (1). This viewpoint is juxtaposed to contemporaneous ideas put forth by Katzman and colleagues (2) who believed that AD was not only prevalent but represented a major public health problem. During the past 10 yr, the diagnosis
of dementia has become increasingly complex, requiring the consideration of an array of conditions, including AD, vascular
dementia (VaD), dementia with Lewy body (DLB), frontal-temporal dementia (FTD), cortical basilar degeneration (CBD), and subcortical
dementias, such as progressive supernuclear palsy (PSP) and Parkinson’s disease.
12/2004: pages 281-293;
