Tania Giovannetti

Naturalistic action impairments in dementia

Naturalistic actions are everyday tasks (e.g. cooking) that require one to use multiple objects and sequence steps to achieve a goal. Naturalistic action impairment has been attributed to executive dysfunction [Higher cortical functions in man. New York: Basic Books, 1966], semantic knowledge degradation [Brain 111 (1988) 1173], and, more recently, general limitations in cognitive resources [Neuropsychology 12 (1998) 13]. Action impairments were explored in 51 dementia participants with the short form of the multi-level action test (MLAT-S). A clinical neuropsychological test protocol was also administered. Regression analyses including measures of executive functioning, semantic knowledge, and global cognitive functioning showed that global cognitive functioning was the best predictor of MLAT-S errors. Furthermore, task demands significantly influenced the type and frequency of errors, and dementia participants showed a pattern of errors similar to that reported in other clinical populations [Cognitive Neuropsychology 15 (1998) 617; Neuropsychologia 37 (1999) 51; Neuropsychology 12 (1998) 13]. Taken together, the present findings are inconsistent with semantic and executive accounts, but support the limited-capacity resource theory of naturalistic action impairment.

Stroke After Aortic Valve Surgery Results From a Prospective Cohort

Background— The incidence and impact of clinical stroke and silent radiographic cerebral infarction complicating open surgical aortic valve replacement (AVR) are poorly characterized. Methods and Results— We performed a prospective cohort study of subjects ≥65 years of age who were undergoing AVR for calcific aortic stenosis. Subjects were evaluated by neurologists preoperatively and postoperatively and underwent postoperative magnetic resonance imaging. Over a 4-year period, 196 subjects were enrolled at 2 sites (mean age, 75.8±6.2 years; 36% women; 6% nonwhite). Clinical strokes were detected in 17%, transient ischemic attack in 2%, and in-hospital mortality was 5%. The frequency of stroke in the Society for Thoracic Surgery database in this cohort was 7%. Most strokes were mild; the median National Institutes of Health Stroke Scale was 3 (interquartile range, 1–9). Clinical stroke was associated with increased length of stay (median, 12 versus 10 days; P=0.02). Moderate or severe stroke (National Institutes of Health Stroke Scale ≥10) occurred in 8 (4%) and was strongly associated with in-hospital mortality (38% versus 4%; P=0.005). Of the 109 stroke-free subjects with postoperative magnetic resonance imaging, silent infarct was identified in 59 (54%). Silent infarct was not associated with in-hospital mortality or increased length of stay. Conclusions— Clinical stroke after AVR was more common than reported previously, more than double for this same cohort in the Society for Thoracic Surgery database, and silent cerebral infarctions were detected in more than half of the patients undergoing AVR. Clinical stroke complicating AVR is associated with increased length of stay and mortality.Background— The incidence and impact of clinical stroke and silent radiographic cerebral infarction complicating open surgical aortic valve replacement (AVR) are poorly characterized. Methods and Results— We performed a prospective cohort study of subjects ≥65 years of age who were undergoing AVR for calcific aortic stenosis. Subjects were evaluated by neurologists preoperatively and postoperatively and underwent postoperative magnetic resonance imaging. Over a 4-year period, 196 subjects were enrolled at 2 sites (mean age, 75.8±6.2 years; 36% women; 6% nonwhite). Clinical strokes were detected in 17%, transient ischemic attack in 2%, and in-hospital mortality was 5%. The frequency of stroke in the Society for Thoracic Surgery database in this cohort was 7%. Most strokes were mild; the median National Institutes of Health Stroke Scale was 3 (interquartile range, 1–9). Clinical stroke was associated with increased length of stay (median, 12 versus 10 days; P =0.02). Moderate or severe stroke (National Institutes of Health Stroke Scale ≥10) occurred in 8 (4%) and was strongly associated with in-hospital mortality (38% versus 4%; P =0.005). Of the 109 stroke-free subjects with postoperative magnetic resonance imaging, silent infarct was identified in 59 (54%). Silent infarct was not associated with in-hospital mortality or increased length of stay. Conclusions— Clinical stroke after AVR was more common than reported previously, more than double for this same cohort in the Society for Thoracic Surgery database, and silent cerebral infarctions were detected in more than half of the patients undergoing AVR. Clinical stroke complicating AVR is associated with increased length of stay and mortality. # CLINICAL PERSPECTIVE {#article-title-47}

Characterization of Everyday Functioning in Mild Cognitive Impairment: A Direct Assessment Approach

Aims: To evaluate the degree and pattern of functional difficulties in mild cognitive impairment (MCI) via direct observation of everyday task performance. Methods: MCI (n = 25), mild Alzheimer’s disease (AD; n = 25), and control (n = 18) participants performed three everyday tasks of increasing complexity. Results: Although caregivers reported no functional difficulties in MCI, direct observation measures of overall impairment and total errors showed MCI participants performed worse than controls, but better than AD participants, even on simple tasks. MCI and control participants exhibited significantly more difficulty performing steps accurately (i.e. commission errors) than completing task steps (i.e. omission errors), but AD participants showed an even distribution of commissions and omissions. Conclusions: Diagnostic criteria for MCI should specify mild functional deficits due to the inefficient and imprecise execution of task steps. Functional deficits characterized by omission of major task segments may indicate a diagnosis of dementia.

Coffee With Jelly or Unbuttered Toast: Commissions and Omissions Are Dissociable Aspects of Everyday Action Impairment in Alzheimer's Disease

Relative to our understanding of the memory and language deficits associated with Alzheimers disease (AD), little is known about problems with everyday action performance (i.e., meal preparation, grooming). The resource theory proposes that everyday action problems are best explained by a unitary deficit in general cognitive resources. However, recent research suggests that omission and commission errors may reflect dissociable aspects of action impairment, with only omissions associated with resource limitations. This study examined everyday action performance in 70 participants with AD who also underwent a neuropsychological evaluation. First, correlation and principal component analyses were performed to examine the construct(s) that might explain everyday action impairment. Second, relations between everyday task component(s) and neuropsychological tests were examined by using correlation and regression analyses. Third, differences in everyday action error patterns were examined among participants of comparable overall impairment levels. Results showed omission and commission errors were uncorrelated and distinct components of everyday action performance, predicted by different neuropsychological tests, and differentially distributed even among participants with comparable overall impairment.

The neuropsychological profile of alcohol-related dementia suggests cortical and subcortical pathology.

The neuropathology associated with chronic alcohol abuse varies across studies, though research suggests generalized reductions in cortical and subcortical grey and white matter. Neuropsychological findings also differ within the literature. The inconsistent findings with respect to the neuropathology and neurobehavior of patients with histories of alcohol abuse may be due, at least in part, to differing nosology and the highly variable inclusion/exclusion criteria employed by researchers. Oslin et al. [Int J Geriatr Psychiatry 1998;13:203–212] have proposed and recently validated specific criteria for probable alcohol-related dementia (ARD). We were interested in comparing the neuropsychological profile of ARD patients with the neurocognitive profiles of typical cortical and subcortical dementia patients. Participants included 14 ARD patients, 15 patients diagnosed with Alzheimer’s disease (AD), 13 patients diagnosed with subcortical vascular dementia (VaD), and 20 normal controls. Patient subgroups were similar with respect to age (mean = 79), education (mean = 12 years) and dementia severity (MMSE; mean = 22.1). The three dementia patient subgroups demonstrated significantly worse performance than the normal controls subgroup on all neuropsychological tests. The ARD subgroup exhibited very similar executive control deficits to VaD patients. However, the different neurocognitive profiles of the patient subgroups suggest that ARD patients may also, in fact, demonstrate some degree of amnesia given that they perform slightly worse than subcortical patients on delayed verbal free recall and recognition. Nonetheless, the ARD patients did not display as severe impairment as the AD patients on the memory tasks. No significant differences between the three patient groups were identified on language tests. In sum, we present preliminary evidence of a distinct neuropsychological profile for ARD patients that includes impairment on both executive control and memory tests. This pattern of performance suggests that long-term alcohol abuse, in comparison to AD and VaD, may be associated with both cortical and subcortical neuropathology.

Verbal Serial List Learning in Mild Cognitive Impairment: A Profile Analysis of Interference, Forgetting, and Errors

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.

Awareness of naturalistic action errors in dementia.

Unawareness of deficit is a common feature of degenerative dementia. The present study explored awareness and correction of naturalistic action errors in 54 dementia participants and 10 healthy controls while they performed a series of everyday tasks, such as toast preparation and gift-wrapping. Awareness for everyday task performance and cognitive functioning was also assessed with questionnaire discrepancy scores, and a neuropsychological test protocol was administered. Dementia participants were aware of and corrected a significantly smaller proportion of errors compared to controls (z = -4.59, p < .001). Awareness and correction of action errors was not significantly correlated with the number of naturalistic errors committed, questionnaire discrepancy scores, or neuropsychological test data. Within-group analyses showed awareness differed across error types, such that participants were aware of a greater proportion of substitution and sequence errors compared to omissions, perseverations, and action addition (i.e., utilization behavior) errors (z < or = -3.2, p < or = .002 for all analyses). Taken together these data suggest that error awareness and correction during the course of action is not related to error production or awareness measured via questionnaire discrepancy scores. Rather, direct assessment of error detection and correction may provide novel information about behavioral monitoring that can not be extrapolated from measures of dementia severity or traditional neuropsychological assessment.

Environmental Adaptations Improve Everyday Action Performance in Alzheimer's Disease: Empirical Support From Performance-Based Assessment

Neuropsychologists often recommend that patients with dementia and their caregivers use environmental adaptations to improve everyday functioning. Although these recommendations are intuitive (e.g., reduce clutter), most have never been experimentally tested. This study examined whether and how environmental adaptations improved everyday action in Alzheimers disease (AD). Forty-six outpatients completed the Naturalistic Action Test (NAT; M. F. Schwartz, L. J. Buxbaum, M. Ferraro, T. Veramonti, & M. Segal, 2003), which requires completion of 3 everyday tasks. The NAT was administered under 2 conditions: standard and user centered. The standard NAT followed the procedures of the manual; object placement was standardized, but objects were not meaningfully arranged on the tabletop. In the user-centered NAT, objects were arranged in the order needed in the task, and a visual cue to monitor performance was placed on the table. These conditions were counterbalanced across participants. The user-centered condition improved performance on all NAT items and reduced commission and omission error rates. However, post hoc examination of commission error types showed improvement of substitution and off-task errors but no difference in anticipation and perseveration errors. Thus, environmental adaptations improved everyday performance in AD by facilitating task accomplishment, object selection, and task-congruent actions.

LEUKOARAIOSIS SEVERITY AND LIST-LEARNING IN DEMENTIA

In patients with dementia, leukoaraiosis (LA) was hypothesized to result in differential patterns of impairment on a verbal serial list-learning test. Using a visual rating scale, 144 dementia patients with ischemic scores <4 were re-categorized as having mild (n = 73), moderate (n = 44), or severe LA (n = 27). Mild LA was predicted to be associated with an amnestic list-learning profile, while severe LA was predicted to be associated with a dysexecutive profile. List-learning performances were standardized to a group of healthy older adults (n = 24). Analyses were conducted on a set of four factors derived from the list-learning paradigm, as well as error scores. Data indicate that LA severity is an important marker for understanding list learning in dementia.

Linking MRI Hyperintensities With Patterns of Neuropsychological Impairment: Evidence for a Threshold Effect

Background and Purpose— Leukoaraiosis (LA) might interrupt intra- and interhemispheric communication and thus induce cognitive impairments and dementia. It remains unclear, however, if there is a volume threshold of LA that is needed before either the signs of dementia and/or a specific pattern of neuropsychological impairment become manifest. Roman et al has suggested that 25% of white matter may need to be involved before white matter alterations influence the clinical signs associated with dementia. The purpose of this study is to ascertain the threshold of MRI-LA as measured with a visual rating scale needed to induce specific patterns of neuropsychological impairment associated with dementia. Methods— One hundred fifteen patients with dementia received a comprehensive neuropsychological examination and the severity of MRI-LA was measured using a 40-point LA scale. Results— Patients were categorized into low (mean LA=4.21±2.92; 3.22%–17.82%), moderate (mean LA=12.58±2.54; 25.01%–37.80%), and severe (mean LA=22.36±4.04; 45.80%–66.00%) LA groups. Patients in the mild LA group obtained markedly lower scores on tests of episodic memory compared with working memory, a neuropsychological profile often associated with Alzheimer disease. Patients with moderate LA displayed equal impairment on neuropsychological tests. Patients in the severe LA group obtained significantly lower scores on tests of working memory as compared with episodic memory. Conclusions— These data provide evidence that a threshold of moderate MRI-LA as measured with a visual rating scale is associated with greater and/or equal impairment on tests of working memory versus episodic memory and provides a benchmark to assess the effect of MRI-LA on the clinical presentation of dementia.