- Email: [email protected]
Rapid visual categorization as a sensitive measure of early Alzheimer's disease
Poster Presentations: P2 the SUVR threshold defined by spares k-means clustering in any one of six ROIs or by exceeding the SUVR threshold in the global cortical region. Results: Separate ANCOVAs were conducted to compare mental age-adjusted means on each neuropsychological measure for the PiB+ versus PiB- subjects. The PiB+ subjects evidenced significantly lower mean scores on several neuropsychological measures, including executive/working memory, delayed recall, and attention/processing speed. These differences are hypothesized to become more pronounced at follow-up time points. Conclusions: This study provides a unique opportunity to study the preclinical manifestations of AD. Findings may not only provide information that could affect early detection, prevention, and treatment of AD for individuals with DS, but also may offer information that will prove extremely useful for the general population.
P2-253
THE EFFICACY OF THE GENERAL PRACTITIONERS ASSESSMENT OF COGNITION (GPCOG) FOR A BRAZILIAN POPULATION IN A PRIMARY CARE CONTEXT: PRELIMINARY RESULTS
Juliana Yokomizo1, Roseli Gueleri1, Mariana Brand~ao1, Glaucia Martins2, Lais Santos2, Bernardo dos Santos3, M^onica Yassuda4, Cassio Bottino5, 1 Department and Institute of Psychiatry, Hospital of Clınicas, S~ao Paulo, S~ ao Paulo, Brazil; 2Gerontology, School of Arts, Sciences and Humanities, University of S~ ao Paulo, S~ ao Paulo, Brazil; 3Instituto de Matematica e Estatıstica, S~ ao Paulo, Brazil; 4University of S~ao Paulo, S~ao Paulo, Brazil; 5 Old Age Research Group - Department and Institute of Psychiatry, Hospital of Clınicas, S~ ao Paulo, S~ao Paulo, Brazil. Contact e-mail: [email protected] Background: Dementia is one of the main causes of dysfunction among elders. Studies suggest that the prevalence rates are still underestimated in Latin America. The early detection of dementia is a prominent challenge for health services, especially for developing countries with an increasing elder population such as Brazil. GPCOG has been considered one of the promising cognitive screening instruments in other countries and it has not been studied in Brazil. Methods: Thirty-two patients aged 60 years or older [mean age: 76.2(5.6), mean education in years: 3.5(3.9)] attended in a primary care service in S~ao Paulo were invited to participate in the re-
P451
search. All ethic procedures were applied. Exclusion criteria were: severe visual or auditory deficits; depression or delirium diagnosis; the absence of a reliable informant. Participants had heterogeneous cognitive profiles. They were submitted to the GPCOG and the Cambridge Cognitive Test (CAMCOG), which included the Mini Mental Status Examination (MMSE); the informants answered the Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE) and the Bayer Activities of Daily Living (BADL). Pearson correlation coefficient was calculated. Results: Results showed a strong correlation between GPCOG total score and CAMCOG (r ¼ 0.874, p < 0.001), MMSE (r ¼ 0.860, p < 0.001) and a good association with the BADL (r ¼ 0.689, p < 0.001). A weaker but still significant correlation was found with the IQCODE (r ¼ 0.483, p ¼ 0.005). Conclusions: Preliminary results suggest there is convergent validity between the the GPCOG and previously validated cognitive instruments when applied in a primary care setting in Brazil. Some of the limitations of these data are the small sample size and the need to control other variables such as occupational background and sociodemographic characteristics. However these limitations can be addressed with a larger sample.
P2-254
THE KITCHEN PICTURE TEST (KPT): A NEW TEST OF PRACTICAL JUDGMENT
William Mansbach1, Elizabeth MacDougall2, Kristen Clark1, Ryan Mace1, Mansbach Health Tools, LLC, Simpsonville, Maryland, United States; 2 Hood College, Frederick, Maryland, United States. Contact e-mail: [email protected] 1
Background: Judgment can be defined as the capacity to make appropriate decisions, in specific contexts, after careful consideration of available information and probable outcomes. It is an important component of cognition with direct implications for real-world functioning. Judgment is widely recognized as an important "executive function," and deficits in judgment can lead to health risks, safety concerns, and hospitalizations. Surprisingly, relatively few tests of judgment have been developed specifically for older adults-a population particularly vulnerable to executive and functional declines. Methods: The Kitchen Picture Test (KPT) is a new judgment screening instrument for use with older adults. Unlike most tests that are linguistically oriented, the KPT is a visually presented kitchen scene in which there are three "dangerous" situations. Patients must identify them, rate severity, and provide problem-solving solutions. It is based on an eight-point scale, with additional language and visual memory features that are not included as part of the judgment score. A comprehensive score, based on all three features, can also be calculated. Results: Two KPT studies are reported. In Study One, 99 subjects from long-term care facilities participated. Psychometric quality was supported by adequate internal consistency reliability (a ¼ .88) and acceptable construct validity. Convergent validity was supported by positive and significant correlations with the NAB - JDG (a validated subtest of Judgment) (r ¼ .66, p < .001) and a specific executive functioning task (OTMT; r ¼ .62, p < .001). Discriminant validity was supported by non-significant correlations with two depression instruments (CSDD; r ¼ .13 and GDS; r ¼ -.05). In Study Two, data from163 subjects from a nursing home rehabilitation unit and an assisted living community were analyzed. Further evidence of reliability and construct validity was found. The KPT was also found to predict cognitive diagnosis (non-dementia versus dementia), and a cut-score was set to maximize sensitivity (.85) and specificity (.72). The area under the ROC curve was .86. Conclusions: The KPT is a valid judgment screening instrument that has potential value for nursing home and hospital discharge planning, safety assessments, and reducing unnecessary re-hospitalizations.
P2-255
RAPID VISUAL CATEGORIZATION AS A SENSITIVE MEASURE OF EARLY ALZHEIMER’S DISEASE
William Heindel, Elena Festa, Brian Ott, Imri Sofer, Thomas Serre, Brown University, Providence, Rhode Island, United States. Contact e-mail: [email protected]
P452
Poster Presentations: P2
Background: Previous investigations in young adults have demonstrated the remarkable speed with which individuals can accurately process and discriminate different classes of objects within visual scenes, and suggest that such rapid categorization is mediated primarily by feed-forward mechanisms within the ventral visual processing stream. The loss of effective connectivity within the visual system in AD due to disruption of corticocortical projections should produce marked deficits on tasks requiring fast, efficient communication across processing stages within the ventral stream. Given the high demands that ultra rapid categorization tasks place on feed-forward connections within visual cortex, these tasks may prove to be particularly sensitive markers of AD pathology in even the earliest stages of the disease. Methods: Groups of healthy young, healthy elderly, and patients diagnosed with amnestic mild cognitive impairment (MCI) performed a rapid classification task in which participants viewed briefly presented scenes containing natural and artificial objects, and were asked to press a button as quickly as possible if they detected an animal within the scene. Stimulus duration was individually thresholded to produce about 80% accuracy under unmasked conditions. Task difficulty was manipulated by presenting a masking stimulus after the scene at varying temporal intervals (ISI: 14ms, 35ms, no mask), and by varying the focal distance of the target object in the scene (i.e., head, close body, mid-body). Results: Young and elderly controls displayed similar patterns of performance, displaying good discrimination under no mask conditions; decreased but still robust discrimination at 35ms mask (although elderly performed significantly worse than young); and near-chance performance at 14ms mask). In contrast, MCI patients displayed robust classification performance under the no mask conditions but performed at near-chance levels under both masked conditions. Conclusions: Results suggest that, despite neural changes associated with normal aging, feed-forward mechanisms within the ventral visual stream remain relatively intact in healthy elderly. In contrast, impaired performance of the MCI group may reflect subtle disruptions of corticocortical projections within the ventral stream even at the preclinical stage of the disease. These findings serve as a critical first step in the development of a sensitive tool for early detection of neurocognitive changes in AD.
P2-256
PERCEPTUAL BINDING OF AUDIOVISUAL SPEECH INFORMATION IS DISRUPTED AT THE PRECLINICAL STAGE OF ALZHEIMER’S DISEASE
Elena Festa, Andrew Katz, Brian Ott, William Heindel, Brown University, Providence, Rhode Island, United States. Contact e-mail: elena_festa@ brown.edu Background: The McGurk effect is a classic phenomenon in which auditory speech perception is altered by the presence of conflicting visual speech information (lip movements), and reflects audiovisual binding at early stages of speech processing: The effect appears to depend on synchronized activity between auditory and visual cortices mediated by feedback from superior temporal sulcus. The disruption of corticortical connections within these regions in early-stage AD should produce a marked disruption of the McGurk effect. Indeed, a recent study using phonemic stimuli found a reduced McGurk effect in AD patients relative to healthy elderly. This study investigates whether disrupted audiovisual binding is detectable even in preclinical AD patients, and whether performance measures could serve as effective diagnostic markers of the disease. Methods: Groups of healthy young, healthy elderly, and patients diagnosed with amnestic mild cognitive impairment (MCI) watched movie clips of an individual mouthing either words or non-words with the voice providing either consistent or inconsistent audio information, and were asked to report the initial consonant sound of each stimulus they heard. The strength of the perceptual binding was manipulated by using different consonant combinations and lexical relations between the audio and visual information that elicit different degrees of audiovisual binding in healthy young adults. Perception of the isolated auditory and visual components of stimuli was also assessed following the audio-
visual binding task. Results: Both healthy groups displayed robust McGurk effects at levels consistent with the variation in stimulus strength (although elderly showed overall significantly more perceptual binding than young). Despite showing normal perception of the unimodal stimuli, the MCI patient group displayed significantly reduced McGurk effects for the perceptually weaker (but not stronger) audiovisual stimuli, relative to healthy elderly. Conclusions: Results suggest that neural changes associated with normal aging may increase the perceptual binding of audiovisual speech information. The demonstration of reduced audiovisual binding in the MCI group may reflect subtle disruptions of corticocortical projections within unimodal and heteromodal cortexes even at the preclinical stage of the disease. These findings serve as a critical first step in the development of a sensitive tool for early detection of neurocognitive changes in AD. P2-257
VALIDATION OF THE MONTREAL COGNITIVE ASSESSMENT – SPANISH VERSION TEST (MOCAS) AS A SCREENING TOOL FOR MILD COGNITIVE IMPAIRMENT AND MILD DEMENTIA IN BOGOTA, COLOMBIA
Laura Gil, Juan Gomez Vega, Carolina Ruiz de Sanchez, Felipe Pretelt Burgos, Pontificia Universidad Javeriana, Bogota D.C., Colombia. Contact e-mail: [email protected] Background: MoCA test was developed as a brief instrument to screen cognoscitive impairment. This is the first validation in Latin America of MoCA in Spanish (MoCA-S) developed in Colombia. Methods: Study of concordance by conformity to evaluated MoCA test in comparison with gold standard (Diagnostic in consensus of interdisciplinary assessment by Clinic of Memory). Assessment of psychometric properties of MoCA-S with interrater reliability, internal consistency and convergent validity. Results: The internal consistency measure with a Cronbach index was 0,863 value similar to that obtained by the original designers of the MoCA test (Nasreddine et al 2005). The interrater reliability was almost perfect with a concordance coefficient of Lin¼0.903 confidence interval (CI) ¼ 95% (0,78-1.00) and the convergent validity was evaluated by means of the high correlation with the MMSE and the concordance with the gold standard of 85% patients perfectly classified by the test with a nomial kappa index of 0,7 (IC: 0,60-0.79).256 subjects were evaluated (64.4% women), of which 138 were patients and 118 healthy individuals. Patients were divided into two subgroups: MCI¼ 44 and MD ¼ 94. Subjects with cognitive impairment averaged MoCA-S ¼ 17.5 and MMSE ¼ 25.3. The healthy group averaged MoCA-S ¼ 25.39 and MMSE ¼ 28.7. MCI subgroup averaged MoCA-S ¼ 20.9 and MMSE ¼ 27.5 (normal range). MD subgroup showed an average of MoCA-S ¼ 15.4 (abnormal range) and MMSE ¼ 24.4 (normal range). The difference of scores in the subgroups is statistically significant
P2-253
THE EFFICACY OF THE GENERAL PRACTITIONERS ASSESSMENT OF COGNITION (GPCOG) FOR A BRAZILIAN POPULATION IN A PRIMARY CARE CONTEXT: PRELIMINARY RESULTS
Juliana Yokomizo1, Roseli Gueleri1, Mariana Brand~ao1, Glaucia Martins2, Lais Santos2, Bernardo dos Santos3, M^onica Yassuda4, Cassio Bottino5, 1 Department and Institute of Psychiatry, Hospital of Clınicas, S~ao Paulo, S~ ao Paulo, Brazil; 2Gerontology, School of Arts, Sciences and Humanities, University of S~ ao Paulo, S~ ao Paulo, Brazil; 3Instituto de Matematica e Estatıstica, S~ ao Paulo, Brazil; 4University of S~ao Paulo, S~ao Paulo, Brazil; 5 Old Age Research Group - Department and Institute of Psychiatry, Hospital of Clınicas, S~ ao Paulo, S~ao Paulo, Brazil. Contact e-mail: [email protected] Background: Dementia is one of the main causes of dysfunction among elders. Studies suggest that the prevalence rates are still underestimated in Latin America. The early detection of dementia is a prominent challenge for health services, especially for developing countries with an increasing elder population such as Brazil. GPCOG has been considered one of the promising cognitive screening instruments in other countries and it has not been studied in Brazil. Methods: Thirty-two patients aged 60 years or older [mean age: 76.2(5.6), mean education in years: 3.5(3.9)] attended in a primary care service in S~ao Paulo were invited to participate in the re-
P451
search. All ethic procedures were applied. Exclusion criteria were: severe visual or auditory deficits; depression or delirium diagnosis; the absence of a reliable informant. Participants had heterogeneous cognitive profiles. They were submitted to the GPCOG and the Cambridge Cognitive Test (CAMCOG), which included the Mini Mental Status Examination (MMSE); the informants answered the Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE) and the Bayer Activities of Daily Living (BADL). Pearson correlation coefficient was calculated. Results: Results showed a strong correlation between GPCOG total score and CAMCOG (r ¼ 0.874, p < 0.001), MMSE (r ¼ 0.860, p < 0.001) and a good association with the BADL (r ¼ 0.689, p < 0.001). A weaker but still significant correlation was found with the IQCODE (r ¼ 0.483, p ¼ 0.005). Conclusions: Preliminary results suggest there is convergent validity between the the GPCOG and previously validated cognitive instruments when applied in a primary care setting in Brazil. Some of the limitations of these data are the small sample size and the need to control other variables such as occupational background and sociodemographic characteristics. However these limitations can be addressed with a larger sample.
P2-254
THE KITCHEN PICTURE TEST (KPT): A NEW TEST OF PRACTICAL JUDGMENT
William Mansbach1, Elizabeth MacDougall2, Kristen Clark1, Ryan Mace1, Mansbach Health Tools, LLC, Simpsonville, Maryland, United States; 2 Hood College, Frederick, Maryland, United States. Contact e-mail: [email protected] 1
Background: Judgment can be defined as the capacity to make appropriate decisions, in specific contexts, after careful consideration of available information and probable outcomes. It is an important component of cognition with direct implications for real-world functioning. Judgment is widely recognized as an important "executive function," and deficits in judgment can lead to health risks, safety concerns, and hospitalizations. Surprisingly, relatively few tests of judgment have been developed specifically for older adults-a population particularly vulnerable to executive and functional declines. Methods: The Kitchen Picture Test (KPT) is a new judgment screening instrument for use with older adults. Unlike most tests that are linguistically oriented, the KPT is a visually presented kitchen scene in which there are three "dangerous" situations. Patients must identify them, rate severity, and provide problem-solving solutions. It is based on an eight-point scale, with additional language and visual memory features that are not included as part of the judgment score. A comprehensive score, based on all three features, can also be calculated. Results: Two KPT studies are reported. In Study One, 99 subjects from long-term care facilities participated. Psychometric quality was supported by adequate internal consistency reliability (a ¼ .88) and acceptable construct validity. Convergent validity was supported by positive and significant correlations with the NAB - JDG (a validated subtest of Judgment) (r ¼ .66, p < .001) and a specific executive functioning task (OTMT; r ¼ .62, p < .001). Discriminant validity was supported by non-significant correlations with two depression instruments (CSDD; r ¼ .13 and GDS; r ¼ -.05). In Study Two, data from163 subjects from a nursing home rehabilitation unit and an assisted living community were analyzed. Further evidence of reliability and construct validity was found. The KPT was also found to predict cognitive diagnosis (non-dementia versus dementia), and a cut-score was set to maximize sensitivity (.85) and specificity (.72). The area under the ROC curve was .86. Conclusions: The KPT is a valid judgment screening instrument that has potential value for nursing home and hospital discharge planning, safety assessments, and reducing unnecessary re-hospitalizations.
P2-255
RAPID VISUAL CATEGORIZATION AS A SENSITIVE MEASURE OF EARLY ALZHEIMER’S DISEASE
William Heindel, Elena Festa, Brian Ott, Imri Sofer, Thomas Serre, Brown University, Providence, Rhode Island, United States. Contact e-mail: [email protected]
P452
Poster Presentations: P2
Background: Previous investigations in young adults have demonstrated the remarkable speed with which individuals can accurately process and discriminate different classes of objects within visual scenes, and suggest that such rapid categorization is mediated primarily by feed-forward mechanisms within the ventral visual processing stream. The loss of effective connectivity within the visual system in AD due to disruption of corticocortical projections should produce marked deficits on tasks requiring fast, efficient communication across processing stages within the ventral stream. Given the high demands that ultra rapid categorization tasks place on feed-forward connections within visual cortex, these tasks may prove to be particularly sensitive markers of AD pathology in even the earliest stages of the disease. Methods: Groups of healthy young, healthy elderly, and patients diagnosed with amnestic mild cognitive impairment (MCI) performed a rapid classification task in which participants viewed briefly presented scenes containing natural and artificial objects, and were asked to press a button as quickly as possible if they detected an animal within the scene. Stimulus duration was individually thresholded to produce about 80% accuracy under unmasked conditions. Task difficulty was manipulated by presenting a masking stimulus after the scene at varying temporal intervals (ISI: 14ms, 35ms, no mask), and by varying the focal distance of the target object in the scene (i.e., head, close body, mid-body). Results: Young and elderly controls displayed similar patterns of performance, displaying good discrimination under no mask conditions; decreased but still robust discrimination at 35ms mask (although elderly performed significantly worse than young); and near-chance performance at 14ms mask). In contrast, MCI patients displayed robust classification performance under the no mask conditions but performed at near-chance levels under both masked conditions. Conclusions: Results suggest that, despite neural changes associated with normal aging, feed-forward mechanisms within the ventral visual stream remain relatively intact in healthy elderly. In contrast, impaired performance of the MCI group may reflect subtle disruptions of corticocortical projections within the ventral stream even at the preclinical stage of the disease. These findings serve as a critical first step in the development of a sensitive tool for early detection of neurocognitive changes in AD.
P2-256
PERCEPTUAL BINDING OF AUDIOVISUAL SPEECH INFORMATION IS DISRUPTED AT THE PRECLINICAL STAGE OF ALZHEIMER’S DISEASE
Elena Festa, Andrew Katz, Brian Ott, William Heindel, Brown University, Providence, Rhode Island, United States. Contact e-mail: elena_festa@ brown.edu Background: The McGurk effect is a classic phenomenon in which auditory speech perception is altered by the presence of conflicting visual speech information (lip movements), and reflects audiovisual binding at early stages of speech processing: The effect appears to depend on synchronized activity between auditory and visual cortices mediated by feedback from superior temporal sulcus. The disruption of corticortical connections within these regions in early-stage AD should produce a marked disruption of the McGurk effect. Indeed, a recent study using phonemic stimuli found a reduced McGurk effect in AD patients relative to healthy elderly. This study investigates whether disrupted audiovisual binding is detectable even in preclinical AD patients, and whether performance measures could serve as effective diagnostic markers of the disease. Methods: Groups of healthy young, healthy elderly, and patients diagnosed with amnestic mild cognitive impairment (MCI) watched movie clips of an individual mouthing either words or non-words with the voice providing either consistent or inconsistent audio information, and were asked to report the initial consonant sound of each stimulus they heard. The strength of the perceptual binding was manipulated by using different consonant combinations and lexical relations between the audio and visual information that elicit different degrees of audiovisual binding in healthy young adults. Perception of the isolated auditory and visual components of stimuli was also assessed following the audio-
visual binding task. Results: Both healthy groups displayed robust McGurk effects at levels consistent with the variation in stimulus strength (although elderly showed overall significantly more perceptual binding than young). Despite showing normal perception of the unimodal stimuli, the MCI patient group displayed significantly reduced McGurk effects for the perceptually weaker (but not stronger) audiovisual stimuli, relative to healthy elderly. Conclusions: Results suggest that neural changes associated with normal aging may increase the perceptual binding of audiovisual speech information. The demonstration of reduced audiovisual binding in the MCI group may reflect subtle disruptions of corticocortical projections within unimodal and heteromodal cortexes even at the preclinical stage of the disease. These findings serve as a critical first step in the development of a sensitive tool for early detection of neurocognitive changes in AD. P2-257
VALIDATION OF THE MONTREAL COGNITIVE ASSESSMENT – SPANISH VERSION TEST (MOCAS) AS A SCREENING TOOL FOR MILD COGNITIVE IMPAIRMENT AND MILD DEMENTIA IN BOGOTA, COLOMBIA
Laura Gil, Juan Gomez Vega, Carolina Ruiz de Sanchez, Felipe Pretelt Burgos, Pontificia Universidad Javeriana, Bogota D.C., Colombia. Contact e-mail: [email protected] Background: MoCA test was developed as a brief instrument to screen cognoscitive impairment. This is the first validation in Latin America of MoCA in Spanish (MoCA-S) developed in Colombia. Methods: Study of concordance by conformity to evaluated MoCA test in comparison with gold standard (Diagnostic in consensus of interdisciplinary assessment by Clinic of Memory). Assessment of psychometric properties of MoCA-S with interrater reliability, internal consistency and convergent validity. Results: The internal consistency measure with a Cronbach index was 0,863 value similar to that obtained by the original designers of the MoCA test (Nasreddine et al 2005). The interrater reliability was almost perfect with a concordance coefficient of Lin¼0.903 confidence interval (CI) ¼ 95% (0,78-1.00) and the convergent validity was evaluated by means of the high correlation with the MMSE and the concordance with the gold standard of 85% patients perfectly classified by the test with a nomial kappa index of 0,7 (IC: 0,60-0.79).256 subjects were evaluated (64.4% women), of which 138 were patients and 118 healthy individuals. Patients were divided into two subgroups: MCI¼ 44 and MD ¼ 94. Subjects with cognitive impairment averaged MoCA-S ¼ 17.5 and MMSE ¼ 25.3. The healthy group averaged MoCA-S ¼ 25.39 and MMSE ¼ 28.7. MCI subgroup averaged MoCA-S ¼ 20.9 and MMSE ¼ 27.5 (normal range). MD subgroup showed an average of MoCA-S ¼ 15.4 (abnormal range) and MMSE ¼ 24.4 (normal range). The difference of scores in the subgroups is statistically significant