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Niels Peter Nielsen, M.D. & Elisabeth H. Wiig, Ph.D. AQT Cognitive Speed Differentiates Adults With and Without ADHD: A Preminilary Study (.pdf)
Intern. Conf. ADHD Berlin, May 2011
   
Niels Peter Nielsen, M.D. & Elisabeth H. Wiig, Ph.D. Comparitive Effects of Methylphenidate and Atomoxetine on AQT Processing Speed & Efficiency: Preliminary Findings (.pdf)
Intern. Conf. ADHD Berlin, May 2011
   
Elisabeth H. Wiig, Ph.D. Is Dual-Task Processing Speed for Non-Symbolic Visual Input an Inherent or a Learned Capacity?
2010 International Association for Research on Learning Disabilities Conference, Miami, FL.

Objective: After a decade of research of individuals with normal and non-normal cognitive speed (i.e., rapid color-form naming), two questions still beg to be addressed: Is cognitive speed determined by inherent neurological factors, by education or by a combination of these? Is cognitive speed predictive of later reading comprehension and reading fluency? The objective is to present a retrospective overview of research of cognitive speed, measured by rapid color-form combination naming, in normal and non-normal populations. The significance of this retrospective review resides in the fact that similar color, form and color-form naming tests were administered to (a) normally developing children and adults (ages 5–85), (b) speakers of different languages and with different levels of education, (c) children with language disorders, and (d) patient groups with well-defined neurological disorders. This allows for forming preliminary hypotheses of factors that influence processing speed and automaticity and for suggesting directions for future studies.

Methods: We present and compare cognitive-speed data from research of (a) more than 1,000 children with normal language development, (b) children with language disorders (English and Spanish speaking) ages 5 to 17-21, (c) 300 normally aging adults ages 15 to 85, and(c) adult patients with ADHD and dementia. All were administered the color, form and color-form naming tests from A Quick Test of Cognitive Speed (AQT).

Results:The results of normally developing children and normally aging adults indicated that there are inter-individual variations in cognitive speed and that the variability decreases with age from age 5 to 15 and remains essentially stable until age 85. We will show that the pattern of increase in AQT cognitive speed is similar in normally developing English- and Spanish-speaking children between ages 5 to 14-15 years. Cognitive speed remains stable between ages 15 and 85 years in normally aging adults with a minimal average reduction in speed of 1 sec. per decade. In studies of normal adult speakers of Krio in Western Africa and of Arabic in Jordan, literate adults (Grade 8+) showed greater cognitive speed than their non-literate/illiterate peers. Cognitive speed is similarly reduced in English- and Spanish-speaking children with severe specific language impairments. AQT cognitive speed is reduced in adults with untreated ADHD, mild-to moderate Alzheimer’s disease and dementia with Lewy bodies and responds to medication in these neurological conditions.

Conclusions: The combined findings suggest an inherent neurological basis for cognitive speed as measured by AQT color-form naming. The cross-cultural studies suggest that education is a secondary factor in the acquisition of cognitive speed. The findings support observations that perceptual speed/automaticity, measured by rapid naming of single dimension stimuli, is highly predictive of early reading acquisition. However, cognitive speed may be more closely related to integration of fluency and comprehension in later reading.


Niels Peter Nielsen, M.D. & Elisabeth H. Wiig, Ph.D.

2010 International association for Research on Learning Disabilities Conference, Miami, FL.

Monitoring the Effects of Medication in Adults with ADHD with A Quick Test of Cognitive Speed: An Exploratory Study.
Background: Clinical psychiatric practice lacks a rapid, objective measure to quantify the effects of, among others, CNS stimulant medication longitudinally. Prior research with A Quick Test of Cognitive Speed (AQT) processing-speed measures suggested their potential for monitoring the effects of medication for attention-deficit/hyperactivity disorder (ADHD).

Research Aims: To evaluate the use of AQT processing-speed measures to monitor CNS medication effects in adult patients with ADHD in a descriptive, longitudinal study.

Methods: Twenty consecutively referred adults, ages 20 to 53, were evaluated weekly-to-biweekly with AQT processing-speed tests during pharmacological treatment of ADHD. Three AQT processing-speed tasks (color-form, color-number and color-letter naming), each consisting of three separate tests, were used as clinical measures. Test 1 is a single-dimension test that requires naming of the color of 40 randomly sequenced squares (black, blue, red, yellow). Test 2 is a single-dimension test that requires naming of 40 randomly sequenced, black stimuli consisting of either forms (circle, square, line, triangle), numbers (2, 4, 5, 7) or letters (a, b, e, k, m, o, p, t). Test 3 is a dual-dimension test that requires naming first the color and then the form, number or letter in 40 stimulus combinations. Tests 1 and 2 measure perceptual speed (i.e., reaction + retrieval + response time). Test 3 measures cognitive speed (i.e., perceptual speed + cognitive overhead from attentional, working memory and set-shifting demands).

Results: At intake, AQT dual-dimension color-form, color-number and color-letter naming times fell predominantly in the slower-than-normal range compared to normative data, indicating significant deficits in cognitive speed. At stabilization after medication, naming times for these tests decreased (i.e., cognitive speed increased) to within normal limits for the majority of patients. One-way ANOVA indicated significant pre-and post-differences for patients who were untreated at intake. When the tests were given more than once at intake there was considerable fluctuation in cognitive speed. At stabilization fluctuations were insignificant. We will present four representative case studies to illustrate the trajectory of the processing-speed measures associated with specific medications (Ritalin, Motiron, Concerta, Strattera).

Conclusions: This study appears to be a first in evaluating the effects of pharmacological treatment of ADHD longitudinally in adults receiving outpatient psychiatric services. The study has acknowledged limitations due to its pragmatic and applied-clinical nature. First, five patients received medication at intake so that no accurate measures of AQT perceptual or cognitive speed could be obtained for an intake baseline. Secondly, the time intervals between office visits were not consistent and varied between one and close to three weeks. Lastly, insufficient lack of control of potentially significant variables did not allow for statistical analyses to identify the significance of group changes in main factors or interactions between factors between intake and stabilization. Whereas we consider the findings preliminary, the individual patient records suggest that a longitudinal follow-up study with strictly controlled variables (e.g., a priori intake criteria, set time intervals, etc.) may prove of clinical value for determining the effects of the pharmacological treatment of ADHD.
 

Fumi Takahashi, Shuichi Awata, Motoyasu Yamashita, Setsu Fukushima, Saori Fujiwara, Elisabeth H. Wiig, Niels Peter Nielsen, Lennart Minthon

2009 International Psychogeriatric Association, 14th International Congress, Montreal, Canada

A Quick Test of Cognitive Speed as a screening tool for elderly Japanese patients with early stage of dementia: A validation study

Background: Recent advances in the treatment of Alzheimer’s disease (AD), in particular at the early phase, has focused on the need for a simplified screening test to positively identify early-stage AD patients. Although neuroimaging techniques and neuropsychological tests can be employed and are effective in identifying AD, positive detection in the pre-dementia stage known as mild cognitive impairment (MCI) often presents diagnostic difficulties. A Quick Test of Cognitive Speed (AQT) is a novel screening test designed to assess perceptual (i.e., reaction + response time) and cognitive speed (i.e., perceptual speed + cognitive overhead from demands on attention, working memory and set-shifting). The AQT color-form naming consists of three sets of stimuli (colors, forms, and color-form combinations). The clinical outcome of the AQT is measured by time (seconds) it takes to name each stimuli page. It has been validated as an effective screening tool for patients with early stage dementia in English, Spanish, Scandinavian, and Greek speaking countries. The aim of this study, the first to be conducted in Asia, is to evaluate the validity of the AQT as a screening tool to detect early stage of dementia in elderly Japanese patients.
 

Materials and Methods--

Subjects: A total of 280 subjects, comprised of 180 AD patients based on NINCDS-ADRDA and DSM-IV criteria, 43 amnestic MCI patients, 32 non-amnestic MCI patients, and 25 controls consisting of patients’ family members were selected for this study. MCI was defined as follows: (1) the subject is neither normal nor demented, (2) there is evidence of cognitive deterioration by either objectively measured decline over time and/or subjective report of decline by self, and/or informant in conjunction with objective cognitive deficits, and (3) activity of daily living are preserved and complex instrumental functions are either intact or minimally impaired.

Measurements: All subjects (n = 280) underwent a set of routine clinical examinations including the AQT, Mini-Mental State Examination (MMSE), Neurobehavioral Cognitive Status Examination (COGNISTAT) and Clinical Dementia Rating Scale (CDR). The AQT color-form naming task consists of 3 tests, each with 40 visual stimuli. Test 1 and 2 require rapid naming of repeated single-dimension stimuli. Test 3 requires rapid naming of repeated dual-dimension stimuli (Figure 1). The original English AQT was translated into Japanese. The MMSE and COGNISTAT are screening tests that examine several cognitive functions. The COGNISTAT examines ten cognitive domains (orientation, attention, comprehension, repetition, naming, constructional ability, memory, calculation, similarities, and judgment).

Statistical Analyses: To evaluate the concurrent validity, the Spearman’s correlation coefficient was used to correlate the AQT color, form and color-form combination with the total scores on the MMSE, COGNISTAT, CDR, and each subscore of the COGNISTAT. To evaluate discriminatory validity, four age and education level-matched groups were selected: AD group (CDR 1, N=25), amnestic MCI group (CDR 0.5, N=25), non-amnestic MCI group (CDR 0.5, N=25), and control group (CDR 0, N=25). For group comparison, the data were analyzed using one-way ANOVA or Kruskal Wallis test when appropriate, and multiple comparisons were made by the Mann-Whitney U test with Bonferroni’s correction. Sensitivity and specificity were calculated using a receiver operating characteristic (ROC) curve analysis for each relevant group comparison. The optimal cutoff score for each group was selected after sensitivity and specificity data were obtained. SPSS 16.0 for Windows (Jpn ver.) was used for all analyses.

Results: The AQT color-form naming time results showed significant correlation with the total scores of the MMSE (P<0.001), COGNISTAT (P<0.001), CDR (P<0.001), and each subscore of the cognitive domains except for judgment in the COGNISTAT (orientation and memory: P<0.05; attention: P<0.01; comprehension, repetition, naming, constructional ability, calculation and similarities: P<0.001). The AQT color-form naming time was significantly worse in AD and MCI groups compared with that of the control group (AD = MCI > control). The ROC curves discriminate AD vs control, amnestic MCI vs control, and non-amnestic MCI vs control.

Conclusions: This study confirmed the concurrent validity of the AQT as an effective and quick screening test for early stage of dementia. The AQT color-form naming test showed significant correlation with higher cortical functions such as perception, language, attention and working memory while it displayed low correlation with memory and orientation. The cut-off times (sec.) to determine cognitive impairment as obtained in this study, the first validation study in Asia, were consistent with those of the original standardized AQT test, indicating that the AQT color-form naming test is not affected by cultural-linguistic background. The results also demonstrate the AQT as a sensitive test that clearly separates MCI (amnestic and non-amnestic MCI) from normal aging controls. Since MCI or CDR 0.5 suggests a high-risk state for dementia, the present findings indicate that the AQT color-form naming test is a useful screening tool for patients with very early-stage of dementia in elderly Japanese population.

 

Elisabeth H. Wiig, Ph.D. Niels P. Nielsen, M.D. Lennart Minthon, M.D. Ph.D. & James Jacobson, M.D.

2008 ICAD Conference, Chicago, ILL.

AQT: Efficacy Of A New Paradigm For Cognitive Screening.

Background: A Quick Test of Cognitive Speed (AQT) (Wiig, Nielsen, Minthon & Warkentin, 2002, 2003) is a processing-speed test for measuring performance of cognitive functions. Unlike current test paradigms, which rely on determining verbal memory for cognitive content, AQT uses time required for identification and recall as performance measures. Subjects name highly familiar colors and forms to measure perceptual speed (reaction and response time) and color-form combinations to measure cognitive speed (cognitive overhead --- attention, visual working memory, set-shifting).

Methods: Research supports the viability of this paradigm for cognitive screening and longitudinal monitoring. This assertion is supported by statistical characteristics, neuroimaging and clinical research.

Results: Among AQT’s statistical characteristics are high test-retest reliability (low to mid 90% range), minimal age effects (about 1 sec. per decade), and absence of gender and age effects above Grade 8 (i.e., literacy) (Jacobson, Nielsen, Minthon et al., 2004; Nielsen & Wiig, 2006; Wiig, Nielsen & Jacobson, 2007). Sensitivity and specificity measures are high (upper 90%), and reduction of AQT cognitive speed can be observed earlier in the disease process than with tests of functional abilities (Nielsen, Wiig, Warkentin & Minthon, 2004; Warkentin, Tsantali, Kiosseoglou et al., 2005; Ross-Swain & Wiig, 2008). AQT facilitates differentiation of Alzheimer’s disease and dementia with Lewy bodies (Anderson, Wiig, Londos & Minthon, 2007). AQT color-form measures correlate with ADAS-Cog measures, are highly stable longitudinally and relate to β-amyloid levels (Wiig, Annas, Basun et al., 2009). Regional cortical blood-flow (rCBF) patterns during AQT color-form naming indicate that normal performance is mediated by activation of temporal-parietal areas bilaterally with concurrent suppression in frontal regions (Wiig et al., 2002). In slight-to-moderate AD, rCBF patterns during color-form naming indicate suppressed blood flow to temporal-parietal regions. Behavioral observations indicate progressive increases in pauses, but not in articulation time (Warkentin, Erikson & Janciauskiene, 2007).

Conclusions: AQT provides a valid paradigm for first-line cognitive screening and longitudinal monitoring of medication or cognitive training. Preliminary evidence suggests that this test of processing speed shows potential for incorporation in differential diagnostic assessments of dementia. AQT’s cost- and time-effectiveness, objectivity, reliability and sensitivity are among potential public benefits.

 

Elisabeth H. Wiig, Ph.D. Deborah Ross-Swain, Ed.D. Nola Radford, Ph.D. & Patricia Zureich, M.A.

2008 Annual Convention of the American Speech-Language-Hearing Association, Chicago, ILL.

Cognitive Speed, Frontal and Temporal-Parietal Executive Functions Across the Life Span.

Cognitive speed --- perceptual speed plus cognitive overhead (e.g., working memory, set shifting, inhibition)--- is required for real-time performance in many domains, including reading and driving. This presentation introduces commonly used processing-speed tests and integrates research of development, regression and brain-behavior relationships from SLP and neuropsychology perspectives. Cognitive speed is reduced in language disorders, dyslexia, ADHD and executive function disorders. In dementia cognitive speed is significantly reduced and cortical activation suppressed. Participants will leave with working knowledge of the importance of evaluating processing speed, including cognitive speed (executive functions) to adapt and monitor treatment and intervention.

 

Elisabeth H. Wiig, Ph.D. & Gail Steingold, M.S.

2005 Annual Convention of the American Speech-Language-Hearing Association, San Diego, CA.
 

Early Detection of MCI/Alzheimer's and Financing Care

Early detection of MCI and Alzheimer's has become a global issue. This presentation includes demographic data, differentiates Alzheimer's from other dementias, delineates the disease progression from MCI to AD, and summarizes and compares recent screening tests for MCI/AD. Screening methods, measurement activity, reliability and clinical utility are emphasized. Screening options are presented within a global perspective with involvement of SLPs. Family support systems, resources and financial realities are discussed. Sources of funding for long term care resulting from AD and other dementias (e.g., Medicare/Medicaid, personal assets) will be identified and resource guides provided. Care delilvery systems emphasize quality of care.


Siegbert Warkentin, Ph.D.1 Eleni Tsantali2
G. Kiosseoglou3 Lennart Minthon, M.D., Ph.D.1 Elisabeth H. Wiig, Ph.D.4
Niels Peter Nielsen, M.D.5
E. Londos, Ph.D.1 M. Tsolaki, M.D., Ph.D.2

2005 AAIC Prevention of Dementia Conference, Clinical Assessment

1Neuropsychiatric Clinic, Malmö University Hospital, Malmö, Sweden;
2Aristotle University of Thessaloniki, Greece;
3Department of Psychology, Thessaloniki, Greece;
4 Knowledge Research Institute, Arlington, TX, USA; 5Psychiatric Center, Copenhagen, Denmark

The AQT© as a Useful Short Screening Test for Dementia. Evidence from Two European Cultures

Backround: Alzheimer's disease (AD) is the most common cause of dementia in the growing elderly population in many countries. The
quests for symptomatic relief and prospects of pharmacological treatments of AD, call for sensitive and reliable screening tests which can be easily used by general practitioners in different countries and cultural settings. General criteria for such screening tests should include easy administration and unequivocal scoring, and independence of factors known to be related to cultural settings and educational level. The AQT is a novel screening test designed to assess cognitive processing speed. Three sets of universal stimuli are presented to patients in a fixed protocol. The administration takes 3 - 5 minutes and the clinical outcome measure is the time (seconds) it takes to perform the test. The AQT is standardized and validated in the USA and in Sweden. It is used by general practitioners and hospital staff throughout Sweden as a supplementary test to the MMSE in the assessment of dementia.

Objective(s): We performed a collaborative research study between two European countries, Sweden and Greece, in order to establish the validity and reliability of the AQT, and to further evaluate whether test results meet the criteria of being independent of language and educational level.

Methods: The Swedish participants were 97 patients with AD, and 59 healthy subjects, while the Greek participants were 75 patients with AD, and 29 healthy subjects, respectively. All patients met the NINCDS-ADRDA and the DSM-IV criteria for dementia. The patients’ educational level ranged from 2 to 17 years, MMSE: mean 22.6. The AQT and the MMSE were assessed in all subjects by experienced psychiatrists and neuropsychologists in routine clinical settings in both countries. The discriminatory values of the AQT and the MMSE in the two countries and languages are presented in the Table below.

  Sensitivity Specificity Predictive Values (%)
AQT Sweden 93.1 99.9 99.9
AQT Greece 98.7 96.6 98.7
MMSE Sweeden 88.7 95.5 97.2
MMSE Greece 93.3 69.0 88.6
Conclusions: The results demonstrate that cognitive processing speed is a general and very sensitive measure that clearly separates mild dementia from normal aging. The usefulness of the AQT in dementia assessment is suggested by the striking similarity of findings in different cultural settings.

Elisabeth H. Wiig, Ph.D.1
Niels Peter Nielsen, M.D2

2004 Annual Convention of the American Speech-Language-Hearing Association, Philadelphia, PA

1Knowledge Research Institute, Arlington, TX, USA; 2Hvidovre Hospital, Copenhagen, Denmark

Clinical Utility of AQT Color-Form Naming: Normal Aging and AD

Abstract: AQT Color-Form Naming and Mini Mental State Examination were administered to 38 adults with mild/moderate Alzheimer’s and 38 controls. Group means differed significantly (p < .001). AQT-CF specificity was 97%; sensitivity 97%. MMSE specificity was 100%, sensitivity 84%. AQT-CF is objective and highly reliable and differentiates AD-affected from non-AD subjects.

Introduction: In this study, we compared the discriminant ability of two single-dimension naming (color and form) and one dual-dimension naming (color-form) test from the AQT Assessment of Parietal Function (Wiig et al., 2002) and Mini Mental State Examination (MMSE) (Folstein et al., 1975) MMSE is an established screening test for Alzheimer’s disease (AD) for which extensive research exists (Molloy et al, 1991; Teng et al., 1998; Tombaugh & MacIntyre, 1992;). It uses formats for assessing cognitive impairments that probe cognitive content such as verbal memory and visual construction. AQT measures processing speed for naming single- and dual-dimension visual stimuli. Similar to other processing speed tests, it uses performance time, rather than content performance, as measures and the outcome measure includes reaction time and response time (Goetz et al., 1989; Teichner, 1975; Strauss et al., 1995; Stroop, 1935) AQT dual-dimension naming (color-form combinations) times allow evaluation of cognitive functions that underlie recognition, attention, working memory, automaticity and retrieval, each of which are adversely affected by dementia (Callahan et al., 1995; Baddeley et al., 1991).

Subjects: There were 38 adults with mild to moderate Alzheimer’s disease (AD) in the age range from 59 to 87 years (M = 73·79 yrs.; SD = 7·42 yrs.) and 38 sex and age matched (within +/-12 mo.), normally functioning adults in the age range from 60 to 87 years (M = 73·89 yrs.; SD = 7·33 yrs.). All subjects underwent a thorough clinical evaluation, including physical, neurological, and psychiatric evaluation, screening laboratory tests, electro-cardiography (EEG), computerized tomography (CT) or magnetic resonance imagining (MRI), investigation of the regional cerebral blood flow (133Xenon inhalation technique) and CFS analysis. The diagnosis of a “probable AD” was made by exclusion in accordance with the NINCDS-ADRDA criteria (McKhann et al., 1984).

Materials: The primary screening task, AQT Color-Form Naming (AQT-CF), consists of three tests. The first two feature 40 randomly repeated, single-dimension visual stimuli (colors: black, blue, green, red; forms: circle, line, square, triangle) and measure perceptual speed. The third features 40 repeated dual-dimension stimuli that require naming of first the color and then the form and measures cognitive speed (attention, working memory, retrieval and verbal automaticity). Test-retest reliability for color, form, and color-form naming is high (r = ·91, ·92, and ·95, respectively), and there is no evidence of habituation, learning, or fatigue in repeated trials over 10 minutes. The tests were preceded by three short, practice trials to establish adequacy in naming. The second measure, MMSE, is a standardized screening test for MCI and dementia. It has a score range from 0 to 30 points, with a normal range from 27 to 30 points. A range of test-retest reliability coefficients are reported with the highest coefficients suggesting a learning effect over short time periods (Tombaugh & McIntyre, 1992).

Results: The mean AQT color, from and color-form combination naming times were 23.12, 29.19, and 53.72 seconds, respectively, for the controls, and 38.73, 51.99, and 90.18 seconds, respectively, for the AD subjects. All mean differences for naming times were highly significant (p < ·001). The mean MMSE score was 29·29 for the controls and 23·05 for the AD subjects, and the difference was highly significant (p < ·001). AQT single-dimension color naming time (sec.) correctly classified 100% of controls and 71% of AD subjects (predictive value 85.5%). Single-dimension form naming correctly identified 97% of the controls and 71% of the AD subjects (predictive value 79%). Dual-dimension color-form naming (AQT-CF) correctly identified 97% of the controls and 97% of the AD subjects (predictive value 97%). The relatively low sensitivity values (71%) for single-dimension color or form naming indicate that it is the combination of the two stimulus dimensions color and form that results in the high sensitivity of color-form naming (97%). By using a combination of AQT naming times (in seconds) for color (100% specificity), form (97% specificity) and color-form (97% specificity) false-positive identifications may be minimized. In comparison, MMSE correctly classified 100% of controls and 84% of AD patients (predictive value 87%). The high predictive value of the AQT-CF (a double task) agrees with findings that Alzheimer’s patients show marked deterioration of the ability to coordinate two tasks when compared to normally aging adults (Baddeley et al., 1991; Callahan et al., 1995).

Discussion: An optimal screening test for Alzheimer’s disease would be expected to: (a) provide high reliability, sensitivity and specificity; (b) be objective and quick and easy to administer and score; (c) unaffected by education and cultural background; (d) not show habituation or effects of learning after repeated administrations; and (e) be relatively inexpensive for the patient (Burns et al., 2002; Crevel et al., 1999). AQT color-form naming responds positively to all of these criteria. AQT-CF has high reliability (r .95); specificity (97%) and sensitivity (97%). It is objective (timed) and the simple methodology allows administration by paraprofessionals after a short period of training. It is minimally affected by age (Jacobson et al., 2003) and exhibits features that are desirable in a culturally diverse society due to the simplicity and universality of the visual stimuli. Perhaps more importantly, AQT-CF can be administered anywhere with a minimum of materials required, provide for a wide range of finely separated measurement points (seconds) and results can be conveyed easily to professionals for judgment of outcomes AQT-CF has no ceiling, as it can measure total naming time to the infinite. In other words, when administered repeatedly, AQT-CF can catch minimal declines in performance even in high-performing adults. In combination these characteristics give AQT-CF several advantages over MMSE and other screening tests of cognitive content. It can be administered repeatedly, identify changes or drifts from a personal (baseline) or normal standard of performance, and monitor changes after medication. It therefore appears to be a candidate for an optimal primary screening test for evidence of decline in cognitive functions, including MCI and ‘probable Alzheimer’s.'


Elisabeth H. Wiig, Ph.D.,
Niels Peter Nielsen, M.D., Lennart Minthon, M.D., Ph.D., Siegbert Warkentin, Ph.D.
Parietal lobe activatioin during rapid, automatized naming.

Background: The identification of neuropsychological tests sensitive enough to detect early brain abnormalities in subjects at risk for developing dementia, such as Alzheimer´s disease (AD), is of great interest in the light of modern pharmacological intervention. We here report on such a test for the assessment of parietal lobe function, and also report on its validation by means of regional cerebral blood flow measurements. Objective: The purpose of this study was 1. to determine whether rapid automatized naming (RAN) functionally engages the parietal lobes in normal healthy subjects, 2. whether this task could be used to identify parietal lobe dysfunction in patients with AD. Methods: The study population was 14 normal healthy subjects and 10 patients with AD (mild to moderate). Patients were diagnosed according to established criteria (DSM-IV, NINDS-ADRDA). Regional cerebral blood flow (rCBF) was assessed with the non-invasive xenon-133 inhalation method using the Cerebrograph Cortexplorer 64 (Ceretronix, Randers, Denmark).Two rCBF-measurements were performed on each subject. After baseline rCBF (rest, eyes open), the subject was remeasured while performing the RAN-task, which involved the repeated reading of 40 different colour and form combinations, as rapidly as possible. The results were compared with normal reference data obtained during rest and during verbal fluency (n=92). Results: Normal rCBF-values were significantly augmented in parietal areas during the RAN-task, when compared with rCBF obtained during rest and during verbal fluency (p<0.0001). In addition, a highly significant (p<0.0001) flow decrease was seen in frontal and frontotemporal areas bilaterally. In contrast, no parietal lobe activation was seen in the AD patients, who also had significantly longer reading times than the normal controls.

Conclusion: This is the first verification that reading simple color-form combinations engages temporaral and parietal areas in the human brain. Increased reading time is related to a parietal functional deficit in Alzheimer's patients.

Neuropsychological tests may serve as sensitive instruments for detection of early brain dysfunction in subjects at risk for developing dementia. In order to be clinically useful and to understad what a test actually measures, it needs to be validated by brain imaging. We here report of the validation of the "Alzheimer's Quick Test" for the functional assessment of the parietal lobes.


 
Alzheimer's Quick Test
 

Subtest:

Instruction: "Read the color-form combinations as quickly as you can."
Retest stability: Less than 3 seconds. No habituation.

  aqt_sm
 

Blood flow measurements were performed with the two-dimentional 133-Xe inhalation methods (Ceretronics, Hadsund, Denmark).

Results:

large_aqt
   
© 2012 Knowledge Research Institute, Inc