Quick Download Links of Scientific Literature

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This page collects in one place scientific literature regarding the CANS-MCI referred to in our other science-related blog posts.

The most comprehensive summary of all the science behind the CANS-MCI is contained in the document titled “Scientific Background of the CANS-MCI”.  This extracts information from the other literature and discusses the science in depth.

Specificity and sensitivity of the tests was assessed using ROC curve analysis. The ACE-R and MoCA total scores showed similar and very high sensitivity (90%) but lower specificity (67%). The CANS-MCI revealed similarly high sensitivity (89%), and the highest specificity (73%) overall. The MMSE showed the lowest sensitivity (80%) and specificity (60%) in discrimination of the groups.

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The Validity of the CANS-MCI II (2005 – 2014)

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Emory Hill, PhD and Jo Anne Laboff, MSW

Scores on the CANS-MCI were compared with the results of full neuropsychological examinations that were blind to the CANS-MCI results. Identical analyses were performed using full independent neuropsychological evaluation classifications on the 74 subjects who returned a year later.

To determine the ability of the Computer-Administered Neuropsychological Screen for Mild Cognitive Impairment (CANS-MCI) as an accurate screen for mild cognitive impairment (MCI), scores on the CANS-MCI were compared with the results of a full neuropsychological examinations that were blind to the CANS-MCI results. Logistic regression models were used to predict the dichotomous outcomes of MCI vs. normal cognitive functioning (as determined by the neuropsychological exam). Because education can affect scores on measures of cognitive impairment[1,2] samples were separated into individuals with a high school degree or less (N=26) and those with schooling beyond high school (N=57). Gender and age were included in the model. Receiver operating characteristic (ROC) analyses were performed to calculate the sensitivity (the proportion of persons who have MCI that are defined as having MCI) and specificity (proportion of persons who have normal cognitive functioning that are defined as having normal functioning) of the CANS-MCI.

The regression model statistics were very strong (Table 1) indicating a good fit of the data to the model. The CANS-MCI has extremely high levels of sensitivity and specificity (100%) in classifying those with an education up to a high school degree. The optimum sensitivity and specificity for those with 13+ years of education is lower (100%; 85%) but still excellent (Table 2). These findings indicate the CANS-MCI can be a useful screening measure to determine if a person needs to be assessed for cognitive impairment.

Table 1:  CANS-MCI Logistic Regression 3

EducationX2Nagelkerke R2Predicted Classification % Correct
Less Than 13 Years35.41.0100
13 or More Years50.3.7984.2

Table 2:  CANS-MCI ROC Analyses

EducationArea Under Curve% Sensitivity% Specificity
Less Than 13 Years1.0100100
13 or More Years.9610084.8

The same analyses were performed using full independent neuropsychological evaluation classifications on the 74 subjects who returned a year later. Despite small numbers of subjects to date, these data indicate that the overall probability that a full neuropsychological evaluation will indicate MCI can be effectively predicted by the CANS-MCI a year earlier. The regression model statistics for the 1-year follow-up evaluations were strong but limited by small sample size. The algorithms correctly classified 85% of participants with a high school degree or less (Chi-square = 11.7; Nagelkerke pseudo-R2 =.63 ) and 80% of those with at least some college (Chi-square = 31.4; Nagelkerke pseudo-R2 =.59) indicating a good fit of the data to the model (Table 3). The CANS-MCI has good levels of sensitivity and specificity in classifying those with an education up to a high school degree. The optimum sensitivity and specificity for those with 13+ years of education is lower but still excellent.

Table 3: CANS-MCI Logistic Regression Analysis (1-year follow-up) 4

EducationX2Nagelkerke R2Predicted Classification % Correct
Less Than 13 Years11.7.6385
13 or More Years31.4.5919.6

Table 4: CANS-MCI ROC Curve Analysis (1-year follow-up) 4

EducationArea Under Curve% Sensitivity% Specificity
Less Than 13 Years.91792.983.3
13 or More Years.88883.973.9

ROC curve analyses on the two educational levels revealed that cut-points lead to sensitivities/specificities of .93/.83 (<=12 yrs) and .84/.74 (13+ yrs). Areas under the curve were high: .917 for <= 12 yrs education and .888 for 13+ yrs (Table 4). Of course, there is the possibility that relative to an external standard the CANS-MCI is more accurate than the independent full neuropsychological evaluations. That appears to be the case in the study by Scanlan et al (2012) which found better agreement between the CANS-MCI measures and well known standard tests. They concluded that “an optimal cognitive screen would be expected to detect all of the patients indicated as demented by the DRS2 and those judged to have MCI by the WMS1/WMS2. By those criteria, the CANS-MCI (typically completed in under 35 minutes) appears as sensitive to dementia and MCI detection as a full neuropsychological examination (typically completed in 2.5 hours).” [5]

Mattis and Wechsler Memory Scale Immediate/Delayed

(Percent of subjects found impaired on Mattis Dementia Rating scale or Wechsler Memory Scale (n>168)

Neuropsychological ExamCANS-MCI Memory alone3-factor CANS-MCI
Mattis Impaired (Memory & Initiation)89%93%100%
Wechsler Impaired (WMS1 & WMS2)79%80%95%

Independent longitudinal research in progress[6] has produced preliminary data confirming the ability of the CANS-MCI to detect the earliest signs of serious decline as determined by imaging. In the first 48 cases analyzed, the CANS-MCI memory factor score and executive functioning factor score showed significant declines in subjects who had initially tested as completely normal but subsequently showed declines in cognitive ability, but would still not be officially classified as MCI or demented by UDS criteria. A subset of subjects (N=21), were also assessed with volumetric MRI, revealing that the CANS-MCI memory factor score was positively related to hippocampal brain volume (right hippocampus: r=.43, p<.05; left hippocampus: r=.38, p<.08) [6]

The CANS-MCI is meant to be used longitudinally, comparing each person to his or her own previous performance. This allows for even more precise predictive detection even in those people who are still above average and would otherwise not seem worthy of immediate medical attention. If new treatments evolve that slow, stop or reverse the progression of cognitive decline toward dementia, the earliest possible prediction of decline will become critical.

Footnotes

  1. Gifford DR, Cummings JL. Evaluating dementia screening tests: Methodological standards to rate their performance. Neurology 1999;52:224-227.
  2. Lorentz WI, Scanlan JM, Borson S. Brief screening tests for dementia. Canadian Journal of Psychiatry2002;47(8):723-732.
  3. Jane B. Tornatore, PhD, Emory Hill, PhD, Jo A. Laboff & Brian Fogel 
Validity of Mild Cognitive Impairment Touch Screen Tests: The CANS-MCI Study. 
International Psychogeriatric Association 11th Congress, Chicago, August, 2003.
  4. Jane B. Tornatore, PhD, Emory Hill, PhD, Jo A. Laboff, MSW, Brian Fogel 
One year Follow-Up Analyses of Scoring Algorithms for a Mild Cognitive Impairment Screen: The CANS-MCI Study, Washington, D.C., June, 2005.
  5. James Scanlan, PhD, Jo Laboff, MSW, Emory Hill, PhD Self-reported memory fails to substitute for objective memory measures. Alzheimer’s & Dementia 2012; 8 (4): S780.
  6. Frederick A Schmitt, PhD Department of Neurology, Alzheimer’s Disease Research Center, University of Kentucky Medical Center, unpublished presentation at Screen, Inc. Annual Science Meeting, January, 2013.

Initial Validation of the CANS-MCI (2005)

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Abstract

The CANS-MCI, a computer administered, scored, and interpreted touch screen battery, was evaluated for its ability to screen for mild cognitive impairment. 310 community-dwelling elders enrolled in an NIA-funded study. One-month test-retest reliability correlations were all significant (p<.05-p<.001). Concurrent validity correlations were all significant (p<.001). A high level of diagnostic validity was attained relative to the WMS-R LMS-II test (p<.001). Confirmatory factor analysis supported a three-factor model indicating the tests measure the intended cognitive dimensions of Memory, Language/Spatial Fluency, and Executive Function/Mental Control. Goodness of fit indicators were strong (Bentler Comparative Fit Index = .99; Root Mean Square Error of Approximation=.055). Initial validation analyses indicate that the CANS-MCI shows promise of being a reliable, valid screening tool to determine whether more intensive testing for early cognitive impairment is warranted.

Published in final edited form as: J Neuropsychiatry Clin Neurosci. 2005; 17(1): 98–105.

Open the article at the US National Library of Medicine website:

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The CANS-MCI for Concussion Assessment

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The early detection of cognitive ability changes due to sports concussion is critical because of the increased vulnerability that follows a concussion.

According to Harmon et al, “Animal and human studies support the concept of post-concussive vulnerability, showing that a second blow before the brain has recovered results in worsening metabolic changes within the cell. Experimental evidence suggests the concussed brain is less responsive to usual neural activation, and when premature cognitive or physical activity occurs before full recovery the brain may be vulnerable to prolonged dysfunction.”[1] This extensive review concludes that recognition and initial assessment of concussion should be guided by a symptom checklist, cognitive evaluation (including orientation, past and immediate memory, new learning, and concentration), balance tests, and further neurologic physical examination. Others agree that the dimensions central to computerized cognitive tests of cognitive ability changes related to concussion are memory, cognitive processing speed, and reaction time.[2,3]

The most neglected but critical aspect of sports-related cognitive ability testing is the bias of testers. Assessment must take place with complete and guaranteed neutrality. Coaches, trainers, and even sports team physicians should not be expected to be objective. The Computer-Administered Neuropsychological Screen for Mild Cognitive Impairments (CANS-MCI) test battery is the only one capable of secure objective neutrality. The creation of test reports by qualified, independent test analysts, the comprehensiveness of testing, the longitudinal comparison against pre-concussion baseline measurement, and the detection of attempts to look bad on baseline testing are all handled more effectively by the CANS-MCI than by any other testing procedure. The CANS-MCI baseline is examined by independent professionals for the presence of errors people almost only make when they are trying to look bad. These errors are otherwise actually very rare.

The CANS-MCI is entirely self-administered. After entry of the identity code for a player, the person responsible for testing leaves the room. The CANS-MCI is the only test battery that does not require the presence, much less training, of a test administrator. When the tests are complete, the data may be automatically sent to a central server where they are kept for comparison. Scoring and longitudinal comparison test analysis is performed by an independent neuropsychology technician who does not know the person tested. Test reports compare post-events or end-of-season tests against baseline.

The CANS-MCI tests were designed to measure attentional speed and flexibility; executive mental control; immediate memory; and delayed recall. In order to measure only these dimensions, most often impaired when there has been a traumatic head injury (TBI), the CANS-MCI Short Form is used. By eliminating the dementia-detecting symbol and fluency tests contained in the Long Form, a significant savings in time is gained along with a sharper focus upon concussion-related changes. Problems with verbal initiation and planning, which can be caused by damage to the front of the brain1 are still detected by the executive control tests.

The concussion-assessment version of the CANS-MCI is designed for use by adults (age 16-60). It is sensitive to patterns of test responding that appear when a person, usually on a baseline test for sports, is trying to look bad. Baseline tests, software and confidential data storage are free.

The risk factor questions can be adjusted for each purpose, according to the age and context relevant to a facility. For example, a 10-question depression scale is often included in the concussion Form. To examine the CANS-MCI without a touch screen and without collecting data, go to our CANS-MCI Demonstration Versions.

The cognitive domains measured on the CANS-MCI Short Form

Attention speed: Executive functioning Factor

The dimension of visual scanning speed, central to our Orientation process and the traditional Trail Making A test, is also central to our Picture Matching[5] and Design Matching[6] brief executive function tests.

Attentional Flexibility: Executive Functioning Factor

The dimension of attentional flexibility is central to our Design Matching[6] and Stroop[7] tests.
Reliability is enhanced by combining scores into an Executive Function factor score based upon a larger sample of subjects and incorporation of independent full neuropsychological evaluation comparisons.

Memory for new learning[8]
  • Significant correlations with the Weschler Memory Scale were published in Tornatore et al (2005).[9]
  • Correlation between the Memory factor score with the Learning Efficiency and Delayed Verbal Recall scores on the Rey Auditory Verbal Learning Test (R-AVLT also indicate a high level of sensitivity to the most critical dimensions of memory impairment.

CANS-MCI longitudinal comparisons between test sessions can be performed frequently because alternative correct items are presented automatically each time a person returns for re-testing. Both the reliability and the usability of the CANS-MCI are unique. The exceptional user friendliness of the CANS-MCI in both English and Spanish has been documented in reviews of all computerized cognitive function testing.[10]

Footnotes

  1. Harmon, KG, Drezner, J, Gammons, M et al. American Medical Society for Sports Medicine Position Statement: Concussion in Sport, Clin J Sport Med 2013;23:1–18.
  2. Ellemberg D, Henry LC, Macciocchi SN, et al. Advances in sport concussion assessment: from behavioral to brain imaging measures.  J Neurotrauma. 2009;26:2365–2382.
  3. Randolph C, McCrea M, Barr WB. Is neuropsychological testing useful in the management of sport-related concussion? J Athl Train. 2005;40: 139–152.
  4. Wood, R. Ll., & McMillan. (2001). Neurobehavioural Disability and Social Handicap Following Traumatic Brain Injury. East Sussex, England: Psychology Press.
  5. Word-to-Picture Matching (Executive function factor – verbal information processing speed):  This is a matching cognition test in which four pictures of objects are presented along with one word, and the person is instructed to touch the picture that goes with the word.  Accuracy and reaction times for 14 trials are measured.
  6. Design Matching: (Executive Function factor – visual information processing speed, and spatial memory): Eight designs are matched with letters.  The letters are not in order. A set of alphabetically arranged letter buttons appears.  Designs are presented one at a time and replaced when any button is touched.  The complexity of attention switching required is increased by within-test interference.  This test lasts for 70 seconds.
  7. Stroop: (Executive Function factor – Mental Control): After guided practice, 12 concordant (word and ink color matched) and 24 discordant (word and ink color mismatched) words are presented.  The average latency for the correct discordant items is precisely measured with this self-administered test for dementia.
  8. Free and Guided Recall, Immediate and Delayed (Memory Factor):  This memory loss screening test involves the acquisition of memory for the names of objects and guides the strategy subjects are likely to use to remember them toward a common strategy (association with an object category).  Five sets of four pictures are presented along with one category for each picture. This test presents the four pictures as four quadrants in a manner that is identical to the previous test, eliminating the distraction that novelty creates on memory tests.  Then a test is presented that contains the four correct objects and incorrect items from the same four categories.  Any incorrect responses result in a second presentation of the set of four pictures.  Five sets of four pictures are presented in this fashion.  After all five acquisition sets, a free recognition test trial is presented.  This is a series of 20 three-button presentations, one correct button and two incorrect from categories other than the correct one.  If any of the 20 correct items are not touched, the person receives a cued recall re-test on that item, consisting of three buttons, the missed item along with two other items in that same category.  After each of the cued recall tests, the items that were not correctly touched on the free recall test are shown again with category prompts for re-acquisition.  One delayed free recall trial is given.  If any of the 20 correct items are not touched, the subject receives a cued recall test on that item (the missed item along with two other items in that same category).
  9. Tornatore, JB, Emory Hill, E, Jo Anne Laboff, J, and Mary E. McGann, ME   Self-Administered Screening for Mild Cognitive Impairment: Validation of a Computerized Test Battery.   Journal of Neuropsychiatry and Clinical Neurosciences, Volume 17, No. 1, 98-105, 2005.
  10. Wild, K, Howieson, D, Webbe,F, Seelye, A, Kaye, J.  Status of computerized cognitive testing in aging: A systematic review.  Alzheimer’s & Dementia, 4 (6), 428-437, 2008.

The CANS-MCI for the Assessment of Alzheimer’s Risk

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There is a critical and increasing research focus upon developing ways to identify high-risk MCI patients for early treatment. Such efforts depend upon knowing as much as possible about who is most likely to progress from MCI to Alzheimer’s disease.

A very recently published study[1] of the most significant predictors of progression from MCI to Alzheimer’s indicates, albeit indirectly, that the CANS-MCI is a very powerful tool for the detection of those predictors. This conclusion is based upon multiple known relationships between the CANS-MCI and all of the measurements used in the study.[Table 1] The Korolev study proposed a precise, extensive model to improve patient selection in clinical trials and identify high-risk MCI patients for early treatment. However, identification of high risk MCI patients may require even earlier and more efficient intervention.

The CANS-MCI was designed to measure all of the cognitive domains known to be most predictive of Alzheimer’s disease (AD): immediate and delayed memory; attentional speed and flexibility; executive mental control; clock hand placement fluency; language fluency. The CANS-MCI is the only test battery that does not require the presence, much less training, of a test administrator. Years of CANS-MCI usability research resulted in its ability to be fully self-administered by elderly people with Mild Cognitive Impairment, regardless of computer experience, even by elderly people with Mild Cognitive Impairment without causing anxiety-based cognitive interference during testing.[2] When the tests are complete, the data may be automatically sent to a central server where they are kept for longitudinal comparisons. Scoring and longitudinal comparison test analysis is performed by an independent neuropsychology technician who does not know the identity of person tested. Hardware, software, installation, support and confidential data storage are low single fee costs.

Recently, the “robust” consistency and validity of the CANS-MCI was confirmed despite changes in the images (all CANS-MCI versions are country-specific) and language used.[3] The sensitivity of the CANS-MCI when discriminating MCI from normal functioning is as high as the hand-administered MoCA and much greater than the sensitivity of the MMSE.[4]

All latency and accuracy measures on the CANS-MCI are scalable scores; longitudinal comparisons may be performed accurately and frequently because alternative correct items are presented automatically each time a person returns for re-testing, eliminating practice effects. The entire set of tests takes about 25 minutes.

The early studies of the CANS-MCI established significant correlations between its Memory Factor Score and the Wechsler Memory Scale Logical Memory II.[8] Korolev et al[1] defined MCI by: (a) a subjective memory complaint; (b) objective memory loss, as measured by age- and education-adjusted scores on Wechsler Memory Scale Logical Memory II, but without significant impairment in other cognitive domains. “MCI subjects recruited as part of ADNI-1 were diagnosed based on the original Petersen (Mayo Clinic) criteria for amnestic Mild Cognitive Impairment. Thus, MCI subjects were limited to those with memory-only impairments (without significant impairments in other cognitive domains), also termed single-domain amnestic MCI. However, even among those MCI patients diagnosed using this single-domain amnestic MCI definition, impairments in multiple cognitive domains in addition to memory were predictive of MCI-to-AD progression. This provides empirical support to the recently revised clinical criteria for MCI, where the concept of “MCI due to AD” is proposed to include “impairment in one or more cognitive domains”.[5] The CANS-MCI tests abilities within these cognitive domains, found in previous studies[6] to be associated with greater risk of progression to AD dementia than are people with isolated memory deficits.

Significant correlations have been found between the CANS-MCI and the predictors of progression from MCI to Alzheimer’s found by Korolev.[1]

Even though the cognitive assessments proved to be the most accurate (76.1%) in predicting MCI-to-dementia progression, the imaging dimensions were also valuable predictors, particularly volume/cortical thickness of the left hippocampus. Our preliminary hippocampal imaging results suggest that CANS-MCI-Memory Factor and CANS-MCI-Executive Functions Factor differences accurately reflect differences in brain volume.[7]

There are several other ways in which Korolev’s finding support the exceptional power of the CANS-MCI (compared to other computer-assisted test batteries). The CANS-MCI avoids the variability (noise) contributed by inter-tester differences, since it is administered entirely, without staff input or training, by the computer itself, using single finger touches only. Although most research, such as Korolev’s, repeatedly train technicians in test administration to maximize inter-tester reliability, such efforts cannot be expected in clinical situations. That is particularly true when a primary care practice is not specialized yet serves as the initial detection situation for most patients who will come to the attention of specialists. The outstanding reliability of the CANS-MCI has been previously documented.[8] The exceptional user friendliness of the CANS-MCI has also been widely acknowledged.[9]

Table 1: Known relationships between the CANS-MCI and Korolev study measurements

Rey Auditory Verbal Learning (Learning Efficiency) and CANS-MCI Memory FactorN=158r=.349 Significance >.001
Rey Auditory Verbal Learning (Delayed Memory) and CANS-MCI Memory FactorN=161r=.426Significance >.001
Rey Auditory Verbal Learning (Delayed Memory) and CANS-MCI Delayed MemoryN=161r=.403Significance >.001
Boston Naming Test and CANS-MCI Naming TestN=32r=.413Significance >.02
Digit-Symbol Coding Test and CANS-MCI Executive Function FactorN=158r=686Significance >.001
Trails A (Visual Scanning) and CANS-MCI Design MatchingN=160r=.436Significance >.001
Trails B (Attention Flexibility) and CANS-MCI Design MatchingN=157r=548Significance >.001
Trails B (Attention Flexibility) and CANS-MCI Executive Function FactorN=159r=.504Significance >.001
Weschler Logical Memory II (Delayed) and CANS-MCI Memory FactorN=162r=.588Significance >.001

Footnotes

  1. Igor O. Korolev · Laura L. Symonds · Andrea C. Bozoki redicting Progression from Mild Cognitive Impairment to Alzheimer’s Dementia Using Clinical, MRI, and Plasma Biomarkers via Probabilistic Pattern Classification.  Feb 2016 · PLoS ONE.
  2. Hill, E. and Hammond, KW Usability of Multimedia Automated Psychological Tests to Screen for
    Alzheimer’s Disease. Proceedings of the American Medical Informatics Association Symposium 2000; 1030.
  3. Cláudia M. Memória, Mônica S. Yassuda, Eduardo Y. Nakano and Orestes V. Forlenza International Psychogeriatrics, Volume 26 / Issue 09 / September 2014, pp 1483-1491.
  4. Samrah Ahmed, Celeste de Jager & Gordon Wilcock A Comparison of screening tools for the assessment of Mild Cognitive Impairment: Preliminary findings. Neurocase Volume 18, No. 4, 336-351, 2012.
  5. Albert MS, DeKosky ST, Dickson D, Dubois B, Feldman HH, Fox NC, et al. The diagnosis of mild cognitive impairment due to Alzheimer’s disease: recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement. 2011;7: 270–279.).
  6. Bozoki A, Giordani B, Heidebrink JL, Foster NL. Mild cognitive impairments predict dementia in non-demented elderly patients with memory loss. Arch Neurol. 2001;58: 411–416.
  7. Frederick A Schmitt, PhD Department of Neurology, Alzheimer’s Disease Research Center, University of Kentucky Medical Center, Presentation at Screen, Inc. Annual Science Meeting, January, 2013.
  8. Tornatore, JB, Emory Hill, E, Jo Anne Laboff, J, and Mary E. McGann, ME Self-Administered Screening for Mild Cognitive Impairment: Validation of a Computerized Test Battery. Journal of Neuropsychiatry and Clinical Neurosciences, Volume 17, No. 1, 98-105, 2005.
  9. Wild, K., Howieson, D., Webbe, F., Seelye, A., Kaye, J. Status of computerized cognitive testing in aging: a systematic review. Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, Volume 4, No. 6, 428-437, 2008.