(CERAD-RA)
Anastasya Glezerman, Ph.D.
Michael L. Drexler, Ph.D.
Laguna Honda Hospital and Rehabilitation Center,
Psychiatry/Neuropsychology Service, San Francisco, CA
Presented at the Annual Meeting of the National Academy of Neuropsychology
November, 2001, San Francisco, California
To request reprints, please e-mail Michael L. Drexler, Ph.D. at:michaeldrexler@netscape.net
or e-mail Anastasya Glezerman, Ph.D. at:aglezerman@yahoo.com
The researchers would like to thank Judith Sachs, Ph.D., for kindly providing a consultation on technical aspect of the CERAD battery and Irene Ginzburg, M.A. for helping with backtranslation.
ABSTRACT
This is a study involving translation and pilot testing of a number of neuropsychological instruments and instructions for their administration into Russian in order to create a brief battery for assessment of Dementia in the Russian-speaking geriatric population. Given the significant increase in the number of Russian-speaking patients over the past few years, there is a need to develop standardized neuropsychological assessment instruments for this population. This study is the first step in the development of such a measure.
The battery is patterned on the commonly used set of tests developed by the Consortium to Establish a Registry for the Alzheimer’s Disease (CERAD). The battery already has successfully been translated into German and French, and similar procedures were used to develop the Russian adaptation. A sample of Russian-speaking patients aged 40-93 diagnosed with various types of dementia and other neurological disorders in an outpatient geriatric day treatment program were referred for neuropsychological testing and were administered the CERAD-RA as well as a number of additional tests.
The clinical and diagnostic utility of this battery was explored. The battery was well tolerated and there were no apparent problems during its administration. The results of the available tests were compiled and compared to the available normative data and the areas of impairment thus revealed were explored. The performances of non-demented, demented, and healthy subjects fell within expected ranges when compared to the normative data for the English-language version of the battery. Further research directions, including psychometric and cross-cultural studies, are discussed.
INTRODUCTION
This is a study involving translation and pilot testing of a number of neuropsychological instruments and instructions for their administration into Russian in order to create a brief battery for assessment of Dementia in the Russian-speaking geriatric population. Given the significant increase in the number of Russian-speaking patients over the past few years (US Census Bureau, 1990), there is a need to develop standardized neuropsychological assessment instruments for this population. This study is the first step in the development of such measures.
The battery is patterned on the commonly used set of tests developed by the Consortium to Establish a Registry for the Alzheimer’s Disease (CERAD) (Morris et al., 1989). The core battery includes the Verbal Fluency Test (Animal Naming), Modified Boston Naming Test (15-item version), Mini-Mental Status Exam, Constructional Praxis Test, and Word List Memory, Recall, and Recognition Tests. Statistical analysis indicated that these tests were composed of three components: memory, language, and praxis (Morris et al., 1989).
The CERAD battery has been translated into French and German (Demers et al., 1994; Satzger et al., 1999) and some studies addressing the validity of these translations were conducted (Satzger et al., 1999; Unverzagt et al., 1999). Thus, the CERAD battery has lent itself well to cross-cultural research. For the current study procedures similar to these used in the past were employed to develop the Russian adaptation (Brislin, 1970; Demers et al., 1994; Flaherty et al., 1988). Because of the importance of test equivalence for cross-cultural research, we made an attempt to ensure the equivalence of the tests belonging to the CERAD battery proper, as explained more fully below.
Additionally, a number of other neuropsychological instruments providing more broad diagnostic and functional information was included in order to increase clinical and treatment planning utility of the battery. These measures included the Shipley Institute of Living Abstract Reasoning Scale (Zachary, 1986), the Verbal Paired Associates Test form the Wechsler Memory Scale-Revised (Wechsler, 1987), Trails A and B (Spreen & Strauss, 1991), Controlled Word Association Test (Spreen & Strauss, 1991), Finger Tapping Test (Spreen & Strauss, 1991), Clock Drawing Test (Tuokko et al., 1992), and recall of Constructional Praxis Test items. The Vocabulary subtest of WAIS-R (already translated into Russian and normed on Russian-speaking population (ИМАТОН, 1995) was also included in order to provide an estimate of premorbid IQ (Lezak, 1995).
METHODS
The tests and their instructions were literally translated into Russian by a bilingual neuropsychologist. The translation was revised in order to ensure semantic equivalence and cultural appropriateness of the instructions. For example, on several instructions typically read as commands, we inserted the Russian word for “please” to avoid apparent rudeness. Practicing neuropsychologists were consulted on the questions of parameters of the tests relevant to construct validity and their suggestions were incorporated into the revision of the test. As an example of this, the letters in the Controlled Oral Word Association Test were selected to approximate the relative frequency of words beginning with letters F, A, and S in the English language. This version was given to an independent bilingual psychologist for back-translation in order to address semantic equivalence of the tests. Several items were revised at this stage.
The resulting battery was administered to 13 Russian-speaking patients at an adult day treatment center in San Francisco, as part of an ongoing study. They ranged in age from 40 to 93 years. Eight of these patients had been diagnosed with various types of dementia (mean age 83, sd = 17.99; 6 females and 2 males) and five had other neurological conditions (mean age 61.5, sd = 11.04; 1 female and 4 males). For further exploratory work, one person was tested for the second time at the 4-month follow-up. Also, one 79-year-old non-patient (male) without any known neurological problems was tested as a case study comparison. At this preliminary stage in the development of the translation, the results for all cases were compared to the normative data for an American population.
RESULTS
The core CERAD battery was found to take 30-40 minutes, which is very similar to the English language original. It was well tolerated by all patients, and at repeated testing for those cases seen in follow up. No misunderstandings or difficulties with instructions were noted. One of the items on the Boston Naming Test was found to have two valid names in different dialects and the scoring instructions were amended to include the second name. No other changes appeared necessary in terms of patients’ ability to understand and tolerate testing.
Additional tests included in this battery were also well tolerated by most patients. The extended battery was found to take 1 to 2 hours. However, 3 patients with severe dementia and/or agitation were unable to complete the full battery because of fatigue. Patients with significant motor problems were not administered the complete Finger Tapping Test, and patients with very little education were not administered the Abstract Reasoning and Trails tests (2 patients reported little or no familiarity with the Russian alphabet).
Encouragingly, the non-patient case performed within normal limits when compared to the normative data for the American non-demented group, while patients diagnosed with dementia performed on average within the moderately demented range (Table 1). Patients with other neurological conditions performed below expectations, but better then demented patients. However, at this time the available sample is too small and varied for meaningful statistical analysis.
A similar pattern of performance was observed on most of the additional tests with the exception of the Controlled Oral Word Association Test (Table 2), where non-demented group mean was lower than that of the demented group. In regards to this apparent discrepancy, it should be noted that several patients in non-demented group had left-side CVAs.
Table 1
CERAD Normative Data and Russian Sample Data
Test | American Non-Demented Mean (SD) | RussianNon-patient’s score | American Moderately Demented Mean (SD) | Russian Demented Mean (SD) | Russian Other Neurological Conditions Mean (SD) |
VF* | 18 (4.8) | 13 | 6.8 (3.8) | 6.9 (4.1) | 10.2 (0.8) |
BNT | 14.6 (0.6) | 15 | 10.5 (3.3) | 8.5 (3.5) | 10.8 (4.4) |
MMSE | 28.9 (1.3) | 29 | 16.1 (4.7) | 17.6 (5.0) | 24.7 (5.4) |
CP | 10.1 (1.2) | 10 | 6.5 (2.9) | 7.8 (2.3) | 8.8 (2.9) |
WLM | 21.1 (3.7) | 18 | 6.3 (3.9) | 7.4 (4.0) | 13.5 (2.8) |
WLR-l | 7.2 (1.8) | 7 | 0.4 (0.8) | 0.9 (1.1) | 3.5 (2.1) |
WLR-r | 9.6 (0.8) | 9 | 3.9 (2.8) | 4.7 (3.9) | 7.8 (2.6) |
Note: *VF – Verbal Fluency test, BNT – Boston Naming Test (15-item), MMSE – Mini-Mental Status Exam, CP – Constructional Praxis test, WLM – Word List Memory test, WLR-l – Word List Recall, and WLR-r – Word List Recognition.
Table 2
Additional Tests Normative Data and Russian Sample Data
Test | American Non-Demented Mean (SD) | RussianNon-patient’s score | Russian Demented Mean (SD) | Russian Other Neurological Conditions Mean (SD) |
SAR* | 16.8 (8.8) | 22 | 6.4 (3.3) | 5.6 (1.7) |
VPAL | 16.8 (4.0) | 22 | 6.5 (4.8) | 10.8 (4.2) |
VPAR | 6.7 (1.4) | 8 | 2.2 (1.8) | 5.2 (2.2) |
CPR | ** | 10 | 2.0 (3.6) | 6.4 (4.2) |
TA | 60.7 (26.0) | 37 | 200.1 (149.8) | 171.2 (211.0) |
TB | 152.2 (83.1) | 147 | 264.7 (71.8) | ** |
COWA | 44.4 (5.7) | 37 | 20.17 (17.7) | 17.5 (13.0) |
FTR | M: 38.7 (5.9)F: 25.6 (5.3) | ** | ** | 30.6 (8.2) |
FTL | M: 37.2 (5.4)F: 24.0 (6.0) | ** | ** | 27.3 (7.7) |
CD | 4 | 4 | 1.7 (0.5) | 2.2 (1.6) |
Note: * SAR – Shipley Abstract Reasoning, VPAL – Verbal Paired Associates Learning, VPAR – Verbal Paired Associates Recall, CPR – Constructional Praxis Recall, TA – Trails A time, TB – Trails B time, COWA – Controlled Oral Word Associations test, FTR – Finger Tapping (right hand), FTL – Finger Tapping (left hand), CD – Clock Drawing test.
** Indicates absence of data.
The norms were used for the oldest group available or for the 80-90 age group.
DISCUSSION
The results of this study provide some preliminary support for the diagnostic utility of the CERAD-RA. The battery was well tolerated, easily understood, and took approximately the same amount of time as the CERAD battery in English. Moreover, the obtained results were within expectations for both non-patient and demented groups and varied in the expected direction for the group of patients with neurological conditions other than dementia, though it should be reiterated that the available sample sizes were small.
These results warrant further research in order to provide normative data for the Russian-speaking geriatric population. They also are encouraging in terms of potential use of this translation for cross-cultural research. However, before such research can be undertaken, a study comparing a large sample of patients with Alzheimer’s disease, other types of dementia, and a control group needs to be undertaken in order to ensure the CERAD-RA’s validity.
Additional tests included in the extended battery were less easily tolerated by patients with severe dementia and agitation. However, they provided a source of diagnostic information and were invaluable in treatment planning. For example, the opportunity to differentiate between the levels of impairment in visual and verbal memory, as well as the improvement obtained with the use of associations and various types of cues have obvious implications for the selection of memory aids. Therefore, it seems reasonable to include these measures in the future normative and validation studies.
REFERENCES
Brislin, R. W. (1970) Back-translation for cross-cultural research. Journal of Cross-Cultural Psychology, 1, 185-216.
Demers, P., Robillard, A., Lafleche, G., Nash, F., Heyman, A., & Fillenbaum, G. (1994) Translation of clinical and neuropsychological instruments into French: The CERAD experience. Age and Ageing, 23, 449-451.
Flaherty, J. A., Gaviria, F. M., Pathak, D., Mitchell, T., Wintrob, R., Richman, J. A., & Birz, S. (1998) Developing instruments for cross-cultural psychiatric research. The Journal of Nervous and Mental Disease, 176, 257-263.
Lezak, M. D. (1995) Neuropsychological Assessment. New York: Oxford University Press.
Morris, J. C., Heyman, A., Mohs, R. C., Hughes, J. P., van Belle, G., Fillenbaum, G., Mellits, E. D., Clark, C., & the CERAD investigators (1989) The Consortium to Establish a Registry for Alzheimer’s Disease (CERAD): Part 1. Clinical and neuropsychological assessment of Alzheimer’s disease. Neurology, 39, 1159-1165.
Satzger, W., Ingrassia, G., Nolde, T., Burger, K., Hampel, H., & Engel, R.R. (1999) The CERAD neuropsychological battery as a screening instrument in differentiating dementia and depression. Presented at the AGNP Symposium in Nuremberg.
Spreen, O. & Stauss, E. (1998) A Compendium of neuropsychological tests. New York: Oxford University Press.
Tuokko, H., Hadjistavropoulos, T., & Miller, J. A. (1992) The Clock Test: a sensitive measure to differentiate normal elderly from those with Alzheimer’s disease. Journal of American Geriatric Society, 40, 1095-1099.
Unverzagt, F. W., Morgan, O. S., Thesiger, C. H., Eldemire, D. A., Luseko, J., Pokuri, S., Hui, S. L., Hall, K. S., & Hendrie, H. C. (1999) Clinical utility of CERAD neuropsychological battery in elderly Jamaicans. Journal of International Neuropsychological Society, 5, 255-259.
Wechsler, D. (1987) Wechsler Memory Scale-Revised Manual. San Antonio: The Psychological Corporation Harcourt Brace Jovanovich, Inc..
Zachary, R. A. (1986) Shipley Institute of Living Scale. Los Angeles: Western Psychological Services.
US Census Bureau (1990) Languages spoken at home by persons 5 years and over. Available at http://www.census.gov