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Neuropsychological performance in dementia of the Alzheimer type and multi-infarct dementia
0887.6177/86 $3.00 + .@I Archives ojC/inic~lNeu~p~.~cho/ogv. Vol. I. pp. 335-340, 1986 Copyright 0 1987 National Academy of Clinical Neuropsycholwists Printed in the USA. All rights reserved.
Neuropsychological Performance in Dementia of the Alzheimer Type and Multi-Infarct Dementia David W. Loring and K. J. Meador Medical College of Georgia
Roderick K. Mahurin Baylor College of Medicine
John W. Largen Kelsey-Seybold Clinic
Neuropsychologicalperformance was examined in patients with dementia of the Alzheimer type (DAT) and in age- and education-matched patients with multiinfarct dementia (MID). Significant differences were observed for FSIQ. VIQ, and Picture Completion. This contrasts to no difference in verbal memory, visual-spatial skills, and sustained attention/concentration. This report illustrates that neuropsychological testing of elderly patients is unable to aid in the differential diagnosis between clinically similar forms of dementia, and should be employed to establish the level of cognitive function IO make inferences regarding the patient’s functional independence.
Dementia of the Alzheimer type (DAT) is the most common cause of intellectual deterioration in senescence and accounts for approximately half of dementia cases (Blessed, Tomlinson, & Roth, 1968; Tomlinson, Blessed, & Roth, 1970). The next most frequent type of dementia, multi-infarct demen-
Requests for reprints should be addressed to David W. Loring, Department of Neurology, Section of Behavioral Neurology, Medical College of Georgia, Augusta, GA 30912-2366. 335
336
D. U! Loring, K. J Meador, R. K. Mahurin, and J WI Largen
tia (MID), results from repeated small cerebral infarction and is seen in IO15% of dementia patients. An additional lo-15% of dementia patients exhibit mixed DAT and MID etiology. The pattern of cognitive decline observed in DAT and MID is similar. Perez, Rivera, Meyer, Gay, and Mathew (1975a) reported significantly poorer performance of DAT patients on selected WAIS measures as compared to MID patients. However, a significant amount of shrinkage was observed upon cross-validation (Perez, Stump, Gay, & Hart, 1976). Further, step-wise regression revealed that the most parsimonious model able to discriminate both replication groups was a noncognitive variable (i.e., education). DAT patients have also been reported to perform significantly more poorly than MID patients on the Wechsler Memory Scale (WMS) (Perez, Gay, Taylor, & Rivera, 1975b). Muramoto (1984) reported no difference between MID and DAT groups for verbal selective reminding performance, while the DAT subjects performed more poorly on visual selective reminding. The purpose of the present study was to re-examine neuropsychological performance in DAT and MID using current diagnostic criteria in patients with mild-to-moderate dementia to determine if reliable differences exist which might aid in the differential diagnosis of these diseases. METHODS
Subjects Twelve patients with a diagnosis of DAT [age = 69.1(8.3)] and 12 patients diagnosed as MID [age=69.7(6.6)] served as subjects. DAT patients averaged 12.1(3.7) years of education and MID patients averaged 12.0(3.6) years. In addition, 12 healthy controls matched for age [67.9(7.3)] and education [13.2(2.8)] were studied to provide a reference for cognitive functioning. Dementia severity was assessed using the Dementia Rating Scale (DAT=4.8, MID=4.3) (Blessed et al., 1968). Representative numbers of males and females were included in all groups. Standard criteria for diagnosis of DAT and MID were employed after the clinical examination by a board certified neurologist (McKhann, Drachman, Folstein, Katzman, Price, & Stadlan, 1984). For DAT, the neurological examination, clinical EEGs, and CT scans, revealed no evidence of focal abnormalities. Mean modified Hachinski ischemia scale (Rosen, Terry, Fuld, Katzman, & Peck, 1980) for the DAT group was 1.3. No DAT patient had a history of any acute neurologic event. The principal criterion for inclusion into the MID group was the modified Hachinski ischemia scale score, with a score of 4 or higher being the
Neuropsychological
Performance
in Dementia
337
operational definition of MID (Mean = 5.8). Although the presence of small infarcts on CT was not an inclusion criterion, eight subjects’ CTs did reveal lacunae and/or focal cortical infarction. The remaining four subjects had histories of multiple acute neurological deficits consistent with cerebral infarction. All of the MID patients had a history of hypertension. Patients with a history of other neurologic and/or major psychiatric disturbances were excluded from both groups. Neuropsychological
Test Battery
The Satz-Mogel short form of the WAIS was selected to provide an estimate of general cognitive functioning (Mogel & Satz, 1963; Satz & Mogel, 1962; Silverstein, 1982). To assess sustained attention and concentration, we administered Digit Cancellation (Moran & Mefferd, 1959), Hidden Words (Moran & Mefferd, 1959), Seashore Rhythm (Reitan, 1979), Continuous Performance (Rosvold, Mirsky, Saason, Bransome, & Beck, 1956), and Sentence Repetition Tests (Spreen & Benton, 1969; Baker & Leland, 1967). The visual-spatial tasks consisted of a 15-pair three-dimensional geometric recognition task adapted from Metzler and Shepard (1974). In this task, a picture of a 3-D cube configuration is presented for 5s followed by a 5s presentation of a similar figure rotated about the vertical axis. The subject’s task is to determine if the second figure is the same or different from the first figure. Additional visual spatial tests included Embedded Figures (Benton & Spreen, 1969) and the geometric designs from the Recurring Figure recognition test (Kimura, 1963). Recent verbal memory was assessed with an eight trial, 12 word list utilizing the Selective Reminding procedure of Buschke and Fuld (1974). In this test, subjects are prompted only on those words not recalled on the immediately preceding trial. Longterm storage is operationally defined as correct recall of a word after two consecutive trials. Consistent long-term retrieval is defined as consistent retrieval from long-term storage without further prompting. The memory values reported are sums across repeated trials. RESULTS Student t-tests between MID and DAT groups were performed for dependent measures and are presented in Table 1. Given the descriptive nature of the paper, no control over experiment-wise Type I error rate was employed in order to maintain maximum per comparison power. Significant group differences were observed for FSIQ, VIQ, and the Picture Completion subtest. No group differences in recent verbal memory was observed.
338
D. W Loring, K. .l Meador, R. K. Mahurin,
Mean Neuropsychological
TABLE 1 Performance Levels (SDS in parentheses) Control
FSIQ
PlQ v1Q
and J. W Largen
DAT
MID
f(22)
82.6 (18.2) 80.6 (18.9) 85.6 (16.1)
97.8 (16.9) 97.2 (22.8) 98.1 (12.8)
2.10* 1.95 2.10* 1.90 1.67 1.50 1.27
113.8 110.9 114.4
(7.8) (8.8) (8.4)
9.8 12.9 10.8 10.8 10.8 12.2
(2.4) (3.7) (3.1) (3.8) (2.8) (1.7)
5.1 7.3 5.8 5.7 5.6 7.2
(2.4) (3.8) (3.4) (2.5) (2.8) (3.4)
7.0 10.0 7.8 7.2 7.2 8.7
(2.6) (4.0) (3.2) (3.2) (3.4) (2.3)
7.9 9.8 7.5 8.8 7.6
(1.8) (1.9) (2.2) (2.0) (1.7)
2.0 4.5 2.7 3.9 4.4
(2.5) (2.4) (2.9) (3.1) (2.4)
4.1 7.8 6.0 5.8 5.4
(3.6) (3.3) (5.4) (2.9) (4.5)
57.0 (13.5)
13.9
(7.9)
Verbal Subtests Information Comprehension Arithmetic Similarities Digit Span Vocabulary
1.24 1.33
Performance Subtests Digit Symbol Pit. Completion Block Design Pit. Arrangement Object Assembly
1.66 2.79’ 1.87 1.54 0.68
Selective Reminding Long-Term Storage Continuous LongTerm Retrieval
10.58 (9.1) 1.75
(3.8)
0.96 0.85
39.2
(6.7)
0.8
(1.5)
26.0 13.0 8.8
(2.8) (1.6) (1.9)
13.6 4.1 7.5
(6.7) (5.1) (2.2)
12.8 (10.2) 6.8 (6.6) 8.5 (3.2)
0.89
32.6 (15.0) 30.2 (19.8) 6.8 (5.0) 13.8 (7.4) 3.2 (4.2)
40.2 (I 1.7) 37.5 (22.9) 8.4 (8.5) 16.2 (9.1) 6.2 (5.3)
1.38 0.83 0.58 0.69 1.48
Visual-Spatial Tests Recurring Figures Embedded Figures Geometric Rotation
0.83
1.67
Attention/Concentration Cont. Performance Digit Cancellation Hidden Words Seashore Rhythm Sentence Repetition
48.3 (2.6) 64.4 (10.6) 15.5 (6.0) 26.3 (1.9) 12.1 (2.8)
*p<.O5, two-tailed.
DISCUSSION
The pattern of differences does not easily lend itself to interpretation. Performance on Picture Completion, which tends to be relatively resistent to the effects of brain pathology, was significantly different @ < .02) between the dementia groups. In contrast, difference in Block Design performance, which can easily be accounted for by either task complexity or visual spatial performance, was not significant (p < .08). Of the verbal subtests, Information is the only measure approaching statistical significance (PC .07), and this is a test of overlearned crystallized information which tends to be resistent to the effects of brain damage (e.g., Lezak, 1983). The absence of a consistent pattern suggests these differences may be due to Type I errors.
Neuropsychological
Performance
in Dementia
339
Unlike Muramoto (1984), we found no support for relatively poorer performance by DAT patients on nonverbal memory tests. The nonverbal selective reminding procedure of Muromoto may be a higher level test of global memory involving many skills necessary for successful completion other than purely visual-spatial memory. That is, task complexity may have produced differences in operational measures of memory function rather than differences in memory per se. Our failure to find a group effect on Selective Reminding performance is especially noteworthy. As previously indicated, reports of significantly different Wechsler Memory Quotients have been made (Perez et al., 1975b). It is important to note that differences in ages existed between groups for that study. Since a significant number of age-correction points are added to a raw score prior to computation of the MQ, their results must be interpreted with caution. In contrast, our subjects were matched for age. Therefore, given the absence of a difference on selective reminding, we think a conclusion of differential memory performance is unwarranted. These data suggest that differentiation between DAT and MID cannot be made on the basis of neuropsychological test performance, even when the patients present with mild-to-moderate dementia and are well matched for age and education. As with other diagnostic criteria, the diagnosis of DAT and MID using behavioral data entails a non-negligible risk of misclassification. Given the absence of reliable differentiation between well matched, homogeneous groups, it appears impossible to make this differentiation on an individual case basis with patients that are more heterogeneous. The major clinical role of neuropsychological assessment in elderly patients with dementia is not to differentiate the specific diagnosis. Rather, it is to establish the level of cognitive function in order to make informed decisions regarding the patient’s functional independence. Acknowledgmenr-Preparation of this article was supported in part by National Institute of Aging Grant K08 AGOO314-01and Medical College of Georgia Research Institute Award to K. J. Meador. We thank Patricia Downs and Crystal J. Sherman for their assistance in manuscript preparation.
REFERENCES Baker, H. J., & Leland, B. (1967). Manual for the Detroit Tests of Learning Aptitude. Indianapolis: Bobbs-Merrill Co. Benton, A. L., & Spreen, 0. (1969). Embeddedfigures test: Manual of instructions and norms. Neuropsychology Laboratory, University of Victoria. Blessed, G., Tomlinson, B. E., & Roth, M. (1968). The association between quantitative measures of dementia and of senile change in the cerebral grey matter of elderly subjects. British Journal of Psychiatry, 114, 797-81 I.
340
D. W Loring, K. J. Meador, R. K. Mahurin, and J W Largen
Buschke, H., & Fuld, P. A. (1974). Evaluating storage, retention, and retrieval in disordered memory and learning. Neurology, 24, 1019-1025. Kimura, D. (1963). Right temporal lobe damage. Archives of Neurology, 8, 264-271. Lezak, M. D. (1983). Neuropsychological assessment (2nd ed.). New York: Oxford University Press. Metzler, J., & Shepard, R. N. (1974). Transformational studies of the internal representation of three-dimensional objects. In R. S. Solso (Ed.) Theories in Cognitive Psychology: The Loyolu Symposium. New York: The Halstead Press. McKhann, G., Drachman, D., Folstein, M., Katzman, R., Price, D., & Stadlan, E. M. (1984). Clinical diagnosis of Alzheimer’s disease: Report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s Disease. Neurology, 34, 939-944. Mogel, S., & Satz, P. (1963). Abbreviation of the WAIS for clinical use: An attempt at validation. Journal of Consulting and Clinical Psychology, 19,298-300. Moran, L. J., & Mefferd, R. B. (1959). Repetitive psychometric measures. Psychological Reports, 5,269-275. Muramoto, 0. (1984). Selective reminding in normal and demented aged people: Auditory verbal versus visual spatial task. Cortex, 20,461-478. Perez, E I., Rivera, V. M., Meyer, J. S., Gay, J. R. A., & Mathew, N. T. (1975a). Analysis of intellectual and cognitive performance in patients with multi-infarct dementia, vertebrobasilar insufficiency with dementia and Alzheimer’s disease. Journal of Neurology, Neurosurgery and Psychiatry, 38,533-540. Perez, F. I., Gay, J. R. A., Taylor, R. L., & Rivera, V. M. (1975b). Patterns of memory performance in the neurologically impaired aged. Canadian Journal of Neurological Science, 2,347-355. Perez, F., Stump, D., Gay, J., & Hart, V. (1976). Intellectual performance in multi-infarct dementia and Alzheimer’s disease. Canadian Journal of Neurological Science, 3, 18I- 187. Reitan, R. M. (1979). Manual for Administration of Neuropsychological Test Batteries for Adults and Children. ncson, Arizona, Reitan Neuropsychology Laboratories, Inc. Rosen, W. G., Terry, R. D., Fuld, P. A., Katzman, R., & Peck, A. (1980). A pathological verification of ischemic score in differentiation of dementias. Annals of Neurology, 7, 484-488. Rosvold, H. E., Mirsky, A. F., Saason, D., Bransome, E. D., & Beck, L. H. (1956). A continuous performance test of brain damage. Journal of Consulting Psychology, 20, 343-350. Satz, P., & Mogel, S. (1962). An abbreviation of the WAIS for clinical use. Journul of Clinical Psychology, l&77-79. Silverstein, A. B. (1982). Validity of Satz-Mogel-Yudin-type short forms. Journal of Consulting and Clinical Psychology, 50,20-21. Spreen, O., & Benton, A. L. (1969). Sentence Repetition Test: Manual of Instructions and Norms. Neuropsychology Laboratory, University of Victoria. Tomlinson, B. E., Blessed, G., &Roth, M. (1970). Observations on the brains of demented old people. Journal of Neurological Science, 11, 205-242.
Neuropsychological Performance in Dementia of the Alzheimer Type and Multi-Infarct Dementia David W. Loring and K. J. Meador Medical College of Georgia
Roderick K. Mahurin Baylor College of Medicine
John W. Largen Kelsey-Seybold Clinic
Neuropsychologicalperformance was examined in patients with dementia of the Alzheimer type (DAT) and in age- and education-matched patients with multiinfarct dementia (MID). Significant differences were observed for FSIQ. VIQ, and Picture Completion. This contrasts to no difference in verbal memory, visual-spatial skills, and sustained attention/concentration. This report illustrates that neuropsychological testing of elderly patients is unable to aid in the differential diagnosis between clinically similar forms of dementia, and should be employed to establish the level of cognitive function IO make inferences regarding the patient’s functional independence.
Dementia of the Alzheimer type (DAT) is the most common cause of intellectual deterioration in senescence and accounts for approximately half of dementia cases (Blessed, Tomlinson, & Roth, 1968; Tomlinson, Blessed, & Roth, 1970). The next most frequent type of dementia, multi-infarct demen-
Requests for reprints should be addressed to David W. Loring, Department of Neurology, Section of Behavioral Neurology, Medical College of Georgia, Augusta, GA 30912-2366. 335
336
D. U! Loring, K. J Meador, R. K. Mahurin, and J WI Largen
tia (MID), results from repeated small cerebral infarction and is seen in IO15% of dementia patients. An additional lo-15% of dementia patients exhibit mixed DAT and MID etiology. The pattern of cognitive decline observed in DAT and MID is similar. Perez, Rivera, Meyer, Gay, and Mathew (1975a) reported significantly poorer performance of DAT patients on selected WAIS measures as compared to MID patients. However, a significant amount of shrinkage was observed upon cross-validation (Perez, Stump, Gay, & Hart, 1976). Further, step-wise regression revealed that the most parsimonious model able to discriminate both replication groups was a noncognitive variable (i.e., education). DAT patients have also been reported to perform significantly more poorly than MID patients on the Wechsler Memory Scale (WMS) (Perez, Gay, Taylor, & Rivera, 1975b). Muramoto (1984) reported no difference between MID and DAT groups for verbal selective reminding performance, while the DAT subjects performed more poorly on visual selective reminding. The purpose of the present study was to re-examine neuropsychological performance in DAT and MID using current diagnostic criteria in patients with mild-to-moderate dementia to determine if reliable differences exist which might aid in the differential diagnosis of these diseases. METHODS
Subjects Twelve patients with a diagnosis of DAT [age = 69.1(8.3)] and 12 patients diagnosed as MID [age=69.7(6.6)] served as subjects. DAT patients averaged 12.1(3.7) years of education and MID patients averaged 12.0(3.6) years. In addition, 12 healthy controls matched for age [67.9(7.3)] and education [13.2(2.8)] were studied to provide a reference for cognitive functioning. Dementia severity was assessed using the Dementia Rating Scale (DAT=4.8, MID=4.3) (Blessed et al., 1968). Representative numbers of males and females were included in all groups. Standard criteria for diagnosis of DAT and MID were employed after the clinical examination by a board certified neurologist (McKhann, Drachman, Folstein, Katzman, Price, & Stadlan, 1984). For DAT, the neurological examination, clinical EEGs, and CT scans, revealed no evidence of focal abnormalities. Mean modified Hachinski ischemia scale (Rosen, Terry, Fuld, Katzman, & Peck, 1980) for the DAT group was 1.3. No DAT patient had a history of any acute neurologic event. The principal criterion for inclusion into the MID group was the modified Hachinski ischemia scale score, with a score of 4 or higher being the
Neuropsychological
Performance
in Dementia
337
operational definition of MID (Mean = 5.8). Although the presence of small infarcts on CT was not an inclusion criterion, eight subjects’ CTs did reveal lacunae and/or focal cortical infarction. The remaining four subjects had histories of multiple acute neurological deficits consistent with cerebral infarction. All of the MID patients had a history of hypertension. Patients with a history of other neurologic and/or major psychiatric disturbances were excluded from both groups. Neuropsychological
Test Battery
The Satz-Mogel short form of the WAIS was selected to provide an estimate of general cognitive functioning (Mogel & Satz, 1963; Satz & Mogel, 1962; Silverstein, 1982). To assess sustained attention and concentration, we administered Digit Cancellation (Moran & Mefferd, 1959), Hidden Words (Moran & Mefferd, 1959), Seashore Rhythm (Reitan, 1979), Continuous Performance (Rosvold, Mirsky, Saason, Bransome, & Beck, 1956), and Sentence Repetition Tests (Spreen & Benton, 1969; Baker & Leland, 1967). The visual-spatial tasks consisted of a 15-pair three-dimensional geometric recognition task adapted from Metzler and Shepard (1974). In this task, a picture of a 3-D cube configuration is presented for 5s followed by a 5s presentation of a similar figure rotated about the vertical axis. The subject’s task is to determine if the second figure is the same or different from the first figure. Additional visual spatial tests included Embedded Figures (Benton & Spreen, 1969) and the geometric designs from the Recurring Figure recognition test (Kimura, 1963). Recent verbal memory was assessed with an eight trial, 12 word list utilizing the Selective Reminding procedure of Buschke and Fuld (1974). In this test, subjects are prompted only on those words not recalled on the immediately preceding trial. Longterm storage is operationally defined as correct recall of a word after two consecutive trials. Consistent long-term retrieval is defined as consistent retrieval from long-term storage without further prompting. The memory values reported are sums across repeated trials. RESULTS Student t-tests between MID and DAT groups were performed for dependent measures and are presented in Table 1. Given the descriptive nature of the paper, no control over experiment-wise Type I error rate was employed in order to maintain maximum per comparison power. Significant group differences were observed for FSIQ, VIQ, and the Picture Completion subtest. No group differences in recent verbal memory was observed.
338
D. W Loring, K. .l Meador, R. K. Mahurin,
Mean Neuropsychological
TABLE 1 Performance Levels (SDS in parentheses) Control
FSIQ
PlQ v1Q
and J. W Largen
DAT
MID
f(22)
82.6 (18.2) 80.6 (18.9) 85.6 (16.1)
97.8 (16.9) 97.2 (22.8) 98.1 (12.8)
2.10* 1.95 2.10* 1.90 1.67 1.50 1.27
113.8 110.9 114.4
(7.8) (8.8) (8.4)
9.8 12.9 10.8 10.8 10.8 12.2
(2.4) (3.7) (3.1) (3.8) (2.8) (1.7)
5.1 7.3 5.8 5.7 5.6 7.2
(2.4) (3.8) (3.4) (2.5) (2.8) (3.4)
7.0 10.0 7.8 7.2 7.2 8.7
(2.6) (4.0) (3.2) (3.2) (3.4) (2.3)
7.9 9.8 7.5 8.8 7.6
(1.8) (1.9) (2.2) (2.0) (1.7)
2.0 4.5 2.7 3.9 4.4
(2.5) (2.4) (2.9) (3.1) (2.4)
4.1 7.8 6.0 5.8 5.4
(3.6) (3.3) (5.4) (2.9) (4.5)
57.0 (13.5)
13.9
(7.9)
Verbal Subtests Information Comprehension Arithmetic Similarities Digit Span Vocabulary
1.24 1.33
Performance Subtests Digit Symbol Pit. Completion Block Design Pit. Arrangement Object Assembly
1.66 2.79’ 1.87 1.54 0.68
Selective Reminding Long-Term Storage Continuous LongTerm Retrieval
10.58 (9.1) 1.75
(3.8)
0.96 0.85
39.2
(6.7)
0.8
(1.5)
26.0 13.0 8.8
(2.8) (1.6) (1.9)
13.6 4.1 7.5
(6.7) (5.1) (2.2)
12.8 (10.2) 6.8 (6.6) 8.5 (3.2)
0.89
32.6 (15.0) 30.2 (19.8) 6.8 (5.0) 13.8 (7.4) 3.2 (4.2)
40.2 (I 1.7) 37.5 (22.9) 8.4 (8.5) 16.2 (9.1) 6.2 (5.3)
1.38 0.83 0.58 0.69 1.48
Visual-Spatial Tests Recurring Figures Embedded Figures Geometric Rotation
0.83
1.67
Attention/Concentration Cont. Performance Digit Cancellation Hidden Words Seashore Rhythm Sentence Repetition
48.3 (2.6) 64.4 (10.6) 15.5 (6.0) 26.3 (1.9) 12.1 (2.8)
*p<.O5, two-tailed.
DISCUSSION
The pattern of differences does not easily lend itself to interpretation. Performance on Picture Completion, which tends to be relatively resistent to the effects of brain pathology, was significantly different @ < .02) between the dementia groups. In contrast, difference in Block Design performance, which can easily be accounted for by either task complexity or visual spatial performance, was not significant (p < .08). Of the verbal subtests, Information is the only measure approaching statistical significance (PC .07), and this is a test of overlearned crystallized information which tends to be resistent to the effects of brain damage (e.g., Lezak, 1983). The absence of a consistent pattern suggests these differences may be due to Type I errors.
Neuropsychological
Performance
in Dementia
339
Unlike Muramoto (1984), we found no support for relatively poorer performance by DAT patients on nonverbal memory tests. The nonverbal selective reminding procedure of Muromoto may be a higher level test of global memory involving many skills necessary for successful completion other than purely visual-spatial memory. That is, task complexity may have produced differences in operational measures of memory function rather than differences in memory per se. Our failure to find a group effect on Selective Reminding performance is especially noteworthy. As previously indicated, reports of significantly different Wechsler Memory Quotients have been made (Perez et al., 1975b). It is important to note that differences in ages existed between groups for that study. Since a significant number of age-correction points are added to a raw score prior to computation of the MQ, their results must be interpreted with caution. In contrast, our subjects were matched for age. Therefore, given the absence of a difference on selective reminding, we think a conclusion of differential memory performance is unwarranted. These data suggest that differentiation between DAT and MID cannot be made on the basis of neuropsychological test performance, even when the patients present with mild-to-moderate dementia and are well matched for age and education. As with other diagnostic criteria, the diagnosis of DAT and MID using behavioral data entails a non-negligible risk of misclassification. Given the absence of reliable differentiation between well matched, homogeneous groups, it appears impossible to make this differentiation on an individual case basis with patients that are more heterogeneous. The major clinical role of neuropsychological assessment in elderly patients with dementia is not to differentiate the specific diagnosis. Rather, it is to establish the level of cognitive function in order to make informed decisions regarding the patient’s functional independence. Acknowledgmenr-Preparation of this article was supported in part by National Institute of Aging Grant K08 AGOO314-01and Medical College of Georgia Research Institute Award to K. J. Meador. We thank Patricia Downs and Crystal J. Sherman for their assistance in manuscript preparation.
REFERENCES Baker, H. J., & Leland, B. (1967). Manual for the Detroit Tests of Learning Aptitude. Indianapolis: Bobbs-Merrill Co. Benton, A. L., & Spreen, 0. (1969). Embeddedfigures test: Manual of instructions and norms. Neuropsychology Laboratory, University of Victoria. Blessed, G., Tomlinson, B. E., & Roth, M. (1968). The association between quantitative measures of dementia and of senile change in the cerebral grey matter of elderly subjects. British Journal of Psychiatry, 114, 797-81 I.
340
D. W Loring, K. J. Meador, R. K. Mahurin, and J W Largen
Buschke, H., & Fuld, P. A. (1974). Evaluating storage, retention, and retrieval in disordered memory and learning. Neurology, 24, 1019-1025. Kimura, D. (1963). Right temporal lobe damage. Archives of Neurology, 8, 264-271. Lezak, M. D. (1983). Neuropsychological assessment (2nd ed.). New York: Oxford University Press. Metzler, J., & Shepard, R. N. (1974). Transformational studies of the internal representation of three-dimensional objects. In R. S. Solso (Ed.) Theories in Cognitive Psychology: The Loyolu Symposium. New York: The Halstead Press. McKhann, G., Drachman, D., Folstein, M., Katzman, R., Price, D., & Stadlan, E. M. (1984). Clinical diagnosis of Alzheimer’s disease: Report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s Disease. Neurology, 34, 939-944. Mogel, S., & Satz, P. (1963). Abbreviation of the WAIS for clinical use: An attempt at validation. Journal of Consulting and Clinical Psychology, 19,298-300. Moran, L. J., & Mefferd, R. B. (1959). Repetitive psychometric measures. Psychological Reports, 5,269-275. Muramoto, 0. (1984). Selective reminding in normal and demented aged people: Auditory verbal versus visual spatial task. Cortex, 20,461-478. Perez, E I., Rivera, V. M., Meyer, J. S., Gay, J. R. A., & Mathew, N. T. (1975a). Analysis of intellectual and cognitive performance in patients with multi-infarct dementia, vertebrobasilar insufficiency with dementia and Alzheimer’s disease. Journal of Neurology, Neurosurgery and Psychiatry, 38,533-540. Perez, F. I., Gay, J. R. A., Taylor, R. L., & Rivera, V. M. (1975b). Patterns of memory performance in the neurologically impaired aged. Canadian Journal of Neurological Science, 2,347-355. Perez, F., Stump, D., Gay, J., & Hart, V. (1976). Intellectual performance in multi-infarct dementia and Alzheimer’s disease. Canadian Journal of Neurological Science, 3, 18I- 187. Reitan, R. M. (1979). Manual for Administration of Neuropsychological Test Batteries for Adults and Children. ncson, Arizona, Reitan Neuropsychology Laboratories, Inc. Rosen, W. G., Terry, R. D., Fuld, P. A., Katzman, R., & Peck, A. (1980). A pathological verification of ischemic score in differentiation of dementias. Annals of Neurology, 7, 484-488. Rosvold, H. E., Mirsky, A. F., Saason, D., Bransome, E. D., & Beck, L. H. (1956). A continuous performance test of brain damage. Journal of Consulting Psychology, 20, 343-350. Satz, P., & Mogel, S. (1962). An abbreviation of the WAIS for clinical use. Journul of Clinical Psychology, l&77-79. Silverstein, A. B. (1982). Validity of Satz-Mogel-Yudin-type short forms. Journal of Consulting and Clinical Psychology, 50,20-21. Spreen, O., & Benton, A. L. (1969). Sentence Repetition Test: Manual of Instructions and Norms. Neuropsychology Laboratory, University of Victoria. Tomlinson, B. E., Blessed, G., &Roth, M. (1970). Observations on the brains of demented old people. Journal of Neurological Science, 11, 205-242.