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afasia apraxia y agnosia demencia

Original Research Article
Dementia 1996;7:23-26
and Agnosia
Department of Psychiatry, University of
California, San Francisco Medical Center,
San Francisco, Calif., USA
D lS g n O S I S
Cortical dementia
Subcortical dementia
The association of aphasia, apraxia and agnosia with cortical but not subcorti­
cal dementias, is a widely held belief. The purpose of the present study was to
determine the frequency of aphasia, apraxia, and agnosia in groups of cortical
and subcortical dementia patients, and to assess the diagnostic utility of these
symptoms. Subjects were 64 patients with subcortical dementias (Parkinson's
disease and normal pressure hydrocephalus) and 192 patients with cortical
dementia (probable Alzheimer’s disease) matched for sex, age, and Mini-Men­
tal State Examination score. Each patient was evaluated for the presence of
aphasia, apraxia, and agnosia. Results indicated that only aphasia was
reported significantly more often in cortical dementia patients than in subcor­
tical dementia patients. The presence of either of these three symptoms has
very low diagnostic sensitivity, specificity, and total predictive value. The
severity of the patient’s dementia was predicted whether the patient had apha­
sia or apraxia; type of dementia had no predictive value. These data led to the
conclusion that cortical and subcortical dementias cannot be reliably disso­
ciated on the basis of aphasia, apraxia, or agnosia.
The term subcortical dementia was introduced in the
1970s to differentiate disorders of the basal ganglia and
other subcortical structures from dementing illnesses pri­
marily affecting the cerebral cortex [1-3]. According to
Cummings [4], cortical dementias, the prototype being
Alzheimer’s disease, present with aphasia, apraxia, agno­
sia, amnesia, and acalculia. In contrast, subcortical de­
mentias are characterized by slow information processing
speed, apathy, depression, and impaired ability to manip­
ulate acquired knowledge [5, 6], Aphasia, apraxia and
This material is based upon work supported by the Alzheimer’s Disease
Program, State of California, Department of Health Services, serviced under
interagency agreement No. 444949-18750.
v r u VVJ L i \
E-Mail [email protected]
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@ 1996 S. Karger AG. Basel
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O f D
e m
d l t i a
agnosia, considered by some to be hallmark features of
cortical dementias, are typically absent in subcortical
dementias [7, 8].
The association of aphasia, apraxia, and agnosia with
cortical but not subcortical dementias is a logical infer­
ence in light of current neuropsychological models that
emphasize how these functions are cortically mediated
[9-11], However, whether aphasia, apraxia, and/or agno­
sia occur more frequently in cortical dementias has not
yet been empirically established. In addition, the diagnos­
tic utility of these symptoms, alone or in combination, has
not been assessed. The purpose of this study was to empir­
ically investigate aphasia, apraxia, and agnosia in cortical
and subcortical dementias.
Joel H. Kramer
Department of Psychiatry
University of California Medical Center
Box 0984-CPT. 401 Parnassus Avenue
San Francisco, CA 94143 (USA)
April 5.1995
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joeih . Kramer
Jennifer M. Duffy
Table 1. Demographic characteristics of
sample (mean ± SD)
75.73 ±6.79
76.05 ± 7.88
75.00 ±3.54
19.01 ±5.57
19.28 ±6.08
19.62 ±5.12
Table 2. Number of patients displaying aphasia, apraxia, and
55 (35.5)
36 (23.7)
21 (13.7)
sia. Aphasia was defined as impairment in the patient’s expressive or
receptive language. Expressive language deficits included impair­
ments in the patient’s ability to express him- or herself orally or in
writing, and could include empty speech, circumlocutions, paraphasic errors, paragrammaticisms, or impairments in repetition, fluency,
and intonation. Receptive language deficits were coded whenever the
patient’s ability to understand spoken or written verbal material was
compromised. Aphasia was not rated as present if the patient’s lan­
guage deficits were attributable to motor output problems (e.g.,
dysarthria), apraxia of speech, impaired hearing, inattention, or
memory impairment. Apraxia was defined as an inability to carry out
purposeful, skilled, and voluntary motor acts. Apraxia was not coded
when the patient’s inability to execute a movement was considered
due to failure to comprehend the command, primary motor impair­
ment, or sensory loss. An agnosia was coded as present whenever the
patient displayed an inability to recognize familiar objects or people
in the absence of sensory impairment, attentional disorder, or
impaired confrontation naming ability. For each patient, aphasia,
apraxia, and agnosia were rated as present, absent, or undeter­
Percentage of group for whom data were available and who dis­
played symptom is in parentheses.
M ethods
Patients Selection
Records from 4,320 patients evaluated by the nine State of Cali­
fornia Alzheimer Centers between 1985 and 1991 were reviewed to
identify patients with subcortical dementia. Each patient received a
comprehensive and multidisciplinary diagnostic evaluation and was
assessed on several medical, neuropsychological, psychiatric, and
psychosocial variables. Laboratory and neuroimaging studies was
routinely performed. The range of diagnoses within this sample was
quite broad, and included probable and possible Alzheimer’s disease,
psychiatric disorders, frontal lobe syndromes, movement disorders,
and treatable medical conditions. Two disorders with primary sub­
cortical involvement were identified: Parkinson’s disease (PD) and
normal pressure hydrocephalus (NPH). A search through the sample
of 4,320 patients located 87 patients with PD and 29 with NPH, for a
total of 116 patients with subcortical disorders. From this group, 36
PD patients were excluded because Alzheimer’s disease could not be
ruled out as a diagnostic possibility. Thirteen NPH patients were
excluded because Alzheimer’s disease was not ruled out, 2 were
excluded because of probable cerebrovascular disease, and 1 was
excluded because of a history of significant head trauma. Sixty-four
patients with subcortical dementia remained in the sample, 51 with
PD and 13 with NPH.
For each patient with a diagnosis of subcortical dementia, 3
patients with probable Alzheimer’s disease (pAD) were selected,
matched on age, sex, and Mini-Mental State Examination score
(MMSE) [12], All patients with pAD met ADRDA-NINCDS criteria
[13]. Descriptive statistics for each group are summarized in table 1.
Each patient was evaluated by the Alzheimer’s Center’s physician
or ncuropsychologist for the presence of aphasia, apraxia and agno­
Dementia 1996;7:23-26
The percentage of patients within each diagnostic
group that displayed aphasia, apraxia, and agnosia is pre­
sented in table 2. Group differences in the frequency of
each symptom were analyzed with the x2statistic. Only
patients for whom the symptom was rated as present or
absent were included in the analyses.
The first set of analyses compared patients with PD
and NPH. No significant differences were found in the
frequency of aphasia, apraxia or agnosia between these
groups. Data from these two diagnostic categories were
therefore combined into a single subcortical dementia
group for subsequent analyses.
Aphasia was reported significantly more often in pa­
tients with cortical dementia than in patients with subcor­
tical dementia (x2 = 5.01; p < 0.05). Cortical dementia
patients were almost twice as likely as subcortical demen­
tia patients to be characterized as aphasic. Despite this
significant group difference, the majority of cortical de­
mentia patients (63.3%) were coded as not having apha­
There were no significant group differences in the fre­
quency of apraxia. A trend in the predicted direction was
found for the frequency of agnosia (x2= 3.42; p = 06), with
agnosia appearing more often in the pAD patients than in
the subcortical patients.
The diagnostic utility of aphasia, apraxia, and agnosia
was assessed several ways. First, patients who had either
aphasia, apraxia, or agnosia were given a predicted diag­
nosis of cortical dementia. The accuracy of the predicted
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The results of this study indicate that when welldefined and matched samples of cortical and subcortical
dementia patients are compared, there are no significant
group differences in the prevalence of apraxia. Aphasia
occurred more frequently in the cortical group than in the
subcortical group and there was a nonsignificant trend for
agnosia to occur more often in the cortical group than in
the subcortical group.
Although group differences in symptom frequency
may occur, information about the presence of aphasia,
apraxia, and agnosia contributes very little toward diag­
nosis. The majority of pAD patients had none of the three
symptoms, whereas almost a quarter of the subcortical
dementia patients displayed at least one of the symptoms.
The total predictive value of these ‘cortical dementia’
symptoms was at chance levels. In addition, knowledge
about aphasia and agnosia contributed less than 3% of the
variance in diagnosis. Finally, aphasia and apraxia were
most highly correlated with the overall degree of dementia
and, when dementia severity was controlled for, this
symptoms were not predictive of dementia type.
Current notions about dementias hold that subcortical
dementias lack the symptoms of aphasia, apraxia, or
agnosia, and that these symptoms are common in patients
with cortical dementia. This study, however, argues that
this distinction is not empirically supported. Results are
consistent with growing evidence that many of the distin­
guishing characteristics used to classify the cortical and
subcortical dementias overlap [15, 16]. Other studies
have also indicated that significant numbers of demented
patients with aphasia, apraxia, or agnosia did not exhibit
enough other evidence for the diagnosis of cortical de­
mentia [17, 18]. Huber et al. [ 19] reported aphasia, aprax­
ia, and agnosia in patients who developed PD and whose
pathology did not support a diagnosis of pAD. The blur­
red distinctions between cortical and subcortical demen­
tias is consonant with the pathologic overlap between
commonly accepted cortical and subcortical disorders.
Neurofibrillary tangles and neuritic plaques have been
found in demented patients with PD [20, 21] and some
researchers have found nigral degenerative changes, in­
cluding Lewy bodies, in patients with pAD [22].
The present study was based on data from nine demen­
tia diagnostic centers. The resulting large sample adds
credence to the results and represents a strength of this
study. A potential disadvantage of a multicenter database,
however, is that despite uniform diagnostic criteria, some
variability between centers in how diagnoses were made
Aphasia, Apraxia and Agnosia
Dementia 1996;7:23-26
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D iscu ssio n
diagnosis was evaluated for sensitivity, specificity, and
total predictive value [14]. Sensitivity is the probability
that the correct diagnosis is cortical dementia whenever
aphasia, apraxia or agnosia are present. Specificity is the
probability that the correct diagnosis is subcortical de­
mentia whenever aphasia, apraxia, or agnosia are absent.
Finally, total predicted value is the total proportion of
patients whose diagnosis is accurately predicted.
Predicting a cortical dementia on the basis of aphasia,
apraxia, or agnosia being present had a sensitivity of only
45.28%. The majority of pAD patients did not present
with aphasia, apraxia, or agnosia. This resulted in most
pAD patients misclassified as belonging to the subcortical
group. Specificity was also poor (75,47%). Almost a quar­
ter of the subcortical group presented with one of the three
‘cortical’ symptoms. The total predictive value was
52.83%, which is at chance levels.
The diagnostic utility of aphasia, apraxia and agnosia
was also assessed using multiple regression. The question
was framed as follows: What proportion of the variance in
diagnosis can be attributed to the presence of aphasia,
apraxia, and agnosia. The degree of dementia was con­
trolled for by virtue of the fact that the subcortical and
cortical dementia groups were originally matched for
MMSE score. Results indicated significant relationships
for aphasia (F = 5.71, p < 0.05) and agnosia (F = 4.05, p <
0.05). The proportion of variance explained was quite
small, however; approximately 2% for agnosia and 2.7%
for aphasia. Apraxia did not contribute a significant pro­
portion of variance in diagnosis (less than 1%).
The low predictive value of aphasia, apraxia, and agno­
sia indicated that these symptoms were only weakly asso­
ciated with the cortical vs subcortical locus of the dement­
ing disorder. This findings raised the question of whether
these symptoms were more strongly associated with vari­
ables other than diagnosis. To address this issue, multiple
regression analyses were carried out to identify patient
characteristics that predicted the presence of the three
symptoms. MMSE score, sex, and diagnosis were entered
into the multiple regression in a stepwise fashion as pre­
dictor variables. None of these patient characteristics pre­
dicted the presence of agnosia. MMSE score explained a
significant proportion of the variance for apraxia (F =
5.54; p < 0.05); no other variables contributed to the vari­
ance. For aphasia, MMSE was also the only variable
remaining in the regression equation (F = 9.14; p < 0.005).
Thus, degree of dementia was significantly correlated
with the presence of aphasia and apraxia and, once
dementia severity was accounted for, diagnosis did not
explain a significant proportion of the variance.
cannot be ruled out. Similarly, although a uniform set of
operational criteria were used, different centers, and dif­
ferent clinicians within a center, may have had different
thresholds for when they coded a patient as having apha­
sia, apraxia, or agnosia. It is unlikely, however, that this
variability affected the results of this study. Any variabili­
ty in coding symptoms should have been equally true for
both cortical and subcortical syndromes and had little
effect on the weak relationship between clinical symptom
and dementia subtype.
Finally, although this study argues that distinctions
between cortical and subcortical dementias cannot be reli­
ably made on the basis of aphasia, apraxia, and agnosia, it
is possible that dissociations can be made according to
other neuropsychological Findings. Some investigators
have pointed to distinctive patterns of memory impair­
ment. Whereas both types of dementia syndromes are
associated with impaired immediate recall, pAD patients,
relative to subcortical patients, have been found to have
more rapid forgetting over time, greater deficits in recog­
nition memory, and a greater tendency to make intrusion
errors [23], Clear distinctions have also been reported on
measures of nondeclarative memory. Patients with pAD
generally show deficits on lexical priming tasks but not
motor skill learning [24], whereas patients with Hunting­
ton’s disease show the opposite pattern. Several studies
have also reported differences in verbal fluency. Because
of their presumed breakdown in semantic structures,
pAD patients are even more impaired in their category
fluency than in their letter fluency. Subcortical patients,
on the other hand, often display the opposite pattern
because their underlying impairment is presumed to be
one of initiation and retrieval [25,26]. Finally, subcortical
syndromes are more strongly associated with deficits in
executive functioning, that is, attention, conceptual rea­
soning, and self-regulation [8].
Dementia 1996;7:23-26
12 Folstein MF, Folstein SE, McHugh PR: ‘Minimental state’. A practical method for grading
the cognitive stale of patients for the clinician.
J Psychiatr Res 1975;12:189-190.
13 McKann G, Drachman D, Folstein M, Katzman R, Price D, Stadia E: Clinical diagnosis of
Alzheimer's disease: Report of the N1NCDSADRDA Work Group under the auspices of
Department of Health and Human Services
Task Force on Alzheimer’s Disease. Neurology
14 Mossman D, Somoza E: Ncuropsychiatric de­
cision making: The role of disorder prevalence
in diagnostic testing. J Neuropsychiatry Clin
Ncurosci 1991:84-88.
15 Kramer JH, Levin BE, Brandt J, Delis DC: Dif­
ferentiation of Alzheimer’s, Huntington's, and
Parkinson's disease patients on the basis of ver­
bal learning characteristics. Neuropsychology
16 Levin BE, Tomer R, Rey G: Cognitive impair­
ments in Parkinson’s disease. Neurol Clin
17 Sulkava R, IJaltia M, Paetau A, Wikstrom J,
Palo J: Accuracy of clinical diagnosis in prima­
ry degenerative dementia: Correlation with
neuropathological findings. J Neurol Neurosurg Psychiatry 1983;46:9-13.
18 Molsa PK, Paljarvi L, Rinne JO, Rinne UK,
Sako E: Validity of clinical diagnosis in demen­
tia: A prospective clinicopathological study. J
Neurol, Neurosurg Psychiatry 1985:48:1085—
19 Huber SJ, Edwin C, Shuttleworth EC, Donald
L, Frcidenberg DC: Neuropsychological differ­
ences between the dementias of Alzheimer’s
and Parkinson's disease. Arch Neurol 1989:46:
20 Hakim AM, Mathieson G: Dementia in Par­
kinson's disease; a neuropathologic study. Neu­
rology 1979:29:1209-1214.
21 Boiler F, Passafiume D, Keefe NC, Rogers K,
Morrow L, Kim Y: Visuospatial impairment in
Parkinson’s disease. Role of perceptual and
motor factors. Arch Neurol 1984:41:485-490.
22 Joachim CL, Morris JH, Selkoe DJ: Clinically
diagnosed Alzheimer's disease: Autopsy results
in 150 cases. Ann Neurol 1988;24:50-56.
23 Massman PJ, Delis DC, Butters N, Levin BE,
Salmon DP: Are all subcortical dementias al­
ike? Verbal learning and memory in Parkin­
son's and Huntington’s disease patients. J Clin
Exp Neuropsychol 1990;12:729-744.
24 Hcindcl WC, Salmon DP, Shults CW, Walicke
PA, Butters N: Neuropsychological evidence
for multiple implicit memory systems: A com­
parison of Alzheimer's, Huntington’s, and Par­
kinson’s disease patients. J Neurosci 1989:9:
25 Monsch AU, Bondi MW, Butters N, Salmon
DP, Katzman R, Thai LJ: Comparison of ver­
bal fluency tasks in the detection of dementia
of the Alzheimer type. Arch Neurol 1992:49:
26 Monsch AU, Bondi MW, Butters N, Paulsen
JS, Salmon DP, Bruggcr P. Swenson MR: A
comparison of category and letter fluency in
Alzheimer’s disease and Huntington’s disease.
Neuropsychology 1994;8:25-30.
Downloaded by:
Thomas Jefferson University Scott Library - 1/2/2018 2:51:17 PM
1 Albert ML, Feldman RG, Willis AG: The ‘sub­
cortical dementia- of progressive supranuclear
palsy. J Neurol Ncurosurg Psychiatry 1974;37:
2 Cummings JL. Benson DF: Psychological dys­
function accompanying subcortical dementias.
AnnuRevMcd 1988:39:53-61.
3 Whitehousc PJ: The concept of subcortical and
cortical dementia: Another look. Ann Neurol
4 Cummings JL: Subcortical dementia. Neuro­
psychology, neuropsychiatry, and pathophysi­
ology. Br J Psychiatry 1986;149:682-697.
5 Cummings JL, Benson DF: Subcortical demen­
tia. Review of an emerging concept. Arch Neu­
rol 1984;41:874-879.
6 Huber SJ, Shultleworlh EC, Paulson GW, Bellchambers MJ, Clapp LE: Cortical vs. subcorti­
cal dementia. Neuropsychological differences.
Arch Neurol 1986:43:392-394.
7 Huber SJ, Paulson GW: The concept of subcor­
tical dementia. Am J Psychiatry 1985;142:
8 Huber SJ, Shuttleworth EC: Neuropsychologi­
cal assessment of subcortical dementia; in
Cummings JL (ed): Subcortical Dementia.
New York, Oxford University Press, 1990.
9 Benson DF: Aphasia; in Heilman KM, Valenstein EV (eds): Clinical Neuropsychology, ed 3,
New York, Oxford Press, 1993.
10 Heilman KM, Gonzalez Rothi LJ: Apraxia; in
Heilman KM, Valenstein EV (eds): Clinical
Neuropsychology, ed 3. New York, Oxford
University Press, 1993.
11 Bauer R: Agnosia; in Heilman KM, Valenstein
EV (eds): Clinical Neuropsychology, cd 3. New
York, Oxford University Press, 1993.