Language Performance of Individuals at Risk for Mild Cognitive Impairment

Purpose Evidence exists that changes in language performance may be an early indicator of mild cognitive impairment (MCI), often a harbinger of dementing disease. The purpose of this study was the evaluation of language performance in individuals at risk for MCI by virtue of age and self-concern and its relation to performance on tests of memory, visuospatial function, and mental status. Method Eighty-three individuals 55 years or older were administered the Arizona Battery for Communication Disorders of Dementia ( Bayles & Tomoeda, 1993 ), a standardized battery with normative data from 86 healthy older adults (HOAs) and 86 individuals with Alzheimer's dementia, the most common dementing disease. A performance criterion of 1-1.5 SDs below the mean of HOAs defined MCI, as recommended in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. We hypothesized that (a) the majority of at-risk participants would score 1 SD or more below the mean of HOAs on 1 or more subtests and (b) language performance tests would present a greater challenge than memory, mental status, and visuospatial construction tests. Results Both hypotheses were confirmed. Sixty-two participants (74.6%) met the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria on at least 1 subtest. Moreover, language subtests were those most likely to elicit a performance 1 SD or more below the mean of HOAs. Conclusions Language performance deficits can appear early before impairment in episodic memory, visuospatial construction ability, or mental status in individuals at risk for MCI. Speech-language pathologists are uniquely qualified to identify subtle changes in language, and standardized language tests with normative data should be used when testing for MCI.

Alzheimer's Disease Symptoms: Prevalence and Order of Appearance

Primary caregivers of 115 patients with probable Alzheimer's disease completed a questionnaire about 25 behavioral symptoms and their order of appearance. The symptom list was derived from the behavioral characteristics described in the Global Deterioration Scale for quantifying severity of dementia. Of interest was the relation between symptom prevalence and appearance order. Using statistical techniques for correlating ranks, symptom prevalence was found to be highly predictive of average rank of appearance for all patients and the subgroup in whom the symptoms were reported. Results of an agglomerative cluster analysis provided no evidence of subpopulations of patients in whom symptom appearance differed markedly. Complaint of memory problems or memory-related deficits were four of the six most prevalent symptoms and complaint of memory problems was the first appearing symptom. Less prevalent and later- appearing symptoms included movement disorder, lack of awareness of surroundings, and incontinence.

The effects of modified spaced-retrieval training on learning and retention of face-name associations by individuals with dementia

The purpose of this project was to assess the effects of spaced-retrieval training (SRT) on learning of new and previously known associations by individuals with dementia in two treatment conditions: one in which the recall intervals were filled with activities unrelated to the information being learned (unrelated condition) and one in which the intervals were filled with related activities (related condition). Thirty-two individuals with mild to moderate dementia (30 with a diagnosis of Alzheimer's disease; two with vascular dementia) participated in the study. On average, participants learned the associations in fewer than four sessions and retained the information for variable amounts of time, up to 6 weeks. Previously known associations were learned significantly faster than new associations. The modified SRT format, in which the within-session recall intervals were filled with information related to the target association, did not result in faster learning or longer retention of learned associations. Participants learned previously known associations in the standard SRT format (with unrelated information in the recall intervals) significantly faster than new associations taught in the modified SRT condition. Cognitive impairment, as measured by the Mini-Mental State Examination, was significantly correlated with time to learn new associations, but did not explain a large proportion of the variance in new learning. Theoretical and clinical implications are discussed.

Effect of presentation modality on immediate and delayed recall in individuals with Alzheimer's disease

Episodic memory (EM) deficits are the hallmark of Alzheimer's disease (AD). Story-retelling tasks are particularly sensitive to EM impairments and require participants to recall a short story immediately and after a delay. The purpose of this study was to determine whether presentation modality influences story recall in AD participants. Thirty AD participants and 30 healthy elders recalled short stories in (a) auditory, (b) visual, and (c) combined auditory-visual modalities. Recall was assessed immediately as well as after 15- and 30-min delays. Presentation modality significantly influenced story recall in AD participants. AD participants demonstrated better recall after silently reading a story than after hearing an examiner tell the story or simultaneously hearing and reading the story. Clinical implications of these results are discussed.

Verbal Perseveration in Individuals with Alzheimer's Disease

Perseveration has been described as a reliable indicator of disturbed brain function and is a common characteristic of neurological conditions such as Alzheimer's disease (AD). This article will begin with a review of recent theories that account for the phenomenon of perseveration, and data from a National Institute on Deafness and Other Communication Disorders (NIDCD)--supported study further delineate the nature of perseveration among individuals with AD. The study investigated the frequency of verbal perseveration in individuals with AD in relation to task type, mental status, and performance on attention and memory tests. Thirty Alzheimer's patients and 40 healthy elders were given a confrontation naming, generative naming, and picture description test. Perseveration was defined as a proportion of total number of responses. Data analysis revealed that individuals with AD perseverated more than normal elders did, but variability was high. Generative naming elicited more perseveration than either confrontation naming or picture description did. When overall frequency of perseveration was correlated with mental status and performance on attention and memory tests, seemingly paradoxical results were obtained, probably because the unique cognitive demands of each language test affected the probability of perseveration differently. Nonparadoxical, strong positive correlations were obtained, however, between language test scores and performance on tests of attention, memory and mental status.

A longitudinal study of neuropsychological change in individuals with Parkinson's disease

OBJECTIVES

Neuropsychological changes in individuals with Parkinson's disease (PD) were studied longitudinally.

METHODS

Sixty-nine idiopathic PD patients, with Mini-Mental State Examination (MMSE) scores falling within normal range, and 37 elderly control participants were given neuropsychological tests twice approximately two years apart.

RESULTS

The PD group performed poorer than the control group on Semantic Fluency, Letter Fluency, Modified Wisconsin Card Sorting Task, and Block Design at test time 1. Two years later, the PD group showed significant decline in Semantic and Letter Fluency. A subset of 12 PD patients declined in mental status by second testing (>4 MMSE points). Cox proportional-hazards models were used to see if any baseline measures were associated with relative risk of decline in mental status. In the final model, Repetition performance and Age were significantly associated with cognitive decline.

CONCLUSIONS

Consistent with previous studies, executive function tasks were those most susceptible to disease progression.

A longitudinal study of neuropsychological change in individuals with Parkinson's disease

Neuropsychological changes in individuals with Parkinson's disease (PD) were studied longitudinally. Sixty-nine idiopathic PD patients, with Mini-Mental State Examination (MMSE) scores falling within normal range, and 37 elderly control participants were given neuropsychological tests twice approximately two years apart. The PD group performed poorer than the control group on Semantic Fluency, Letter Fluency, Modified Wisconsin Card Sorting Task, and Block Design at test time 1. Two years later, the PD group showed significant decline in Semantic and Letter Fluency. A subset of 12 PD patients declined in mental status by second testing (> or =4 MMSE points). Cox proportional-hazards models were used to see if any baseline measures were associated with relative risk of decline in mental status. In the final model, Repetition performance and Age were significantly associated with cognitive decline. Consistent with previous studies, executive function tasks were those most susceptible to disease progression.

Improving the functioning of individuals with Alzheimer's disease: emergence of behavioral interventions

Alzheimer's disease (AD) is a neurodegenerative process that invariably results in diminished communicative functioning. Historically, it was thought that little could be done to improve the functioning of affected individuals. However, in recent years the value of behavioral interventions has increasingly been explored, resulting in a changing perspective. Some of the factors contributing to this changing view include: understanding that memory is not a unitary phenomenon, recognizing that certain types of memory are relatively spared in AD, a growing realization that conceptual knowledge is largely intact, and a greater understanding of how people learn and remember. Intervention techniques that capitalize on spared memory systems and take advantage of principles of learning and remembering have been successful in teaching individuals with AD new information and allowing them to maintain better functioning throughout the disease course.

LEARNING OUTCOMES

(1) The participant will be able to describe the historical perspective on behavioral interventions, and four factors that have contributed to a changing perspective. (2) The participant will be able to list behavioral strategies that clinicians can use in order to improve functioning of individuals with AD.

Effects of working memory deficits on the communicative functioning of Alzheimer's dementia patients

Individuals with Alzheimer's disease experience frontal lobe pathology and deficits in working memory processes are well documented. Less documented is how various working memory deficits impact communicative functioning. The performance data of individuals with mild and moderate Alzheimer's dementia on five tests of language comprehension and four tests of language expression are presented and discussed in the context of possible contributions from impaired working memory functions. The argument is advanced that diminished scores on tests of language comprehension and production result primarily from attenuated span capacity, difficulty focusing attention, encoding, and activation of long-term knowledge rather than from loss of linguistic knowledge. Techniques that may advantage Alzheimer's patients in the comprehension and expression of linguistic information are discussed.(1) Readers will become familiar with the typical functioning of individuals with Alzheimer's disease on common linguistic expression and comprehension tasks. (2) Readers will become familiar with the distinction between language knowledge and performance and its importance in understanding the cause of communication breakdowns in individuals with Alzheimer's disease. (3) Readers will become familiar with techniques that may facilitate the communicative functioning of individuals with Alzheimer's disease.

Retained neuropsychological abilities of individuals with Alzheimer's disease

Individuals with Alzheimer's disease (AD) retain certain cognitive abilities over the course of the disease. In this article, we describe retained cognitive-linguistic abilities and the status of activities of daily living (ADLs) of individuals in the early, middle, and late stages of AD. Knowledge of preserved abilities in AD is necessary for clinicians to structure communication-stimulation programs and to train caregivers in the most effective ways to facilitate communication. Using the Global Deterioration Scale (GDS) for staging severity of AD, an outline of preserved abilities by disease stage is provided. Attention, memory, and communication abilities are discussed, and samples of discourse from patients at different stages are included.

Understanding the neuropsychological syndrome of dementia

The syndrome of dementia is most commonly caused by Alzheimer's disease (AD), an age-related neurodegenerative process that primarily affects the cortex. Approximately 4 million Americans carry the diagnosis, and the number is expected to rise to 14 million by the year 2040. Affected individuals suffer multiple cognitive deficits that progressively affect the ability to communicate. Typically the earliest symptom is impairment of episodic memory, but other forms of declarative memory are ultimately impaired. To understand the communication problems of individuals with Alzheimer's, clinicians need to understand disease effects on knowledge stores and cognitive and memory processes. Using spared memory systems and less effortful cognitive processes to compensate for impaired stores and processes is the primary means by which optimal care can be provided. Recent advances in our understanding of disease effects on semantic memory suggest a greater potential for habilitation than previously thought. In this article, the neuropathology of AD is reviewed, effects on cognitive and communicative functions are specified, and principles for providing optimal patient care are discussed.

Communication abilities of individuals with late-stage Alzheimer disease

The communication abilities of 49 individuals in the late stage of Alzheimer disease were examined in relation to other markers of late-stage Alzheimer disease (e.g., incontinence and ambulatory ability). Two existing tools used to stage severity of dementia, the Global Deterioration Scale and the Functional Assessment Stages, have represented communication abilities in individuals with late-stage Alzheimer disease to be minimal to nonexistent. The individuals in this sample showed greater communication skills and verbal output than would be predicted by these scales.

Performance of Alzheimer's disease patients in judging word relatedness

Sixty individuals with probable Alzheimer's disease (AD) and 48 normal elders were given a task in which they had to judge the relatedness of concepts as a means of evaluating semantic memory. Very mild AD patients performed similarly to normal elders. Mild AD patients were significantly inferior in performance to normals but the pattern of their performance did not suggest a loss of conceptual knowledge. Moderate AD patients were significantly inferior in performance to mild AD patients, and 8 moderate AD patients (compared to 1 mild AD patient) were unable to do the task. The pattern of performance of moderate patients suggests that conceptual knowledge may degrade and ultimately be lost.

Gender differences in language of Alzheimer disease patients revisited

Results of recent investigations suggest that Alzheimer disease (AD) has a more deleterious effect on language in women than in men. This intriguing finding motivated an analysis of the language performance of probable AD patients, equally divided as to gender, on a variety of language comprehension and production tests. Cross-sectional data were available for 63 probable AD subjects and longitudinal data were available for 26. In addition to analysis of covariance used with the cross-sectional data, effect sizes were calculated. The longitudinal data were analyzed with repeated-measures analyses of covariance. The sum of scores on the orientation items of the Mini-Mental State Examination was used as the covariate in both analyses. No significant differences between the performance scores of male and female subjects were obtained for either the cross-sectional or longitudinal data. All effect sizes of gender were relatively small, with female patients outperforming males on most language tests. Results are discussed in the context of previous findings and comparison of the effect sizes among studies.

Comparing the difficulty of letter, semantic, and name fluency tasks for normal elderly and patients with Parkinson's disease

Research on the effect of Parkinson's disease (PD) on verbal fluency has produced conflicting results. In this study, 88 PD patients with no dementia, 11 PD patients with questionable mental status, 15 PD patients with dementia, and 46 elders free from mental disorder were administered a variety of semantic, letter, and name fluency tasks. The results revealed that, contrary to popular assumption, semantic fluency was not always superior to letter fluency. Rather, verbal fluency was influenced by the nature of the individual categories. Interestingly, the relative difficulty of many categories was fairly stable across groups. The results also indicated that the individual fluency tasks were differentially sensitive to the mental status of the PD patients. Overall, the findings suggest that closer attention to the nature of the tested categories may help clarify the inconsistent effects of PD on verbal fluency.

Comparing the difficulty of letter, semantic, and name fluency tasks for normal elderly and patients with Parkinson's disease

Research on the effect of Parkinson's disease (PD) on verbal fluency has produced conflicting results. In this study, 88 PD patients with no dementia, 11 PD patients with questionable mental status, 15 PD patients with dementia, and 46 elders free from mental disorder were administered a variety of semantic, letter, and name fluency tasks. The results revealed that, contrary to popular assumption, semantic fluency was not always superior to letter fluency. Rather, verbal fluency was influenced by the nature of the individual categories. Interestingly, the relative difficulty of many categories was fairly stable across groups. The results also indicated that the individual fluency tasks were differentially sensitive to the mental status of the PD patients. Overall, the findings suggest that closer attention to the nature of the tested categories may help clarify the inconsistent effects of PD on verbal fluency.

Change in cognitive function in idiopathic Parkinson disease

OBJECTIVE

To study the effects of Parkinson disease (PD) on cognitive function by determining the frequency and amount of change in Mini-Mental State Examination (MMSE) performance.

DESIGN

During a 4-year period, 77 patients with idiopathic PD and 43 normal elders were administered a neuropsychological test battery twice at 2 years apart.

RESULTS

A 4-point score difference on the MMSE was the amount that was statistically calculated to be a significant difference at the .05 probability level. Using this metric, 17 (22%) patients with PD had a change in their MMSE performance during a 2-year period. Fifteen individuals performed poorer, and 2 individuals improved. Using the same metric, no normal subjects changed in their MMSE performance. The groups of patients with PD who had a change and did not have a change in their MMSE performance were not characterized by significant differences in their years of education, duration of illness, age at onset, age at test time 1, estimated premorbid intelligence, Hamilton Psychiatric Rating Scale for Depression score at test time I, or Unified Parkinson's Disease Rating Scale score. The singular difference was the higher frequency of change that was found in subjects who were taking dopamine agonists at the second test time.

CONCLUSION

A change in cognitive function in patients with PD, as measured by a change of 4 points or more in their MMSE performance, was observed in only 22% of a sample of 77 patients with idiopathic PD during a 2-year period.

Phrase repetition in Alzheimer's disease: effect of meaning and length

Repetition ability depends in part on the intactness of semantic memory. If the conceptual contents of semantic memory are lost as a function of Alzheimer's disease (AD) pathology, meaningfulness of stimuli should have progressively less effect on the ability to repeat as the disease worsens. This study was designed to evaluate the effects of meaningfulness and length of phrasal stimuli on repetition ability in mild and moderate AD patients and normal elderly subjects. Fifty-seven AD patients and 52 normal subjects were given six- and nine-syllable phrases that were meaningful, improbable in meaning, or meaningless. Cross-sectional and longitudinal data analyses were conducted and results failed to confirm a performance pattern consistent with a semantic memory loss theory. Meaningless nine-syllable phrases were those most difficult to repeat for moderate as well as mild AD patients and normal controls.

Category and attribute knowledge deterioration in Alzheimer's disease

A prevalent theory regarding the deterioration of semantic memory in Alzheimer's disease is that it is a bottom-up process. If this is true, performance on tests of attribute knowledge should decline more rapidly than performance on tests of categorical knowledge as dementia severity increases. In the present study, a convincing pattern of findings to either support or reject the theory failed to emerge. This raised questions regarding the ability to separate attribute and categorical knowledge, and whether one can be tested without influence of the other. Questions also were raised regarding the additional cognitive processes needed to complete tasks of semantic memory.

Cross-sectional analysis of Alzheimer disease effects on oral discourse in a picture description task

To examine the relation of dementia severity to the quality and quantity of oral discourse of individuals with Alzheimer disease (AD), a picture description task was administered to elicit oral discourse samples from 63 AD subjects, five individuals with very mild cognitive impairment, and 52 normal controls. Eight measures of discourse were used: total words, information units, conciseness, circumlocutions, frustrations, aborted phrases, revisions, and ideational repetitions. Information units, which decreased with increased dementia severity, proved to be the best measure for evaluating the effects of AD on oral descriptive discourse. The conciseness index also decreased with increased dementia severity, and a significantly greater proportion of AD discourse samples contained ideational repetitions. Circumlocutions and frustrations rarely occurred, and although the discourse of AD subjects was more likely to contain an aborted phrase, the frequency of aborted phrases did not vary by stage of dementia. Revisions were commonly observed in the discourse of both normal controls and AD subjects and did not differentiate the two groups.

Use of the Arizona Battery for Communication Disorders of Dementia in the UK

The Arizona Battery for Communication Disorders of Dementia (ABCD) (Bayles & Tomoeda, 1993) was given to groups of young and old normal subjects and to subjects with moderate Alzheimer's disease in the UK. Very few significant differences were found between their raw scores and those of the original standardisation sample in the USA, which makes the ABCD an appropriate test to use in the UK. Although some subjects commented on several of the test stimuli, cultural differences in pictures and vocabulary did not produce notable effects on test performance and so alterations to test materials are not required for the test to be used in the UK.

Memory impairment and executive control in individuals with stroke-induced aphasia

The purpose of this study was to examine memory abilities of aphasic individuals in relation to site of neurological lesion. Fourteen individuals with stroke-induced aphasia (7 with anterior lesions; 7 with posterior lesions) and 14 demographically matched control subjects were given selected tests of short-term memory (STM) and long-term memory (LTM). Stroke patients were impaired relative to control subjects on tests of verbal memory, with greater impairment of LTM associated with anterior lesions and greater impairment of STM associated with posterior lesions. Verbal memory performance did not correlate highly with language ability, and did not appear to be simply a consequence of language impairment. Executive control deficits were postulated as explanatory of the LTM impairment associated with anterior lesions.

Generative naming in Parkinson disease patients

The generative naming ability (verbal fluency) of 88 idiopathic Parkinson disease (PD) patients was evaluated and compared to that of 21 Alzheimer disease (AD) patients and 43 normal age- and education-matched normal control subjects. The PD patients were classified according to whether they scored within the normal range on the Mini-Mental State Examination (MMSE), a score of 27 or higher, or in the abnormal range, a score of 26 or lower. Semantic and letter generative naming tasks were administered to assess verbal fluency. Results of the study provide evidence that letter category naming is inherently more difficult than semantic category naming; that age significantly affects generative naming; that PD patients with normal MMSE scores were significantly inferior to normal control subjects in generative naming even after the effects of age and mental status are controlled; that PD patients with non-normal MMSE scores performed like AD patients after controlling for the effects of age and mental status; and, that ideational perseveration is the most common type of error response for all subject groups.

Confrontation naming in Alzheimer's patients: relation to disease severity

Reports of Alzheimer's disease patients in whom naming performance is disproportionate to other cognitive performances raise questions about the stage model, or dementia-severity level, for predicting naming performance. Thus, dementia severity as defined by Global Deterioration Scale ratings, Mini-Mental State Examination scores, and combinations of them was evaluated as a predictor of naming performance in 102 Alzheimer's patients and was found to account for approximately 1/3 of performance variability. Additional contributions from age at onset, duration, family history, and gender were negligible. Therefore, naming ability can be argued to have a subcomponent that is not subsumed by overall cognitive ability.

Acquired mutism: physiopathy and assessment

The speechless patient presents a unique challenge to the clinician working with neurologically impaired adults. Acquired speechlessness, or mutism, has been associated with a variety of clinical states and syndromes after damage to central and peripheral nervous system structures. The intent of this paper is to summarize the reported states and syndromes associated with acquired mutism (eg, persistent vegetative state, akinesia), and to organize this information in a framework for clinical assessment of the speechless patient. For the purpose of discussion, speech production is divided into five interrelated processes: arousal; cognitive processing; affect and drive; motor initiation, planning, programming, and coordination; and execution of movement. Disorders characterized by mutism are classified according to the process or processes of speech production that primarily are affected. Each subtype of acquired mutism is characterized by a cluster of neurologic signs, which has been incorporated into a decision-making framework for use in a clinical setting.

Confrontation naming in Alzheimer's patients: Relation to disease severity

Reports of Alzheimer's disease patients in whom naming performance is disproportionate to other cognitive performances raise questions about the stage model, or dementia-severity level, for predicting naming performance. Thus, dementia severity as defined by Global Deterioration Scale ratings, Mini-Mental State Examination scores, and combinations of them was evaluated as a predictor of naming performance in 102 Alzheimer's patients and was found to account for approximately 1/3 of performance variability. Additional contributions from age at onset, duration, family history, and gender were negligible. Therefore, naming ability can be argued to have a subcomponent that is not subsumed by overall cognitive ability.

Alzheimer's Disease Effects on Semantic Memory: Loss of Structure or Impaired Processing?

Results of several prior studies, in which Alzheimer's disease (AD) patients missed the same concepts on multiple tasks, have been used to substantiate the theory that AD causes concept-specific loss of information from semantic memory However, sample sizes in these studies are modest, test-retest intervals small, and typically only a few tasks were used. In the present study 69 An subjects were annually administered 11 tasks, each using the same 13 concepts. Only a few instances were observed in which a concept was missed across all 11 tasks. When performances on the Oral Reading and Dictation tasks were removed from analysis, because of their questionable reliance on semantic memory, the number of missed concepts rose only modestly. A substantial rise in the number of missed concepts occurred, however, when performances on the four multiple- choice tasks were removed. Interpreting the larger number of missed concepts on the five remaining generative semantic tasks as evidence of item-specific loss is problematic, nonetheless, because the generative semantic tasks were among the hardest in the battery and the frequency with which an individual subject missed a concept across all tasks accorded with the subject's dementia severity level. Results also indicate that task difficulty, more than concept specificity, determine whether a concept is missed. Overall, results suggest that a concept will “disappear” when all of the tasks in which it is a stimulus become too difficult for the patient to perform. Study results call into question the appropriateness of using batteries of effortful, attention demanding tasks for ascertaining whether AD causes item-specific loss of conceptual knowledge.

Caregiver report of prevalence and appearance order of linguistic symptoms in Alzheimer's patients

We interviewed primary caregivers of 99 Alzheimer's disease patients about the existence and appearance order of linguistic symptoms in a longitudinal study of disease effects on communication. The most prevalent linguistic symptom was difficulty finding the correct word and the least prevalent was increased talkativeness. The prevalence of linguistic symptoms was strongly correlated with order of symptom appearance, with difficulty writing a meaningful letter appearing first and word finding difficulty appearing second. Based on caregiver perceptions, symptom prevalence and order of appearance are specified and discussed in relation to onset of nonlinguistic memory deficit, dementia severity, and performance on a linguistic communication test battery.

Age at onset of Alzheimer's disease. Relation to language dysfunction

A later age at onset of Alzheimer's disease (AD) was found to be related to diminished language performance in 86 patients with probable AD. A hierarchical linear model was constructed to assess effects of age at onset and disease duration on the performance of patients with AD on four language tasks (naming, reading, auditory comprehension, and writing to dictation) after controlling for disease severity. Results of univariate analysis, in which the dependent variable was the averaged language task performances, revealed a significant effect for age at onset of AD, but not for disease duration. To assess the possibility that the relationship between the age at onset of AD and language performance reflects effects of normal aging, the language tasks were given to 33 normal subjects of similar ages who scored perfectly on dementia severity measures. A convincing relationship was not found between test score and age.

Semantic memory deterioration in Alzheimer's subjects: evidence from word association, definition, and associate ranking tasks

The nature of semantic memory impairment in 23 persons with dementia of the Alzheimer type (DAT) was studied using three semantic tasks: word association, definition, and associate rank ordering. Using hierarchical log-linear analysis of the responses to the word association task, DAT subjects were more likely than normal control subjects to give multiword, repetitious, or unrelated responses. Additionally, the ratio of paradigmatic to syntagmatic responses was significantly decreased in DAT subjects. Surprisingly, DAT subjects were able to provide definitions for many stimulus words for which they were unable to provide meaningful associates. This finding suggests the need for caution in interpreting a decrease in the number of paradigmatic responses as indicative of a loss of conceptual knowledge. Results of other analyses demonstrated that DAT subjects had significant impairment in identifying highly related and unrelated semantic associates of words. Taken together, results of this study indicate that one feature of DAT is deterioration in the associative relations between concepts.

Delayed recall deficits in aphasic stroke patients: evidence of Alzheimer's dementia?

In a comparative study of the performance of patients with Alzheimer's disease (AD), aphasia resulting from stroke, and normal elders on a variety of neuropsychological tasks, 3 aphasic patients performed similarly to AD patients in the delayed recall of verbal material. The memory deficit of these aphasic patients raised the question of incipient dementia because memory impairment is the hallmark characteristic of AD. However, when the performance profiles of the aphasic patients on all four memory measures administered in the study were compared to those of AD patients, differences made the presence of dementia unlikely. Nonetheless, the possibility remained that a deficit in delayed free recall might be the primordial symptom of dementia. Therefore, the four memory tasks were readministered to the 3 aphasic patients 2 years later, and intergroup performance comparisons again were made. The performance profiles of the aphasic patients obtained 2 years later were superior to and distinct from the AD patients, confirming the absence of dementia at Test Time 1.

Language and Parkinson disease

Previously published reports of deficits in linguistically oriented tasks were reviewed for both demented and nondemented Parkinson disease (PD) patients in a discussion of the question of whether PD affects language. Additionally, to illustrate the methodological problems inherent in evaluating linguistic competence, the performance on four linguistically oriented tasks of 12 PD patients who scored 8 or better on the Mental Status Questionnaire was compared to that of 32 age- and education-matched control subjects. These tasks, from which a composite variable representing performance was formed, were oral object description, story retelling, the Peabody Picture Vocabulary Test, and the Similarities subtest of the Wechsler Adult Intelligence Scale (WAIS), a test of verbal associative reasoning. After controlling for the effects of disease severity, a significant effect was observed for the presence of PD. However, when the additional effects of performance on the Block Design subtest of the WAIS were controlled, the PD effect was of borderline significance. These results typify those in the literature, that is, whereas nondemented PD patients can be demonstrated to perform significantly more poorly on linguistically oriented tasks, the performance deficit cannot be conclusively demonstrated to result from a language deficit per se.

Differentiating Alzheimer's patients from the normal elderly and stroke patients with aphasia

The performance of individuals with mild and moderate Alzheimer's disease (AD), normal age-matched elderly individuals, and stroke patients with fluent and nonfluent aphasia were compared on a group of neuropsychological tasks. The unique performance profiles associated with each subject group are discussed, and the best tasks for intergroup differentiation specified. Whereas the tasks employed were efficacious for discriminating early- and middle-stage AD patients from normal subjects and aphasic stroke patients, and early- from middle-stage AD patients, they were not efficacious for subtyping aphasia patients according to fluency. Generally, memory measures were best for intergroup differentiation.

Confrontation naming impairment in dementia

The effects of dementia etiology and severity on the confrontation naming ability of individuals with Alzheimer's, Huntington's, and Parkinson's diseases and multi-infarct dementia are investigated. Although naming impairment is reported as a consequence of dementing illness, confrontation naming is not found to be significantly impaired in mildly involved patients. Further, although moderate Huntington's and Parkinson's patients made more naming errors than normals, only moderate Alzheimer's disease patients are found to be significantly different. Regardless of etiology, most misnamings are found to be semantically related or semantically and visually related to the stimulus. Results challenge the theory that misnamings of dementia patients result primarily from misperception.

The potential of language tasks for identifying senile dementia

More than two million elderly Americans suffer from senile dementia, an age-related disease affecting memory, intellect, and communication. The purpose of this study was to explore the diagnostic efficacy of language tasks for identifying senile dementia. The performance of 35 dementia patients was compared to that of 28 normal senescents on five language tasks and certain psychological measures reputed to be sensitive to the disease such as the Block Design and Similarities subtests of the Wechsler Adult Intelligence Scale, the Mental Status Questionnaire (MSQ), and the Nonsense Syllable Learning Tests. Language tasks presented were: Story-retelling, Naming, Sentence Disambiguation, Verbal Expression, and Sentence Correction. A discriminant analysis found the Sentence Correction Task, the MSQ, and the Verbal Expression Test to best discriminate patients with senile dementia from normal aged subjects. Semantic functions were found to be more vulnerable than phonologic and syntactic to the effects of progressive cortical atrophy.