Mild Senile Dementia Of The Alzheimer Type Research Articles

Component analysis of a rhythmic finger tapping task in individuals with senile dementia of the Alzheimer type and in individuals with Parkinson's disease.

The present experiment examined different components of motor control that may be impaired in normal aging, senile dementia of the Alzheimer type (SDAT), and Parkinson's disease (PD). Specifically, A. M. Wing and A. B. Kristofferson's (1973) formal quantitative model of rhythmic finger tapping was used to obtain estimates of central timekeeping and response execution components of timing control. Subjects included young college students, healthy older adults, nondemented individuals with PD, and individuals with very mild and mild SDAT. Individuals with mild SDAT exhibited a breakdown in the central timekeeping mechanism but not in the execution of the response. Both very mild SDAT and PD individuals did not show any deficits in the two timing mechanisms relative to age-matched healthy controls. Finally, there was no effect of normal aging on timing control in this task. This study underscores the importance of examining issues of motor control in SDAT as a function of separate processing components and stages of disease progression. Senile dementia of the Alzheimer type (SDAT) is characterized by a relatively generalized breakdown in cognitive performance. Although the deficits observed in Alzheimer's disease appear to encompass most aspects of cognitive performance, it is has been shown that isolatable aspects of cognitive performance appear to deteriorate at different rates as the disease progresses (see, e.g., Balota & Duchek, 1991). The isolation of such subcomponents in SDAT is important because it will allow a better understanding of the cognitive breakdowns in these individuals and potentially help in the development of better screening procedures. Finally, such an analysis may also provide useful information regarding models of healthy cognitive functioning (e.g., see Balota & Ferraro, 1993). Although there is an extensive literature delineating cognitive deficits in SDAT individuals in the areas of attention, memory, and language (see Nebes, 1989, for a review), one component of performance that has received relatively little attention is the area of motor control. Moreover, the few available reports addressing motor control in SDAT have

Driving Performance in Persons with Mild Senile Dementia of the Alzheimer Type

To assess the effect of mild senile dementia of the Alzheimer type (SDAT) on driving ability. Cross-sectional study with correlation analysis. A university-based Alzheimer's Disease Research Center, which evaluates community-living older adult volunteers, and the university's Program in Occupational Therapy. Healthy elderly controls (n = 13) and subjects with very mild (n = 12) and mild (n = 13) SDAT. Dementia severity was staged by the Washington University Clinical Dementia Rating. The driving ability of participants on the in-car road test was scored independently by a driving instructor, blinded to the study design and to the dementia status of the subjects, and an unblinded occupational therapist. Interview-based perceptions of driving ability were obtained independently from the subjects and their collateral sources. Attentional and visuospatial performances of the subjects were assessed prior to the road test. All control and very mild SDAT subjects were judged to be "safe" drivers (ie, passed the in-car road test), but five (40%) of the mild SDAT subjects had driving impairment sufficient to "fail" the road test. Neither subject self-assessment nor caregiver perceptions of driving ability consistently predicted driving performance. Attentional task performance correlated well with road test results. Some SDAT subjects retain "safe" driving skills. The greater the dementia severity, the greater the likelihood of poor driving ability. Performance-based (road test) evaluations are necessary to properly determine driving skills at present, but attention and other cognitive screening measures should be developed.

Glucose and memory in mild senile dementia of the Alzheimer type.

Glucose utilization appears to play a role in memory, and patients with Senile Dementia of the Alzheimer Type (SDAT) show particular abnormalities of the glucose system. The present study examined the effects of glucose administration on memory in subjects with mild SDAT and age-matched controls. SDAT subjects demonstrated greater overall increases in blood glucose levels following glucose administration. Normal subjects whose blood glucose levels returned to near baseline following glucose administration showed facilitated memory performance, whereas SDAT subjects whose blood glucose levels remained elevated showed significant improvement following glucose administration. The results suggest that impaired glucose regulation contributes to memory impairment in SDAT.

Paired Associate Learning in Senile Dementia of the Alzheimer Type

A study was conducted to examine the potential explicit learning ability in senile dementia of the Alzheimer type (SDAT) as a function of (1) the difficulty of the to-be-remembered material and (2) the severity of the dementia. The Associate Learning task from the Wechsler Memory Scale was administered to healthy older adults and individuals with questionable, mild, and moderate SDAT. Individuals with SDAT showed poorer learning performance across trials than healthy older adults. Individuals with questionable and mild SDAT did show evidence for learning across trials for highly related paired associates. For unrelated-paired associates, however, only individuals with questionable SDAT showed some evidence for increased learning across trials.

Parvalbumin Neurons in the Hippocampus in Senile Dementia of the Alzheimer Type, Parkinson's Disease and Multi-Infarct Dementia (Part 2 of 2)

The immunogold-silver-staining method (IGSS) was used for the detection of hippocampal neurons containing the cytoplasmic calcium-binding protein parvalbumin in senile dementia of the Alzheimer type (SDAT), Parkinson's disease and multi-infarct dementia (MID). Computer-based image analysis of cell numbers in the hippocampus proper and the entorhinal cortex, measurement of total dendritic length of selected neurons and quantitative microdensitometry of immunoreacted sections was performed. In severe SDAT cases a loss of parvalbumin-immunoreactive (parv-i) neurons and a reduction of dendritic fields was detected especially in CA1 and the subiculum. In the entorhinal cortex the general atrophy exceeded the decrease of parvalbumin immunoreactivity. Mild SDAT cases showed only minor alterations of parv-i neurons and in cases of parkinsonism without cognitive disorders or in those with depression parv-i neurons were not affected. However, in cases of parkinsonism with dementia and in MID a severe cell loss and a drastic reduction of dendritic arborization in the hippocampus proper was detected, which was accompanied by additional morphological alterations due to ischemic damage. We conclude that parv-i neuronal networks in the hippocampus are damaged in some patients with dementing disorders in SDAT, Parkinson's disease and MID consecutive to Alzheimer or ischemia related pathology.

Parvalbumin Neurons in the Hippocampus in Senile Dementia of the Alzheimer Type, Parkinson's Disease and Multi-Infarct Dementia (Part 1 of 2)

The immunogold-silver-staining method (IGSS) was used for the detection of hippocampal neurons containing the cytoplasmic calcium-binding protein parvalbumin in senile dementia of the Alzheimer type (SDAT), Parkinson's disease and multi-infarct dementia (MID). Computer-based image analysis of cell numbers in the hippocampus proper and the entorhinal cortex, measurement of total dendritic length of selected neurons and quantitative microdensitometry of immunoreacted sections was performed. In severe SDAT cases a loss of parvalbumin-immunoreactive (parv-i) neurons and a reduction of dendritic fields was detected especially in CA1 and the subiculum. In the entorhinal cortex the general atrophy exceeded the decrease of parvalbumin immunoreactivity. Mild SDAT cases showed only minor alterations of parv-i neurons and in cases of parkinsonism without cognitive disorders or in those with depression parv-i neurons were not affected. However, in cases of parkinsonism with dementia and in MID a severe cell loss and a drastic reduction of dendritic arborization in the hippocampus proper was detected, which was accompanied by additional morphological alterations due to ischemic damage. We conclude that parv-i neuronal networks in the hippocampus are damaged in some patients with dementing disorders in SDAT, Parkinson's disease and MID consecutive to Alzheimer or ischemia related pathology.

Mild senile dementia of the Alzheimer type: 3. Longitudinal and cross‐sectional assessment

Sixty-six subjects diagnosed by validated criteria as having senile dementia of the Alzheimer type (SDAT) were assessed with clinical measures commonly used to study dementia. The severity of the SDAT was mild in 24, moderate in 24, and severe in 18. The data from these three groups in a cross-sectional study were compared with results in our earlier study of 43 subjects enrolled with mild SDAT and followed longitudinally. We concluded that the cross-sectional method underestimates the severity of progression as indicated by some of the clinical measures. Additionally, the 24 new subjects with mild SDAT were assessed longitudinally. This replication study confirmed our earlier conclusions that four of six clinical measures showed similar patterns over time and were useful throughout the study, global measures being more informative than brief individual measures with ceiling or floor effects.

Bender-Gestalt Test performance in senile dementia of the Alzheimer type.

Bender-Gestalt Test performances of 144 persons with very mild, mild, or moderate senile dementia of the Alzheimer type (SDAT) and 96 healthy older adults ranging in age from 63 to 95 were compared. Total scores and error types according to the modified Hutt-Briskin scoring system are reported. The Bender-Gestalt Test does not appear to be useful in differentiating very mild or mild SDAT from normal aging.

アルツハイマー型老年痴呆の脳循環代謝と痴呆性疾患の鑑別におけるポジトロンＣＴの有用性に関する研究

This study was designed to estimate cerebral dysfunction in senile dementia of the Alzheimer's type (SDAT). Regional cerebral blood flow (rCBF), oxygen extraction fraction (rOEF) and cerebral oxygen consumption (rCMRO2) were studied in 16 patients with SDAT and 5 age-matched normal elderly people by positron emission tomography (PET), using the 15O labeled CO2 and O2 inhalation technique. This technique was also applied to the evaluation of PET in diagnosing the dementing illnesses. In this study, a total of 19 pairs of bilateral cerebral regions were analyzed and the reductions of rCBF and rCMRO2 in each region were compared with those of the primary sensorimotor cortex to demonstrate any significant localized difference between each clinical stage of the SDAT and normal controls. In the mild SDAT group, CMRO2 of the temporal cortex was significantly reduced, as compared with that of controls. In the moderate SDAT group, CBF of the temporal cortex and CMRO2 of the temporal and parietal cortices were significantly reduced. In the severe SDAT group, CBF and CMRO2 of the frontal cortex were also reduced and those of the occipital cortex were relatively unchanged. This suggested that mildly demented patients showed a metabolic reduction in the temporal cortex and as the dementia progressed, metabolic reductions were extended to the parietal and frontal cortices. Reductions in blood flow were followed by further metabolic reductions. More detailed investigation of the PET images of SDAT revealed that relative oxygen hypometabolism of the posterior temporal and posterior parietal association cortices occurred in the mildly demented patients earlier than that of the other association cortices. These findings are consistent with neuropathological studies of SDAT. The right/left ratio of rCMRO2 was also analyzed in each region. The right/left oxygen metabolic asymmetry in the temporal and parietal cortices was correlated with the difference between speech and visuospatial functions. Namely, the patients with a lower metabolism in the left hemisphere had more disturbances in speech than visuospatial functions. In addition, the PET images of SDAT were compared with those of multi-infarct dementia (MID) and Pick disease. In patients with MID, there were reductions of CBF and CMRO2 unhomogenously all over association cortices, but the reductions were most remarkable in the frontal cortex. Patients with Pick disease showed diffuse lobar reductions of CBF and CMRO2 in the frontal and temporal cortices.(ABSTRACT TRUNCATED AT 400 WORDS)

Very mild senile dementia of the Alzheimer type. II. Psychometric test performance.

A brief battery of psychometric tests was used to compare 41 individuals with very mild senile dementia of the Alzheimer type (SDAT) with 83 healthy participants and 66 individuals with mild SDAT. Although canonical analysis indicated that the same psychological functions (memory, speeded psychomotor performance, and language) are involved in both very mild and mild SDAT, objective levels of performance by the very mildly affected individuals overlapped extensively with those of both healthy aged and mildly demented individuals. Consideration of premorbid individual differences in psychological functions will probably be required if psychometric test performances are to be effective in detecting SDAT in the very mild stage.

The progression of personality changes in senile dementia of the Alzheimer's type.

Passive, agitated, and self-centered behavioral changes were noted on initial evaluation in two-thirds, one-third, and one-third, respectively, of subjects with mild senile dementia of the Alzheimer's type (SDAT). Over a 50-month follow-up period, the percentage of patients who exhibited agitated and self-centered behaviors doubled. The percentage of subjects who demonstrated all three behavioral changes increased from 11% at entry to the study (mild SDAT) to over 50% when the dementia had reached a severe stage. The presence of personality changes at a mild stage of dementia did not predispose subjects to more rapid progression to a more advanced stage of illness.

Behavioral changes in patients with mild senile dementia of the Alzheimer's type

Behavioral changes in 44 subjects with well-characterized mild senile dementia of the Alzheimer's type (SDAT) and 16 subjects with only questionable SDAT were compared to a control group of 58 subjects. Answers to both open-ended questions and personality items from the Blessed Dementia Scale were examined. Seventeen items were classified into seven categories by factor analysis and then further categorized into four clinically useful groups: passive, agitated, self-centered, and suspicious. Over 75% of subjects with mild SDAT had behavioral changes compared to 10% of controls. Passive symptoms were the most common, occuring in two-thirds of mild SDAT subjects. Agitated and self-centered symptoms were also common, occuring half as frequently as passive symptoms. Passive symptoms occured alone in 25% of those with mild SDAT, whereas passive symptoms, together with agitated and/ or self-centered symptoms, were present in 11–16% of subjects with mild SDAT. Agitated or self-centered symptoms rarely occured alone. Characterizing the behavioral symptoms of SDAT is important for their clinical implications and for an approach to understanding brain-behavioral relationships.

Language disintegration in dementia: Effects of etiology and severity

The speech characteristics on a standardized picture description task of 26 subjects with presumed senile dementia of the Alzheimer type (SDAT) and 13 subjects with stroke-related dementia (SRD) were compared to 15 normal subjects over age 59 years. Compared to the normal subjects, the dementia subjects used fewer total words, fewer unique words, fewer prepositional phrases, fewer subordinate clauses, and more incomplete sentence fragments. Lexical deficits tended to be more severe than syntactic ones, confirming prior suggestions that lexicon is more vulnerable to disruption in dementia than syntax. Greater dementia severity among the SDAT subjects was associated with marked difficulties in accessing the mental lexicon (increased use of empty words, indefinite anaphora, and pronouns). Greater dementia severity in the SRD subjects was associated with laconic speech that was syntactially less complex. Diffuse brain injury (as typified by SDAT) appears to disproportionately affect lexicon whereas multifocal injury (as typified by SRD) has a disproportionate effect on syntax (assuming that focal lesions of the posterior language zone have been excluded). The speech characteristics of the mild SDAT subjects showed similarities to those of anomic or semantic aphasia whereas the speech of the more advanced SDAT subjects showed similarities to Wernicke aphasia or transcortical sensory aphasia. The speech of the subjects with more severe SRD showed some similarities to Broca aphasia. The most important nonlinguistic deficit in both the SRD and the SDAT groups was a failure to make relevant observations during the picture description task. Perseverations were present in the speech of both the SRD and SDAT subjects, whereas aposiopesis, logorrhea, and palilalia were more typical of the SDAT subjects. Laconic speech was more characteristic of the SRD subjects.

Sleep, EEG and mental function changes in senile dementia of the Alzheimer's type

—Sleep, EEG and mental function variables were studied in 44 subjects diagnosed as having probable senile dementia of the Alzheimer's type (SDAT) and 22 controls matched for age and minimal depression. Results indicate that sleep, EEG and mental function variables all undergo significant change even in the early, mild stage of SDAT, with further change in the moderate and severe stages of dementia. Mental function variables also underwent significant decline across levels of dementia. Sleep and mental function variables had strong power in correctly classifying subjects into control vs. mild dementia groups (90 and 100%, respectively). Dominant occipital rhythm frequency, a clinical EEG measure, also discriminate as well (75%). The results indicate that sleep and EEG variables discriminate well for early, mild SDAT in minimally depressed aged individuals.