Focal cognitive deficits in dementia of the Alzheimer type.

It is widely accepted that the natural history of Alzheimer type-dementia is accurately described by a relatively fixed, invariant sequence of stages of behavioral, cognitive, and neurological symptoms. This stage-wise deterioration model is examined and found wanting. The evidence shows that there is no generalization about the inevitable ordering of symptoms that has not been contradicted by reports in the literature. Two alternatives to the stage-wise model are discussed, both of which reject the notion of a homogeneous disintegration of function and take as a goal the delimitation of a set of symptom domains that define and differentiate patients. Of these 2 alternatives, the subgroups model and the multiple components model, the latter seems to accord best with the available data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preserved cognitive skills in dementia of the Alzheimer type

OBJECTIVE: To describe preserved cognitive skills in patients with dementia. DESIGN: Case series. SETTING: Community clinic. PATIENTS: Five patients who met National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for probable Alzheimer's disease and were claimed to retain a cognitive skill. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Standard neuropsychological tests and individualized measures of patient's skilled behaviors. For patients who remained skilled at games, performance was compared with that of normal controls in direct competition. For the patient-trombonist, raters compared premorbid and postmorbid recordings of his play. RESULTS: One patient continued to play the trombone in a Dixieland band, although he could not name well-known numbers that he played. Another continued to solve adult jigsaw puzzles. A third patient retained skill at canasta, the fourth at dominoes. The fifth patient remained a skillful contract bridge player, although he could not name the suits or articulate simple bidding rules. Four patients had impaired performance on standard anterograde and remote memory and naming tests but performed normally on pursuit rotor and letter fluency tests. Mini-Mental State Examination scores for these patients ranged from 10 to 22. One patient refused neuropsychological testing but displayed his skill. CONCLUSIONS: Together with previous studies of preserved piano playing or painting skills, our findings indicate that a broad range of complex cognitive abilities may be preserved in patients with dementia of the Alzheimer type who cannot perform simpler actions.     

A comparison of cognitive impairments in dementia of the Alzheimer type and depression in the elderly

General cognitive function and specific language and memory processing abilities were compared in dementia of the Alzheimer type (DAT), depressed and normal control subjects. Several tests clearly differentiated between DAT and depressed subjects including a verbal fluency task, several components of a word memory test, an IQ deterioration index, and the Mini-Mental State Examination. The inability of DAT subjects to take advantage of semantic cues in both the verbal fluency and in the memory test contrasted with the performance of depressed and normal subjects, who were able to benefit from semantic cues. Depressed patients displayed deficits compared with normal controls on the more effortful verbal fluency task but not on the memory test. Tasks that are least effortful, rely on semantic associations, and require declarative memory are most likely to discriminate between DAT and depression.     

Correlation between cognitive brain function and electrical brain activity in dementia of Alzheimer type

Enterocytes were detached from various parts of the digestive tract of chickens by treatment with DTT or with hyaluronidase. Isolated enterocytes were exposed to suspensions of the V4 strain of Newcastle disease virus (NDV). Removal of virus from the supernatant fluid was taken as evidence of binding of virus to enterocytes and residual virus was measured both by infectivity assay and by ELISA. Enterocytes from duodenum, jejunum, ileum, caecum, and rectum bound the virus; enterocytes from oesophagus, crop and proventriculus did not.     

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 yrs 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serial position effects in dementia of the Alzheimer type

We evaluated the usefulness of an automated hematology analyzer (SE-9000) for the identification and counting of peripheral blood stem cells (PBSCs). The samples tested were from 14 patients with hematological malignancies. Peripheral blood samples were collected from the subjects before and after a course of chemotherapy. From the leukapheresis sample, CD34+ cells, assumed to be hematopoietic stem cells, were obtained with an immunomagnetic cell separator. The CD34+ cells obtained accumulated in the gate corresponding to low recurrent frequencies of the automated hematology analyzer. This gate shows results of the 'immature information' (IMI) channel. Software for detection of only the cells that accumulated in this gate was therefore developed. With this trial program, the regression coefficient between the percentage of leukocytes from the blood samples that were CD34+ and the percentage of such leukocytes that appeared on the IMI channel was 0.79. With this analyzer, the number of PBSC could be counted in about 80 s. The identification and counting of cells picked up by the IMI channel should be clinically useful for the monitoring of changes in PBSC after chemotherapy for mobilization.     

Musical structural determinants of emotional judgments in dementia of the Alzheimer type.

People with dementia of the Alzheimer type (DAT) may well be emotionally soothed by listening to music. However, very few systematic studies have been conducted to support the anecdotal evidence. DAT does damage certain cerebral structures that subsume emotional processing, and some studies have demonstrated deficits affecting emotional judgments of facial expression and prosody in DAT. Accordingly, this study addressed the question of whether DAT might leave musical emotional judgment intact. Twelve early DAT participants and 12 healthy elderly participants took part in this study. Emotional judgments were examined in relation to mode and tempo, two important structural properties that contribute to the happy-sad distinction in music. Their respective contributions were assessed in four different experimental conditions. The DAT participants' responses were similar to those of healthy elderly participants, showing spared ability to employ tempo and mode as cues for emotional interpretation. The DAT participants' performance was not correlated with their global cognitive functioning. These results constitute a preliminary empirical demonstration that, in early DAT, musical emotional judgments appear to be based on normal structural analysis of musical input. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deficits in reading performance in very mild dementia of the Alzheimer type.

Reading of irregular words using the American version of the National Adult Reading Test ([AMNART] E. Grober & M. Sliwinski; see record 1992-16981-001) was examined in 101 healthy older adults and compared with 50 people with very mild and 62 people with mild dementia of the Alzheimer type. Significant deficits were observed in both the very mild and mild dementia groups. Performance on this reading test was substantially correlated with other measures of semantic memory, which are also affected early in the course of the disease. Use of this test as an indicator of premorbid intelligence in people with dementia of the Alzheimer type does not appear wise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A longitudinal study of the course of Alzheimer type dementia

OBJECTIVE: We carried out a prospective longitudinal study of 41 patients diagnosed as probably having a mild form of Alzheimer's disease according to the data of an investigation of prevalence done in 1991 in the municipality of Habana Vieja. MATERIAL AND METHODS: The research covered two phases, with an interval of one year between them. During both phases the patients were interviewed by the same neurology resident in a door-to-door survey using the Mini-Mental State, Hughes scale (CDR) and Blessed scale, to evaluate higher mental functions. We determined the progress of the disease over the course of two years (1991-1992 and 1992-1993) and the frequency and degree of deterioration of cognitive functions during a period of one year. RESULTS AND CONCLUSIONS: There was evidence of progressive worsening of the illness in 46.4% of the patients. In 34.2% this was to a moderate form and in 12.2% to a severe form. There was no progression in 46.3%. In this group 17.0% continued with a diagnosis of doubtful dementia and 29.3% as having slight dementia. The other 7.3% of the total number of patients (n = 41) were reclassified as normal. Cognitive functions almost always showed a tendency to deteriorate over time, but in a small percentage of patients they did not deteriorate and some even improved. The cognitive functions which deteriorated most were those of orientation, language and copying, with an average deterioration of 28% and 24% respectively with regard to their initial values.     

Autonomic dysfunction in patients with dementia of the Alzheimer type

Abnormalities of the noradrenergic system have been documented in the central nervous system of patients with dementia of the Alzheimer's type (DAT). To evaluate the autonomic sympathetic system in DAT, we measured lying and standing blood pressure (BP), pulse, and plasma epinephrine (E) and norepinephrine (NE) in 60 DAT patients (mean age +/- SD = 65 +/- 8 years), and 20 normal elderly controls. DAT patients had normal baseline findings (BP, pulse, NE, and E). Upon standing, plasma NE and E significantly increased in both DAT patients and controls, without group differences. However, the systolic BP response to standing was reduced in DAT patients compared with the normal controls (repeated measures ANOVA, p < 0.01). This impaired response of the systolic BP on standing was particularly evident in DAT patients with symptoms of depression. Severely impaired DAT patients did not differ in E, NE, BP, pulse, or in orthostatic changes from mild-to-moderately impaired patients. These results suggest that the sympathetic response to the stress of standing is functionally impaired in DAT. This deficit was especially evident when DAT was accompanied by depression, consistent with prior studies in non-demented depressed patients.     

An analysis of confrontation naming errors in senile dementia of the Alzheimer type.

Examined confrontation naming performance as reflected by the Boston Naming Test (BNT) in 25 healthy elderly adults (aged 63–83 yrs), 25 age-matched adults with very mild senile dementia of the Alzheimer type (DAT), and 24 age-matched adults with mild DAT. Errors were classified within 17 different categories that differentially reflected perceptual, lexical, and semantic mechanisms. Early in DAT, there was a loss of lexical information and some loss in specific semantic attributes. As the disease progressed, there was increasing involvement of core semantic structures. These observations were supported by analyses of linguistically related errors, 4-alternative forced-choice recognition performance, and correlational analyses between performance on the BNT and 12 standard psychometric tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A neuropsychological investigation into frontal lobe involvement in dementia of the Alzheimer type.

Studied frontal lobe involvement in dementia of the Alzheimer type (DAT) using 4 neuropsychological tests (verbal fluency, delayed alternation, subject-ordered pointing, and the Wisconsin Card Sorting Test) in 25 patients suffering from DAT and 12 age-matched normal controls. The first 3 tasks demonstrated that a frontal lobe impairment is present at all stages of the disease and is related to disease severity. Results offer information regarding the frontal component in DAT by providing neuropsychological support for the findings of an anterior pathology as reflected in blood flow and metabolism studies. The need for suitable frontal tasks with minimal memory involvement in the study of dementia is emphasized, and the delayed alternation task is recommended. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Event understanding and memory in healthy aging and dementia of the Alzheimer type.

Segmenting ongoing activity into events is important for later memory of those activities. In the experiments reported in this article, older adults' segmentation of activity into events was less consistent with group norms than younger adults' segmentation, particularly for older adults diagnosed with mild dementia of the Alzheimer type. Among older adults, poor agreement with others' event segmentation was associated with deficits in recognition memory for pictures taken from the activity and memory for the temporal order of events. Impaired semantic knowledge about events also was associated with memory deficits. The data suggest that semantic knowledge about events guides encoding, facilitating later memory. To the extent that such knowledge or the ability to use it is impaired in aging and dementia, memory suffers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition priming with nonverbal stimuli in patients with dementia of the Alzheimer type.

Perceptual repetition priming was examined in patients with dementia of the Alzheimer type (DAT) and normal control (NC) participants using a task involving the discrimination of geometric designs that had either a continuous ("closed") or discontinuous ('open") perimeter. With the open stimuli, the groups displayed significant and equivalent levels of priming after immediate repetition of the stimuli, whereas only the NC group primed significantly over a delay of three intervening items. Neither group demonstrated significant priming with the closed stimuli. Results indicate that under some conditions DAT patients can exhibit normal repetition priming with stimuli that do not have pre-existing representations but that (due possibly to a deficiency in the level of steady-state cortical activation) this priming dissipates more rapidly in DAT patients than in NC participants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speed of scanning in primary memory in persons with dementia of the Alzheimer type.

The nature of the search of primary memory by persons with a presumptive diagnosis of mild Alzheimer's disease (dementia of the Alzheimer type [DAT]) was compared with that of normal elderly and young persons using the S. Sternberg (1966) paradigm. DAT Ss evidenced a substantial deficit in the speed of scanning in primary memory and a deficit in at least one other stage of processing. These findings are consistent with the hypothesis that the decline in memory performance evidenced by persons with DAT may be attributable to an increase in the time requirements of mnemonic processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identity negative priming in older adults and individuals with dementia of the Alzheimer type.

This study addressed the question of whether dementia of the Alzheimer type (DAT) produces a breakdown in aspects of the inhibitory component underlying selective attention. Two measures of identity negative priming and 2 measures of distractor interference were obtained. In Experiment 1, participants were presented with overlapping picture stimuli, and in Experiment 2, participants were presented with overlapping written word stimuli. The results of both experiments produced reliable and similar size negative priming in young and old adults, but there was no evidence of negative priming in the individuals with DAT. In contrast, the naming latencies of all 3 groups showed a reliable and similar size distractor interference effect. These results suggest that although the inhibitory component underlying selective attention is impaired in individuals with DAT, the ability to differentiate a target from a distractor may be preserved under certain task conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amygdala-hippocampal atrophy and memory performance in dementia of Alzheimer type

The aim of the present study was to examine the involvement of brain structures, especially the amygdala-hippocampal complex, in dementia of Alzheimer type (DAT), and to assess the relation of amygdala-hippocampal atrophy with memory dysfunction. 14 patients with DAT and 10 healthy age-matched controls were examined with different neuropsychologic tests including the UCLA-Auditory Verbal Learning Test. MRI was performed with a conventional 1.5-tesla scanner. Atrophy was found in many brain structures of demented subjects in comparison with healthy age-matched controls. The volumes of amygdala-hippocampal complexes and of the temporal lobes of demented subjects were more reduced than the total brain volume and other structures. Memory dysfunction was highly correlated with atrophy of the amygdala-hippocampal complexes and of the temporal lobes. Consequently, DAT seems to affect the amygdala-hippocampal complex and their related function (i.e. memory) more than other cerebral structures, but cerebral degeneration in DAT is not restricted to these structures.     

Reading in dementia of the Alzheimer type: A preserved ability?

Assessed 45 patients with a probable diagnosis of dementia of the Alzheimer type (DAT), varying from minimal to moderate levels of dementia, on 3 tasks of reading aloud: (1) an extensive list of regular and exception words across a range of word frequencies, (2) the National Adult Reading Test (NART), and (3) a test of nonword reading. On the first test, the patients showed substantial effects of regularity, word frequency, and disease severity. Reading of less common words with atypical spelling-sound correspondences was significantly impaired in the moderately demented subgroup of patients and significantly correlated with measures of semantic memory for the patient group as a whole. This impaired exception word reading was attributed to the breakdown in semantic memory that occurs as the DAT disease process advances. A significant drop in performance on both the NART and nonword reading also accompanied increasing disease severity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pharmacotherapy of Alzheimer dementia: therapy of cognitive symptoms--new results of clinical studies

Recent investigations have given new insights into pathogenetical determinants of Alzheimer's disease. Amyloid deposition and neurofibrillary tangles are no longer considered to be primary pathological changes. Neurobiological research tries to work out the etiopathogenital cascade that finally causes Alzheimer's disease. So far, several relevant pathogenetical factors have been detected, e.g. pertubated control of glucose breakdown, impairment of oxidative metabolism, impaired neuroprotection due to increased oxidative stress and non-enzymatic protein glycation as well as immunological disturbances. Thus, new strategies for the development of cognition-enhancing drugs are emerging. The authors review reports on agents, that are under investigation for the treatment of cognitive symptomatology in Alzheimer's disease. Some of these agents have already been used for treatment of other medical conditions, e.g. nimodipine, memantine as well as selegiline. Many of them are still experimental. Promising strategies include antioxidative agents (e.g. vitamin E, vitamin C, beta-carotin), acetylcholinesterase-inhibitors with central selectivity (e.g. ENA 713), M1- and M4-muscarinic receptor agonists (milameline) as well as sabeluzole, a benzothazide derivative that shows neurotrophic activities and anti-inflammatory substances like indomethacin.