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.     

Selective reminding procedure in depression and dementia.

Patients with mild dementia of the Alzheimer's type (DAT), patients with major depression, and normal elderly control subjects were administered a verbal learning task using the selective reminding procedure. Depressed patients were impaired on total recall and the proportion of items retained from one trial to the next without reminding and did not benefit from imagery in retaining items over consecutive trials. The DAT patients were impaired on all measures derived from the test, including storage and recognition memory. With the exception of the ability to benefit from imagery, all of the measures distinguished depressed and mild DAT patients. These findings are consistent with deficient encoding in DAT and performance deficits as a function of effortful cognitive processing in depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rate of forgetting in dementia and depression.

Patients with mild dementia of the Alzheimer's type (DAT), patients with major depression, and normal control subjects were examined for rate of forgetting line drawings of common objects after the groups had been equated for acquisition by the variation of stimulus exposure time. Depressed and DAT patients demonstrated learning impairments, but only the DAT group showed rapid forgetting in the first 10 min after learning to criterion. This finding suggests that some form of deficient consolidation contributes to memory loss in DAT but not in depression and implicates the disruption of different psychobiological mechanisms in these disorders. The rate of forgetting paradigm may be clinically useful for distinguishing patients with early DAT from elderly depressed patients with memory deficits. (53 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

WAIS-R Factor Structure in Alzheimer's Disease Patients: A Comparison of Alternative Models and an Assessment of Their Generalizability.

The WAIS-R is often used in neuropsychological evaluations of individuals with probable Alzheimer's disease (AD), but its factor structure in this population is unknown. Moreover, theories and past research findings make competing predictions concerning its structure. Using confirmatory factor analysis, the authors compared 5 alternative WAIS-R factor models among 516 AD patients: 1-factor (Spearman's g) and 2-factor (Verbal IQ and Performance IQ) models; a 3-factor model including Verbal Comprehension (VC), Perceptual Organization (PO), and Freedom From Distractibility (FD) factors; a 3-factor model in which Digit Symbol loads on PO rather than FD; and a 3-factor model in which Digit Symbol loads on both PO and FD. Results favored the 3-factor model in which Digit Symbol loads on PO rather than FD. Moreover, this model fit the data best among subsamples of patients defined by age, dementia severity, years of education, and gender. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurophysiological and psychological picture of solvent poisoning

Neurophysiological and psychological tests were administered to 107 patients--48 men and 59 women--with a diagnosis of solvent poisoning after longstanding (mean 9.6 years for males and mean 7.6 years for females) occupational exposure. Electroencephalography (EEG) and a wide psychological test battery were applied in all cases, and electroneurographic measurements were performed in 77 subjects. Sixty-five percent of the patients showed an abnormal EEG, and excessive beta activity, not induced by drugs, was found in 54% of patients. At least one abnormally slow nerve conduction velocity (CV) was found in 48 out of 77 patients. The scores of Wechsler Adult Intelligence Scale (WAIS) subtests Digit Span (DSp) and Digit Symbol (DSy) among the men and scores of Similarities (Sim), Digit Symbol (DSy), Picture Completion (PC), and Block Design (BD) among the women were statistically significantly lower than in the Finnish standardization sample. Long duration of exposure was related to poor performance in the Santa Ana Dexterity test in both sexes, to poor visual memory among the men and to poor visuoconstructive intellectual tasks among the women. The background frequency in the EEG showed a correlation to the DSp test of WAIS and some relationship emerged also between the former and the BD, the Symmetry Drawing test, the Santa Ana Dexterity test, and the Mira test. Focal slow wave abnormalities were related to inaccurate hand movements in the psychomotor Mira test. Neurophysiological and psychological tests seem to reflect partly different aspects of neurologic effects and their combined use helps in the evaluation of hazards of solvent exposure.     

Correlates of memory decline: A 4-year longitudinal study of older adults with memory complaints.

Change in memory performance and its correspondence to change in speed of performance and self-reported memory functioning were investigated longitudinally in 30 older adults with memory complaints. Ss were assessed by self-report questionnaires and cognitive tests 3 times, at near 2-yr intervals. A significant decline in word-recall scores was found, which was accompanied at the group level by significant self-reported decline in everyday memory functioning and nonsignificant decline in Wechsler Adult Intelligence Scale (WAIS) Digit Symbol scores (α?=?.05). The oldest Ss showed the most substantial declines in memory performance. At the individual level, however, memory change did not significantly correlate with either change in self-reports or change in Digit Symbol scores. Although these results do not support a cognitive slowing model of decline at the intraindividual level, they do have implications for intervention of age-related memory decline. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

Effects of hyperglycemia on memory and hormone levels in dementia of the Alzheimer type: A longitudinal study.

The effect of hyperglycemia on hormone levels, metabolite levels, and memory performance was examined in 22 Ss with very mild and mild probable dementia of the Alzheimer type (DAT) and in 12 normal elderly adults. Ss were tested in 3 plasma glucose conditions (fasting baseline, 175 mg/dl, and 225 mg/dl) at initial and 18-mo follow-up sessions. Initially, adults with very mild DAT showed memory facilitation and elevations in plasma insulin in the 225-mg/dl glucose condition relative to baseline. At follow-up, very mild DAT patients whose dementia had progressed showed significant decreases in insulin and hyperglycemic memory facilitation. Changes in basal insulin and cortisol levels over time were correlated with memory changes for DAT Ss. These results suggest that glucoregulatory abnormalities may contribute to the pathophysiology of DAT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive functioning ten years following traumatic brain injury and rehabilitation.

Many previous studies investigating long-term cognitive impairments following traumatic brain injury (TBI) have focused on extremely severely injured patients, relied on subjective reports of change and failed to use demographically relevant control data. The aim of this study was to investigate cognitive impairments 10 years following TBI and their association with injury severity. Sixty TBI and 43 control participants were assessed on tests of attention, processing speed, memory, and executive function. The TBI group demonstrated significant cognitive impairment on measures of processing speed (Symbol Digit Modalities Test [SDMT], Smith, 1973; Digit Symbol Coding, Wechsler, 1997), memory (Rey Auditory Verbal Learning Test [RAVLT]; Rey, 1958; Lezak, 1976), Doors and People tests; Baddeley, Emslie & Nimmo-Smith, 1994) and executive function (Hayling C [Burgess & Shallice, 1997] and SART errors, Robertson, Manly, Andrade, Baddeley & Yiend, 1997). Logistic Regression analyses indicated that the SDMT, Rey AVLT and Hayling C and SART errors most strongly differentiated the groups in the domains of attention/processing speed, memory and executive function, respectively. Greater injury severity was significantly correlated with poorer test performances across all domains. This study shows that cognitive impairments are present many years following TBI and are associated with injury severity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preclinical cognitive markers of dementia of the Alzheimer type.

56 nondemented elderly normal control (NC) Ss were studied at 3 consecutive annual administrations of the California Verbal Learning Test (CVLT). NC Ss with a positive family history for progressive dementia performed significantly worse than individuals with a negative family history for progressive dementia on several quantitative and qualitative indices of the CVLT and were more likely to undergo changes in diagnostic status over time (i.e., develop dementia of the Alzheimer type [DAT]). Stepwise discriminant function analyses of critical CVLT indices of the NC Ss and of 25 patients with mild DAT classified 5 NC Ss as DAT patients 1–2 yrs prior to their eventual changes in diagnostic status. Results suggest that specific memory deficits may serve as preclinical cognitive markers for DAT, especially in individuals with risk factors for DAT such as a positive family history. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Executive functioning and olfactory identification in young adults with attention deficit-hyperactivity disorder.

Young adults with attention deficit-hyperactivity disorder (ADHD; N?=?105) were compared with a control group (N?=?64) on 14 measures of executive function and olfactory identification using a 2 (group) × 2 (sex) design. The ADHD group performed significantly worse on 11 measures. No Group × Sex interaction was found on any measures. No differences were found in the ADHD group as a function of ADHD subtype or comorbid oppositional defiant disorder. Comorbid depression influenced the results of only 1 test (Digit Symbol). After IQ was controlled for, some group differences in verbal working memory, attention, and odor identification were no longer significant, whereas those in inhibition, interference control, nonverbal working memory, and other facets of attention remained so. Executive function deficits found in childhood ADHD exist in young adults with ADHD and are largely not influenced by comorbidity but may be partly a function of low intelligence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory span procedures in Alzheimer's disease.

In a working memory framework, the forward memory span involves a subsidiary system that maintains information, and the backward span relies on a central executive system (CES) that allocates processing resources. The authors hypothesized that a measure of the CES derived from the backward span would distinguish Alzheimer's disease (AD) patients (n&≠&?9) from elderly controls without dementia (n&≠&?9), vary as a function of disease severity, and underlie other cognitive disturbances. Memory span procedures were Digit Span Forward and Backward and Visual Memory Span Forward and Backward. Derived CES measures discriminated between groups, predicted dementia severity, and predicted performance on some of the cognitive tasks examined. However, working memory subsidiary systems also appeared to be affected in AD, and some cognitive deficits in AD were independent of working memory disturbances. The visual memory span backward was the best predictor of group and of dementia severity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sepsis and endotoxaemia in mice stimulate the expression of interleukin-I and interleukin-6 in the central nervous system

This retrospective chart review examines the impact of selective serotonin reuptake inhibitors on 20 patients with both depression and psychosis complicating dementia of the Alzheimer type (DAT) and other dementias. Fifteen of the 20 patients had moderate to marked improvement in depressive and psychotic symptoms. Eleven of 12 patients with DAT had moderate to marked improvement compared to only four of eight patients with dementia from other causes. The drugs were effective in diminishing or eliminating psychotic symptoms in six patients who had previously not responded to a trial of a neuroleptic. The selective serotonin reuptake inhibitors may have an important role to play in patients with DAT who have coexisting depression and psychosis. These drugs are very well tolerated and may have a place as first-line agents in non-emergent settings where a clinician might otherwise think of instituting a neuroleptic or as a second-line agent when a neuroleptic has proven ineffective.     

Parameters of self-reinforcement and depression.

Assessed the levels of 3 components of self-reinforcement (self-expectation, self-evaluation, and self-reward) in 2 groups of 40 hospitalized psychiatric patients (clinically depressed and clinically nondepressed). Tasks included a word association measure, the WAIS Digit Symbol subtest, and a task involving decisions that would benefit the ward. The depressed group showed significantly lower levels on all 3 variables, which were significantly interrelated. Ss in the depressed group were significantly more reinforcing to others on all 3 variables than to themselves, as compared with the nondepressed group. Despite lower levels of self-reinforcement, there were no differences between the 2 groups' objective performances. The overall results suggest qualifications to a self-reinforcement theory of depression. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prospective memory and apolipoprotein e in healthy aging and early stage Alzheimer's disease.

The present study examined whether prospective memory performance discriminates healthy aging from very mild dementia of the Alzheimer type (DAT) and individuals at risk for DAT because of the presence of the apolipoprotein E (ApoE) ε4 allele. Four groups (young subjects, young-old control subjects, old-old control subjects, and subjects with very mild DAT) engaged in an event-based prospective memory task wherein they responded to a specific word embedded in a general knowledge test. Results indicated that prospective memory performance was clearly impaired in the very mild DAT group relative to the healthy older control groups. Moreover, prospective memory performance appears to capture unique variance in discriminating these 2 groups above and beyond standard retrospective memory tests. However, prospective memory was not affected by ApoE status in the young-old control group and, contrary to predictions, the ε4+ old-old control subjects showed better performance than did the ε4- subjects. In contrast to the healthy individuals, in the very mild DAT group, ε4+ subjects showed deficits in performance relative to the ε4- subjects. Discussion focuses on prospective memory as a cognitive indicator of early stage DAT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic, phonological, and hybrid veridical and false memories in healthy older adults and in individuals with dementia of the Alzheimer type.

Five groups of participants [young, healthy old, healthy old-old, very mild dementia of the Alzheimer type (DAT), and mild DAT] studied 12-item lists of words that converged on a critical nonpresented word (cold) semantically (chill, frost, warm, ice), phonologically (code, told, fold, old), or in a hybrid list of both (chill, told, warm, old). The results indicate that (a) veridical recall decreased with age and dementia; (b) recall of the nonpresented items increased with age and remained fairly stable across dementia; and (c) false recall varied by list type, with hybrid lists producing superadditive effects. For hybrid lists, individuals with DAT were 3 times more likely to recall the critical nonpresented word than a studied word. When false memory was considered as a proportion of veridical memory, there was an increase in relative false memory as a function of age and dementia. Results are discussed in terms of age- and dementia-related changes in attention and memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparability, Reliability, and Practice Effects on Alternate Forms of the Digit Symbol Substitution and Symbol Digit Modalities Tests.

The present study examined the comparability of 4 alternate forms of the Digit Symbol Substitution test and the Symbol Digit Modalities (written) test, including the original versions. Male contact-sport athletes (N=112) were assessed on 1 of the 4 forms of each test. Reasonable alternate form comparability was demonstrated through establishing normality of form distributions and conducting pairwise form comparisons of means, variability, and intraclass correlations. Nonetheless, alternate forms are likely an insufficient means of controlling practice in speeded measures at brief (1-2 weeks) retest intervals. Reliable change indices demonstrated that practice must be accounted for in individual retesting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

Episodic and semantic memory in Alzheimer's disease and progressive supranuclear palsy: a comparative study

We compared 13 patients with dementia of the Alzheimer's type (DAT) and 9 progressive supranuclear palsy (PSP) patients, matched by age, sex, education, and the overall level of cognitive deterioration, measured by using the Dementia Rating Scale, and 12 normal controls. The results of this study confirm that the pattern of cognitive deterioration of PSP patients differs from that of DAT patients. While episodic memory is severely affected early in the course of DAT, it appears to be relatively spared in PSP. In contrast to previous suggestions, we found no evidence for differentially rapid forgetting in DAT, although we did confirm relatively preserved recognition memory in PSP. We had predicted that the performance of the DAT group on tests of semantic memory (the Boston Naming Test, the ADA Synonym Judgement Test, and the Pyramids and Palm Trees Test) would be worse than that of the PSP group. However, there was, in fact, no difference on any of these measures, except that the PSP patients showed a significantly greater deficit on the Synonym Judgement Test. We suggest that the underlying cause of the semantic memory impairment might, however, be different in the two pathologies.