Differentiation of vascular dementia from AD on neuropsychological tests.

BACKGROUND: The concept of vascular dementia (VaD) is currently in a state of evolution. Memory impairment is emphasized as a primary criterion, reflecting the influence of AD on the concept of dementia. We have systematically reviewed whether the nature of neuropsychological dysfunction is distinct in AD and VaD, and whether similar defining criteria for the concept of dementia in both disorders can be supported. METHODS: We searched five bibliographic databases (Medline, Biological Abstracts, EMBASE, PsychINFO, PsychLIT) for research articles in which VaD and AD had been compared using neuropsychological tests and that met criteria for scientific merit. RESULTS: Of the 45 studies, 18 were excluded because of inadequacies, and the remaining 27 were analyzed. There were a number of similarities of dysfunction between VaD and AD. However, when matched for age, education, and severity of dementia, VaD patients had relatively superior function in verbal long-term memory and more impairment in frontal executive functioning compared with AD patients. Interpretation of the results is limited by uncertainty in diagnostic criteria for VaD, possible inclusion bias due to use of clinical diagnosis alone, possible overlap of AD and VaD, and the methodologic shortcomings of some studies. CONCLUSIONS: The neuropsychological differentiation of VaD from AD was consistent with the different neuroimaging findings in the two disorders, and argues for differential criteria for the definition of the syndromes. The simple application of Alzheimer's dementia criteria to VaD, with the inclusion of cerebrovascular disease etiology, may not be sufficient to capture the uniqueness of VaD.     

Detection of malingering using atypical performance patterns on standard neuropsychological tests

Cut-off scores defining clinically atypical patterns of performance were identified for five standard neuropsychological and psychological tests: Benton Visual Form Discrimination (VFD), Fingertapping (FT), WAIS-R Reliable Digit Span (RDS), Wisconsin Card Sorting Failure-to-Maintain Set (FMS), and the Lees-Haley Fake Bad Scale (FBS) from the MMPI-2. All possible pair-wise combinations of scores beyond cut-off (e.g., for VFD and FT; for RDS and FBS), correctly identified 21 of 24 subjects (87.5%) meeting criteria for definite malingered neurocognitive dysfunction, and 24 of 27 (88.9%) subjects with moderate to severe closed head injury. On cross-validation, 15 of 17 subjects (88.2%) meeting criteria for probable malingered neurocognitive dysfunction were correctly identified, with 13 of 13 nonlitigating neurologic patients, and 14 of 14 nonlitigating psychiatric patients correctly classified as having motivationally-preserved performance. Combining the derivation and cross-validation samples yielded a sensitivity of 87.8%, specificity of 94.4%, and combined hit rate of 91.6%.     

Ecologic validity in neuropsychological assessment: prediction of wayfinding.

This study compared the ability of clinical and ecologic simulation measures to predict performance on environment-specific criterion measures of wayfinding. Thirty-one unilateral stroke participants comprised the right and left hemisphere groups (16 patients with left sided and 15 patients with right sided strokes). Participants completed a battery of clinical tasks (e.g., traditional paper-and-pencil measures of visualization, mental rotation, visual memory and spatial orientation), ecologic simulations (e.g., slide route recall and visualization of a model town from differing perspectives) and environment specific criterion tasks (e.g., route recall and directional orientation). The groups were equivalent in age, sex, education, handedness, and weeks since stroke. Both ecologic simulation tasks were found to have fairly good internal consistency and 1 simulation task was significantly related to real world wayfinding. Of the clinical tasks, 1 visual memory test was correlated with a directional orientation criterion task, but none correlated with route navigation ability. Results are consistent with literature purporting the benefits of ecologic simulation tasks as predictors of real world functioning.     

Exploratory eye movements and neuropsychological tests in schizophrenic patients.

Exploratory eye movements in schizophrenic and nonschizophrenic subjects were examined with an eye mark recorder while the subjects viewed geometric figures. Elementary components of eye movements and the responsive search score (RSS), a function of the number of sections on which the subjects fixated, were measured by means of an eye movement analyzer and slow motion replay. The schizophrenic group and the depressed patient group had fewer eye fixations than the normal control group and the obsessive-compulsive disorder group. The schizophrenic group had a lower RSS average than patients with depression, patients with obsessive-compulsive disorders, or subjects in the normal control group. These results in conjunction with those of our previous studies suggest that a low RSS is specific to schizophrenia. We examined the relationship between these eye movements and neuropsychological tests and also investigated the relation between the eye movements and clinical symptoms by means of the Brief Psychiatric Rating Scale, Schedule for Affective Disorders and Schizophrenia, and the Scale for the Assessment of Negative Symptoms. The RSS correlated positively with the performance IQ and Wechsler's Maze test, but not with the Wisconsin Card Sorting Test or the verbal IQ result. The RSS also correlated negatively with negative symptoms. These results suggest that the RSS has two characteristic features: it is strongly associated with the interpersonal response and it may be connected with visuospatial and visuomotor functions including attention.     

Continuing challenges for computer-based neuropsychological tests

A number of issues critical to the development of computer-based neuropsychological testing systems that remain continuing challenges to their widespread use in occupational and environmental health are reviewed. Several computer-based neuropsychological testing systems have been developed over the last 20 years, and they have contributed substantially to the study of neurologic effects of a number of environmental exposures. However, many are no longer supported and do not run on contemporary personal computer operating systems. Issues that are continuing challenges for development of computer-based neuropsychological tests in environmental and occupational health are discussed: (1) some current technological trends that generally make test development more difficult; (2) lack of availability of usable speech recognition of the type required for computer-based testing systems; (3) implementing computer-based procedures and tasks that are improvements over, not just adaptations of, their manually-administered predecessors; (4) implementing tests of a wider range of memory functions than the limited range now available; (5) paying more attention to motivational influences that affect the reliability and validity of computer-based measurements; and (6) increasing the usability of and audience for computer-based systems. Partial solutions to some of these challenges are offered. The challenges posed by current technological trends are substantial and generally beyond the control of testing system developers. Widespread acceptance of the "tablet PC" and implementation of accurate small vocabulary, discrete, speaker-independent speech recognition would enable revolutionary improvements to computer-based testing systems, particularly for testing memory functions not covered in existing systems. Dynamic, adaptive procedures, particularly ones based on item-response theory (IRT) and computerized-adaptive testing (CAT) methods, will be implemented in new tests that will be more efficient, reliable, and valid than existing test procedures. These additional developments, along with implementation of innovative reporting formats, are necessary for more widespread acceptance of the testing systems.     

A study of the relationship between metabolism using 1H-MRS and function using several neuropsychological tests in temporal lobe epilepsy.

Several investigators have reported on the relationship between metabolism, using magnetic resonance spectroscopy (MRS), and function, using neuropsychological tests in temporal lobe epilepsy (TLE) patients, but the opinions regarding the results remain in contention. The aim of this study is to examine the relationship between metabolism, using proton MRS ((1)H-MRS), and function using several neuropsychological tests in the temporal lobes of TLE patients. We studied 29 TLE patients at our hospital using(1)H-MRS and neuropsychological tests. We used a clinical 1.5 T MR unit. We conducted five neuropsychological tests to examine the function of the left or right temporal lobe. There were significant correlations between the N-acetylaspartate/creatine + phosphocreatine (NAA/Cr) ratios and the scores of almost all of the neuropsychological tests for the temporal lobe function ipsilateral to the spike focus. However, in two Wechsler Memory Scale-Revised (WMS-R) subtests we found no significant correlation in the ipsilateral side. These findings suggest that the NAA/Cr ratios, which reflect neural metabolism, are closely related to function in the temporal lobes of TLE patients. The disparity between the results in two subtests of WMS-R show that several tests may be necessary in order to assess temporal lobe function.     

Validity of some neuropsychological tests in the assessment of mental deterioration.

Eighty-three control subjects and 200 patients suspected of diffuse cerebral damage were submitted to the Mental Deterioration Battery. Three independent judges evaluated each patient on the basis of all available data. Only 103 patients, unanimously classed as demented by the three judges were retained. On the basis of controls' performances, the scores obtained by each demented patient in the various tests were corrected for age and educational level. Both single tests and the Battery as a whole discriminated normal controls from demented patients at a very satisfactory level.     

Brain atrophy: neuropsychological and electroencephalographic tests

Neuropsychological and electroencephalographic investigations of 200 patients with tomographically confirmed brain atrophy failed to demonstrate significant differences in relation to control group of patients without this atrophy in whom CT was done for the same clinical indications as in the studied group. In both groups the results of neuropsychological investigations were correlated with age. In the EEG the only statistically significant difference was a greater frequency of seizure activity in the patients with brain atrophy.     

Normative data for the halstead-reitan neuropsychological tests

Abstract

Normative data from a large neurologically intact, nonpsychiatric adult sample (male=111, female = 82) are presented. Despite the size limitations in the upper age ranges, these data are consistent with previously published norms. Sex effects are evident, with females appearing weaker and slower than males on motor tests. The higher than average WAIS FSIQ displayed by this normal sample and the previous use of psychiatric patients as control subjects is discussed.     

The use of neuropsychological tests to assess intelligence

Abstract

Objective: We sought to derive a ‘neuropsychological intelligence quotient’ (NIQ) to replace IQ testing in some routine assessments. Method: We administered neuropsychological testing and a seven-subtest short form of the Wechsler Adult Intelligence Scale to a community sample of 394 adults aged 18–96 years. We regressed Wechsler Full Scale IQs (W-FSIQ) on 23 neuropsychological scores and derived an NIQ from 9 measures that explained significant variance in W-FSIQ. We then compared subgroups of 284 healthy and 108 unhealthy participants in NIQ and W-FSIQ to assess criterion validity, correlated NIQ and W-FSIQ scores with education level and independence for activities of daily living to assess convergent validity, and compared validity coefficients for the NIQ with those of ‘hold’ and ‘no-hold’ indices. Results: By design, NIQ and W-FSIQ scores correlated highly (r = .84), and both were higher in healthy participants. The difference was larger for NIQ, which accounted for more variability in activities of daily living. The NIQ and ‘no-hold’ index were better predicted by health status and less predicted by educational status than the ‘hold’ index. Conclusions: We constructed an NIQ that correlates highly with Wechsler FSIQ. Tests required to obtain NIQ are commonly used and can be administered in about 45 min. Validity properties of NIQ and W-FSIQ are similar. The NIQ bore greater resemblance to a ‘no-hold’ than ‘hold’ index. One can obtain a reasonably accurate estimate of current Full Scale IQ without formal intelligence testing from a brief neuropsychological battery.     

Preclinical trials in autosomal dominant AD: Implementation of the DIAN-TU trial

The Dominantly Inherited Alzheimer's Network Trials Unit (DIAN-TU) was formed to direct the design and management of interventional therapeutic trials of international DIAN and autosomal dominant Alzheimer's disease (ADAD) participants. The goal of the DIAN-TU is to implement safe trials that have the highest likelihood of success while advancing scientific understanding of these diseases and clinical effects of proposed therapies. The DIAN-TU has launched a trial design that leverages the existing infrastructure of the ongoing DIAN observational study, takes advantage of a variety of drug targets, incorporates the latest results of biomarker and cognitive data collected during the observational study, and implements biomarkers measuring Alzheimer's disease (AD) biological processes to improve the efficiency of trial design. The DIAN-TU trial design is unique due to the sophisticated design of multiple drugs, multiple pharmaceutical partners, academics servings as sponsor, geographic distribution of a rare population and intensive safety and biomarker assessments. The implementation of the operational aspects such as home health research delivery, safety magnetic resonance imagings (MRIs) at remote locations, monitoring clinical and cognitive measures, and regulatory management involving multiple pharmaceutical sponsors of the complex DIAN-TU trial are described.     

"Preclinical" AD revisited: neuropathology of cognitively normal older adults

OBJECTIVE: To classify neuropathologic alterations in the brains of nondemented older adults using current sets of criteria for AD. BACKGROUND: AD neuropathologic alterations are found in the brains of some nondemented elderly subjects and suggest the possibility of presymptomatic AD. Three sets of guidelines have been developed to classify AD using senile plaques, neuritic plaques, and neurofibrillary tangles (NFT). METHODS: Neuropathologic changes in 59 older adults followed longitudinally with a standard battery of mental status measures were investigated using Khachaturian, Consortium to Establish a Registry for Alzheimer's Disease (CERAD), and National Institute on Aging-Reagan Institute (NIA-RI) guidelines. AD neuropathologic markers were evaluated in neocortical and allocortical regions. Cases were categorized as neuropathologically "normal" or "AD-like" and compared for possible mental status differences. RESULTS: Between 11 and 49% of cases met one or more of the three classifications of AD. With adjustments for multiple comparisons, only NFT in hippocampal CA1 region were associated with autopsy age, suggesting that this may represent a pathologic process associated with normal brain aging. Using the NIA-RI guidelines, subjects in the AD-like group performed less well on the immediate paragraph recall and word-list delayed recall than their counterparts who did not meet these guidelines. CONCLUSIONS: These data indicate that the prevalence of "preclinical" AD in our population is relatively low based on the NIA-RI classification. Although many subjects had AD-like changes based on CERAD and Khachaturian guidelines, they exhibited no differences in mental performance, suggesting that the aging brain may be able to withstand such structural changes without meaningful impact on mental functioning.     

Relationships between event-related potentials and neuropsychological tests in neurologically healthy adults.

The aim of this study was to investigate the relationship between conventional neuropsychological tests and an event-related potential (P300). Subjects were 118 neurologically normal healthy adults 18-74 years old with no history of neurological, neurosurgical, or psychiatric disorders. We administered a neuropsychological test battery and recorded auditory P300 in all subjects. A significant correlation was seen between P300 latency and age, but not between amplitude and age. While significant negative correlations were apparent between some neuropsychological tests and age and P300 latency, stepwise regression analysis to assess the significance of each factor determined that age alone correlated with P300 latency. We therefore concluded that P300 measurements cannot be replaced by neuropsychological tests; rather, brain function should be evaluated by both methods.     

The prediction of change: normative neuropsychological trajectories

While the application of normative standards is vital to the practice of clinical neuropsychology, data regarding normative change remains scarce despite the frequency of serial assessments. Based on 285 normal individuals, we provide co-normed baseline data with demographic adjustments and test-retest standardized regression based (SRB) models for three time points for several measures. These models delineate normal, expected change across time, and yield standardized z-scores that are comparable across tests. Using a new approach, performance on any previous trial was accounted for in the subsequent models of change, yielding serial normative formulas that model change trajectories rather than simple change from point to point. These equations provide indices of deviation from expected baseline and change for use in clinical or research settings.     

Event-related potentials and neuropsychological tests in obsessive-compulsive disorder

OBJECTIVE: Previous studies have provided evidence from event-related potentials (ERPs) and neuropsychological testing of abnormal cognitive processing in obsessive-compulsive disorder (OCD). The aim of this study was to further characterize the cognitive functions of the patients with OCD by utilizing ERPs and neuropsychological tests. METHODS: ERPs were recorded in a group of 31 drug-free OCD patients without depression and 30 normal controls following verbal auditory stimuli using an oddball paradigm. The specific neuropsychological tests administered to assess cognitive functions in all participants were the Stroop Test, Trail Making Test, Design Fluency Test, Controlled Word Association Test (Verbal Fluency test). RESULTS: The patient group showed shorter P300 duration compared to normal controls. In neuropsychological tests, no significant differences were found between the two groups. Negative correlations between Stroop duration and P300 amplitudes in occipital, parietal, and temporal anterior regions were observed. CONCLUSION: Shorter P300 duration may indicate an acceleration in the P300 process, and speeding of cognitive processing, dysfunction of cortico-subcortical circuits, or some combination of all of the above.     

The ecological validity of pediatric neuropsychological tests of attention

Neuropsychological tests are frequently used clinically to predict real-world, or adaptive functioning; however, there are too few data to support such predictions. The relationship between adaptive functioning and, in particular, attention tests, has not been documented. The present study sought to determine the association between several domains of attention and adaptive functioning in a heterogeneous clinical sample of 119 children. A significant omnibus canonical correlation (Rc=.54) indicated that attention and adaptive functioning are correlated even when controlling for intelligence. Tests of attention and adaptive functioning domains that give rise to the overall association are discussed in terms of their clinical utility.     

On the value of neuropsychological short tests in epileptology

Cognitive deficits are common in patients with epilepsy refractive to therapy and have considerable influence on the quality of life in this group of patients. Therefore, neuropsychological investigations should play an important role in the comprehensive evaluation of patients with chronic epilepsy. The aim of this study was to examine whether a reliable screening for cognitive deficits in these patients may be reduced to the assessment of two bedside tests. In a prospective study we analyzed the results of 40 patients with epilepsy refractive to therapy subjected to a 45-min neuropsychological screening battery and compared them with the results of a short battery consisting of two bedside tests. Using the screening battery as the gold standard, the short battery had a sensitivity of 50% and a specificity of 100%. Changing the criteria for pathological results in the short battery, sensitivity could be raised to 81.25% but specificity fell to 50%. Therefore, bedside tests instead of longer neuropsychological testing cannot be recommended as a screening method for cognitive deficits in patients with chronic epilepsy.     

Symptom validity test failure indicates invalidity of neuropsychological tests

Neuropsychological and symptom validity test results from 220 archival cases were analyzed to determine if failing a symptom validity test (SVT) affects the relationship between neuropsychological tests and brain damage. Results reveal that among those who failed either the Word Memory Test (WMT) or the Computerized Test of Attention and Memory (CTAM) there was no correlation between the results of 25 commonly used neuropsychological tests and objectively determined brain damage. For those who passed SVTs, the expected relationship between neuropsychological tests and brain damage was found. Consistent with earlier findings, effort had a greater effect on test performance than did brain damage. SVT performance was not correlated with either brain damage or the presence of external incentives. Results indicate the need for symptom validity testing in all cases and that failure of a single SVT can invalidate the expected brain-behavior relationship that underlies neuropsychological test interpretation.