Search

In clinical neuropsychology, it is often necessary to estimate a patient’s premorbid level of cognitive functioning in order to evaluate whether his scores on cognitive tests should be considered abnormal. In practice, test results from before the onset of brain pathology are rarely available, and the patient’s level of education is used instead as an estimate of his premorbid level. Unfortunately, level of education may be expressed on many different scales of education, which are difficult to use interchangeably. Here, we introduce a new scale that has the capacity to replace existing scales and can be used interchangeably with any of them: the Universal Scale of Intelligence Estimates (USIE). To achieve this, we propose to map all levels of existing educational scales to standard IQ scores. This USIE point estimate is supplemented with an estimation interval. We assert that USIE offers some important benefits for clinical practice and research. [ABSTRACT FROM AUTHOR]

Longer cognitive tests, such as the Alzheimer's disease assessment scale (ADAS-cog) or the Cambridge cognitive examination (CAMCOG), are more precise but less efficient than briefer tests, such as the Mini Mental State Examination (MMSE). We examined if computerized adaptive testing (CAT) of cognitive impairment can combine brevity with precision by tailoring a precise test to each individual patient. We conducted a prospective study of 84 participants [normal aging, n = 41; mild cognitive impairment (MCI), n = 21; dementia, n = 22]. CAT estimated a participant's ability during testing by selecting only items of appropriate difficulty from either the CAMCOG or the CAMCOG supplemented with ADAS-cog items and neuropsychological tests (the CAMCOG-Plus). After tailored testing with CAT, the remaining CAMCOG and CAMCOG-Plus items not selected by CAT were administered. The time needed to complete the CAT was compared to that needed for the whole CAMCOG and CAMCOG-Plus. Results showed that testing time reductions achieved with CAT were 37% or more compared to the whole CAMCOG and 55% or more compared to the whole CAMCOG-Plus. Estimated ability levels with CAT were in excellent agreement with those based on the whole CAMCOG and CAMCOG-Plus (intraclass correlations 0.99 and 0.98, respectively). Diagnostic accuracy of detecting mild dementia and MCI seemed better for the CAT administered tests than for the MMSE, but the differences were not significant. We conclude that adaptive testing combines brevity with precision, especially in grading the severity of cognitive impairment. [ABSTRACT FROM AUTHOR]

Validation studies of symptom validity tests (SVTs) in children are uncommon. However, since children's cognitive abilities are not yet fully developed, their performance may provide additional support for the validity of these measures in adult populations. Four SVTs, the Test of Memory Malingering (TOMM), the Word Memory Test (WMT), the Amsterdam Short-Term Memory (ASTM) test, and the Word Completion Memory Test (WCMT), along with several neuropsychological instruments were administered to 48 Dutch school children aged 7–12. All children scored above the established adult cut-offs on the TOMM and the WMT. They could pass the ASTM test if their reading skills were at a level equivalent to that of 9 year olds. All children passed our criterion of a negative WCMT score. However, the WCMT does seem sensitive to the level of verbal fluency. Implications for the applicability of these SVTs in adult populations are discussed. [ABSTRACT FROM PUBLISHER]

Objectives: Chronic toxic encephalopathy (CTE) caused by long term occupational exposure to organic solvents is still a controversial disorder. Neuropsychological testing is the cornerstone for diagnosing the syndrome, but can be negatively influenced by motivational problems. In this nationwide study, we investigated the neuropsychological functioning and psychological symptoms of a large group of patients with suspected CTE, and ruled out alternative explanations for their complaints, including suboptimal performance due to insufficient effort. Methods: We studied participants with suspected CTE (n = 386) who were referred for further diagnosis to the Netherlands Centre of Occupational Diseases in the period 1998–2003 and who had completed the entire diagnostic protocol. Patients were excluded if there was the slightest suspicion that test performance had been negatively influenced by insufficient effort (n = 221), or if comprehensive assessment identified an alternative diagnosis (n = 80). Insufficient effort was defined by a combination of three indices. The neuropsychological test scores of the patient group (n = 85) were compared with those of a control group of building trade workers matched for sex, age, and educational level (n = 35). Results: The patient group had significantly more psychological complaints and performed significantly worse than the control group on tests of speed of information processing and memory and learning. However, only a small percentage of the patients had clearly abnormal scores for cognitive speed (9%) or memory (8%). Attention, verbal abilities, and constructional functions were not disturbed. Exposure duration and cognitive complaints were significantly correlated, whereas the correlation between exposure duration and neuropsychological domain scores was not significant. Conclusions: Insufficient effort was present in a substantial part of the patient group. After minimising the likelihood that insufficient effort negatively influenced neuropsychological scores, we still found neuropsychological deficits in speed of cognitive processing and memory; however, these scores were clearly abnormal only in a minority of patients with suspected CTE. Screening instruments should focus on these domains. [ABSTRACT FROM AUTHOR]

Objectives: The validity of memory and concentration complaints that are often reported after a whiplash trauma is controversial. The prevalence of malingering or underperformance in post-whiplash patients, and its impact on their cognitive test results were studied.Methods: The Amsterdam short term memory (ASTM) test, a recently developed malingering test, was used as well as a series of conventional memory and concentration tests. The study sample was a highly selected group of patients, who were examined either as part of a litigation procedure (n=36) or in the normal routine of an outpatient clinic (n=72).Results: The prevalence of underperformance, as defined by a positive score on the malingering test, was 61% (95% CI: 45-77) in the context of litigation, and 29% (95% CI: 18-40) in the outpatient clinic (p=0.003). Furthermore, the scores on the memory and concentration test of malingering post-whiplash patients (n=43) and non-malingering post-whiplash patients (n=65) were compared with the scores of patients with closed head injury (n=20) and normal controls (n=46). The malingering post-whiplash patients scored as low as the patients with closed head injury on most tests.Conclusions: The prevalence of malingering or cognitive underperformance in late post-whiplash patients is substantial, particularly in litigation contexts. It is not warranted to explain the mild cognitive disorders of whiplash patients in terms of brain damage, as some authors have done. The cognitive complaints of non-malingering post-whiplash patients are more likely a result of chronic pain, chronic fatigue, or depression. [ABSTRACT FROM AUTHOR]

We describe a patient with advanced Parkinson's disease who developed pathological gambling within a month after successful bilateral subthalamic nucleus (STN) stimulation. There was no history of gambling. On neuropsychological testing, slight cognitive decline was evident 1 year after surgery. Stimulation of the most dorsal contact with and without medication induced worse performances on decision making tests compared with the more ventral contact. Pathological gambling disappeared after discontinuation of pergolide and changing the stimulation parameters. Pathological gambling does not seem to be associated with decision making but appears to be related to a combination of bilateral STN stimulation and treatment with dopamine agonists. [ABSTRACT FROM AUTHOR]

Objectives: To examine whether cognitive testing can be tailored to individual patients by selecting only items of appropriate difficulty from a large and precise neuropsychological battery. The advantage is a combination of measurement precision with the brevity (of shorter tests). Methods: 39 patients with cognitive complaints and 8 partners who visited a geriatric day care clinic were randomly assigned to administration of the CAMCOG or an extended CAMCOG i.e. with ADAS-cog and neuropsychological tests. Item difficulties were estimated and their validity examined with Rasch analysis. Tailored testing was achieved by Computerised Adaptive Testing (CAT). CAT repeatedly selected an easier item after an incorrect response and a more difficult item after a correct response to estimate the total score. CAT finished the item selection after reaching sufficient reliability (standard error < 0.15). Results: For test reductions by CAT ranging from 25 to 15 items, intraclass correlations between the CAT estimated total score and actual total score (CAT administered plus remaining items) ranged from .99 to .98 for the CAMCOG and from 0.98 to 0.91 for the extended CAMCOG. Testing time reduction ranged from 42-55% for the CAMCOG (M testing time CAMCOG 39.6 minutes, M testing times CAT 22.9 to 17.8 minutes) and from 45-68% for the extended CAMCOG (M testing time extended CAMCOG 111.3 minutes, M testing times CAT 61-35 minutes). Conclusions: Substantial test reductions and excellent agreement with the whole battery supports the use of tailored cognitive testing to economically administer batteries that are time consuming in their entire form. [Copyright &y& Elsevier]