Cognitive evaluation in adult patients with Möbius syndrome.

OBJECTIVE: To establish the occurrence of mental retardation in a group of patients with Möbius syndrome and subsequently, if mental retardation is absent, to screen major aspects of memory and attention, in order to assess possible pervasive dysfunction in these cognitive domains which might be responsible for the current view that mental retardation occurs frequently in Möbius syndrome. METHODS: In a group of 12 Dutch Möbius patients, intellectual performance, memory function and attention were assessed using a number of standardized neuropsychological tests. RESULTS: The mean general intellectual performance did not differ significantly from that of the Dutch population. Screening of selective attention and memory did not provide indications of pervasive dysfunctions in these domains. CONCLUSION: The rate of occurrence of mental retardation in our group of Möbius patients did not differ from that in the normal Dutch population. Furthermore, there was no evidence of attention and memory dysfunction in our group of Möbius patients.

Cognitive styles in high-functioning adolescents with autistic disorder.

This study addressed the operationalization, the identification, and the prevalence of weak central coherence and poor cognitive shifting in 35 high-functioning adolescents with autism. Central coherence and cognitive shifting were represented by two factors in a factor analysis, each reflecting a constituent aspect of the domain in question. With regard to central coherence, these aspects were the ability of piecemeal processing and the ability to process meaning. The aspects related to cognitive shifting concerned internally and externally controlled shifting. Weak central coherence and poor cognitive shifting did not appear to be related to measures of symptom severity, social understanding, and social competence. Both these cognitive styles did not appear to be universal to autism. In our sample, weak central coherence and poor cognitive shifting were found to be significantly more common than in normative control subjects.

Relationship between memory strategies and motor symptoms in Parkinson's disease.

Patients with Parkinson's disease(PD) show a serious decrease in performance on tasks which lack explicit guidelines and which necessitate the subject to develop his or her own strategy. Using the California Verbal Learning Task(CVLT) we have found evidence that this phenomenon becomes also manifest in learning and memory. The goal of the present study on PD was to investigate whether or not there is an intrinsic relationship between PD-specific deviant learning characteristics and the severity of motor symptomatology. The results show, as expected, a significant correlation between the severity of bradykinetic/hypokinetic symptoms and the serial clustering gradient of the CVLT: the more bradykinetic PD patients (n = 48) were, the more they were dependent on the externally guided serial learning strategy. The findings are discussed in the context of our hypothesis that the actual deficit in patients with PD is a deficient processing of ambiguous internal cues.

Cognitive deficits following stroke in the basal ganglia.

OBJECTIVE: To examine the effect of a stroke in the basal ganglia on cognitive functioning. DESIGN: As part of a larger prospective study on the neuropsychological and psychosocial consequences of stroke, 12 patients with a stroke confined to the basal ganglia were examined. SETTING: The patients were assessed in one of the three participating hospitals. SUBJECTS: The results of 12 patients with a stroke in the basal ganglia (mean age 55 years), were compared to 24 controls (mean age 54.3 years). MAIN OUTCOME MEASURES: Different aspects of memory, attention and concentration, visuospatial and visuoconstructive functions, language and arithmetic were assessed using neuropsychological tests. RESULTS: The data show a significant abnormality in cognitive functioning on all cognitive domains. CONCLUSIONS: The results stress the notion that subcortical damage may lead to substantial neuropsychological disorders and have clear implications for neurological rehabilitation.

[Cognitive deficits in Parkinson's disease]. / Cognitieve aspecten van de ziekte van Parkinson.

In neuropsychological studies of Parkinson's disease, cognitive deficits are frequently reported, but the nature of these deficits is not clear. As far as cognitive deficits are manifest in parkinsonian patients at an early stage of the disease, many studies tend to describe them as fitting a frontal syndrome. As a consequence of dysfunction of the striatum, the (pre)frontal cortex receives deficient input from the striatum, which might explain the similarity of the cognitive deficits of parkinsonian patients with those of patients with frontal dysfunction. The present studies provide evidence that the cognitive deficits of parkinsonian patients display a certain similarity with those of patients with frontal dysfunction at the level of the ultimate performance, but that the underlying processes have a distinct character. Parkinsonian patients exhibit a decrease in self-generated problem-solving. This deficit is manifest at a level of cognitive function, which goes beyond task or domain. Among all disease variables, only severity of the disease and especially rigidity proved to be related consistently to this decrease in self-generated problem-solving.

Memory performance under varying cueing conditions in patients with Parkinson's disease.

The present study is a continuation of a previous study in memory performance which showed that Parkinson's disease (PD) patients increasingly relied on explicit cues which prompt the external strategy of serial clustering, in comparison to control subjects (CS), who profited increasingly from implicit cues which prompt the internal and more effective strategy of semantic clustering. In this study, we investigated whether the recall of PD patients can be affected by adding or removing explicit cues. We manipulated the California Verbal Learning Test in two ways. First, we told the subjects under study in advance from which categories the items to be recalled were derived, thus making the implicit cue to cluster semantically explicit (explicit condition). Next, we permuted the sequence of the items in each trial, thus preventing the subjects from adhering to the serial order, i.e. to explicit cues (permuted condition). We included the data of our previous study (mixed condition) in the analysis of memory and learning performance in the three conditions. Learning of PD patients, as reflected in the semantic ratio, proved to be more affected by the cueing conditions than that of CS. Total performance and the serial ratios did not show a significant interaction between group and cueing condition. The results are discussed in terms of external and internal generation of problem-solving strategies.

Executive functions and disease characteristics in Parkinson's disease.

In the present study, we investigated the association of two executive functions with disease characteristics in Parkinson's disease (PD), especially with severity of motor symptoms. We operationalized two executive functions, viz. fluency and cognitive shifting, each in a number of tests with heterogeneous materials, but with an identical format. We calculated the correlations between test performance and disease characteristics, including the factor scores of the Unified Parkinson's Disease Rating Scale (UPDRS). The results of this study show that only cognitive shifting was consistently associated with the severity of motor symptoms in PD, in particular with rigidity. None of the fluency tests had a significant association with severity of motor symptoms. The present study indicates that PD, as reflected by the severity of motor symptoms, is not associated with a general decrease in executive function. In spite of the fact that both are executive functions and both require generation of items, fluency and cognitive shifting are differentially related to PD.

Card sorting performance in Parkinson's Disease: a comparison between acquisition and shifting performance.

In the present study we tested the hypothesis that learned irrelevance underlies the frequently observed poor performance of Parkinson's disease (PD) patients on card sorting tests. If learned irrelevance accounts for the poor performance of PD patients on card sorting tests, PD patients and control subjects (CS) will not differ in the acquisition phase, during which basic concept formation is assessed, but they will differ in the subsequent shifting phases. We presented three distinct card sorting tests with an identical format to 51 PD patients and 24 normal controls. The groups did not differ with respect to intelligence, memory, or attention. PD patients showed a slightly better performance in the acquisition phase. In the first shifting phase, the performance of PD patients was significantly poorer than that of control subjects after correction for basic concept formation. In the second shifting phase this difference disappeared. We conclude that learned irrelevance does not account for the poor performance of PD patients in card sorting tests. The results are discussed in terms of self-generation of problem solving strategies.

Cognitive function in early adult and adult onset myotonic dystrophy.

INTRODUCTION: Most studies revealing intellectual deficits in myotonic dystrophy (MyD) involved heterogeneous groups of patients with respect to intelligence and onset of disease. The present study was undertaken to investigate whether patients with early adult and adult MyD show subtle cognitive deficits despite a normal intelligence. MATERIALS AND METHODS: We compared 26 MyD patients of normal intelligence with mild symptoms and early adult and adult onset to 25 matched control subjects (CS) on a range of neuropsychological tests and a number of motor tasks of increasing complexity, which required increasing cognitive control. RESULTS: The groups did not differ as far as the neuropsychological tests were concerned, with the exception of the Stroop Color Word Test. With respect to motor performance, the MyD patients were poorer scorers on simple and automatic motor tasks than CS, but the difference disappeared as the complexity of the tasks increased and required correspondingly more cognitive control. CONCLUSION: We found hardly any evidence of cognitive dysfunction in our group of MyD patients with early adult and adult onset.

Memory and learning strategies in patients with Parkinson's disease.

Parkinson's disease patients (PD) do not differ from control subjects (CS) when they have to execute a problem solving task in which external cues for solving the problem are given. However, when PD have to solve a problem by means of an internally generated strategy, they show a serious decrease in performance. We hypothesised that this distinction may also apply to the way PD and CS organize recall. In order to test our hypothesis the California Verbal Learning Test (CVLT) was administered to 59 PD and 30 CS. The test consists of five learning trials using a 16-word target list, composed of four items from each of four semantic categories. The fact that the word list was built on this implicit organization was not divulged in advance. The sequence in which the words were read is fixed; each subsequent word belongs to a category being different from the category to which the preceding word belongs. The organization in recall according to the semantic categories is considered to be the result of an unprompted, internally generated strategy. Recall according to the sequence in which the words are read by the experimenter, is viewed as an externally offered strategy. The results prove to be in line with our hypothesis: unlike CS who appeared to rely mainly and increasingly on an internally generated semantic organization, PD showed evidence of gradually adhering more to the externally imposed serial sequence.

Cognitive shifting as a predictor of progress in social understanding in high-functioning adolescents with autism: a prospective study.

Although striking and pervasive failure of social understanding is commonly viewed as a major defining characteristic of people with autism, few follow-up reports were published that have focused on improvement of social intelligence. In this prospective study in which 17 high-functioning adolescents with autism were involved, cognitive shifting as measured by card sorting tests, unlike overall intelligence, was shown to be the only significant factor in predicting progress in social understanding as assessed by social comprehension tests. A pretest-posttest design was used. During the 2-year follow-up all the subjects were in residential care and enrolled in educational curricula focusing on the development of social intelligence, living, and vocational skills.

Impaired cognitive shifting in parkinsonian patients on anticholinergic therapy.

In this study we established that cognitive shifting, an ability that is known to be affected in PD, is more impaired in PD patients, treated with anticholinergics, than in de novo patients. Eleven PD patients on anticholinergic monotherapy were compared with 30 de novo patients. The groups did not differ with respect to age, duration and severity of PD, and depression, nor with respect to general intelligence or attention. We assessed cognitive shifting with three different card-sorting tests. The patients on anticholinergics showed a poorer performance on all card-sorting tests than the de novo patients did. The patients on anticholinergics needed significantly more trials in two card-sorting tests and discovered significantly less categories in total. There was also a significant difference in memory performance, but memory performance did not correlate with any score on the card-sorting tests. This indicates that the performance on card-sorting tests and the memory performance were independent.

Bimanual simultaneous motor performance and impaired ability to shift attention in Parkinson's disease.

The ability to share time and to shift attention between bimanual simultaneous motor tasks were studied in 18 patients with Parkinson's disease (PD) and 19 age- and intelligence-matched controls. The task consisted of drawing triangles with the dominant hand and squeezing a rubber bulb with the nondominant hand. Motor performance was measured using the variables: amplitude of squeezing, frequency of squeezing and velocity of drawing triangles. After eliminating variance due to baseline differences in single-handed performance, the bimanual simultaneous performance of PD and controls turned out to be similar to the frequency of squeezing and the velocity of drawing triangles. The amplitude of squeezing, however, differed between the two groups: it was significantly reduced in PD. Arguably the disturbance in the bimanual performance of PD patients was not due to a disorder of time sharing, but to a decreased ability to shift attention from the visually cued task to the non visually cued task. The results agree with current evidence that PD patients are more impaired when they have to rely upon internal control for the regulation of shifting attention than when external cues are available.

Haloperidol and cognitive shifting.

In this study haloperidol appeared to affect the performance on a selected category of cognitive tasks considered to represent shifting aptitude. A pretest--post-test design was used with two groups of subjects: 17 patients suffering from idiopathic spasmodic torticollis, and 17 controls who were matched for age and intelligence. The results are discussed in relation to previous findings on haloperidol and cognition, shifting disorder in Parkinson's disease and changes in behavioural organization found in animals with an experimentally induced dopaminergic hypoactivity.

Spasmodic torticollis: the problem of pathophysiology and assessment.

In 17 patients with idiopathic spasmodic torticollis (ST) quantitative indices for both signs (extent and direction of the head deflexions) and complaints (of deflexion, shaking and pain) were collected. In the literature deflexion in the horizontal plane is most frequently considered, but analysis of the data shows that deflexion in the coronal and sagittal planes is also important. Furthermore, it is found that especially the deflexions in the coronal and sagittal plane covariate with the patients' complaints, but not with horizontal deflexion. On the basis of these and related data, it is suggested that we are dealing with at least two subtypes of ST. Finally, the patient's neuroticism and depression scale values are within the normal range and do not show significant correlations with ST duration. The present study provides no evidence that ST is a psychogenic disorder. ST should be regarded as a central nervous system disorder of unknown aetiology.