Role of perceptual and organizational factors in amnesics' recall of the Rey-Osterrieth complex figure: a comparison of three amnesic groups

Neuropsychological longitudinal study of patients with low-grade gliomas: Cognitive impairment

This study is part of a longitudinal research program, in which patients diagnosed with low-grade gliomas (LGG: n = 13), as well as healthy controls (n = 13), were consecutively recruited and neuropsychologically followed for 7 years. The patients are followed up regardless of variations in treatment. A composite score is used (Global Deficit Score: GDS) included cognitive measures where at least five patients had a negative change: information processing speed, speed of naming, construction ability, verbal fluency, non-verbal thinking, and immediate non-verbal memory. The most important finding in this 7-year follow-up study is that two-thirds of the patients developed cognitive impairment. The remaining third of the patients showed stability in their cognitive ability and were still alive 17 years after diagnosis. Younger patients with tumors in the right frontal or posterior regions showed a more favorable development. Patients with frontal tumors and a declined GDS show also significant changes in executive functions. Given the limited number, no firm conclusions can be drawn regarding the impact of tumor localization. The impact of LGG on cognition and the survival time after diagnosis varies considerably between patients. However, most of the patients (69%) showed cognitive impairment during the seven years we followed them.

Nonverbal memory tests revisited: Neuroanatomical correlates and differential influence of biasing cognitive functions

The detection of right temporal lobe dysfunction with nonverbal memory tests has remained difficult in the past. Reasons for this might be the potential influence of other biasing cognitive functions such as executive functions or the verbalisability of nonverbal material. The aim of this study was to investigate three classic nonverbal memory tests by identifying their neuroanatomical correlates with lesion-symptom mapping (LSM) and by probing their independence from verbal encoding abilities and executive functions. In a cohort of 119 patients with first-time cerebrovascular accident, memory performance was assessed in the Nonverbal Learning and Memory Test for Routes (NLMTR), the Rey Complex Figure Test (RCFT), and the Visual Design Learning Test (VDLT). Calculating multivariate LSM, we identified crucial brain structures for these three nonverbal memory tests. Behavioural analyses were performed to assess the impact of executive functions and verbal encoding abilities with regression analyses and likelihood-ratio tests. LSM revealed for the RCFT mainly right-hemispheric frontal, insular, subcortical, and white matter structures and for the NLMTR right-hemispheric temporal (hippocampus), insular, subcortical, and white matter structures. The VDLT did not reach significance in LSM analyses. Behavioural results showed that amongst the three nonverbal memory tests the impact of executive functions was most pronounced for RCFT, and the impact of verbal encoding abilities was most important in VDLT. Likelihood-ratio tests confirmed that only for NLMTR did the goodness of fit not significantly improve by adding executive functions or verbal encoding abilities. These results suggest that amongst the three nonverbal memory tests the NLMTR, as a spatial navigation test, could serve as the most suitable marker of right-hemispheric temporal lobe functioning, with the right hippocampus being involved only in this test. In addition, the behavioural results propose that only NLMTR seems mostly unaffected by executive functions and verbal encoding abilities.

Visual memory performance following mild traumatic brain injury and its relationship with intellectual functioning

To compare the visual memory performance of uncomplicated and complicated mild TBI (mTBI) groups with that of a control group on the Rey Complex Figure Test (RCFT). We also aimed to explore the influence of factors such as age, gender, education, occupation, and intellectual functioning on visual memory in individuals with mTBI. The RCFT and the Wechsler Abbreviated Scale of Intelligence (WASI-II) were administered to 138 participants (90 uncomplicated mTBI patients, 19 complicated mTBI patients, and 29 controls). The mTBI patients demonstrated significantly lower scores than control participants on both immediate and delayed RCFT recall conditions, with performance in the low average and borderline range. However, there was no difference in performance between the two mTBI groups on the recall conditions. In addition, no significant differences were observed across the three groups on the recognition condition. The WASI-II Performance and Verbal IQ scales explained most of the variance in the immediate and delayed RCFT recall conditions but were not associated with performance on the recognition condition. In contrast with the recognition processes involved in visual memory, recall processes seem to be more vulnerable following mTBI and both verbal and performance IQ seem to be related to visual memory performance.

Neurocognitive Function in Newly Diagnosed Low-grade Glioma Patients Undergoing Surgical Resection With Awake Mapping Techniques

BACKGROUND:

Low-grade glioma (LGG) patients have increased life expectancy, so interest is high in the treatments that maximize cognition and quality of life.

OBJECTIVE:

To examine presurgical baseline cognitive deficits in a case series of LGG patients and determine cognitive effects of surgical resection with awake mapping.

METHODS:

We retrospectively assessed neurological deficits, subjective concerns from patient or caregiver, and cognitive deficits at baseline and postsurgery for 22 patients with newly diagnosed LGG who underwent baseline neuropsychological evaluation and magnetic resonance imaging before awake surgical resection with mapping. Twelve of the 22 patients returned for postoperative evaluation approximately 7 months after surgery.

RESULTS:

At baseline, 92% of patients/caregivers reported changes in cognition or mood. Neurological examinations and Montreal Cognitive Assessment Scale scores were largely normal; however, on many tests of memory and language, nearly half of individuals showed deficits. After surgery, 45% had no deficits on neurological examination, whereas 55% had only transient or mild difficulties. Follow-up neuropsychological testing found most performances stable to improved, particularly in language, although some patients showed declines on memory tasks.

CONCLUSION:

Most LGG patients in this series presented with normal neurological examinations and cognitive screening, but showed subjective cognitive and mood concerns and cognitive decline on neuropsychological testing, suggesting the importance of comprehensive evaluation. After awake mapping, language tended to be preserved, but memory demonstrated decline in some patients. These results highlight the importance of establishing a cognitive baseline before surgical resection and further suggest that awake mapping techniques provide reasonable language outcomes in individuals with LGG in eloquent regions.

Frontal-executive constructional apraxia: when delayed recall is better than copying

In assessments of visuospatial function and memory, patients are often required to copy a figure and later to reproduce that figure from memory. Whereas most people perform better on a copying task than when drawing from memory, in this study we describe an unusual pattern of performance in which patients are better at drawing from memory than copying. Consecutive patients in a neurocognitive disorders clinic were given a battery of clinical cognitive tests that included copying a figure of intersecting pentagons and then drawing the figure from memory. Patterns of drawing performance at the two time points were compared to the profile of other cognitive deficits.

RESULTS

A subgroup of four patients with frontal dysfunction showed marked improvement in drawings at a delay compared to copying. Prior studies have indicated that most patients have declines in drawing performance at a delay. The unusual pattern of better performance at a delay compared to an initial copy occurred in patients with frontal dysfunction. These patients' visuoconstructive deficit and subsequent improvement could be related to either a failure to disengage when a model is present, to memory consolidation with increased reliance on top-down processing in the delay condition, or to relative preservation of global versus local aspects of a stimulus in memory. The addition of a task to assess drawing after a delay to a standard clinical screening battery such as the Mini-Mental Status Examination (MMSE) provides the opportunity to evaluate this phenomenon that may be indicative of frontal-executive dysfunction.

Self versus family ratings of the frontal systems behaviour scale and measured executive functions: adult outcomes following childhood traumatic brain injury

Traumatic brain injury (TBI) frequently occurs during childhood and adolescence with long-term neuropsychological and behavioral effects. Greater personal awareness of injury is associated with better outcomes. However, personal awareness is often assessed using ratings obtained from family members or significant others. Surprisingly, the accuracy of family-ratings compared with self-ratings has not been well studied in the TBI population. Thus, the purpose of this study was to examine self versus family-ratings of frontal dysfunction and secondly, the association between self/family reported frontal dysfunction and measured executive function outcomes. A total of 60 participants, approximately 10 years post-TBI, comprised 3 groups including; moderate/severe TBI (N=26; mean age 22.9, SD=3.0), mild TBI (N=20; mean age, 21.7, SD=2.7), and control (N=14: mean age, 21.6, SD=3.7). Neuropsychological testing was used to obtain domain scores for executive function and working memory/attention for each participant, and nominated family members and participants with TBI were asked to complete the Frontal Systems Behaviour Scale (FrSBe), consisting of three sub-scales; apathy, disinhibition, and executive dysfunction. Using the FrSBe there was no significant difference between the groups in executive function score, but the moderate/severe and mild groups had significantly lower working memory/attention scores compared with the control group (p<0.05). Repeated measures analysis of variance showed higher self-ratings on all sub-scales compared with family in each group (p<0.05). Scores on executive function and working memory/attention domains correlated with self, but not family reported executive dysfunction. Self-rated executive dysfunction explained 36% of the variance in executive function (p<0.001). While agreement between self-rated and family-rated total FrSBe scores was significant in all groups (p<0.001), our results showed that self-ratings were of higher predictive utility for executive functioning compared with family ratings. Further, at 10 years post-TBI, patients show greater awareness of deficits compared with family who rate consistently closer to the normal functioning range.

Differential contributions of objective memory and mood to subjective memory complaints in refractory focal epilepsy

People with epilepsy frequently present with bitter memory complaints. Previous research variously attributes this to symptoms of mood disturbance or objective memory deficits. To investigate the influence of the epileptogenic region on this variability, we examined interrelationships between mood, objective memory, and memory complaints in a sample of patients with refractory focal epilepsy and controls (N = 96). Patients had either mesial temporal (MT, n = 39) or non mesial-temporal (NMT, n = 21) foci. In contrast to controls (n = 36), both patient groups were highly concerned about their memory (P<0.001) and were more likely to have a history of depression (P = 0.005). Multiple regression showed that objective memory dysfunction and current depressive symptoms predicted the memory complaints of patients with MT epilepsy (P = 0.005), whereas a history of depression predicted the complaints of patients with NMT epilepsy (P = 0.008). These findings suggest that patients have concerns about their memory underpinned by distinct psychological and neurobiological factors depending on the location of their epileptogenic focus.

Judgment and memory performance for emotional stimuli in patients with alcoholic Korsakoff syndrome

In this study we investigated whether alcoholic Korsakoff patients are impaired in categorizing neutral and emotional stimuli according to their valence and whether memory performance for this material is reduced. In a group of Korsakoff patients and a comparison group two experimental tasks--one containing emotional and neutral pictures and the other containing words-were administered. Results showed that patients had difficulties in affective judgments due to problems in classifying neutral stimuli. Memory for emotional and neutral material was impaired to a similar degree. Thus, the facilitating effect of emotional valence on memory performance is absent in Korsakoff patients.

A neuropsychological assessment of frontal cognitive functions in Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is associated with a characteristic behavioural phenotype whose main features are, alongside compulsive hyperphagia, deficits in social behaviour: social withdrawal, temper tantrums, perseverative speech and behaviour, mental rigidity, stereotyped behaviour, impulsiveness, etc. Similar symptoms may also be found in autistic spectrum disorders and lesional pathologies of the frontal lobe. In both cases, such symptoms have been related to dysfunctions in frontal cognitive processes such as attention, working memory and executive functions. This study uses standardized neuropsychological instruments to analyse the degree to which these processes are affected in PWS.

METHODS

The sample comprised 16 individuals with a genetically confirmed PWS diagnosis. Subjects' IQ (Wechsler Adult Intelligence Scale), academic level, laterality and body mass index (BMI) were calculated. Attention, memory and executive functions were analysed using standard, widely employed neuropsychological tests. We compared the results of the sample group with the general population. Correlation analyses were carried out with IQ, academic level and BMI.

RESULTS

In all the neuropsychological measures focusing on attention, executive functions and visuoperceptual organization, the study sample scored significantly lower than the normative reference population. The scores of the tests used for measuring immediate memory were also significantly lower when trials required sequential processing, although not when they required simultaneous processing. In the memorization of a list of words, subjects showed an initial deficit which disappeared with repetition, enabling them to obtain scores similar to the reference population. No significant correlations were found with BMI, and a higher IQ or academic level did not improve scores in the majority of tests.

CONCLUSIONS

The study shows a deficit in elementary frontal cognitive processes in PWS patients. This deficit may be involved in the social behaviour disorders that characterize such patients, as described in other development or frontal syndrome pathologies. However, we cannot affirm that the deficits found are specific to PWS; they could also occur in other causes of intellectual disability. Although in the study sample IQ did not correlate with frontal deficits, further research is needed to establish whether the neuropsychological alterations described form part of a cognitive phenotype for PWS. We believe that our understanding of the social behaviours typical of PWS may be improved by taking into consideration the cognitive functioning models of the prefrontal lobe, particularly those applied to pervasive developmental disorders.

Rey Complex Figure Test Performance After Traumatic Brain Injury

The influence of factors such as a cerebral injury characteristics, education, perceptual organization skills, and speed of information processing on performance on the Rey Complex Figure Test & Recognition Trial (RCF) was examined by means of hierarchical regression analyses in 100 consecutively referred persons with traumatic brain injury at a median of 2.5 months post-injury. Patients with premorbid (e.g., psychiatric history) or comorbid (e.g. financial compensation seeking) complicating factors were excluded. Perceptual organization skills and the presence of a diffuse intracranial lesion but not education or speed of processing were statistically significant predictors of the variance in RCF variables. A large proportion of the sample improved by at least a standard deviation from independent delayed recall to multiple-choice recognition, and this was mediated by perceptual organization skills but not by injury parameters. It is concluded that performance on the RCF after traumatic brain injury is affected relatively more by perceptual organization skills than by injury severity characteristics.

Differential Impact of Executive Function on Visual Memory Tasks

Despite their common use in neuropsychological evaluation, little is known about the differential contribution of executive functioning to visual memory tests. In this study, hierarchical regression was used to determine the role of executive functioning on the Visual Reproduction subtest of the Wechsler Memory Scale--Third Edition, and the Rey-Osterrieth Complex Figure (ROCF) in a mixed neurological sample of 193 patients. Executive functioning was predictive of Visual Reproduction but not ROCF recall variables after accounting for demographic variables and global cognitive functioning. Only executive tests with a visuospatial component, the Trail-Making Test Part B and Wisconsin Card Sorting Test perseverative responses, were predictive of recall of Visual Reproduction stimuli. Organization of the ROCF was predictive of both Visual Reproduction and ROCF recall. These findings increase our understanding of the executive contribution to two common visual memory tests and may aid in the clinical interpretation of seemingly discrepant visual memory performance.

A comparison of administration procedures for the Rey-Osterrieth Complex Figure: flowcharts versus pen switching

The Rey-Osterrieth Complex Figure (ROCF) is commonly used to assess visuospatial skills, visuoconstruction, visual memory, and executive functioning. Two different methods are traditionally used to record the order in which the figure is drawn: the flowchart method and the pen-switching method. Although it has been suggested that pen switching may interfere with performance, to date no research has been conducted to assess whether ROCF performance significantly differs due to administration method. As part of routine neuropsychological evaluation, 100 inpatients and outpatients were randomly assigned to either method. Using the Boston Qualitative Scoring System and the traditional 36-point scoring method, the authors unexpectedly found that the pen-switching group generally performed better than the flowchart group, and productions drawn with pen switching were also significantly faster to score.