Nicolle Zimmermann

Brazilian preliminary norms and investigation of age and education effects on the Modified Wisconsin Card Sorting Test, Stroop Color and Word test and Digit Span test in adults

Executive functions are involved in a series of human neurological and psychiatric disorders. For this reason, appropriate assessment tools with age and education adjusted norms for symptom diagnosis are necessary. Objective To present normative data for adults (19-75 year-olds; with five years of education or more) on the Modified Wisconsin Card Sorting Test (MWCST), Stroop color and word test and Digit Span test. Age and education effects were investigated. Methods Three samples were formed after inclusion criteria and data analysis: MWCST (n=124); Digit Span (n=123), and Stroop test (n=158). Groups were divided into young (19-39), middle-aged (40-59) and older (60-75) participants with five to eight years of education and nine years of education or more. Two-way ANOVA and ANCOVA analyses were used. Results Education effects were found in most variables of the three tasks. An age effect was only found on color naming and color-word naming speed from the Stroop test. No interactions were detected. Conclusion In countries with heterogeneous educational backgrounds, the use of stratified norms by education to assess at least some components of executive functions is essential for an ethical and accurate cognitive diagnosis.

Longitudinal assessment of subcortical gray matter volume, cortical thickness, and white matter integrity in HIV-positive patients

To longitudinally evaluate the cortical thickness and deep gray matter structures volume, measured from T1 three‐dimensional (3D) Gradient echo‐weighted imaging, and white matter integrity, assessed from diffusion tensor imaging (DTI) of HIV‐positive patients.

Regional Cerebral Gray Matter Volume in HIV‐Positive Patients with Executive Function Deficits

To evaluate whether human immunodeficiency virus (HIV)‐positive patients with and without executive functions deficits and healthy control subjects differ on cortical thickness and subcortical brain structures volume in vivo.

Global Cognitive Impairment in Systemic Lupus Erythematosus Patients: A Structural MRI Study.

ObjectiveThis study investigated differences in subcortical brain volumes of SLE patients with cognitive deficits (SLE-CD) and SLE patients with normal cognitive performance (SLE-CN), regardless of the presence of other neuropsychiatric symptoms.MethodWe studied 40 patients divided into two-matched groups (SLE-CD nu2009=u200920; SLE-CN nu2009=u200920), with age ranging from 21 to 63 years old (100u2009% female) and 14.73u2009±u200910.18 years of diagnosis. Magnetic resonance imaging exams were performed on a 1.5xa0T scanner. A neuropsychological flexible battery was applied individually, including reasoning/problem-solving, praxis, episodic and working memory, processing speed, language/fluency, executive functions (inhibition and flexibility), and sustained attention. Z scoreu2009≤u2009−u20092.0 in any dimension was considered as a cut-off for being considered to possess cognitive deficits. One-way analyses of covariance (ANCOVA) were performed to compare the brain structure volumes between groups. The analyses were controlled for the effects of lupus-related neuropsychiatric disorders.ResultsSLE patients with cognitive deficits had significantly smaller volumes in the left hippocampus, amygdala, and the right hippocampus than SLE patients without cognitive deficits.ConclusionSLE patients with cognitive deficits appeared to have reduced temporal lobe structures when compared with SLE without cognitive deficits. These results corroborate a systems vulnerability model that investigated temporal lobe vulnerability during normal aging and in other neurological disorders.

Evaluation of white matter integrity in systemic lupus erythematosus by diffusion tensor magnetic resonance imaging: a study using tract-based spatial statistics.

IntroductionThe aim of this study was to evaluate the white matter integrity in brains of patients with systemic lupus erythematosus (SLE) using a voxel-based analyses of diffusion tensor imaging (DTI) data.MethodsFifty-seven patients with SLE were compared to 36 control patients who were matched by gender, age, education, and Mini Mental State Examination score. DTI was performed along 30 noncollinear directions in a 1.5 Tesla scanner. For tract-based spatial statistics (TBSS), a white matter skeleton was created, and a permutation-based inference with 5000 permutations and a threshold of pu2009<u20090.05 was used to identify abnormalities in fractional anisotropy (FA). The mean (MD), radial (RD), and axial diffusivities (AD) were also projected onto the mean FA skeleton.ResultsWe found a significant decrease of global FA in SLE patients compared to controls. The areas of reduced FA included the right superior corona radiata, the right superior longitudinal fasciculus, the body of the corpus callosum, the right inferior fronto-occipital fasciculus, the right thalamic radiation, and the right uncinate fasciculus. Patients with SLE also had increased AD and RD in several areas. Substantial overlap of areas with increased AD and RD occurred and were spatially much more extensive than the areas of reduced FA.ConclusionSignificant increases of AD values were concordant to those of RD and MD and more extensive than FA changes. Analyzing all diffusivity parameters, using TBSS, can detect more white matter microstructural changes in patients with SLE than analyzing FA alone.

Longitudinal evaluation of resting-state connectivity, white matter integrity and cortical thickness in stable HIV infection: Preliminary results

Purpose The objectives of this study were to determine if HIV-infected patients treated with highly active antiretroviral therapy (HAART), without dementia, suffer from longitudinal gray matter (GM) volume loss, changes in white matter (WM) integrity and deterioration in functional connectivity at rest, in an average interval of 30 months. Methods Clinically stable HIV-positive patients (on HAART, CD4u2009+u2009T lymphocyteu2009>u2009200 cells/μl, and viral loads <50 copies/μl) were recruited. None of them had HIV-associated dementia. Each patient underwent two scans, performed in a 1.5-T magnetic resonance imaging (MRI) scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of GM structures. WM integrity was assessed using tract-based spatial statistics to post-process diffusion tensor imaging data, and FMRIBs Software Library tools were used to post-process resting-state functional magnetic resonance imaging (RS-fMRI). Results There were no significant differences in cortical thickness, deep GM volumes, or diffusivity parameters between the scans at the two time points. Five resting-state networks were identified in our patients. In the second MRI, HIV-positive patients presented increased areas of functional connectivity in visual pathways, frontoparietal and cerebellar networks, compared with the first MRI (considering pu2009<u20090.05). Conclusions RS-fMRI revealed potentially compensatory longitudinal alterations in the brains of HIV-positive patients, attempting to compensate for brain damage related to the infection.

Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques

IntroductionThe objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE).MethodsPatients (nxa0=xa019) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (nxa0=xa019), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of pxa0<xa00.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton.ResultsPatients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls.ConclusionAbnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies.

Brain morphology and cortical thickness variations in systemic lupus erythematosus patients: Differences among neurological, psychiatric, and nonneuropsychiatric manifestations

To determine whether systemic lupus erythematosus (SLE) affecting subcortical white matter volumes, deep gray matter volumes, and cortical thickness differ between groups of SLE patients with psychiatric (P‐SLE), neurological (N‐SLE), or nonneuropsychiatric (non‐NPSLE) presentations.

Episodic memory impairment in systemic lupus erythematosus: involvement of thalamic structures

Episodic memory deficits in systemic lupus erythematosus (SLE) have been frequently reported in the literature; however, little is known about the neural correlates of these deficits. We investigated differences in the volumes of different brain structures of SLE patients with and without episodic memory impairments diagnosed by the Rey Auditory Verbal Learning Test (RAVLT). Groups were paired based on age, education, sex, Mini Mental State Examination score, accumulation of disease burden (SLICC), and focused attention dimension score. Patients underwent magnetic resonance imaging (MRI). Cortical volumetric reconstruction and segmentation of the MR images were performed with the FreeSurfer software program. SLE patients with episodic memory deficits presented shorter time of diagnosis than SLE patients without episodic memory deficits. ANOVA revealed that SLE patients with episodic memory deficits had a larger third ventricle volume than SLE patients without episodic memory deficits and controls. Additionally, covariance analysis indicated group effects on the bilateral thalamus and on the third ventricle. Our findings indicate that episodic memory may be impaired in SLE patients with normal hippocampal volume. In addition, the thalamus may undergo volumetric changes associated with episodic memory loss in SLE.

Contributions of the ecological approach to the neuropsychology of executive functions

Neurocognitive assessment involves several different types of processes, techniques and instruments. Traditionally, clinical and/or standardized methods have been the most extensively used in neuropsychological research and clinical practice. Ecological instruments are characterized by the standardized administration of tasks with similar cognitive demands to those observed in everyday situations. Although executive functions are often required in daily living tasks, the lack of a consensus as to their theoretical defi nition has posed several hurdles to their assessment and rehabilitation. The aim of this paper was to present the contributions of an ecological neuropsychological approach to assessment, rehabilitation, and neuroimaging, while discussing the theoretical implications of these processes on the neuropsychology of executive functions. This was achieved through a non-systematic review of classical and contemporary literature on ecological assessment tools. The use of an ecological approach has contributed to the understanding and assessment of functional impairment, as well as to the development of rehabilitation programs focusing on practical daily living activities, allowing for a clearer understanding of the neural correlates of complex environmental and individual factors, and for a more thorough reassessment of the validity of theoretical models of executive functions .