Structural MRI correlates of the MMSE and pentagon copying test in Parkinson's disease.

BACKGROUND: Cognitive impairment in Parkinson's disease (PD) is common and recent studies have focused on addressing the most suitable screening tool for its assessment. MMSE is commonly used in clinical practice and longitudinal studies found a relationship between the MMSE pentagon copying item and progression to dementia, but its neuroanatomical correlates have been poorly investigated. The aim of this study is to investigate the MRI structural correlates of the global MMSE and the pentagon item scores in PD patients in the absence of dementia. METHODS: We selected a sample of 92 PD patients and 36 controls. MMSE was used as a global measure of cognitive status, and the pentagon copying test as a measure of visuospatial performance. FreeSurfer software was used to assess intergroup differences in cortical thickness (CTh) and global atrophy measures, as well as their relationship with cognitive performance. RESULTS: Compared to controls, patients showed significant differences in measures of global atrophy, which correlated with performance on MMSE and the pentagon item. Regional differences in CTh were seen between PD patients and controls bilaterally in the temporo-parietal-occipital region. Patients with impaired performance compared with those of normal performance also showed CTh reductions in these regions. CONCLUSION: Our results suggest MMSE and the pentagon item reflect brain changes which at a regional level involve mainly posterior regions. Correlates of the pentagon item were seen in the same regions where PD patients exhibited significant thinning, and involved more areas and bigger cluster sizes than the correlates of MMSE global scores.

White matter integrity related to functional working memory networks in traumatic brain injury.

OBJECTIVE: This study explores the functional and structural patterns of connectivity underlying working memory impairment after severe traumatic axonal injury. METHODS: We performed an fMRI n-back task and acquired diffusion tensor images (DTI) in a group of 19 chronic-stage patients with severe traumatic brain injury (TBI) and evidence of traumatic axonal injury and 19 matched healthy controls. We performed image analyses with FSL software and fMRI data were analyzed using probabilistic independent component analysis. Fractional anisotropy (FA) maps from DTI images were analyzed with FMRIB's Diffusion Toolbox. RESULTS: We identified working memory and default mode networks. Global FA values correlated with both networks and FA whole-brain analysis revealed correlations in several tracts associated with the functional activation. Furthermore, working memory performance in the patient group correlated with the functional activation patterns and with the FA values of the associative fasciculi. CONCLUSION: Combining structural and functional neuroimaging data, we were able to describe structural white matter changes related to functional network alterations and to lower performance in working memory in chronic TBI.

Raven's Coloured Progressive Matrices as a measure of cognitive functioning in Cerebral Palsy.

BACKGROUND: Cognitive dysfunction is frequent in Cerebral Palsy (CP). CP motor impairment and associated speech deficits often hinder cognitive assessment, with the result being that not all CP studies consider cognitive dysfunction. Raven's Coloured Progressive Matrices is a simple, rapid test which can be used in persons with severe motor impairment and speech limitations. We studied whether this test can offer a reliable measure of cognitive functioning in CP. METHOD: Visuoperceptual, language, memory and frontal lobe functions were evaluated in 30 participants with severe motor impaired CP and a variety of speech difficulties. The relationship between Raven's Coloured Progressive Matrices and a variety of tests was analysed. RESULTS: Raven's Coloured Progressive Matrices performance was associated with visuoperceptual, language, visual and verbal memory but not with frontal functions. Receptive vocabulary and visuospatial measures were the best predictors of Raven's Coloured Progressive Matrices raw scores. CONCLUSIONS: Raven's Coloured Progressive Matrices is a fast, easy-to-administer test able to obtain a measure related with linguistic, visuoperceptual, and memory cognitive functioning in persons with CP despite their motor and speech disorders.

Use of geotextile tubes with chemical amendments to dewater dairy lagoon solids.

Three geo-textile filtration tubes were used to dewater lagoon solids from a first stage dairy lagoon using chemical amendments (aluminum sulfate and a polymer) to enhance the separation process. This experiment had previously been done without chemical amendment. The chemical amendments speeded the dewatering process so that filling could be accomplished sooner, and also increased the removal rate of nutrients, especially phosphorus into the solid phase. Chemically amended slurry was pumped from the lagoon into the tube with the filtered liquid seeping from the tube and returning to the lagoon. Each tube was filled five to six times at 2-5-day intervals, and then allowed to dewater for 2 weeks before sampling the solid fraction in the tube. Separation efficiency improved from 79% to 99% for phosphorous and from 92% to 100% for organic nitrogen with chemical amendment. Time required for dewatering was significantly reduced by chemical amendment. Cost for the tube was approximately $10/m(3) of recovered solids with no chemical amendment and cost including the chemicals was approximately $14/m(3) of recovered solids.

Abnormal orbitofrontal development due to prematurity.

OBJECTIVE: To investigate the effects of prematurity on sulcal formation. METHODS: We evaluated the depth and volume of the primary olfactory sulcus (developed at 16 weeks' gestation) and the secondary orbital sulci (which start to develop at 28 weeks' gestation) in a sample of 22 adolescents with history of very-preterm birth (VPTB). We compared this preterm sample with a sample of subjects born at term and matched by age, gender, and sociocultural status. The Anatomist/BrainVISA 3.0.1 package was used to identify and quantify the sulci. In addition, voxel-based morphometry (VBM) was used to analyze possible reductions of gray and white matter in the orbitofrontal area. RESULTS: Compared with controls, we found a significant reduction in the secondary sulci depth but not in the primary sulcus in the VPTB. VBM analysis showed reduced gray-matter volume in VPTB in the orbital region. CONCLUSIONS: Premature birth affects cerebral gyrification, and this impairment is not reversible during childhood. Identification of the specific factors involved in abnormal brain maturation may lead to effective interventions.

Responses of broilers to dietary zinc concentrations and sources in relation to environmental implications.

1. Since high concentrations of zinc are associated with reduced crop yields, environmental concerns are emerging regarding zinc accumulation in areas where poultry production is prevalent. This study investigates growth performance and zinc utilisation during the life cycle of broilers when diets were supplemented with various concentrations of zinc from two different sources. 2. A total of 740 Cobb 500 1-d-old male broiler chicks was randomly distributed into 88 battery cages. Excreta were collected over a 48-h period on d 10, 17, 24, 31, 38, and 45 to measure zinc excretion on a dry matter basis. 3. During the 45-d experimental period, broilers were given a maize-soybean meal basal diet (30 mg/kg zinc) supplemented with 0, 20, 40, and 80 mg/kg of zinc from zinc sulphate, Availa Zn amino acid complex, or an equal combination of zinc sulphate and Availa Zn amino acid complex. 4. Progressive additions of zinc to the basal diet significantly increased body weight gain of broilers, but did not affect feed conversion or mortality. Optimum body weight gain was achieved at 80 mg/kg supplemental zinc, which exceeds the NRC recommendations of 40 mg/kg. 5. During each excreta collection period, increased supplemental zinc concentrations significantly increased zinc excretion. However, the zinc source did not influence zinc utilisation. 6. As compared with zinc sulphate supplementation, the cumulative zinc excretion data indicate that adding zinc to the basal diet in the form of Availa Zn amino acid complex decreased zinc excretion.

[Functional magnetic resonance in the evaluation of the activity of the anterior cingulate cortex using Stroop's paradigm]. / Resonancia magnética funcional en la evaluación de la actividad del cingulado anterior mediante el paradigma de Stroop.

INTRODUCTION: Stroop s paradigm has been used to evaluate the anterior attention system which regulates the inhibitory capacity of automatic responses. Functional neuroimaging techniques have shown a preponderant role for the anterior cingulate cortex in carrying out this paradigm. OBJECTIVE: To evaluate the activity of the anterior cingulate cortex in view of its clinical importance in the study of neurological and psychiatric disorders. PATIENTS AND METHODS: Eleven healthy volunteers took part in the study. The functional images were analyzed using the software SPM99 and by second order individual and group analysis. RESULTS: Initial local analysis showed activation in the right anterior cingulated cortex (Brodmann s area 32) and left central (areas 31 and 23); caudate nucleus (right body and left tail) and thalamus (bilateral). Overall there was significant activation of the left hemisphere, in areas 44 (Broca s area), 7, 40 (supra marginal gyrus and insular cortex, and in the right hemisphere in area 19. In spite of this there was great individual variation. CONCLUSIONS: The overall results are concordant with complex functional connections for attention and the control of automatic responses. In our study the anterior cingulated cortex was not selectively activated. The activation of the thalamus and caudate nucleus may be explained by their involvement in the frontostriatal circuits. The lack of individual consistency may be due to different personal cognitive styles of resolving conflicts. According to our results, Stroop s paradigm would not be clinically useful for showing good or bad functioning of the anterior cingulated cortex.

Resonancia magnética funcional en la evaluación de la actividad del cingulado anterior mediante el paradigma de Stroop / Functional magnetic resonance in the evaluation of the activity of the anterior cingulate cortex using Stroop's paradigm

Introducción. El paradigma de Stroop se ha utilizado para evaluar el `sistema atencional anterior' que regula la capacidad inhibitoria de respuestas automáticas. Técnicas de neuroimagen funcional han evidenciado un papel preponderante del cingulado anterior en la ejecución de este paradigma. Objetivos. Evaluar la activación del cingulado anterior, dado su interés clínico en el estudio de enfermedades neurológicas y psiquiátricas. Pacientes y métodos. Participaron en el estudio 11 sujetos voluntarios sanos. Las imágenes funcionales se analizaron con el programa informático SPM99, mediante análisis individual y por grupos de segundo orden. Resultados. Un primer análisis local evidenció activación en el cingulado anterior derecho (área 32 de Brodmann) y central izquierdo (áreas 31 y 23), núcleo caudado (cuerpo derecho y cola izquierda) y tálamo (bilateral). Globalmente, se halló activación significativa en el hemisferio izquierdo, en las áreas 44 (área de Broca), 7, 40 (giro supramarginal) y córtex insular, y en el hemisferio derecho, en al área 19. A pesar de ello, existen grandes diferencias individuales. Conclusiones. Los resultados globales son acordes con el modelo de una compleja conectividad funcional para la atención y el control de automatismos. En nuestro estudio, el cingulado anterior no se activa de forma selectiva. La activación del tálamo y del núcleo caudado podría explicarse por su implicación en los circuitos frontoestriatales. La ausencia de consistencia individual puede deberse a diferentes estilos cognitivos personales en la resolución del conflicto. Según estos resultados, el paradigma de Stroop no serviría clínicamente para indicar el buen o mal funcionamiento del cingulado anterior (AU)

Effects of bilateral subthalamic stimulation on cognitive function in Parkinson disease.

BACKGROUND: Chronic bilateral subthalamic deep brain stimulation (STN-DBS) is known to improve motor function in patients with Parkinson disease (PD). However, the possible effects of STN-DBS on neuropsychological functions have been studied less. OBJECTIVE: To investigate the effects of STN-DBS on neuropsychological functions in PD. DESIGN: Before-after trial. PATIENTS AND METHODS: Fifteen consecutive patients were assessed before and 3 months after implantation of stimulators for STN-DBS (postsurgical assessment with the stimulators switched on). Both assessments were performed with patients in a drug-free condition. The neuropsychological battery consisted of tests measuring memory and visuospatial and frontal functions. RESULTS: The comparison between presurgical and postsurgical performance showed a moderate deterioration in verbal memory and prefrontal and visuospatial functions, and a moderate improvement in a prefrontal task and obsessive-compulsive traits. The motor state improved in all patients. CONCLUSION: Therapy with STN-DBS improves motor symptoms in PD without any clinically relevant neuropsychological deterioration.

MRI atrophy parameters related to cognitive and motor impairment in Parkinson's disease.

BACKGROUND: Patients with Parkinson's disease (PD) show specific neuropsychological deficits in attention, memory, visuospatial or frontal lobe functions, which can arise from degeneration of different cerebral structures. OBJECTIVE: The aim of the present study was to analyze the role of focal degeneration (basal ganglia and substantia nigra) and diffuse cerebral atrophy (ventricular enlargement) in motor/cognitive impairment in PD. PATIENTS AND METHODS: We administered to 14 patients with advanced PD the following tests: Purdue Pegboard, Rey's Auditory-Verbal Learning test (RAVLT), Benton's Line Orientation, Trail Making, phonemic verbal fluency and Stroop test. Ventricular system, caudate and putamen nuclei and pars compacta of the substantia nigra were quantitatively measured by magnetic resonance imaging. Correlation analyses were carried out. RESULTS: The results showed that ventricular enlargement is negatively correlated with the performance on RAVLT and Stroop test. No relationship was found between caudate atrophy and cognitive deficits. Degeneration of putamen nucleus was found to be associated with motor deficits. CONCLUSION: Memory and frontal impairment are related to diffuse cerebral degeneration and the motor deficit is related to degeneration of the putamen nucleus.

Obsessive-compulsive symptoms in Parkinson's disease.

To systematically investigate obsessive-compulsive traits in Parkinson's disease, patients were administered the Maudsley obsessional-compulsive inventory (MOCI) and a modification of the Leyton obsessional inventory (LOI) to a sample of non-demented and non-depressed patients with Parkinson's disease. Patients with severe Parkinson's disease showed more obsessive traits than normal controls in MOCI and LOI total scores, and in the "checking", "doubting", and "cleaning" subscales of the MOCI. By contrast, patients with mild disease did not differ from controls. A significant correlation was found between severity and duration of illness and MOCI total score. These results support the involvement of basal ganglia in obsessive-compulsive symptomatology. As patients with mild Parkinson's disease did not differ from controls, obsessive-compulsive disorder does not seem to be directly related to the initial nigrostriatal dopaminergic deficiency which causes clinical Parkinson's disease symptomatology. The appearance of obsessive symptoms could be related to the subset of neurochemical changes taking place at the level of the basal ganglia circuitry as disease progresses.

Parámetros de atrofia por IRM relacionados con alteraciones cognitivas y motoras en la enfermedad de Parkinson / MRI atrophy parameters related to cognitive and motor impairment in Parkinson's disease

FUNDAMENTO: Los pacientes con la enfermedad de Parkinson (EP) manifiestan déficit neuropsicológicos en atención, memoria, visuospaciales o frontales, los cuales pueden ser debidos a la degeneración de diferentes estructuras cerebrales. OBJETIVO: El objetivo del presente estudio consistió en analizar el papel de la degeneración focal (ganglios basales y sustancia negra) y la atrofia cerebral difusa (dilatación ventricular) en la alteración motora/cognitiva en la EP. PACIENTES Y MÉTODOS: Se administraron a 14 pacientes con EP avanzada las siguientes pruebas: Purdue Pegboard, Prueba de Aprendizaje AuditivoVerbal de Rey (RAVLT), Orientación de Líneas de Benton, Trail Making, fluencia verbal fonética y test de Stroop. Se midieron cuantitativamente, a partir de imágenes de resonancia magnética, el sistema ventricular, núcleo caudado, putamen y la parte compacta de la sustancia negra. Se realizaron análisis de correlación. RESULTADOS: Los resultados demostraron que la dilatación ventricular está negativamente correlacionada con el rendimiento en el RAVLT y en el test de Stroop.No se encontró correlación entre la atrofia del caudado y los déficit cognitivos. Se halló relación entre la degeneración del núcleo putamen y los déficit motores. CONCLUSIóN: La alteración frontal y en memoria está relacionada con la degeneración cerebral difusa, en tanto que el déficit motor se relaciona con la degeneración del núcleo putamen (AU)

The effect of medial frontal and posterior parietal demyelinating lesions on stroop interference.

Functional imaging has consistently shown that attention-related areas of medial frontal and posterior parietal cortices are active during the attentional conflict induced by color naming in the presence of distracting words (Stroop task). Such studies, however, have provided few details of the correlational nature between observed regional brain activations and reaction time delay occurring in this situation. We analyzed the effect of medial frontal and posterior parietal lesions on the Stroop response in a group of patients with multiple sclerosis, a neurological disorder in which Stroop response speed is affected to varying degrees. Forty-five patients were assessed using a computer-presented verbal version of the Stroop task and specific MRI protocol. Demyelination areas were measured on five anatomical divisions of the medial frontal white matter and on white matter of the posterior parietal lobe. We found that a combination of frontal and parietal lesion measurements accounted for 45% of the Stroop interference time variance. Patients with more right frontal than left parietal demyelination showed slowed Stroop responses, whereas the predominance of lesions in the left posterior parietal region was associated with a reduced Stroop interference. These results may contribute to defining the specific participation of these attention-related brain areas in the conflict of attention represented by the Stroop paradigm. They also help to explain the variability of the Stroop effect in multiple sclerosis patients and suggest that the Stroop test does not assess just a single cognitive operation, but rather the combined effect of anatomically segregated neural processes.

[Attention deficit hyperactivity disorder. Cerebral asymmetry observed on magnetic resonance]. / Trastorno por déficit de atención con hiperactividad. Asimetrías cerebrales observadas en resonancia magnética.

INTRODUCTION: Anatomical and functional neuroimaging data from subjects with Attention Deficit Hyperactivity Disorder (ADHD) have consistently implicated a reversal of cerebral asymmetry and suggested a fronto-striatal dysfunction in this disorder. OBJECTIVE: The aim of this study is to investigate the brain asymmetries in a homogeneous and non-medicated sample of adolescents with ADHD who had been previously studied in our laboratory. PATIENTS AND METHODS: T1-weighted magnetic resonance images were obtained for 11 adolescents with ADHD and 19 control subjects. Frontal and posterior brain regions, caudate nucleus, and ventricular system were quantitatively measured. RESULTS: A reversed pattern of asymmetry for the caudate nucleus (right > left) was found in ADHD when compared to the control group. We also found a reversed pattern of asymmetry for the frontal lobe (right < left) and a smaller right frontal volume (prefrontal specifically) in the ADHD subjects most severely impaired. Right caudate and frontal measures were inversely correlated. CONCLUSIONS: ADHD is associated with fronto-striatal abnormalities, which may be explicable via extant neurodevelopmental theories. Enlargement of the right caudate nucleus may suggest the failure of a process of synaptic 'pruning' by which attentional functions could be improperly transferred from the basal ganglia to frontal regions during development.

Trastorno por déficit de atención con hiperactividad. Asimetrías cerebrales observadas en resonancia magnética / Attention deficit hyperactivity disorder. Cerebral asymmetry observed on magnetic resonance

Introducción. Los estudios de neuroimagen estructural y funcional en sujetos con trastorno por déficit de atención con hiperactividad (TDAH) han sugerido una inversión de los patrones de asimetría cerebral y una disfunción del sistema fronto-estriatal. Objetivo. El propósito de esta investigación es estudiar las asimetrías cerebrales de una muestra homogénea y no medicada de adolescentes con TDAH. Pacientes y métodos. Se realizaron las resonancias magnéticas potenciadas en T1 de 11 adolescentes con TDAH y 19 sujetos normales que formaban el grupo control. Se realizó la medición cuantitativa semiautomatizada de diversas regiones y estructuras cerebrales: regiones frontal y posterior, núcleo caudado y sistemaventricular.Resultados.Seobservaunpatróninversodeasimetría del núcleo caudado (derecho > izquierdo) en el grupo TDAH en comparación con el grupo control. También en el grupo TDAH se aprecia la asimetría inversa de los lóbulos frontales (derecho < izquierdo) y un menor volumen frontal derecho (región prefrontal concretamente) en los sujetos con TDAH más gravemente afectados.El núcleo caudado y las medidas frontales presentaron una correlación negativa. Conclusiones. ElTDAH está asociado con alteraciones del sistema fronto-estriatal cerebral, alteración que es coherente conlas teorías del neurodesarrollo. El fracaso en el fenómeno regresivo que conlleva el proceso de apoptosiso `muerte neuronal programada' podría ser el mecanismo subyacente al mayor tamaño del núcleo caudado derecho. Como consecuencia, la transferencia de las funciones atencionales de los ganglios basales al lóbulo frontal se produciría de forma inapropiada a lo largo del desarrollo (AU)

Effects of unilateral posteroventral pallidotomy on 'on-off' cognitive fluctuations in Parkinson's disease.

In Parkinson's disease, cognitive performance can vary according to levodopa levels (on-off states). Both positive and negative effects of dopaminergic stimulation have been reported. Pallidotomy is also able to change cognitive performance, in addition to levodopa pharmacokinetics. The aim of this investigation was to study the effects of pallidotomy on cognitive on-off fluctuations in Parkinson's disease. A brief neuropsychological battery was administered to 15 PD patients during on and off states before and after surgery. Before pallidotomy, patients performed better in the on condition on Trail Making test B; after pallidotomy levodopa no longer improved performance, and the interaction between surgery and state was significant. In relation to the difference between preoperative and postoperative performance in Trail Making B test, there was a significant postsurgical improvement only in off state. Verbal fluency decreased after pallidotomy in both on and off conditions. Our results suggest that pallidotomy can change the effects of levodopa on neuropsychological functions.

Cognitive and behavioral changes after unilateral posteroventral pallidotomy: relationship with lesional data from MRI.

We investigated cognitive and behavioral changes after unilateral posteroventral pallidotomy, and their relationship with lesion size and location as identified in magnetic resonance image quantitative analysis. Fifteen consecutive patients with Parkinson's disease were assessed neuropsychologically before and after unilateral posteroventral pallidotomy (five right and 10 left). Immediate postsurgery evaluation (1 week) demonstrated significant worsening of memory, motor learning, motor speed, and verbal fluency. In the 3-month follow up, learning, memory, and speed returned to the presurgical level, but verbal fluency remained below the baseline. Significant improvements were observed in visuospatial functions and obsessive-compulsive behavior. Lesional volume did not correlate with neuropsychologic changes. Left lesions produced more impairment in verbal fluency than right-sided lesions. Regression analysis identified two lesional areas in the pallidum mediale internum. These regions accounted for 68% of the variance in the visuospatial changes.

Overestimation and unreliability in "feeling-of-doing" judgements about temporal ordering performance: impaired self-awareness following frontal lobe damage.

"Feeling-of-doing" accuracy in a temporal ordering task in 33 patients with frontal lobe lesions and a matched control group was investigated. The temporal ordering task used word lists that had high, medium, or no semantic interrelatedness. Patients with frontal lobe lesions showed an impairment in temporal ordering across all three word lists. Both groups performed better on the lists with higher semantic interrelatedness. Patients with frontal lobe lesions overestimated their ability to order words accurately. On the less semantically interrelated lists, metamemory judgment in patients with frontal lesions did not correlate with their performance. These results indicate that both temporal order judgment and metacognitive decisions about temporal order judgment are subserved by the prefrontal cortex and further clarifies the role of the frontal lobes in behavioral monitoring.

Impaired estimation of word occurrence frequency in frontal lobe patients.

Neuroanatomical correlates of the estimation of occurrence frequency have received little attention. This study investigates the possible role of the frontal lobe in estimating word occurrence frequency. A sample of 27 patients with frontal lesions were matched with normal controls by sex, age and years of education. Significant differences between patients and controls were found for frequency estimation, but not for item recognition. Studying accuracy of estimation as a function of actual frequency, the frontal group performed worse, especially at high frequencies of occurrence. As far as lesion lateralization is concerned, the right frontal subgroup performed worse than the control group in the estimation of frequency. Our results suggest that the prefrontal cortex plays a role in estimating word occurrence and that there is a dissociation between frequency memory and recognition memory, pointing to the involvement of two different cerebral systems.

[Neuropsychological consequences of perinatal asphyxia]. / Consecuencias neuropsicológicas de la asfixia perinatal.

Perinatal asphyxia has been classically related to important neurological diseases such as cerebral palsy, but it it also stated that a high percentage of child with a good outcome did not show any sequelae. We reviewed cerebral lesions demonstrated by post-mortem analysis and the structural MRI contributions to the anatomo-functional correlates. The most frequent neuropsychological disturbances showed by these patients in the general intelligence, perceptive functions, memory and emotional and social behavior were also summarized.