Cognitive outcomes following functional neurosurgery in refractory OCD patients: a systematic review.

Neurosurgery is a therapeutic option for patients with refractory obsessive-compulsive disorder who do not respond to previous treatments. Although its efficacy in reducing clinical symptomatology has been proven, few studies have analyzed its effects at the cognitive level. The aim of this systematic review was to describe the cognitive outcomes of functional neurosurgery in patients that went through capsulotomies or cingulotomies. PubMed, Medline, Scopus, PsycInfo, PsyArticles, and Web of Knowledge were searched for studies reporting cognitive outcomes in refractory obsessive-compulsive patients after capsulotomies and cingulotomies. The risk of bias was assessed with the Assessment Tool for Before-After (Pre-Post) Studies With No Control Group tool; 13 studies met inclusion criteria, including 205 refractory obsessive-compulsive disorder patients for both surgical procedures. Results showed a substantial number of studies that did report significant cognitive improvement after surgery, being this improvement specially related to memory and executive functions. The second-most frequent finding is the maintenance of cognitive performance (nor improvement or worsening). From a neuropsychological point of view, this outcome might be considered a success, given that it is accompanied by amelioration of obsessive-compulsive symptoms. Subtle cognitive adverse effects have also been reported. Neurosurgery procedures appear to be safe from a cognitive point of view. Methodological issues must be improved to draw clearer conclusions, but capsulotomies and cingulotomies constitute an effective alternative treatment for refractory obsessive-compulsive disorder patients.

Apathetic symptoms and white matter integrity after traumatic brain injury.

PRIMARY OBJECTIVE: The aim of the study was twofold. First, to study the relationship among apathy in the long term, initial clinical measures, and standard outcome scores after traumatic brain injury (TBI). Second, to describe white matter integrity correlates of apathy symptoms. RESEARCH DESIGN: Correlational study. Methods and Procedures: Correlation and Bayesian networks analyses were performed in a sample of 40 patients with moderate to severe TBI in order to identify the relationship among clinical variables, functionality, and apathy. A diffusion tensor imaging study was developed in 25 participants to describe correlations between fractional anisotropy (FA) measures and apathetic symptoms. MAIN OUTCOMES AND RESULTS: Correlation analysis revealed associations between pairs of variables as apathy in the long term and functional score at discharge from hospital. Bayesian network illustrated the relevant role of axonal injury mediating the relationship between apathy and initial clinical variables. FA in the superior longitudinal fasciculus, the inferior longitudinal fasciculus, and the internal capsule were negatively correlated with apathy measures. Widespread brain areas showed positive correlations between FA and apathy. CONCLUSIONS: These results highlight the relevance of white matter integrity measures in initial assessment after TBI and its relationship with apathetic manifestations in the chronic phase.

Evolution of cognitive impairment after a traumatic brain injury: is there any improvement after controlling the practice effect? / Evolución de las alteraciones cognitivas tras un traumatismo craneoencefálico: ¿hay mejoría tras controlar el efecto de la práctica?

INTRODUCTION: The importance of knowing the pattern of evolution of cognitive deficits in the first months after a traumatic brain injury (TBI) has encouraged the development of numerous longitudinal studies. However, the results of most of them should be taken with caution due to the lack of adequate control of practice effects that can lead to overestimating the genuine recovery of cognitive processes. AIM: To describe the cognitive changes between the acute and subacute phases of the TBI controlling the effect of the practice. PATIENTS AND METHODS: Twenty-two patients were assessed in two different time points after TBI (immediately and after six months) using the following tests: Trail Making Test (A, B, B/A, B-A), Stroop Test (W, C, CW, interference), Digit Symbol-Coding, Symbol Search, Digits Forward and Backward, Verbal Fluency and Short-term Memory. To control for the practice effects, a transformation of the scores was performed applying the procedure proposed by Calamia et al. RESULTS. Before controlling the practice effects, the scores of all tests improved (p > 0.001). However, afterward, the improvement remained only in the Trail Making Test-B, B/A and B-A, Digit Symbol-Coding, Symbol Search, Stroop CW and Digits Backward. CONCLUSIONS: The lack of control of practice effects in longitudinal studies can generate misleading interpretations about the evolution of cognitive deficits. The pattern of recovery after a TBI varies depending on the cognitive process.

TITLE: Evolución de las alteraciones cognitivas tras un traumatismo craneoencefálico: ¿hay mejoría tras controlar el efecto de la práctica?Introducción. La importancia de conocer el patrón de evolución de los déficits cognitivos en los primeros meses tras un traumatismo craneoencefálico (TCE) ha fomentado el desarrollo de numerosos estudios longitudinales. Sin embargo, los resultados de la mayoría de ellos deberían tomarse con cautela debido a la falta de un control adecuado del efecto de la práctica, que puede llevar a sobreestimar la recuperación genuina de los procesos cognitivos. Objetivo. Describir los cambios cognitivos entre las fases aguda y subaguda del TCE controlando el efecto de la práctica. Pacientes y métodos. Veintidós pacientes realizaron dos evaluaciones neuropsicológicas tras el TCE (inmediata y tras seis meses) mediante los siguientes tests: Trail Making Test (A, B, B/A y B-A), test de Stroop (P, C, PC e interferencia), clave de números, búsqueda de símbolos, dígitos directos e inversos, fluidez verbal y memoria inmediata. Para controlar el efecto de la práctica se realizó una transformación de las puntuaciones aplicando el procedimiento propuesto por Calamia et al. Resultados. Antes de controlar el efecto de la práctica, se evidenció una mejoría en las puntuaciones de todos los tests (p > 0,001). Sin embargo, tras él, la mejoría permaneció sólo en el Trail Making Test-B, B/A y B-A, la clave de números, la búsqueda de símbolos, el test de Stroop PC y los dígitos inversos. Conclusiones. La falta de control del efecto de la práctica en estudios longitudinales puede generar interpretaciones erróneas sobre el perfil de evolución de los déficits cognitivos. El patrón de recuperación tras un TCE varía en función del proceso cognitivo.

[Effects of motor activity on cognitive performance of patients with traumatic brain injury during dual tasking]. / Efectos de la actividad motora en el rendimiento cognitivo de pacientes con traumatismo craneoencefalico durante tareas duales.

INTRODUCTION: The use of dual task paradigms has revealed behavioural interactions between certain motor tasks, like standing or walking, and cognitive tasks when performed simultaneously. Despite the potential relevance of these findings accounting for certain neurological symptoms (i.e., falls), or for the design of new therapeutic interventions, there is few information available about such interaction effects in traumatic brain injury (TBI). AIM: To assess the presence of cognitive-motor interactions during dual tasking in TBI patients. SUBJECTS AND METHODS: Twenty TBI patients and 19 healthy matched controls performed two attentional and two working memory tasks (simple reaction times, complex reaction times, 1-back numeric, 1-back spatial) during dual task conditions, that is, at the same time than one motor task (standing and walking), and during single task conditions (without a motor task). Reaction times were recorded in response to all cognitive tasks. RESULTS: Patients exhibit slower performance than controls in all cognitive tasks (p < 0.05). While neither patients nor controls showed changes in reaction times in the two simpler attentional tasks during dual tasking as compared to single tasking conditions, TBI patients do exhibit improvements in working memory tasks (F(2, 74) = 2.9; p < 0.05) during dual tasking-walking (p < 0.02). CONCLUSIONS: The possible causes of positive cognitive-motor interactions during simultaneous execution of motor-working memory tasks in TBI patients are discussed, as well as the potential therapeutic value of dual task paradigms in the rehabilitation of these patients.

TITLE: Efectos de la actividad motora en el rendimiento cognitivo de pacientes con traumatismo craneoencefalico durante tareas duales.Introduccion. El empleo de paradigmas de tarea dual ha mostrado interacciones conductuales entre ciertas tareas motoras, como el equilibrio o la marcha, y tareas cognitivas al ser realizadas simultaneamente. Pese a la potencial relevancia de estos hallazgos en la explicacion de ciertos sintomas neurologicos (por ejemplo, caidas) o en el diseño de nuevas intervenciones, son escasos los datos sobre tales efectos en traumatismos craneoencefalicos (TCE). Objetivo. Evaluar la presencia de interacciones cognitivomotoras durante la realizacion de tareas duales en TCE. Sujetos y metodos. Veinte pacientes con TCE y 19 controles sanos realizaron diferentes tareas cognitivas de atencion y memoria operativa (tareas de tiempo de reaccion simple, tiempo de reaccion compleja, 1-back numerica y 1-back espacial) en tarea dual, es decir, al tiempo que una tarea motora (bipedestacion y marcha), y en tarea simple (sin tarea motora). Se registraron los tiempos de reaccion en respuesta a las tareas cognitivas. Resultados. Los pacientes mostraron peor rendimiento que los controles en todas las tareas (p < 0,05). Mientras que ninguno de los grupos mostro cambios en los tiempos de reaccion medidos en las tareas atencionales durante la ejecucion dual en comparacion con la ejecucion simple, los pacientes con TCE si mostraron mejoria en las tareas de memoria operativa (F(2, 74) = 2,9; p < 0,05) durante la tarea dual de marcha (p < 0,02). Conclusiones. Se discuten las posibles causas de interacciones cognitivomotoras positivas durante la ejecucion simultanea de tareas de marcha y memoria operativa en pacientes con TCE, y el potencial valor terapeutico de los paradigmas duales en la rehabilitacion de estos pacientes.

[Processing speed in relapsing-remitting multiple sclerosis: the role played by the depressive symptoms]. / Velocidad de procesamiento en la esclerosis multiple remitente recurrente: el papel de los sintomas depresivos.

INTRODUCTION: Reduced speed of information processing seems to characterize neuropsychological performance in multiple sclerosis (MS) patients. However, the impact in speed of information processing of depressive symptoms, that are highly prevalent in this population, has not been precisely defined yet due to the presence of some methodological limitations in most preceding studies. SUBJECTS AND METHODS: 42 MS remittent recurrent patients, 20 with depressive symptoms (BDI > 13), and 22 without, were compared to 24 healthy controls in neuropsychological tasks of speed of processing (SDMT, Stroop, TMT y PASAT-BNB). RESULTS: MS patients without depressive symptoms performed significantly worse than healthy controls the Stroop (W, C and WC), and the PASAT-BNB (execution time) tests. MS patients with depressive symptoms performed significantly worse than healthy controls the Stroop (W, C and WC), SDMT, TMT (A, B and B-A), and the PASAT-BNB (execution time and errors) tests. MS patients with depressive symptoms performed significantly worse than MS patients without depressive symptoms the SDMT, TMT (A, B and B-A), and the PASAT-BNB (execution time) tests. CONCLUSIONS: MS impact was not generalized in neuropsychological performance of patients. Depressive symptoms seem to play and important role determining the speed deficit. While MS reduced speed of information processing, depressive symptoms were associated to specific cognitive deficit different from speed ones.

Construct validity of the Trail Making Test: role of task-switching, working memory, inhibition/interference control, and visuomotor abilities.

The aim of this study was to clarify which cognitive mechanisms underlie Trail Making Test (TMT) direct and derived scores. A comprehensive review of the literature on the topic was carried out to clarify which cognitive factors had been related to TMT performance. Following the review, we explored the relative contribution from working memory, inhibition/interference control, task-switching ability, and visuomotor speed to TMT performance. Forty-one healthy old subjects participated in the study and performed a battery of neuropsychological tests including the TMT, the Digit Symbol subtest [Wechsler Adult Intelligence Scale (Third Version) (WAIS-III)], a Finger Tapping Test, the Digits Forward and Backward subtests (WAIS-III), Stroop Test, and a task-switching paradigm inspired in the Wisconsin Card Sorting Test. Correlation and regression analyses were used in order to clarify the joint and unique contributions from different cognitive factors to the prediction of TMT scores. The results suggest that TMT-A requires mainly visuoperceptual abilities, TMT-B reflects primarily working memory and secondarily task-switching ability, while B-A minimizes visuoperceptual and working memory demands, providing a relatively pure indicator of executive control abilities.

Trail Making Test in traumatic brain injury, schizophrenia, and normal ageing: sample comparisons and normative data.

The Trail Making Test (TMT) has been a useful assessment tool to investigate executive function. Several studies have recently improved the existing TMT norms by mean of large samples of healthy individuals stratified by a number of demographic variables from different populations. In contrast, criticisms have been raised about the utility of norms from healthy samples to detect changes across time in clinical samples where TMT performance used to be altered. In addition, few studies have compared groups of patients with deficits in TMT performance, making it difficult to decide whether a single set of norms is sufficient to assess different clinical populations. We provide normative data from three large samples of patients with traumatic brain injury (TBI) (n=90), schizophrenia spectrum disorders (n=127), and healthy Spanish speakers (n=223). Differences between healthy participants and patients in all TMT direct (TMT-A, TMT-B) and derived (B-A, B:A, B-A/A) scores were found. TMT performance was poorer in TBI patients than in schizophrenia patients except for the B:A and B-A/A scores, suggesting a similar underlying executive deficit. Normal ageing impaired both direct and derived TMT indices, as revealed by lower scores in the healthy elderly group (55-80 years old) as compared with young (16-24) and middle-aged (25-54) healthy participants. Three different sets of norms stratified by age, education, or both are presented for clinical use. Recommendations on TMT scores are made for future research.

[Frontal seizures recorded by magnetoencephalography. Case report]. / Crisis frontales registradas mediante magnetoencefalografía. Caso clínico.

INTRODUCTION: This paper reports the usefulness of magnetoencephalography (MEG) in the anatomical localization of the onset and spread of seizures. CASE REPORT: In a 34-year-old male patient who suffered from drug-resistant complex partial seizures (sometimes generalized) with loss of awareness, magnetic resonance imaging revealed a probable left frontobasal cortical dysplasia. Ictal scalp electroencephalogram showed left frontotemporal theta waves. Electrocorticography (ECoG) registered interictal polyspike discharges and located the seizure onset in the lateral orbital side of the left frontal lobe. Three seizures were registered by MEG, clinically similar to the ones usually experienced by the patient. MEG ictal spike dipole location showed seizure onset coming from the left inferior frontal gyrus (as the ECoG), spreading on to other frontal areas, insula and temporal lobe, all in the left hemisphere. CONCLUSION: MEG may be considered as a useful diagnosis modality in the study of partial seizure physiopathology as well as in its presurgical evaluation.

[Electrophysiology of executive functions]. / Electrofisiología de las funciones ejecutivas.

INTRODUCTION: In neuropsychology, executive functions have been defined as those that coordinate the flow of information processing in the brain. In the last decade its study has undergone an important development, partly due to the use of functional neuroimaging. DEVELOPMENT: Electrophysiological techniques have also provided a link between two specific components of the event related brain potential (ERP) and certain control and monitoring processes, as those described in theoretical frameworks of executive functioning (i.e., Norman & Shallice). On the one hand, attentional set shifting paradigms allow us to relate the anteriorly (P3a; latency 300-350 ms) and posteriorly (P3b; latency 450-600 ms) distributed components of the so called 'novelty P3', with a more general mechanism of attentional set shifting that could account for both stimulus and task novelty. On the other hand, 'error related negativity' (ERN or En) has shown its sensitivity to action monitoring (i.e., error detection and error correction processes), during the execution of response selection RT tasks. CONCLUSIONS: The comprehension of these two executive processes represents critical aspects in our understanding of brain function, and has direct applications to the design of both theoretical models and assessment and rehabilitation programs for patients with dysexecutive disorders.

[Madrid adaptation of the Wisconsin card sorting test: a comparative study of internal consistency]. / Adaptación Madrid del test de clasificación de cartas de Wisconsin: un estudio comparativo de consistencia interna.

INTRODUCTION: WCST (Wisconsin Card Sorting Test) is still a widely used neuropsychological test for evaluation of disorders of the frontal lobes. Recent studies have cast doubt on the validity of WCST as a marker for frontal dysfunction. OBJECTIVES: We present a simplified version of WCST specially designed to evaluate the capacity to change the criteria for attention. Our objectives were to examine the difference in standards and in internal consistency between our adaptation and the conventional WCST. SUBJECTS AND METHODS: The two tests were applied to a group of 60 young persons with no cerebral disorders. The principal components of both tests were analysed for determine their internal structure. RESULTS: We found statistically significant differences between the scores of Spanish persons and the standard data for WCST. Analysis of the main components showed a solution of two components in the conventional WCST and a solution of three components in our adaptation. CONCLUSIONS: The American rating system underestimated the level of performance in the Spanish sample. Analysis of the internal consistency showed the excessively redundant and simple factorial structure of the conventional WCST. Our adaptation was shown to have a richer internal structure, with the order of error scores more in accord with the type of cognitive process involved. These advantages may be attributed to more exact analysis of non perseverant errors, subclassified as efficient errors (i.e. linked to comparison of hypotheses) and random errors (i.e. linked to loss of criteria for attention).