Sex differences in cognition in healthy elderly individuals

Sex differences in patterns of cognitive test performance have been attributed to factors, such as sex hormones or sexual dimorphisms in brain structure, that change with normal aging. The current study examined sex differences in patterns of cognitive test performance in healthy elderly individuals. Cognitive test scores of 957 men and women (age 67-89), matched for overall level of cognitive test performance, age, education, and depression scale score, were compared. Men and women were indistinguishable on tests of auditory divided attention, category fluency, and executive functioning. In contrast, women performed better than men on tests of psychomotor speed and verbal learning and memory, whereas men outperformed women on tests of visuoconstruction and visual perception. Our finding that the pattern of sex differences in cognition observed in young adults is observed in old age has implications for future studies of both healthy elderly individuals and of those with cognitive disorders

Levodopa is not a useful treatment for Lesch-Nyhan disease

Item does not contain fulltextLesch-Nyhan disease (LND) is characterized by dystonia, cognitive abnormalities, and self-injurious behavior. No effective therapies are available. LND is associated with a presynaptic dopaminergic deficit, but the reported effects of dopamine replacement therapy are conflicting. The current prospective open-label study assesses the effects of levodopa on both neurological and behavioral features of LND. All 6 study participants discontinued levodopa early, due to lack of effect and sometimes worsening of motor function. The results provide important clues for pathophysiological mechanisms and suggestions for future treatment options

Test UD Interferencia: Creación y validación de un nuevo instrumento de resistencia a la interferencia. Normalización y estandarización en población española

Resumen: Introducción: El test UD Interferencia evalúa la velocidad de procesamiento y la atención, y está basado en el concepto de interferencia del test de Stroop. El objetivo principal de este estudio es proporcionar una versión alternativa del test de Stroop que evite algunas de las limitaciones de versiones anteriores, relacionadas con el daltonismo y las dificultades de lectura en personas mayores, y obtener datos normativos y estandarizados para este test, adaptados a población española. Métodos: El estudio se enmarca dentro del proyecto Normacog, para el cual se evaluó a 905 participantes (18-93 años). Se analizó la fiabilidad y la validez concurrente y de constructo del test. Se analizaron el efecto de la edad, nivel educativo y sexo sobre el rendimiento en UD Interferencia y se crearon percentiles y puntuaciones escalares ajustadas por edad y nivel educativo. Resultados: El test muestra buena fiabilidad (α = 0,875) y validez concurrente (r de 0,443 a 0,725; p < 0,001) y de constructo (r de 0,472 a 0,737; p < 0,001). Se observó un efecto significativo de la edad y el nivel educativo sobre el rendimiento en UD Interferencia, explicando del 12 al 40% de la varianza. El sexo únicamente presentó un efecto significativo en la variable índice de resistencia a la interferencia. Conclusiones: Se presenta una versión alternativa del test de Stroop que presenta algunas ventajas sobre anteriores versiones. Se aportan baremos estandarizados y normalizados para población española que permiten corregir el test teniendo en cuenta la edad y educación de la persona evaluada. Abstract: Introduction: The UD Interference Test measures processing speed and attention, and is based on the concept of interference of the Stroop Test. The main purpose of the study is to provide an alternative version of the Stroop Test that overcomes some of the limitations of previous versions in assessing individuals with daltonism or age-related reading difficulties, and to obtain normative and standardised data for the Spanish population. Methods: This study is part of the Normacog project. We evaluated 905 individuals (age range, 18-93 years) to analyse the test's reliability and concurrent and construct validity. We evaluated the effect of age, sex, and level of education on UD Interference Test performance and calculated percentiles and age- and education-adjusted scaled scores. Results: The test has good reliability (α = 0.875) and concurrent (r = 0.443-0.725; p < .001) and construct validity (r = 0.472-0.737; p < .001). We observed age and educational level to have a significant effect on UD Interference Test scores, explaining 12-40% of variance. Sex only had a significant effect on the resistance to interference index. Conclusions: We present an alternative version of the Stroop Color and Word Test with some advantages over previous versions. We provide standardised and normalised data for the Spanish population to correct the test according to the subject's age and level of education

Deep brain stimulation in Lesch-Nyhan disease: outcomes from the patient's perspective.

To provide insight into outcome and long-term safety and efficacy of deep brain stimulation (DBS), from the perspective of individuals with Lesch-Nyhan disease (LND) and their families. We used patient-centered outcome measures to assess long-term outcomes of DBS for 14 individuals (mean [SD] age 10y 10mo [5y 6mo], range 5-23y, all males) with LND, after an average duration of 5y 6mo (range 11mo-10y 5mo) after surgery. We compared these results with a comprehensive review of previously published cases. Patients and their families reported that DBS of the globus pallidus can be effective both for motor and behavioral disturbances in LND. However, outcome measures were often not significantly changed owing to substantial variability among individuals, and were overall less positive than in previous reports based on clinician assessments. In addition, there was an unexpectedly high rate of adverse events, tempering overall enthusiasm for the procedure. Although DBS might be an effective treatment for LND, more research is needed to understand the reasons for response variability and the unusually high rates of adverse events before DBS can be recommended for these patients. What this paper adds Individuals with Lesch-Nyhan disease and their families report variable efficacy of deep brain stimulation. Long-term outcomes are associated with a high adverse event rate

Delineation of the motor disorder of Lesch-Nyhan disease.

Contains fulltext : 51161.pdf (publisher's version ) (Open Access)Lesch-Nyhan disease (LND) is caused by deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). Affected individuals exhibit over-production of uric acid, along with a characteristic neurobehavioural syndrome that includes mental retardation, recurrent self-injurious behaviour and motor disability. Prior studies involving relatively small numbers of patients have provided different conclusions on the nature of the motor disorder. The current study includes the results of a multi-centre international prospective study of the motor disorder in the largest cohort of patients studied to date. A total of 44 patients ranging from 2 to 38 years presented a characteristic motor syndrome that involved severe action dystonia superimposed on baseline hypotonia. Although some patients also displayed other extrapyramidal or pyramidal signs, these were always less prominent than dystonia. These results are compared with a comprehensive review of 122 prior reports that included a total of 254 patients. Explanations for the differing observations available in the literature are provided, along with a summary of how the motor disorder of LND relates to current understanding of its pathophysiology involving the basal ganglia

Equilibrium and Adverse Selection

The nature of equilibrium in markets with adverse selection evoked considerable interest following George Akerlof's famous paper on the market for lemons. Whereas Akerlof argued that markets with adverse selection may yield no equilibrium, Charles Wilson has argued that multiple equilibria may result. In this paper, it is shown that if the distribution of quality follows some standard distribution, then a unique equilibrium will result. In the (less plausible) context of multiple-equilibria, conditions are derived under which both buyers and sellers will prefer higher price-equilibria