Mes: junio 2015

Previous research on semantic dementia (SD) has demonstrated a link between conceptual representations and ability on a range of ´non-semantic´ tasks, both verbal and nonverbal. In all cases, SD patients perform well on items that conform to the underlying statistical ´surface´ structure of the domain in question but poor performance on items that are atypical with respect to these statistics. For such items, there is a strong tendency for the patients´ erroneous responses to reflect the more typical pattern. To date, most research on this topic has been conducted with English-speaking patients, and where extended to non-English languages, directly comparable aspects of each language have been probed. In this study we tested the generalisation of this theory by probing performance on an aspect of Spanish with no analogue in English (grammatical gender). As predicted, Spanish SD patients provided the correct gender to high frequency words or where the phonology of the noun strongly predicted the gender. For low frequency, atypical nouns, however, the patients made many more errors (preferring the statistically typical gender). As expected, performance on nouns with atypical grammatical gender was strongly correlated with the degree of semantic impairment across the case-series of SD patients.

The results not only provide another example of the critical relationship between semantic memory and ´non-semantic´ cognition, but also indicate that this theoretical framework generalises to novel aspects of non-English languages – suggesting that the phenomenon is based on brain-general mechanisms.

Postural deformities are frequent and disabling complications of Parkinson’s disease (PD) and atypical parkinsonism. These deformities include camptocormia, antecollis, Pisa syndrome, and scoliosis. Recognition of specific postural syndromes might have differential diagnostic value in patients presenting with parkinsonism. The evidence to date suggests that postural deformities have a multifactorial pathophysiology. Contributing factors include muscular rigidity; axial dystonia; weakness caused by myopathy; body scheme defects due to centrally impaired proprioception; and structural changes in the spine. The relative contribution of these different factors varies between patients and across specific syndromes. Improved understanding of the mechanisms underlying postural deformities in PD might ultimately lead us to more effective management strategies for these disabling and drug-refractory complications.

Over the past five to ten years, neuroimaging capability for neurodegenerative diseases has made remarkable progress. However, debate remains as to the true clinical utility of these advanced and costly investigations. Not only is the place of these tests in diagnostic algorithms unclear, but the access to them varies both within and between countries. We sought to gather informed opinion from recognized leaders in the field who can combine both an academic and a clinical perspective on the use of neuroimaging in their own countries. Opinion is presented from Scotland, Argentina, the Czech Republic, France, the USA and Australia. The emerging consensus was one of ongoing caution. While in most countries there was a sense that the use of more advanced imaging techniques was growing, their hour has not yet cometh. However, these techniques, rather than falling from the Ivory Tower, should descend slowly step by step onto fertile and receptive clinics from where better clinical guidelines will emerge.

Over a 100 years have passed since Pick’s description of what is now termed frontotemporal lobar degeneration (FTLD). FTLD is a topic of intense current research interest yet some relevant contributions by non-English speaking authors have received little attention, which makes the history of FTLD research incomplete. In the hopes of filling some of the gaps in the history of FTLD research, the present article introduces fundamental work carried out in Argentina during the first half of the 20th century by Christfried Jakob and Braulio A. Moyano. Jakob’s neurophilosophy, as well as his empirical descriptions on dementia and theoretic insights into the role of the frontal lobes are highlighted. Moyano’s works on frontotemporal dementia (FTD), specifically concerning language deficits and the concept of focal pathology in Alzheimer disease presenting with progressive aphasia are introduced. These early contributions are examined in the light of the current knowledge on FTLD, highlighting some of the authors’ early original contributions, as well as their misconceptions. These authors remain largely unknown despite the fact that their contributions were fundamental in kindling interest in behavioral neurology in Latin America, which continues to this day.

OBJECTIVES: Bipolar Disorders are among the ten leading causes of morbity and lithium is considered first-line treatment and the most cost-effective. Nevertheless, its use takes a back seat to other treatment options less effective, safe and more expensive; and the reasons for this remains unclear. The present study investigates clinical concepts related to its underutilization. METHOD: An anonymous questionnaire concerning different aspects of lithium clinical use (compared efficacy, adverse effects, practical aspects regarding its use, use in special populations) was administered during the XXV Congress of the Argentinean Psychiatrist Association. RESULTS: 164 questionnaires were analyzed. Less than one-third of the sample referred lithium as their most frequent treatment option, although almost 60% qualified it as effective. Almost two-thirds considered its utilization as more complex and ill-ascribed adverse effects to it. One third referred not to use it in youth and senior populations. CONCLUSIONS: contrary to current recommendations, lithium is under utilized. This is the first report on the possible causes leading to such phenomena, which can be related to ill concepts regarding its safety, clinical use and adverse effects; although not to its effectiveness.

When context is hard to integrate: cortical measures of congruency in schizophrenics and healthy relatives from multiplex families. Autores Ibanez A, Riveros R, Aravena P, Vergara V, Cardona JF, Garcia L, Hurtado E, Martin-Reyes M, Barutta J, Manes F.  Año 2011 Journal  Ibanez A, Riveros R, Aravena P, Vergara V, Cardona JF, Garcia L, Hurtado E, Martin-Reyes M, Barutta J, Manes F.  Volumen 126(1-3): 303-305 Abstract   Otra información    

The emerging impact of social neuroscience on neuropsychiatry and clinical neuroscience. Autores Mendez MF, Manes F.  Año 2011 Journal  Mendez MF, Manes F.  Volumen 6(5-6): 415-419 Abstract   Otra información    

Pathological Gambling in a Bipolar Patient treated with Pramipexole. Autores Strejilevich S, Martino D, Igoa A, Manes F. Año 2011 Journal  Strejilevich S, Martino D, Igoa A, Manes F. Volumen 23(1): E2-E3 Abstract   Otra información    

Several case reports have linked solvent exposure to Parkinson disease (PD), but few studies have assessed associations with specific agents using an analytic epidemiologic design. We tested the hypothesis that exposure to specific solvents is associated with PD risk using a discordant twin pair design. METHODS: Ninety-nine twin pairs discordant for PD ascertained from the National Academy of Sciences/National Research Council World War II Veteran Twins Cohort were interviewed regarding lifetime occupations and hobbies using detailed job task-specific questionnaires. Exposures to 6 specific solvents selected a priori were estimated by expert raters unaware of case status. RESULTS: Ever exposure to trichloroethylene (TCE) was associated with significantly increased risk of PD (odds ratio [OR], 6.1; 95% confidence interval [CI] 1.2-33; p = 0.034), and exposure to perchloroethylene (PERC) and carbon tetrachloride (CCl(4) ) tended toward significance (respectively: OR, 10.5; 95% CI, 0.97-113; p = 0.053; OR, 2.3; 95% CI, 0.9-6.1; p = 0.088). Results were similar for estimates of exposure duration and cumulative lifetime exposure. INTERPRETATION: Exposure to specific solvents may increase risk of PD. TCE is the most common organic contaminant in groundwater, and PERC and CCl(4) are also ubiquitous in the environment. Our findings require replication in other populations with well-characterized exposures, but the potential public health implications are substantial.

Several lines of experimental evidence support an association between facial processing and social cognition, but no direct link between cortical markers of facial processing and complex cognitive processes has been reported until now. In the current study, we tested the hypothesis that cortical electrophysiological markers for the processing of facial emotion are associated with individual differences in executive and social cognition skills. We tested for correlations between the amplitude of event-related potentials (N170) in a dual valence task and participants’ scores on three neuropsychological assessments (general neuropsychology, executive functioning, and social cognition). N170 was modulated by the stimulus type (face versus word) and the valence of faces (positive versus negative). The neural source of N170 was estimated to be the fusiform gyrus. Robust correlations were found between neuropsychological markers and measures of facial processing. Social cognition skills (as measured by three tests: the Reading the Mind in the Eyes test, the Faux Pas test, and the Iowa Gambling Task) correlated with cortical measures of emotional discrimination. Executive functioning ability also correlated with the cortical discrimination of complex emotional stimuli. Our findings suggest that the cortical processing of facial emotional expression is associated with social cognition skills.