Categoría: Papers con abstracts

We investigated the frequency and neurocognitive correlates of attention deficit hyperactivity disorder and traits of this disorder (ADHD/Traits) after childhood stroke and orthopedic diagnosis in medical controls. Twenty-nine children with focal stroke lesions and individually matched children with clubfoot or scoliosis were studied with standardized psychiatric, intellectual, academic, adaptive, executive, and motivation function assessments. Lifetime ADHD/Traits were significantly more common in stroke participants with no prestroke ADHD than in orthopedic controls (16/28 vs. 7/29; Fisher’s Exact p < .02). Lifetime ADHD/Traits in the orthopedic controls occurred exclusively in males with clubfoot (7/13; 54%). Participants with current ADHD/Traits functioned significantly worse (p < .005) than participants without current ADHD/Traits on all outcome measures. Within the stroke group, current ADHD/Traits was associated with significantly lower verbal IQ and arithmetic achievement (p < .04), more nonperseverative errors (p < .005), and lower motivation (p < .004). A principal components analysis of selected outcome variables significantly associated with current ADHD/Traits revealed "impaired neurocognition " and "inattention-apathy " factors. The latter factor was a more consistent predictor of current ADHD/Traits in regression analyses. These findings suggest that inattention and apathy are core features of ADHD/Traits after childhood stroke. This association may provide clues towards the understanding of mechanisms underlying the syndrome.

Comparative neuropsychology has identified a role for the ventral striatum (VS) in certain forms of aggression. To address whether the homologous region in humans also contributes to the emotion anger, we studied a case series of four human subjects with focal lesions affecting the VS. All four demonstrated a disproportionate impairment in recognizing human signals of aggression. By contrast, a control group of individuals with damage to more dorsal basal ganglia (BG) regions showed no evidence of an anger impairment. Our findings demonstrate that the VS makes a significant contribution to coding signals of aggression in humans, and emphasize the importance of an approach to human affective neuroscience based on cross-species homologies. The results are discussed in relation to the ventral striatal dopamine system’s role in the pursuit of biological resources in general. We propose that the role of the VS in the recognition of human signals of anger may reflect a more general role in the coordination of behaviour relevant to the acquisition and protection of valued resources, including detection of signals of conspecific challenge (anger).

Neuropsychological, psychophysiological and functional imaging research has begun to offer insights into the everyday difficulties in decision-making experienced by some patients with frontal lobe damage. It is widely accepted that the ventral prefrontal cortex plays a pivotal role in social and emotional decision-making. This article will review experimental findings using the Iowa Gambling Task and the Cambridge Gamble Task that explore the brain mechanisms of decision-making. Convergent evidence from the two tasks confirms the importance of ventral PFC, but also highlights the relevance of lesion laterality, lesion aetiology, and the contribution of other brain regions (including the dorsal prefrontal cortex and amygdala) to decision-making abilities. The extent to which disrupted decision-making can be separated from the broader domain of executive function is discussed.

Focal autobiographical amnesia in association with Transient Epileptic Amnesia. Autores Manes F, Hodges J R, Graham KS, Zeman A.  Año 2001 Journal  Manes F, Hodges J R, Graham KS, Zeman A.  Volumen 2001(124): 499-509 Abstract   Otra información  Although problems with remembering significant events from the past (e.g. holidays, weddings, etc.) have been reported previously in patients with transient epileptic amnesia … Leer más

Emotion processing in the minimally conscious state. Autores Bekinschtein T, Leiguarda R, Jorge Armony , Owen A, Carpintiero S, Niklison J 3rd, Olmos L, Sigman M, Manes F.  Año 2004 Journal  Bekinschtein T, Leiguarda R, Jorge Armony , Owen A, Carpintiero S, Niklison J 3rd, Olmos L, Sigman M, Manes F.  Volumen 75(5): 788 Abstract   Otra información    

Rapid transcranial magnetic stimulation (rTMS) applied to the left dorsal lateral frontal cortex has been shown to produce antidepressant effects. Older depressed patients, however, in one study showed a lower response rate than younger patients. The current study examined treatment response in 20 depressed, treatment-refractory patients (mean age 60.7 +/- 9.8 years) given five sessions of rTMS at 20 Hz for 2 seconds over 20 trains at 80% of motor threshold or identical placebo stimulation, after patients had been withdrawn from their antidepressants. There were no significant differences in Hamilton Depression Scale scores either before or after treatment at 7 days’ follow-up. There were three responders to active treatment and three to sham treatment and responders had significantly greater frontal lobe volume than nonresponders (p = .03). These findings suggest that the stimulation parameters used in this study were probably insufficient to produce treatment response and that frontal atrophy may interfere with the effectiveness of rTMS.

We are trapped in old nosological classifications. Autores Strejilevich S, Bustin J.  Año 2004 Journal  Strejilevich S, Bustin J.  Volumen 15(55): 67-72 Abstract   Otra información    

In this article, the author reviews the description of the cycloid psychosis out of the researches of the German psychiatric Karl Leonhard, placing them inside the wide field of the endogenous psychosis.

Object and spatial visual working memory are impaired in schizophrenic patients. It is not clear if the impairments reside in each memory subsystem alone or also in the central executive component that coordinates these processes. In order to elucidate which memory component is impaired, we developed a paradigm with single spatial and object working memory tasks and dual ones with two different delays (5 and 30 s). Fifteen schizophrenic patients and 14 control subjects performed these tests. Schizophrenic patients had a poorer performance compared to normal controls in all tasks and in all time delays. Both schizophrenics and controls performed significantly worse in the object task than in the spatial task. The performance was even worse in the dual task compared to the singles ones in schizophrenic patients but not in controls. These data suggest that visuospatial performance deficits in schizophrenia are due to both visuospatial memory subsystems impairments and central executive ones. The pattern of deficits observed points to a codification or evocation deficit and not to a maintenance one.

OBJECTIVE: To investigate the association between focal stroke lesions of the putamen and either attention-deficit/hyperactivity disorder or traits of the disorder (ADHD/Traits). METHOD: Twenty-five children with focal stroke lesions were studied with standardized psychiatric assessments and anatomic brain magnetic resonance imaging. The pattern of lesion overlap in subjects with ADHD/Traits was determined. RESULTS: Fifteen of 25 subjects had ADHD/Traits. The densest area of overlapping lesions (n = 7) in subjects with ADHD/Traits included the posterior ventral putamen. The median lesion volume was 9.7 cm3, and the distribution was highly skewed. Lesion volume was not associated with ADHD/Traits. Therefore the following analyses focused on the 13 subjects with lesions < 10 cm3: ADHD/Traits were exhibited in 6/7 subjects with putamen lesionsversus 2/6 with no putamen lesions (Fisherexacttestp= .1). Half (4/8) of the subjects with ADHD/Traits had overlapping lesions encompassing the posterior ventral putamen. None of the 5 subjects without ADHD/Traits had lesions in this empirically derived region of interest (Fisher exact test p = .1). CONCLUSIONS: Lesions within the dopamine-rich ventral putamen, which is part of the ventral or limbic striatum, tended to increase the risk of ADHD/Traits. ADHD/Traits may therefore be a disinhibition syndrome associated with dysfunction in this cortical-striato-thalamocortical loop.