Categoría: Papers con abstracts

OBJECTIVE: To investigate the association between focal stroke lesions of Posner’s executive attention network and a specific region of interest in the frontal lobes (orbital frontal and mesial frontal) and either attention-deficit/hyperactivity disorder (ADHD) or traits of the disorder (ADHD symptomatology). METHOD: Twenty-nine children with focal stroke lesions were studied with standardized psychiatric assessments and anatomical brain magnetic resonance imaging. The pattern of lesion overlap in subjects with ADHD symptomatology was determined. RESULTS: Fifteen of 28 subjects with no prestroke ADHD were diagnosed with ADHD symptomatology at the time of assessment. The extent of lesions within the executive attention network was marginally related to ADHD symptomatology (p = .088; effect size = 0.66), whereas the extent of lesions in the specific frontal region of interest was significantly related to ADHD symptomatology (p = .040; effect size = 0.82). CONCLUSIONS: Lesions within Posner’s executive attention network and its orbital frontal connections may be linked to important mechanisms in the expression of ADHD symptomatology after childhood stroke. These findings are consistent with functional and structural imaging findings in studies of idiopathic ADHD.

The consensus guidelines of argentine experts in the treatment of bipolar disorders are the result of three days of work of the 10 main local experts under the organization of the Argentine Association of Biological Psychiatry (AAPB). It was adopted a mixed criterion for its preparation: all the recent data of the evidence medicine based published until now were discussed and were balanced with the knowledge acquired from clinical experience of the local experts on the bipolar field. It presents general recommendations and suggested therapeutic sequences for the phase of maintenance, the manic/hypomanic or mixed episode and the depressive episode. These have been divided according to the classification in type I and II; with or without rapid cycling. Since the group of experts identified the delay and miss-diagnoses like the most important barrier for a suitable treatment enclosed a series of recommendations for differential diagnosis of bipolar disorders.

Lesions to prefrontal cortex (PFC) in humans can severely disrupt everyday decision-making, with concomitant effects on social and occupational functioning. Forty-six patients with unilateral lesions to prefrontal cortex and 21 healthy control subjects were administered three neuropsychological measures of decision-making: the Iowa Gambling Task, the Cambridge Gamble Task, and the Risk Task. Magnetic resonance imaging (MRI) scans were acquired from 40 patients, with region of interest (ROI) mapping of prefrontal subregions. The frontal patients showed only limited damage in medial and orbital prefrontal cortex, but greater damage in lateral prefrontal regions of interest. Patients with right frontal lesions preferred the risky decks on the Iowa Gambling Task, and differed significantly from left frontal and control subjects. Within the right frontal group, the preference for the risky decks was correlated with the total lesion volume and the volume of damage outside of the ventromedial prefrontal region. Right and left frontal groups did not differ significantly on the Cambridge Gamble Task or the Risk Task, and performance was not associated with lesion volume. The results indicate a laterality effect on the Iowa Gambling Task, and the contribution of prefrontal regions outside the ventromedial region to task performance. The Cambridge Gamble Task and Risk Task were less sensitive to the effects of unilateral frontal lobe lesions, and may be more selectively associated with ventral prefrontal damage.

Subjective responses to pharmacological treatments in bipolar patients. Autores Strejilevich S, García-Bonetto G.  Año 2003 Journal  Strejilevich S, García-Bonetto G.  Volumen 77(2): 191-192 Abstract   Otra información    

Schizophrenia is an illness characterized by its syndromic polimorphism and a global impairment of personality traits, that means a lot of suffering for patients and their families. Lately, under the framework of the «neurodevelopmental theory of schizophrenia «, the scientific community has paid attention to the need of detecting the illness before onset or as soon as possible. The study of premorbid personality traits, as «schizotaxia » or schizoid or schyzotypal personality, altogether with the study of the so called «basic symptoms » an premorbid states are designed to detect at risk subjects. The need of not waiting until acute onset syndromes in an attempt to more early interventions, due to the fact that there is strong evidence about the existence of early symptoms which proper identification will allow, in the future, to identify subjects at risk an earlier interventions. In this paper we will review only some of the great number of papers recently published on the subject.

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