Autor: Ineco

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.

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    

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    

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: Early detection and treatment of Bipolar Disorder (BD) determine a significant relief in the considerable burden this disease implies. In order to adequately plan the strategies to guarantee access to treatment, it is useful to consider data which reflect the everyday vicissitudes the people affected by this pathology have to deal with. People on treatment for BD in centres in Argentina and Chile were surveyed, collecting data on their access to diagnosis and treatment. The centre surveyed in Chile, unlike those in Argentina, operates as a specialized unit. METHODOLOGY: An anonymous assisted survey was carried out; a random sample of people assisted in the participating centres with a diagnosis of BD type I or II, and stabilized for a period no shorter than 12 months, was assessed. RESULTS: 100 people were surveyed in Argentina and 69 in Chile (70% women, age 45.2 +/- 14.7, average schooling 12 years). Seventy one percent began symptoms at adult age (28,43 +/- 13 years), 14% during childhood. Age at first consultation was: 30 +/- 12.5; 85% reported having suffered psychotic symptoms, 46.4% suicide attempts, 71% hospitalisations for BD. Sixty-nine percent reported diagnostic delays longer than a year (median 8 years), 75% reported having received other diagnosis prior to their BD diagnosis (62% unipolar depression, 41% schizophrenia). Forty-one percent reported being unemployed. Delays and diagnostic errors were associated to a significant increase in the functional impact reported. CONCLUSION: Approximately 7 out of 10 people report difficulties in the access to a BD diagnosis. These difficulties magnify the already important impact of the disease.

Clozapine has been shown not only to be effective in ameliorating dopaminomimetic psychosis but to improve parkinsonian symptomatology. Six parkinsonian patients with motor fluctuations under levodopa treatment and severe interdose «off » periods (believed to be mediated by an inhibitory effect of subthreshold levels of levodopa) underwent a trial of clozapine. The effects of this drug on levodopa response were measured by means of an acute levodopa test both before and after receiving clozapine. After 1 month of treatment, clozapine 25 mg/day reduced parkinsonian scores at all stages of the evaluation (pre-levodopa «off, » «on, » and interdose «off «). The effect was consistently more significant for the interdose «off. » Clozapine could be exerting its beneficial effects through the inhibition of an inhibitory effect mediated by low-level dopaminergic stimulation, thus behaving as an apparent anti-parkinsonian drug.

This study examined the prevalence and correlates of pathological affect in Alzheimer’s disease. A consecutive series of 103 patients with Alzheimer’s disease were examined with a comprehensive psychiatric assessment that included the pathological laughing and crying scale (PLACS). Forty patients (39%) showed pathological affect: 25% showed crying episodes, and 14% showed laughing or mixed (laughing and crying) episodes. Patients with pathological affect crying showed significantly higher depression scores and a significantly higher frequency of major depression and dysthymia than patients with no pathological affect. Patients with mixed pathological affect showed significantly more subcortical atrophy on CT than patients with pathological affect crying. Forty seven per cent of the patients with pathological affect had no congruent mood disorder, and they showed a significantly longer duration of illness and more severe anosognosia than patients with pathological affect that was congruent with an underlying mood disorder. The study validates the PLACS, and shows the high prevalence of pathological affect in Alzheimer’s disease.

We examined the prevalence and correlates of apathy and irritability in a consecutive series of 101 patients with probable Alzheimer’s disease (AD). Based on clinical criteria, 46 (46%) patients had apathy, and 13 (13%) patients had irritability. Apathy was significantly associated with more severe impairments in activities of daily living, significantly more severe extrapyramidal signs, and a significantly higher frequency of both major depression and dysthymia. Patients with irritability had significantly more severe impairments in activities of daily living and significantly higher depression and anosognosia scores. On the other hand, neither apathy nor irritability were significantly associated with deficits in specific cognitive domains.

Acute single-dose response of drug-induced parkinsonism (DIP) to L-Dopa and apomorphine challenge was evaluated in a double-blind crossover study in 12 schizophrenic patients. There were two noteworthy negative findings. First, neither L-Dopa nor apomorphine produced significant improvements in DIP and second, no changes (neither improvement nor worsening) were found in patients’ psychiatric status. Findings suggest that, for a stimulation dose reaching almost 90% of the responsive dose for idiopathic Parkinson’s disease, no significant changes may reasonably be expected in the parkinsonism of schizophrenic patients treated with neuroleptic drugs.