Categoría: Papers con abstracts

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.

OBJECTIVE: To investigate the nature of deficits in social cognition and real-life decision making in a group of patients with Alzheimer’s disease (AD). DESIGN: A comprehensive neuropsychological and psychiatric assessment, including the Moral Judgment Interview and the Bechara’s Card Test, was carried out in 25 patients with AD and 20 age-comparable normal controls. SETTING: Outpatient clinic. RESULTS: AD patients had significantly lower scores in the Moral Judgment Interview and obtained significantly less earnings in the card test when compared to the normal control group. The Moral Judgment Interview score correlated significantly with Raven’s Progressive Matrices and Block Design, whereas the card test correlated significantly with both the Benton Visual Retention Test and the Buschke Selective Reminding Test. No significant correlations were observed between the experimental tasks and the psychiatric variables. CONCLUSIONS: AD patients demonstrated significant deficits on tasks assessing social cognition and real-life decision making. These impairments correlated with deficits on specific neuropsychological tasks, but not with behavioral problems frequently found in AD patients.

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.

The authors examined specific deficits of cerebral blood perfusion in autistic patients as measured with [(99m)Tc]HMPAO single-photon emission computed tomography (SPECT). The study, conducted in an outpatient clinic setting, included a consecutive series of 30 patients with autism and 14 patients with mental retardation but no autism comparable in chronological age, mental age, height, weight, and head circumference. All participants were examined with a comprehensive psychiatric and neuropsychological battery and received a [(99m)Tc]HMPAO SPECT scan. Autistic patients had significantly lower perfusion than the control group in the following brain regions: right temporal lobe (basal and inferior areas), occipital lobes, thalami, and left basal ganglia. The study demonstrated significant perfusion deficits in specific brain areas of moderately to severely mentally retarded autistic patients.

Interest in the role of indolamines in the pathogenesis of psychoses has been renewed in recent years by the development of atypical antipsychotic drugs such as clozapine, olanzapine, and risperidone, which act on serotonin receptors. Discovery of the hallucinogenic compounds called methylated indolealkyalamines (MIAs) (e.g. N,N-dimethylserotonin, or bufotenin, and N,N-dimethyltryptamine, or DMT) led proponents of the transmethylation hypothesis of schizophrenia to theorize that through some inborn error of metabolism, serotonin or tryptamine might undergo the addition of extra methyl radicals, thereby forming MIAs with hallucinogenic properties. Various studies have attempted to detect the excretion of MIAs, especially DMT, in the body fluids of psychotic patients and normal controls. Some of these studies have demonstrated elevated MIA concentrations in psychotic patients, including those with schizophrenia, compared with normal persons, and others have not. A number of variables may account for these contradictory findings. The mechanism whereby the beverage ayahuasca, which is used in certain cure and divination rituals in the Amazon Basin, exerts its hallucinogenic effects may serve as a model to explain the mechanism underlying hallucinogenic symptoms in schizophrenia and may lend support to the transmethylation hypothesis. Certain studies suggest that specific perceptual disturbances manifested by schizophrenic patients could contribute to progressive deterioration and negative symptomatology. All these findings point to the need for further study of the neurophysiology of MIAs and their pathogenetic role in endogenous psychoses.