RESUMEN
Accessible Summary What is known on the subject? Functioning is one of the most affected areas in schizophrenia. Social, occupational and personal domains are affected, and these deficits are responsible for a major part of the disability associated with the disorder. There are several instruments to measure functioning, but the HoNOS provides a wide assessment of impairment in 12 areas of functioning. What does the paper add to existing knowledge? The Spanish version of the HoNOS shows good properties in terms of reliability and validity for use in schizophrenia patients. Although some authors divide the scale according to proposed underlying dimensions, in schizophrenia this division may not be appropriate. What are the implications for practice? A reliable and easy-to-use measure of impairment in different areas of functioning is useful for optimizing the treatment and rehabilitation of patients with schizophrenia. ABSTRACT: INTRODUCTION: The HoNOS scale was designed for the assessment of psychosocial impairment in various domains. While it is widely used in psychiatric settings, it has not been validated in Spanish for use in patients with schizophrenia. AIM: To examine the psychometric properties of the Spanish version of the HoNOS scale in a sample of schizophrenia patients. METHOD: A total of 194 individuals aged 18 to 65 with schizophrenia spectrum diagnoses were evaluated using the HoNOS. Illness severity and level of functioning were also assessed. RESULTS: The HoNOS showed moderate internal consistency, good inter-observer reliability and good test-retest reliability. Factor analysis revealed an internal structure consisting of four factors, with item distribution differing from the theoretical dimensions proposed for the original scale. DISCUSSION: The Spanish version of the HoNOS scale is a reliable and valid instrument for assessing psychosocial impairment in individuals diagnosed with schizophrenia spectrum disorders. However, further research is needed to determine its internal structure more accurately. IMPLICATIONS FOR PRACTICE: The HoNOS scale provides researchers and clinicians with a valid measure of impairment in twelve different domains, which can facilitate and guide the treatment of schizophrenia patients.
RESUMEN
BACKGROUND: Schizophrenic symptoms are known to segregate into reality distortion, negative and disorganization syndromes, but the correlates of these syndromes with regional brain structural change are not well established. Cognitive impairment is a further clinical feature of schizophrenia, whose brain structural correlates are the subject of conflicting findings. METHODS: 165 patients with schizophrenia were rated for symptoms using the PANSS, and cognitive impairment was indexed by estimated premorbid-current IQ discrepancy. Cortical volume was measured using surface-based morphometry in the patients and in 50 healthy controls. Correlations between clinical and cognitive measures and cortical volume were examined using whole-brain FreeSurfer tools. RESULTS: No clusters of volume reduction were seen associated with reality distortion or disorganization. Negative symptom scores showed a significant inverse correlation with volume in a small cluster in the left medial orbitofrontal gyrus. Larger estimated premorbid-current IQ discrepancies were associated with clusters of reduced cortical volume in the left precentral gyrus and the left temporal lobe. The cluster of association with negative symptoms disappeared when estimated premorbid-current IQ discrepancy was controlled for. CONCLUSIONS: This study does not provide support for an association between brain structural abnormality and reality distortion or disorganization syndromes in schizophrenia. The cluster of volume reduction found in the left medial orbitofrontal cortex correlated with negative symptoms may have reflected the association between this class of symptoms and cognitive impairment. The study adds to existing findings of an association between cognitive impairment and brain structural changes in the disorder.
Asunto(s)
Disfunción Cognitiva , Esquizofrenia , Humanos , Esquizofrenia/complicaciones , Esquizofrenia/diagnóstico por imagen , Encéfalo , Lóbulo Frontal , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/etiología , Lóbulo Temporal , Imagen por Resonancia MagnéticaRESUMEN
Different lines of evidence indicate that the structure and physiology of the basal ganglia and the thalamus is disturbed in schizophrenia. However, it is unknown whether the volume and shape of these subcortical structures are affected in schizophrenia with auditory hallucinations (AH), a core positive symptom of the disorder. We took structural MRI from 63 patients with schizophrenia, including 36 patients with AH and 27 patients who had never experienced AH (NAH), and 51 matched healthy controls. We extracted volumes for the left and right thalamus, globus pallidus, putamen, caudate and nucleus accumbens. Shape analysis was also carried out. When comparing to controls, the volume of the right globus pallidus, thalamus, and putamen, was only affected in AH patients. The volume of the left putamen was also increased in individuals with AH, whereas the left globus pallidus was affected in both groups of patients. The shapes of right and left putamen and thalamus were also affected in both groups. The shape of the left globus pallidus was only altered in patients lacking AH, both in comparison to controls and to cases with AH. Lastly, the general PANSS subscale was correlated with the volume of the right thalamus, and the right and left putamen, in patients with AH. We have found volume and shape alterations of many basal ganglia and thalamus in patients with and without AH, suggesting in some cases a possible relationship between this positive symptom and these morphometric alterations.
Asunto(s)
Esquizofrenia , Humanos , Esquizofrenia/complicaciones , Esquizofrenia/diagnóstico por imagen , Ganglios Basales/diagnóstico por imagen , Tálamo/diagnóstico por imagen , Putamen/diagnóstico por imagen , Alucinaciones/diagnóstico por imagen , Imagen por Resonancia MagnéticaRESUMEN
STUDY OBJECTIVE: Currently the videographic review of emergency intubations is an unstructured, qualitative process. We created a taxonomy of errors that impede the optimal procedural performance of emergency intubation. METHODS: This was a prospective, observational, study reviewing a convenience sample of deidentified laryngoscopy recordings of emergency department intubations that were qualitatively flagged before the study as demonstrating suboptimal technique. These videos were coded for the presence of 13 predetermined performance errors. Our primary outcome was the incidence of each of these specified errors during emergency intubation. Errors fell into 3 categories: errors of structure recognition during laryngoscope insertion, errors of vallecula manipulation, and errors of device delivery. RESULTS: A total of 100 intubation attempts were reviewed. The most common error was inadequate lifting force with the blade tip in the vallecula which lowered the percent of glottic opening, occurring in 45% of the attempts. The least common performance error was the premature removal of the laryngoscope during bougie placement, occurring in only 9% of the videos. CONCLUSION: We developed a taxonomy of 13 performance errors of laryngoscopy. Further study is warranted to determine how to best incorporate these into emergency airway training and the airway review process.
RESUMEN
INTRODUCTION: Few studies have examined the functional brain correlates of the performance of the Stroop task in bipolar disorder (BD). It is also not known whether it is associated with failure of de-activation in the default mode network, as has been found in studies using other tasks. METHODS: Twenty-four BD patients and 48 age, sex and educationally estimated intellectual quotient (IQ) matched healthy subjects (HS) underwent a functional MRI during performance of the counting Stroop task. Task-related activations (incongruent versus congruent condition) and de-activations (incongruent versus fixation) were examined using whole-brain, voxel-based methodology. RESULTS: Both the BD patients and the HS showed activation in a cluster encompassing the left dorsolateral and ventrolateral prefrontal cortex and the rostral anterior cingulate cortex and supplementary motor area, with no differences between them. The BD patients, however, showed significant failure of de-activation in the medial frontal cortex and the posterior cingulate cortex/precuneus. CONCLUSIONS: The failure to find activation differences between BD patients and controls suggests that the 'regulative' component of cognitive control remains intact in the disorder, at least outside episodes of illness. The failure of de-activation found adds to evidence documenting trait-like default mode network dysfunction in the disorder.
Asunto(s)
Trastorno Bipolar , Corteza Motora , Humanos , Trastorno Bipolar/psicología , Corteza Prefrontal/diagnóstico por imagen , Test de Stroop , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Mapeo EncefálicoRESUMEN
BACKGROUND: A leading theory of the negative symptoms of schizophrenia is that they reflect reduced responsiveness to rewarding stimuli. This proposal has been linked to abnormal (reduced) dopamine function in the disorder, because phasic release of dopamine is known to code for reward prediction error (RPE). Nevertheless, few functional imaging studies have examined if patients with negative symptoms show reduced RPE-associated activations. METHODS: Matched groups of DSM-5 schizophrenia patients with high negative symptom scores (HNS, N = 27) or absent negative symptoms (ANS, N = 27) and healthy controls (HC, N = 30) underwent fMRI scanning while they performed a probabilistic monetary reward task designed to generate a measure of RPE. RESULTS: In the HC, whole-brain analysis revealed that RPE was positively associated with activation in the ventral striatum, the putamen, and areas of the lateral prefrontal cortex and orbitofrontal cortex, among other regions. Group comparison revealed no activation differences between the healthy controls and the ANS patients. However, compared to the ANS patients, the HNS patients showed regions of significantly reduced activation in the left ventrolateral and dorsolateral prefrontal cortex, and in the right lingual and fusiform gyrus. HNS and ANS patients showed no activation differences in ventral striatal or midbrain regions-of-interest (ROIs), but the HNS patients showed reduced activation in a left orbitofrontal cortex ROI. CONCLUSIONS: The findings do not suggest that a generalized reduction of RPE signalling underlies negative symptoms. Instead, they point to a more circumscribed dysfunction in the lateral frontal and possibly the orbitofrontal cortex.
Asunto(s)
Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagen , Dopamina , Recompensa , Encéfalo/diagnóstico por imagen , Lóbulo Frontal , Imagen por Resonancia MagnéticaRESUMEN
BACKGROUND AND HYPOTHESIS: The existing developmental bond between fingerprint generation and growth of the central nervous system points to a potential use of fingerprints as risk markers in schizophrenia. However, the high complexity of fingerprints geometrical patterns may require flexible algorithms capable of characterizing such complexity. STUDY DESIGN: Based on an initial sample of scanned fingerprints from 612 patients with a diagnosis of non-affective psychosis and 844 healthy subjects, we have built deep learning classification algorithms based on convolutional neural networks. Previously, the general architecture of the network was chosen from exploratory fittings carried out with an independent fingerprint dataset from the National Institute of Standards and Technology. The network architecture was then applied for building classification algorithms (patients vs controls) based on single fingers and multi-input models. Unbiased estimates of classification accuracy were obtained by applying a 5-fold cross-validation scheme. STUDY RESULTS: The highest level of accuracy from networks based on single fingers was achieved by the right thumb network (weighted validation accuracy = 68%), while the highest accuracy from the multi-input models was attained by the model that simultaneously used images from the left thumb, index and middle fingers (weighted validation accuracy = 70%). CONCLUSION: Although fitted models were based on data from patients with a well established diagnosis, since fingerprints remain lifelong stable after birth, our results imply that fingerprints may be applied as early predictors of psychosis. Specially, if they are used in high prevalence subpopulations such as those of individuals at high risk for psychosis.
Asunto(s)
Aprendizaje Profundo , Trastornos Psicóticos , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagen , Redes Neurales de la Computación , Algoritmos , Trastornos Psicóticos/diagnóstico por imagenRESUMEN
BACKGROUND: Relapse prevention is an important goal in the clinical management of psychosis. Cognitive deficits/deterioration can provide useful insights for monitoring relapse in psychosis patients. METHODS: This was a prospective, naturalistic 1-year follow-up study involving 110 psychosis patients with full clinical remission. Relapse, defined as the recurrence of psychotic symptoms, was monitored monthly along with digital tracking of verbal and visual working memory using a mobile app developed for this study. Cognitive deterioration was defined as worsening performance over 2 months prior to relapse or study termination, whichever was earlier. Other clinical, cognitive, functioning, and psychosocial variables were also collected. RESULTS: At 1 year, 18 (16.36%) patients relapsed, of which 6 (33.33%) required hospitalization. Relapse was predicted by verbal working memory deterioration 2 months prior to relapse (p = 0.029), worse medication adherence (p = 0.018), and less resilience (p = 0.014). CONCLUSIONS: Verbal working memory deterioration is a novel early sign of relapse. It is a clearly defined, objectively measurable, and reproducible marker that can help clinicians and healthcare workers identify patients at risk of relapse and make decisions about maintenance therapy. Moreover, digital monitoring is a viable tool in the management of relapse.
Asunto(s)
Memoria a Corto Plazo , Trastornos Psicóticos , Humanos , Estudios de Seguimiento , Estudios Prospectivos , Trastornos Psicóticos/complicaciones , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/tratamiento farmacológico , Enfermedad Crónica , RecurrenciaRESUMEN
BACKGROUND: The brain functional correlates of delusions have been relatively little studied. However, a virtual reality paradigm simulating travel on the London Underground has been found to evoke referential ideation in both healthy subjects and patients with schizophrenia, making brain activations in response to such experiences potentially identifiable. METHOD: Ninety patients with schizophrenia/schizoaffective disorder and 28 healthy controls underwent functional magnetic resonance imaging while they viewed virtual reality versions of full and empty Barcelona Metro carriages. RESULTS: Compared to the empty condition, viewing the full carriage was associated with activations in the visual cortex, the cuneus and precuneus/posterior cingulate cortex, the inferior parietal cortex, the angular gyrus and parts of the middle and superior temporal cortex including the temporoparietal junction bilaterally. There were no significant differences in activation between groups. Nor were there activations associated with referentiality or presence of delusions generally in the patient group. However, patients with persecutory delusions showed a cluster of reduced activation compared to those without delusions in a region in the right temporal/occipital cortex. CONCLUSIONS: Performance of the metro task is associated with a widespread pattern of activations, which does not distinguish schizophrenic patients and controls, or show an association with referentiality or delusions in general. However, the finding of a cluster of reduced activation close to the right temporoparietal junction in patients with persecutory delusions specifically is of potential interest, as this region is believed to play a role in social cognition.
Asunto(s)
Trastornos Psicóticos , Esquizofrenia , Humanos , Deluciones/diagnóstico , Esquizofrenia/complicaciones , Imagen por Resonancia Magnética/métodos , EncéfaloRESUMEN
BACKGROUND: The negative symptoms of schizophrenia have been proposed to reflect prefrontal cortex dysfunction. However, this proposal has not been consistently supported in functional imaging studies, which have also used executive tasks that may not capture key aspects of negative symptoms such as lack of volition. METHOD: Twenty-four DSM-5 schizophrenic patients with high negative symptoms (HNS), 25 with absent negative symptoms (ANS) and 30 healthy controls underwent fMRI during performance of the Computerized Multiple Elements Test (CMET), a task designed to measure poor organization of goal directed behaviour or 'goal neglect'. Negative symptoms were rated using the PANSS and the Clinical Assessment Interview for Negative Symptoms (CAINS). RESULTS: On whole brain analysis, the ANS patients showed no significant clusters of reduced activation compared to the healthy controls. In contrast, the HNS patients showed hypoactivation compared to the healthy controls in the left anterior frontal cortex, the right dorsolateral prefrontal cortex (DLPFC), the anterior insula bilaterally and the bilateral inferior parietal cortex. When compared to the ANS patients, the HNS patients showed reduced activation in the left anterior frontal cortex, the left DLPFC and the left inferior parietal cortex. After controlling for disorganization scores, differences remained in clusters in the left anterior frontal cortex and the bilateral inferior parietal cortex. CONCLUSIONS: This study provides evidence that reduced prefrontal activation, perhaps especially in the left anterior frontal cortex, is a brain functional correlate of negative symptoms in schizophrenia. The simultaneous finding of reduced inferior parietal cortex activation was unexpected, but could reflect this region's involvement in cognitive control, particularly the 'regulative' component of this.
Asunto(s)
Esquizofrenia , Psicología del Esquizofrénico , Objetivos , Humanos , Imagen por Resonancia Magnética/métodos , Corteza Prefrontal/diagnóstico por imagenRESUMEN
The DISC1 gene is one of the most relevant susceptibility genes for psychosis. However, the complex genetic landscape of this locus, which includes protective and risk variants in interaction, may have hindered consistent conclusions on how DISC1 contributes to schizophrenia (SZ) liability. Analysis from haplotype approaches and brain-based phenotypes can contribute to understanding DISC1 role in the neurobiology of this disorder. We assessed the brain correlates of DISC1 haplotypes associated with SZ through a functional neuroimaging genetics approach. First, we tested the association of two DISC1 haplotypes, the HEP1 (rs6675281-1000731-rs999710) and the HEP3 (rs151229-rs3738401), with the risk for SZ in a sample of 138 healthy subjects (HS) and 238 patients. This approach allowed the identification of three haplotypes associated with SZ (HEP1-CTG, HEP3-GA and HEP3-AA). Second, we explored whether these haplotypes exerted differential effects on n-back associated brain activity in a subsample of 70 HS compared to 70 patients (diagnosis × haplotype interaction effect). These analyses evidenced that HEP3-GA and HEP3-AA modulated working memory functional response conditional to the health/disease status in the cuneus, precuneus, middle cingulate cortex and the ventrolateral and dorsolateral prefrontal cortices. Our results are the first to show a diagnosis-based effect of DISC1 haplotypes on working memory-related brain activity, emphasising its role in SZ.
Asunto(s)
Esquizofrenia , Encéfalo/metabolismo , Haplotipos , Humanos , Imagen por Resonancia Magnética , Memoria a Corto Plazo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Polimorfismo de Nucleótido Simple , Esquizofrenia/diagnóstico por imagen , Esquizofrenia/genéticaRESUMEN
RATIONALE: How striatal dopamine synthesis capacity (DSC) contributes to the pathogenesis of negative symptoms in first-episode schizophrenia (SZ) and delusional disorder (DD) has seldom been explored. As negative symptoms during active psychotic episodes can be complicated by secondary influences, such as positive symptoms, longitudinal investigations may help to clarify the relationship between striatal DSC and negative symptoms and differentiate between primary and secondary negative symptoms. OBJECTIVE: A longitudinal study was conducted to examine whether baseline striatal DSC would be related to negative symptoms at 3 months in first-episode SZ and DD patients. METHODS: Twenty-three first-episode age- and gender-matched patients (11 DD and 12 SZ) were consecutively recruited through an early intervention service for psychosis in Hong Kong. Among them, 19 (82.6%) patients (9 DD and 10 SZ) were followed up at 3 months. All patients received an 18F-DOPA PET/MR scan at baseline. RESULTS: Baseline striatal DSC (Kocc;30-60) was inversely associated with negative symptoms at 3 months in first-episode SZ patients (rs = - 0.80, p = 0.010). This association remained in SZ patients even when controlling for baseline negative, positive, and depressive symptoms, as well as cumulative antipsychotic dosage (ß = - 0.69, p = 0.012). Such associations were not observed in first-episode DD patients. Meanwhile, the severity of negative symptoms at 3 months was associated with more positive symptoms in DD patients (rs = 0.74, p = 0.010) and not in SZ patients. CONCLUSIONS: These findings highlight the role of striatal DSC in negative symptoms upon resolution of active psychotic episodes among first-episode SZ patients. Baseline striatal dopamine activity may inform future symptom expression with important treatment implications.
Asunto(s)
Dopamina , Trastornos Psicóticos , Cuerpo Estriado/diagnóstico por imagen , Cuerpo Estriado/metabolismo , Dopamina/metabolismo , Humanos , Estudios Longitudinales , Trastornos Psicóticos/metabolismo , Esquizofrenia Paranoide/metabolismoRESUMEN
Schizophrenia, characterised by psychotic symptoms and in many cases social and occupational decline, remains an aetiological and therapeutic challenge. Contrary to popular belief, the disorder is modestly more common in men than in women. Nor is the outcome uniformly poor. A division of symptoms into positive, negative, and disorganisation syndromes is supported by factor analysis. Catatonic symptoms are not specific to schizophrenia and so-called first rank symptoms are no longer considered diagnostically important. Cognitive impairment is now recognised as a further clinical feature of the disorder. Lateral ventricular enlargement and brain volume reductions of around 2% are established findings. Brain functional changes occur in different subregions of the frontal cortex and might ultimately be understandable in terms of disturbed interaction among large-scale brain networks. Neurochemical disturbance, involving dopamine function and glutamatergic N-methyl-D-aspartate receptor function, is supported by indirect and direct evidence. The genetic contribution to schizophrenia is now recognised to be largely polygenic. Birth and early life factors also have an important aetiological role. The mainstay of treatment remains dopamine receptor-blocking drugs; a psychological intervention, cognitive behavioural therapy, has relatively small effects on symptoms. The idea that schizophrenia is better regarded as the extreme end of a continuum of psychotic symptoms is currently influential. Other areas of debate include cannabis and childhood adversity as causative factors, whether there is progressive brain change after onset, and the long-term success of early intervention initiatives.
Asunto(s)
Esquizofrenia , Psicología del Esquizofrénico , Experiencias Adversas de la Infancia/psicología , Terapia Cognitivo-Conductual , Antagonistas de Dopamina/uso terapéutico , Femenino , Humanos , Masculino , Fumar Marihuana/efectos adversos , Factores de Riesgo , Esquizofrenia/diagnóstico , Esquizofrenia/epidemiología , Esquizofrenia/etiología , Esquizofrenia/terapia , Factores SexualesRESUMEN
The Stroop task, which examines an aspect of executive function/cognitive control, the ability to inhibit prepotent responses, has been relatively little examined in schizophrenia, and the findings have been inconsistent. Whether performance of this task is associated with failure of de-activation in the disorder is also uncertain. We examined 42 schizophrenic patients and 61 healthy controls during performance of an fMRI-adapted version of the Stroop task, the counting Stroop task. Task-related activations (incongruent > congruent condition) and de-activations (baseline > incongruent) were examined using whole-brain, voxel-based methods. In the healthy controls, task performance was found to be associated with activations in the left dorsolateral prefrontal cortex and the dorsal anterior cingulate cortex, among other regions. De-activations were seen in the medial frontal cortex, the middle and posterior cingulate gyrus and cuneus, the parahippocampal gyrus and the hippocampus. The schizophrenic patients did not show reduced activation compared to the healthy controls. They did, however, show failure of de-activation in the medial frontal cortex. Our negative finding with respect to hypoactivation during performance of a task requiring inhibition of prepotent responses suggests that brain functional abnormality in schizophrenia may not affect all aspects of executive function/cognitive control. The finding of medial frontal cortex failure of de-activation adds to existing findings of default mode network dysfunction in the disorder.
Asunto(s)
Imagen por Resonancia Magnética , Esquizofrenia , Encéfalo , Mapeo Encefálico , Humanos , Imagen por Resonancia Magnética/métodos , Esquizofrenia/diagnóstico por imagen , Test de StroopRESUMEN
Auditory verbal hallucinations (AVH, 'hearing voices') are an important symptom of schizophrenia but their biological basis is not well understood. One longstanding approach proposes that they are perceptual in nature, specifically that they reflect spontaneous abnormal neuronal activity in the auditory cortex, perhaps with additional 'top down' cognitive influences. Functional imaging studies employing the symptom capture technique-where activity when patients experience AVH is compared to times when they do not-have had mixed findings as to whether the auditory cortex is activated. Here, using a novel variant of the symptom capture technique, we show that the experience of AVH does not induce auditory cortex activation, even while real speech does, something that effectively rules out all theories that propose a perceptual component to AVH. Instead, we find that the experience of AVH activates language regions and/or regions that are engaged during verbal short-term memory.
Asunto(s)
Alucinaciones/fisiopatología , Memoria a Corto Plazo/fisiología , Esquizofrenia/fisiopatología , Percepción del Habla/fisiología , Estimulación Acústica/métodos , Adulto , Corteza Auditiva/diagnóstico por imagen , Corteza Auditiva/fisiopatología , Mapeo Encefálico/métodos , Femenino , Alucinaciones/diagnóstico , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Esquizofrenia/diagnóstico , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
Schizophrenia is a complex psychiatric disorder that displays an outstanding interindividual variability in clinical manifestation and neurobiological substrates. A better characterization and quantification of this heterogeneity could guide the search for both common abnormalities (linked to lower intersubject variability) and the presence of biological subtypes (leading to a greater heterogeneity across subjects). In the current study, we address interindividual variability in functional connectome by means of resting-state fMRI in a large sample of patients with schizophrenia and healthy controls. Among the different metrics of distance/dissimilarity used to assess variability, geodesic distance showed robust results to head motion. The main findings of the current study point to (i) a higher between subject heterogeneity in the functional connectome of patients, (ii) variable levels of heterogeneity throughout the cortex, with greater variability in frontoparietal and default mode networks, and lower variability in the salience network, and (iii) an association of whole-brain variability with levels of clinical symptom severity and with topological properties of brain networks, suggesting that the average functional connectome overrepresents those patients with lower functional integration and with more severe clinical symptoms. Moreover, after performing a graph theoretical analysis of brain networks, we found that patients with more severe clinical symptoms had decreased connectivity at both whole-brain level and within the salience network, and that patients with higher negative symptoms had large-scale functional integration deficits.
Asunto(s)
Conectoma , Esquizofrenia , Encéfalo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Red Nerviosa , Esquizofrenia/diagnóstico por imagenRESUMEN
The Computerised Multiple Elements Test (CMET) is a novel executive task to assess goal management and maintenance suitable for use within the fMRI environment. Unlike classical executive paradigms, it resembles neuropsychological multi-elements tests that capture goal management in a more ecological way, by requiring the participant to switch between four simple games within a specified time period. The present study aims to evaluate an fMRI version of the CMET and examine its brain correlates. Thirty-one healthy participants performed the task during fMRI scanning. During each block, they were required to play four simple games, with the transition between games being made either voluntarily (executive condition) or automatically (control condition). The executive condition was associated with increased activity in fronto-parietal and cingulo-opercular regions, with anterior insula activity linked to better task performance. In an additional analysis, the activated regions showed to form functional networks during resting-state and to overlap the executive fronto-parietal and cingulo-opercular networks identified in resting-state with independently defined seeds. These results show the ability of the CMET to elicit activity in well-known executive networks, becoming a potential tool for the study of executive impairment in neurological and neuropsychiatric populations in a more ecological way than classical paradigms.
Asunto(s)
Mapeo Encefálico , Función Ejecutiva , Encéfalo/diagnóstico por imagen , Corteza Cerebral , Humanos , Imagen por Resonancia Magnética , Red NerviosaRESUMEN
The ability of attributing mental states to oneself and to the others (theory of mind, ToM) is impaired in schizophrenia. ToM is not a monolithic function, it includes different capacities: some implies the decoding of affective states, others the reasoning about mental states. We have developed the BAT, a Battery to Assess Theory of mind abilities in adult psychotic subjects in an ecological audiovisual format. The performance on the BAT and three other test of social cognition was compared in a sample of schizophrenic patients with a control group. The samples were matched in terms of age and premorbid IQ. The BAT was sensitive to detect the ToM impairments in schizophrenia, showed good internal consistency and concurrent validity. The area under the ROC curves established a cutoff point that would correctly classify controls and patients in a 96.6% of cases. The factorial analysis isolated two factors: empathy and reasoning, with a good adjustment. Our results showed that the BAT could be a valid, ecological and usable tool to assess ToM in psychotic patients, with good psychometric properties, that would allow obtaining a more complete profile of their impairment.
Asunto(s)
Esquizofrenia/diagnóstico , Psicología del Esquizofrénico , Percepción Social , Teoría de la Mente/fisiología , Adulto , Emociones , Femenino , Humanos , Masculino , Persona de Mediana Edad , PsicometríaRESUMEN
BACKGROUND: The brain functional correlates of autobiographical recall are well established, but have been little studied in schizophrenia. Additionally, autobiographical memory is one of a small number of cognitive tasks that activates rather than de-activates the default mode network, which has been found to be dysfunctional in this disorder. METHODS: Twenty-seven schizophrenic patients and 30 healthy controls underwent functional magnetic resonance imaging while viewing cue words that evoked autobiographical memories. Control conditions included both non-memory-evoking cues and a low level baseline (cross fixation). RESULTS: Compared to both non-memory evoking cues and low level baseline, autobiographical recall was associated with activation in default mode network regions in the controls including the medial frontal cortex, the posterior cingulate cortex and the hippocampus, as well as other areas. Clusters of de-activation were seen outside the default mode network. There were no activation differences between the schizophrenic patients and the controls, but the patients showed clusters of failure of de-activation in non-default mode network regions. CONCLUSIONS: According to this study, patients with schizophrenia show intact activation of the default mode network and other regions associated with recall of autobiographical memories. The finding of failure of de-activation outside the network suggests that schizophrenia may be associated with a general difficulty in de-activation rather than dysfunction of the default mode network per se.