[Functional neuroimaging in the study of aggressive behaviour in patients with schizophrenia]. / Neuroimagen funcional en el estudio de las conductas agresivas en pacientes con esquizofrenia.

INTRODUCTION: Although aggressive behaviours are not always very highly prevalent in schizophrenia, their occurrence does represent a significant problem for patients and those around them. Although neuroimaging studies have made it possible to further our knowledge of the biology of these behaviours, there is still a notable degree of clinical heterogeneity in the study samples that makes it difficult to obtain conclusive results that can be compared with each other. AIM: To determine whether there are variations in the brain activity, as measured with functional magnetic resonance imaging, of a homogenous group of patients with schizophrenia and aggressive behaviour. PATIENTS AND METHODS: The sample consisted of 32 patients with refractory schizophrenia and auditory hallucinations selected for the study. The subjects were submitted to a functional magnetic resonance imaging examination using an auditory paradigm with emotional stimulation, while the degree of aggressiveness was measured by means of the Brief Psychiatric Rating Scale. RESULTS: Significant correlations were found between functional activation and the degree of aggressiveness, which show focal hyperactivations in patients with a greater association to violent behaviours. The areas identified were located in the left hippocampus (p < 0.003, corrected) and in the right medial frontal gyrus (p < 0.004, corrected). CONCLUSIONS: This study determines the association between the degree of aggressiveness and certain regions in the brain that are responsible for cognitive and emotional processing in a phenotypically very homogenous group of patients with chronic auditory hallucinations and schizophrenia. This alteration of the neuronal circuits can favour loss in the processes involved in empathy and sensitivity, thus favouring the appearance of aggressive behaviours.

Neuroimagen funcional en el estudio de las conductas agresivas en pacientes con esquizofrenia / Functional neuroimaging in the study of aggressive behaviour in patients with schizophrenia

Introduction. Although aggressive behaviours are not always very highly prevalent in schizophrenia, their occurrence does represent a significant problem for patients and those around them. Although neuroimaging studies have made it possible to further our knowledge of the biology of these behaviours, there is still a notable degree of clinical heterogeneity in the study samples that makes it difficult to obtain conclusive results that can be compared with each other. Aim. To determine whether there are variations in the brain activity, as measured with functional magnetic resonance imaging, of a homogenous group of patients with schizophrenia and aggressive behaviour. Patients and methods. The sample consisted of 32 patients with refractory schizophrenia and auditory hallucinations selected for the study. The subjects were submitted to a functional magnetic resonance imaging examination using an auditory paradigm with emotional stimulation, while the degree of aggressiveness was measured by means of the Brief Psychiatric Rating Scale. Results. Significant correlations were found between functional activation and the degree of aggressiveness, which show focal hyperactivations in patients with a greater association to violent behaviours. The areas identified were located in the left hippocampus (p < 0.003, corrected) and in the right medial frontal gyrus (p < 0.004, corrected). Conclusions. This study determines the association between the degree of aggressiveness and certain regions in the brain that are responsible for cognitive and emotional processing in a phenotypically very homogenous group of patients with chronic auditory hallucinations and schizophrenia. This alteration of the neuronal circuits can favour loss in the processes involved in empathy and sensitivity, thus favouring the appearance of aggressive behaviours(AU)

Introducción. Aunque las conductas agresivas no tienen una prevalencia muy elevada en la esquizofrenia, su desarrollo supone un problema significativo para los pacientes y su entorno. Pese a que los estudios de neuroimagen han permitido profundizar en el conocimiento biológico de estas conductas, sigue existiendo una notable heterogeneidad clínica en las muestras de estudio que hace difícil la obtención de resultados concluyentes y comparables entre sí. Objetivo. Determinar si existen variaciones en la actividad cerebral medidas con resonancia magnética funcional en un grupo homogéneo de pacientes con esquizofrenia y conducta agresiva. Pacientes y métodos. Se seleccionaron 32 pacientes con esquizofrenia y alucinaciones auditivas resistentes al tratamiento. Los sujetos se sometieron a una exploración por resonancia magnética funcional utilizando un paradigma auditivo de estimulación emocional, al tiempo que se recogió el grado de agresividad a través de la Brief Psychiatric Rating Scale. Resultados. Se obtuvieron correlaciones significativas entre la activación funcional y el grado de agresividad, que muestran hiperactivaciones focales en aquellos pacientes con mayor asociación a conductas violentas. Las áreas identificadas se localizaron en el hipocampo izquierdo (p < 0,003, corregida) y en la circunvolución frontal media derecha (p < 0,004, corregida). Conclusiones. Este estudio determina la asociación entre el grado de agresividad y ciertas regiones cerebrales responsables del procesamiento cognitivo y emocional en un grupo fenotípicamente muy homogéneo de pacientes con esquizofrenia y alucinaciones auditivas crónicas. Esta alteración de los circuitos neuronales puede favorecer una pérdida en los procesos de empatía y sensibilidad, favoreciendo la aparición de conductas agresivas(AU)