RESUMEN
Functional imaging studies have implicated the orbitofrontal cortex (OFC) in the pathophysiology of borderline personality disorder (BPD). To date, however, volume-based magnetic resonance imaging (MRI) studies have yielded mixed results. We used a surface-based processing approach that allowed us to measure five morphometric cortical features of the OFC, including volumetric (cortical thickness and surface area) and geometric (mean curvature, depth of sulcus, and metric distortion - three indicators of cortical folding) parameters. Participants comprised 25 female BPD patients with no other current psychiatric comorbidity and 25 age- and gender-matched healthy controls who received structural MRI scans. Images were processed using the Freesurfer package. All BPD patients had a history of comorbid psychiatric disorder(s) and were currently on medications. Compared with controls, the BPD group showed reduced cortical thickness, surface area, mean curvature, depth of sulcus, and metric distortion in the right medial OFC. In the left medial OFC, the BPD group had reduced cortical thickness and mean curvature, but increased metric distortion. This study confirmed the utility of surface-based analysis in the study of BPD cortical structures. In addition, we observed extensive structural abnormalities in the medial OFC of female subjects with BPD, findings that were most pronounced in the right OFC, with preliminary data suggesting hemispheric asymmetry.
Asunto(s)
Trastorno de Personalidad Limítrofe/patología , Encéfalo/patología , Imagen por Resonancia Magnética/métodos , Adulto , Trastorno de Personalidad Limítrofe/psicología , Estudios de Casos y Controles , Corteza Cerebral/patología , Estudios Transversales , Femenino , Sustancia Gris/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Persona de Mediana Edad , Tamaño de los Órganos , Índice de Severidad de la Enfermedad , Sustancia Blanca/patologíaRESUMEN
Cluster B personality disorders (PD), characterized as emotional instability, immaturity, lack of discipline, and rapid mood changes, have been observed among patients with juvenile myoclonic epilepsy (JME) and have been associated with a worse seizure outcome. Proper understanding of the neurobiology of PD associated with JME could contribute to understanding the basis for earlier and more effective interventions. In the present study, volumetric and geometric features of cortical structure were assessed through an automated cortical surface reconstruction method aiming to verify possible structural cortical alterations among patients with JME. Twenty-two patients with JME with cluster B PD, 44 patients with JME without psychiatric disorders, and 23 healthy controls were submitted to a psychiatric evaluation through SCID I and SCID II and to an MRI scan. Significant cortical alterations in mesiofrontal and frontobasal regions, as well as in other limbic and paralimbic regions, were observed mainly in patients with JME with PD. The present study adds evidence to the hypothesis of frontal and limbic involvement in the pathophysiology of cluster B PD in JME, regions linked to mood and affective regulation, as well as to impulsivity and social behavior. Moreover, a multidimensional pattern of frontal, limbic, and paralimbic changes was observed through a method of structural analysis which offers different and simultaneous geometric features, allowing the elaboration of important pathophysiologic insights about cluster B PD in JME.
Asunto(s)
Corteza Cerebral/patología , Epilepsia Mioclónica Juvenil/complicaciones , Epilepsia Mioclónica Juvenil/patología , Trastornos de la Personalidad/complicaciones , Adulto , Mapeo Encefálico , Electroencefalografía , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Escalas de Valoración Psiquiátrica , Adulto JovenRESUMEN
Several recent studies in literature have identified brain morphological alterations associated to Borderline Personality Disorder (BPD) patients. These findings are reported by studies based on voxel-based-morphometry analysis of structural MRI data, comparing mean gray-matter concentration between groups of BPD patients and healthy controls. On the other hand, mean differences between groups are not informative about the discriminative value of neuroimaging data to predict the group of individual subjects. In this paper, we go beyond mean differences analyses, and explore to what extent individual BPD patients can be differentiated from controls (25 subjects in each group), using a combination of automated-morphometric tools for regional cortical thickness/volumetric estimation and Support Vector Machine classifier. The approach included a feature selection step in order to identify the regions containing most discriminative information. The accuracy of this classifier was evaluated using the leave-one-subject-out procedure. The brain regions indicated as containing relevant information to discriminate groups were the orbitofrontal, rostral anterior cingulate, posterior cingulate, middle temporal cortices, among others. These areas, which are distinctively involved in emotional and affect regulation of BPD patients, were the most informative regions to achieve both sensitivity and specificity values of 80% in SVM classification. The findings suggest that this new methodology can add clinical and potential diagnostic value to neuroimaging of psychiatric disorders.