RESUMEN
Our objective was to test for differences between subjects with obsessive-compulsive disorder (OCD) and healthy controls with respect to white matter architecture within the cingulum bundle (CB) and anterior limb of the internal capsule (ALIC). We studied eight subjects with active OCD and 10 matched healthy controls using diffusion tensor magnetic resonance imaging (DT-MRI) at 1.5 T (Tesla). Fractional anisotropy (FA) was evaluated in both CB and ALIC. Both voxelwise and region-of-interest methods of analysis were employed. Within both the left CB and the left ALIC, subjects with OCD exhibited significantly greater FA than healthy controls. In the right CB, subjects with OCD exhibited significantly decreased FA versus healthy control subjects. Additionally, the OCD group exhibited abnormal asymmetry (left > right) of FA in the CB. These results provide preliminary evidence for abnormal architecture within the CB and ALIC in OCD. FA differences in these areas are consistent with the presence of abnormal connections between the nodes linked by these tracts. This could explain why surgically severing these tracts is therapeutic. Additional studies are needed to replicate these findings and to clarify their pathological and clinical significance.
Asunto(s)
Imagen de Difusión por Resonancia Magnética , Giro del Cíngulo/patología , Procesamiento de Imagen Asistido por Computador , Cápsula Interna/patología , Fibras Nerviosas Mielínicas/patología , Red Nerviosa/patología , Trastorno Obsesivo Compulsivo/diagnóstico , Adolescente , Adulto , Dominancia Cerebral/fisiología , Femenino , Humanos , Masculino , Valores de ReferenciaRESUMEN
Hoarding behavior occurs frequently in obsessive-compulsive disorder (OCD). Results from previous studies suggest that individuals with OCD who have hoarding symptoms are clinically different than non-hoarders and may represent a distinct clinical group. In the present study, we compared 235 hoarding to 389 non-hoarding participants, all of whom had OCD, collected in the course of the OCD Collaborative Genetics Study. We found that, compared to non-hoarding individuals, hoarders were more likely to have symmetry obsessions and repeating, counting, and ordering compulsions; poorer insight; more severe illness; difficulty initiating or completing tasks; and indecision. Hoarders had a greater prevalence of social phobia and generalized anxiety disorder. Hoarders also had a greater prevalence of obsessive-compulsive and dependent personality disorders. Five personality traits were independently associated with hoarding: miserliness, preoccupation with details, difficulty making decisions, odd behavior or appearance, and magical thinking. Hoarding and indecision were more prevalent in the relatives of hoarding than of non-hoarding probands. Hoarding in relatives was associated with indecision in probands, independently of proband hoarding status. The findings suggest that hoarding behavior may help differentiate a distinct clinical subgroup of people with OCD and may aggregate in some OCD families. Indecision may be a risk factor for hoarding in these families.
Asunto(s)
Conducta Compulsiva , Trastorno Obsesivo Compulsivo/psicología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Toma de Decisiones , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Trastorno Obsesivo Compulsivo/genética , Personalidad , Escalas de Valoración PsiquiátricaRESUMEN
BACKGROUND: Corticostriatal circuitry has been implicated in the pathophysiology of obsessive-compulsive disorder (OCD). The serial reaction time (SRT) task, a paradigm that tests implicit sequence learning, has been used with imaging to probe striatal function. Initial studies have indicated that OCD patients exhibit deficient striatal activation and aberrant hippocampal recruitment compared with healthy control (HC) subjects. Here, we used the SRT and functional magnetic resonance imaging (fMRI) to replicate prior results in a larger sample and to test for relationships between regional activation and OCD symptom dimensions. METHODS: Using SPM99, fMRI-SRT data from 12 OCD and 12 matched HC subjects were analyzed. Symptom dimensions followed a four-factor model scored on a 0- to 10-point scale. RESULTS: For the implicit learning versus random contrast, group by condition interactions revealed aberrant recruitment within the hippocampus as well as orbitofrontal cortex (OCD > HC) but no striatal group differences. However, an inverse correlation was found between striatal activation and specific symptom factors. CONCLUSIONS: These results replicate previous smaller studies showing aberrant hippocampal recruitment in OCD during SRT performance. Although findings of deficient striatal activation in OCD were not replicated, correlation results suggest that this inconsistency may be attributable to differences among OCD symptom dimensions.
Asunto(s)
Encéfalo/fisiopatología , Aprendizaje/fisiología , Trastorno Obsesivo Compulsivo/fisiopatología , Trastorno Obsesivo Compulsivo/psicología , Adulto , Corteza Cerebral/fisiopatología , Estudios de Cohortes , Femenino , Hipocampo/fisiopatología , Humanos , Imagen por Resonancia Magnética , Masculino , Neostriado/fisiopatología , Vías Nerviosas/fisiopatología , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Reclutamiento NeurofisiológicoRESUMEN
CONTEXT: Previous studies have demonstrated subtle neurologic dysfunction in chronic posttraumatic stress disorder (PTSD) manifest as increased neurologic soft signs (NSSs). The origin of this dysfunction is undetermined. OBJECTIVE: To resolve competing origins of increased NSSs in PTSD, namely, preexisting vulnerability factor vs acquired PTSD sign. DESIGN: Case-control study of identical twins. SETTING: A Veterans Affairs and academic medical center (ambulatory). PARTICIPANTS: A convenience sample of male Vietnam veteran twins with (n = 25) and without (n = 24) PTSD and their combat-unexposed identical (monozygotic) co-twins. INTERVENTIONS: Neurologic examination for 45 NSSs. MAIN OUTCOME MEASURE: Average scores for 45 NSSs, each scored on an ordinal scale from 0 to 3, masked to diagnosis and combat exposure status. RESULTS: There was a significant between-pair main effect of PTSD diagnosis (as determined in the combat-exposed twin) on average NSS score in the absence of a significant combat exposure main effect or diagnosis x exposure interaction. Combat veterans with PTSD had significantly higher NSS scores than combat veterans without PTSD. The "high-risk," unexposed co-twins of the former also had significantly higher NSS scores than the "low-risk," unexposed co-twins of the latter. This result could not be explained by age, number of potentially traumatic lifetime noncombat events, alcoholism, or the presence of a comorbid affective or anxiety disorder. The average NSS score in unexposed co-twins was not significantly associated with combat severity in combat-exposed twins. CONCLUSIONS: These results replicate previous findings of increased NSSs in Vietnam combat veterans with PTSD. Furthermore, results from their combat-unexposed identical co-twins support the conclusion that subtle neurologic dysfunction in PTSD is not acquired along with the trauma or PTSD but rather represents an antecedent familial vulnerability factor for developing chronic PTSD on exposure to a traumatic event.
Asunto(s)
Trastornos de Combate/diagnóstico , Trastornos de Combate/epidemiología , Enfermedades en Gemelos/diagnóstico , Enfermedades en Gemelos/epidemiología , Enfermedades del Sistema Nervioso/diagnóstico , Enfermedades del Sistema Nervioso/epidemiología , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/epidemiología , Atención Ambulatoria , Estudios de Casos y Controles , Enfermedad Crónica , Trastornos de Combate/genética , Comorbilidad , Susceptibilidad a Enfermedades/diagnóstico , Susceptibilidad a Enfermedades/epidemiología , Enfermedades en Gemelos/genética , Humanos , Acontecimientos que Cambian la Vida , Masculino , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/genética , Examen Neurológico , Pruebas Neuropsicológicas , Desempeño Psicomotor , Factores de Riesgo , Índice de Severidad de la Enfermedad , Trastornos por Estrés Postraumático/genética , Gemelos MonocigóticosRESUMEN
Results from twin and family studies suggest that obsessive-compulsive disorder (OCD) may be transmitted in families but, to date, genes for the disorder have not been identified. The OCD Collaborative Genetics Study (OCGS) is a six-site collaborative genetic linkage study of OCD. Specimens and blinded clinical data will be made available through the National Institute of Mental Health (NIMH) cell repository. In this initial report, we describe the methods of the study and present clinical characteristics of affected individuals for researchers interested in this valuable resource for genetic studies of OCD. The project clinically evaluated and collected blood specimens from 238 families containing 299 OCD-affected sibling pairs and their parents, and additional affected relative pairs, for a genome-wide linkage study. Of the 999 individuals interviewed to date, 624 were diagnosed with "definite" OCD. The mean age of subjects was 36 years (range 7-95). The majority of affected individuals (66%) were female. The mean age at onset of obsessive-compulsive symptoms was 9.5 years. Specific mood disorders, anxiety disorders, eating disorders, and skin picking were more prevalent in female cases, whereas tics, Tourette disorder, and alcohol dependence were more prevalent in male cases. Compared to "definite" cases of OCD, "probable" cases (n = 82) had, on average, later age at onset of obsessive-compulsive symptoms, lower severity score, and fewer numbers of different categories of obsessions and compulsions, and they were less likely to have received treatment for their symptoms.
Asunto(s)
Trastorno Obsesivo Compulsivo/diagnóstico , Trastorno Obsesivo Compulsivo/genética , Adolescente , Adulto , Factores de Edad , Edad de Inicio , Anciano , Anciano de 80 o más Años , Investigación Biomédica/métodos , Niño , Bases de Datos Factuales , Familia , Salud de la Familia , Femenino , Genotipo , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Trastorno Obsesivo Compulsivo/epidemiología , Proyectos de Investigación , Factores Sexuales , Hermanos , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: Previous functional neuroimaging studies have demonstrated exaggerated amygdala responses and diminished medial prefrontal cortex responses during the symptomatic state in posttraumatic stress disorder (PTSD). OBJECTIVES: To determine whether these abnormalities also occur in response to overtly presented affective stimuli unrelated to trauma; to examine the functional relationship between the amygdala and medial prefrontal cortex and their relationship to PTSD symptom severity in response to these stimuli; and to determine whether responsivity of these regions habituates normally across repeated stimulus presentations in PTSD. DESIGN: Case-control study. SETTING: Academic medical center. PARTICIPANTS: Volunteer sample of 13 men with PTSD (PTSD group) and 13 trauma-exposed men without PTSD (control group). MAIN OUTCOME MEASURES: We used functional magnetic resonance imaging (fMRI) to study blood oxygenation level-dependent signal during the presentation of emotional facial expressions. RESULTS: The PTSD group exhibited exaggerated amygdala responses and diminished medial prefrontal cortex responses to fearful vs happy facial expressions. In addition, in the PTSD group, blood oxygenation level-dependent signal changes in the amygdala were negatively correlated with signal changes in the medial prefrontal cortex, and symptom severity was negatively related to blood oxygenation level-dependent signal changes in the medial prefrontal cortex. Finally, relative to the control group, the PTSD group tended to exhibit diminished habituation of fearful vs happy responses in the right amygdala across functional runs, although this effect did not exceed our a priori statistical threshold. CONCLUSIONS: These results provide evidence for exaggerated amygdala responsivity, diminished medial prefrontal cortex responsivity, and a reciprocal relationship between these 2 regions during passive viewing of overtly presented affective stimuli unrelated to trauma in PTSD.
Asunto(s)
Amígdala del Cerebelo/fisiopatología , Expresión Facial , Miedo/fisiología , Imagen por Resonancia Magnética/estadística & datos numéricos , Corteza Prefrontal/fisiopatología , Trastornos por Estrés Postraumático/diagnóstico , Percepción Visual/fisiología , Nivel de Alerta/fisiología , Emociones/fisiología , Lateralidad Funcional/fisiología , Habituación Psicofisiológica/fisiología , Felicidad , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Oxígeno/sangreRESUMEN
BACKGROUND: To assess the amygdala response to emotional faces in obsessive-compulsive disorder (OCD) using functional magnetic resonance imaging (fMRI). METHODS: Ten subjects with current OCD and 10 healthy control subjects underwent fMRI, during which they viewed pictures of fearful, happy, and neutral human faces, as well as a fixation cross. RESULTS: Across both groups, there was significant activation in left and right amygdala for the fearful versus neutral faces contrast. Data extracted from these functionally defined regions of interest indicated that OCD subjects exhibited a weaker response than control subjects bilaterally across all face conditions versus fixation. No group-by-face condition interactions were observed. CONCLUSIONS: Contrary to findings in other anxiety disorders, there was no observed increase in amygdala responsivity to fearful versus neutral human faces in OCD as compared with healthy control subjects. Moreover, across all face conditions, amygdala responsivity was attenuated in OCD subjects relative to control subjects. Therefore, the present findings are consistent with abnormal amygdala function in OCD and are of a character that may distinguish OCD from other anxiety disorders.
Asunto(s)
Amígdala del Cerebelo/fisiopatología , Emociones/fisiología , Expresión Facial , Trastorno Obsesivo Compulsivo/fisiopatología , Adulto , Amígdala del Cerebelo/irrigación sanguínea , Amígdala del Cerebelo/patología , Mapeo Encefálico , Femenino , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos , Masculino , Oxígeno/sangre , Estimulación Luminosa/métodosRESUMEN
CONTEXT: Theoretical neuroanatomic models of posttraumatic stress disorder (PTSD) and the results of previous neuroimaging studies of PTSD highlight the potential importance of the amygdala and medial prefrontal regions in this disorder. However, the functional relationship between these brain regions in PTSD has not been directly examined. OBJECTIVE: To examine the relationship between the amygdala and medial prefrontal regions during symptom provocation in male combat veterans (MCVs) and female nurse veterans (FNVs) with PTSD. DESIGN: Case-control study. SETTING: Academic medical center. PARTICIPANTS: Volunteer sample of 17 (7 men and 10 women) Vietnam veterans with PTSD (PTSD group) and 19 (9 men and 10 women) Vietnam veterans without PTSD (control group). MAIN OUTCOME MEASURES: We used positron emission tomography and the script-driven imagery paradigm to study regional cerebral blood flow (rCBF) during the recollection of personal traumatic and neutral events. Psychophysiologic and emotional self-report data also were obtained to confirm the intended effects of script-driven imagery. RESULTS: The PTSD group exhibited rCBF decreases in medial frontal gyrus in the traumatic vs neutral comparison. When this comparison was conducted separately by subgroup, MCVs and FNVs with PTSD exhibited these medial frontal gyrus decreases. Only MCVs exhibited rCBF increases in the left amygdala. However, for both subgroups with PTSD, rCBF changes in medial frontal gyrus were inversely correlated with rCBF changes in the left amygdala and the right amygdala/periamygdaloid cortex. Furthermore, in the traumatic condition, for both subgroups with PTSD, symptom severity was positively related to rCBF in the right amygdala and negatively related to rCBF in medial frontal gyrus. CONCLUSIONS: These results suggest a reciprocal relationship between medial prefrontal cortex and amygdala function in PTSD and opposing associations between activity in these regions and symptom severity consistent with current functional neuroanatomic models of this disorder.
Asunto(s)
Amígdala del Cerebelo/irrigación sanguínea , Imágenes en Psicoterapia , Corteza Prefrontal/irrigación sanguínea , Trastornos por Estrés Postraumático/fisiopatología , Veteranos/psicología , Amígdala del Cerebelo/patología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Corteza Prefrontal/patología , Flujo Sanguíneo Regional , Tomografía Computarizada de Emisión , Vietnam , Guerra , Heridas y Lesiones/psicologíaRESUMEN
Present understanding of the neural circuitry of anxiety has come from a variety of sources, including animal, clinical, and most recently, neuroimaging studies. Evidence from these sources has converged to form a translational bridge from animal models to human pathophysiology. In particular, the classical fear conditioning paradigm has served as a foundation for this bridge. Proposed models for the neural circuitry of normal anxiety as well as the anxiety disorders are discussed. A brief review of specific findings from neuroimaging studies of posttraumatic stress disorder, specific phobia, social phobia, obsessive-compulsive disorder, and generalized anxiety disorder is also provided.
Asunto(s)
Ansiedad/fisiopatología , Red Nerviosa/irrigación sanguínea , Red Nerviosa/fisiopatología , Humanos , Imagen por Resonancia Magnética , Trastorno Obsesivo Compulsivo/fisiopatología , Trastornos Fóbicos/fisiopatología , Trastornos por Estrés Postraumático/fisiopatología , Tomografía Computarizada de EmisiónRESUMEN
The concept of an obsessive-compulsive spectrum of disorders has become useful. This article reviews what has been learned about these conditions (especially in the last few years), and how this information may be helpful to clinicians and researchers who work with patients with chronic nonmalignant pain.