The posttraumatic stress disorder project in Brazil: neuropsychological, structural and molecular neuroimaging studies in victims of urban violence.

BACKGROUND: Life trauma is highly prevalent in the general population and posttraumatic stress disorder is among the most prevalent psychiatric consequences of trauma exposure. Brazil has a unique environment to conduct translational research about psychological trauma and posttraumatic stress disorder, since urban violence became a Brazilian phenomenon, being particularly related to the rapid population growth of its cities. This research involves three case-control studies: a neuropsychological, a structural neuroimaging and a molecular neuroimaging study, each focusing on different objectives but providing complementary information. First, it aims to examine cognitive functioning of PTSD subjects and its relationships with symptomatology. The second objective is to evaluate neurostructural integrity of orbitofrontal cortex and hippocampus in PTSD subjects. The third aim is to evaluate if patients with PTSD have decreased dopamine transporter density in the basal ganglia as compared to resilient controls subjects. This paper shows the research rationale and design for these three case-control studies. METHODS AND DESIGN: Cases and controls will be identified through an epidemiologic survey conducted in the city of São Paulo. Subjects exposed to traumatic life experiences resulting in posttraumatic stress disorder (cases) will be compared to resilient victims of traumatic life experiences without PTSD (controls) aiming to identify biological variables that might protect or predispose to PTSD. In the neuropsychological case-control study, 100 patients with PTSD, will be compared with 100 victims of trauma without posttraumatic stress disorder, age- and sex-matched controls. Similarly, 50 cases and 50 controls will be enrolled for the structural study and 25 cases and 25 controls in the functional neuroimaging study. All individuals from the three studies will complete psychometrics and a structured clinical interview (the Structured Clinical Interview for DSM-IV and the Clinician-Administered PTSD Scale, Beck Anxiety Inventory, Beck Depression Inventory, Global Assessment of Function, The Social Adjustment Scale, Medical Outcomes Study 36-Item Short-Form Health Survey, Early Trauma Inventory, Clinical global Impressions, and Peritraumatic Dissociative Experiences Questionnaire). A broad neuropsychological battery will be administered for all participants of the neuropsychological study. Magnetic resonance scans will be performed to acquire structural neuroimaging data. Single photon emission computerized tomography with [(99m)Tc]-TRODAT-1 brain scans will be performed to evaluate dopamine transporters. DISCUSSION: This study protocol will be informative for researchers and clinicians interested in considering, designing and/or conducting translational research in the field of trauma and posttraumatic stress disorder.

Attention and memory deficits in crack-cocaine users persist over four weeks of abstinence.

BACKGROUND: Crack-cocaine addiction is an important public health problem worldwide. Although there is not a consensus, preliminary evidence has suggested that cognitive impairments in patients with crack-cocaine dependence persist during abstinence, affecting different neuropsychological domains. However, few studies have prospectively evaluated those deficits in different phases of abstinence. OBJECTIVES: The main aim of present study was to examine neuropsychological performance of patients with crack-cocaine dependence during early abstinence and after four weeks, comparing with matched controls. METHODS: Thirty-five males with crack-cocaine dependence, aged 18 to 50years, who met DSM-IV criteria for cocaine dependence and a control group of 33 healthy men were enrolled. They were assessed through Block Design, Digit Span and Vocabulary of Wechsler Adult Intelligence Scale (WAIS-III), the Rey Auditory Learning Test (RAVLT) and the Verbal Fluency (FAS) between 3 and 10days (mean of 6.1±2.0days) and after 4weeks of abstinence. RESULTS: Compared to controls, the crack-cocaine dependent group exhibited deficits in cognitive performance affecting attention, verbal memory and learning tasks in early withdrawal. Most of the cognitive deficits persisted after four weeks of abstinence. CONCLUSION: Present results observed that the group of patients with crack-cocaine dependence presented persistent deficits affecting memory and attention even after four weeks of abstinence, confirming previous studies that had disclosed such cognitive impairments.

Attentional and executive functions are differentially affected by post-traumatic stress disorder and trauma.

BACKGROUND: Among the neurocognitive impairments observed in patients with Post-traumatic Stress Disorder (PTSD), attentional and executive dysfunctions appear to correlate with negative effects on education, work, daily life activities, and social relations, as well as the re-experiencing, avoidance, and hyperarousal symptoms of PTSD. However, there is no consensus regarding which aspects of attentional and executive functions are impaired in PTSD patients. METHODS: Attentional and executive functions were assessed using the digit span (WAIS-III) and spatial span (WMS-III) tests under forward and backward recall conditions, the Stroop Test, and the Wisconsin Card Sorting Test (WCST). Our sample was composed of victims of urban violence who developed PTSD (PTSD+) (n = 81), victims of urban violence who did not develop PTSD (PTSD-) (n = 70), and healthy controls not exposed to trauma (HC) (n = 50). RESULTS: The PTSD+ group had poorer performance on the spatial span forward subtest (p = 0.023; eta(2) = 0.038) and poorer execution time (p = 0.023; eta(2) = 0.042) and accuracy (p = 0.019; eta(2) = 0.044) on the Stroop Test compared to HC. CONCLUSIONS: These data suggest that there are few differences between the PTSD+ and HC groups, which are restricted to less complex measures of attentional and executive functional processes (short term capacity, selective attention, processing speed, and inhibitory control) and are related to visual stimuli. Therefore, cognitive impairments directly correlated with the manifestation of PTSD.

Dopamine transporter density by [99mTc]-TRODAT-1 SPECT and neurocognitive performance - a preliminary pilot study

Introducción: los déficits cognitivos están relacionados con el deterioro funcional y con la baja calidad de vida en la enfermedad de Parkinson (EP). El sistema dopaminérgico de los ganglios basales es importante para el funcionamiento cognitivo y motor. Radiomarcadores de transportador de Dopamina (TAD) han sido utilizados para calcular la pérdida neuronal dopaminérgica en humanos. Objetivos: estudiar la relación entre el deterioro cognitivo y la pérdida neuronal dopaminérgica estriatal en pacientes con EP. Métodos: quince pacientes fueron escaneados con [99mTc]-TRODAT-1 y SPECT. El estriado (STR) y el lóbulo occipital (BKG) fueron definidos como regiones de interés (RIs) para la obtención del potencial de ligación (PL = [STR - BKG] / BKG). Exámenes neurocognitivos fueron aplicados, incluyendo el Rey Auditory Verbal Learning Test (RAVLT), Wisconsin Card Sorting Test (WCST), Ravens Progressive Matrices, Digit Span y Tavis 3. Resultados: El PL fue correlacionado negativamente con los exámenes de RAVLT 4 y 5, que evalúan el aprendizaje verbal. El PL también fue correlacionado negativamente con el artículo de aprendizaje de WCST y los artículos de Tavis 3, el error de acción y el número de aciertos. Conclusiones: este estudio indica que la pérdida de TAD estriatal está asociada con un desempeño mas pobre en tareas de flexibilidad cognitiva y aprendizaje verbal. Estos resultados están de acuerdo con un estudio previo con participantes sanos que encontró una relación entre la densidad de TAD del caudado y el desempeño en tareas de aprendizaje verbal. La segmentación del caudado/putamen en una muestra mayor está en desarrollo y podrá proveer más información sobre déficits cognitivos y pérdida de TAD estriatal.