Article

Quantitative meta-analysis of neural activity in posttraumatic stress disorder.

National Center for PTSD, VA Boston Healthcare System, Boston, MA, USA. .
Biology of mood & anxiety disorders 05/2012; 2(1):9. DOI: 10.1186/2045-5380-2-9
Source: PubMed

ABSTRACT In recent years, neuroimaging techniques such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) have played a significant role in elucidating the neural underpinnings of posttraumatic stress disorder (PTSD). However, a detailed understanding of the neural regions implicated in the disorder remains incomplete because of considerable variability in findings across studies. The aim of this meta-analysis was to identify consistent patterns of neural activity across neuroimaging study designs in PTSD to improve understanding of the neurocircuitry of PTSD.
We conducted a literature search for PET and fMRI studies of PTSD that were published before February 2011. The article search resulted in 79 functional neuroimaging PTSD studies. Data from 26 PTSD peer-reviewed neuroimaging articles reporting results from 342 adult patients and 342 adult controls were included. Peak activation coordinates from selected articles were used to generate activation likelihood estimate maps separately for symptom provocation and cognitive-emotional studies of PTSD. A separate meta-analysis examined the coupling between ventromedial prefrontal cortex and amygdala activity in patients.
Results demonstrated that the regions most consistently hyperactivated in PTSD patients included mid- and dorsal anterior cingulate cortex, and when ROI studies were included, bilateral amygdala. By contrast, widespread hypoactivity was observed in PTSD including the ventromedial prefrontal cortex and the inferior frontal gyrus. Furthermore, decreased ventromedial prefrontal cortex activity was associated with increased amygdala activity.
These results provide evidence for a neurocircuitry model of PTSD that emphasizes alteration in neural networks important for salience detection and emotion regulation.

2 Bookmarks
 · 
185 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: About ten percent of people experiencing a traumatic event will subsequently develop post-traumatic stress disorder (PTSD). PTSD is characterized by an exaggerated fear response which fails to extinguish over time and cannot be inhibited in safe contexts. The neurobiological correlates of PTSD involve enhanced salience processing (i.e. amygdala, dorsal anterior cingulate cortex (dACC) and anterior insula (AI) hyperactivity), and reduced top-down inhibitory control over this fear response (i.e. dorsal and ventromedial prefrontal cortex (vmPFC) hypoactivity and diminished structural and functional connectivity between the vmPFC, hippocampus and amygdala). Therefore, dampening the exaggerated fear response (i.e. by reducing amygdala hyperactivity) and enhancing top-down inhibitory control (i.e. by promoting prefrontal control over the amygdala) during psychotherapy is an important target for medication-enhanced psychotherapy (MEP) in PTSD patients. Since the neuropeptide oxytocin (OT) has been found to act on these two processes, we propose that OT is a promising pharmacological agent to boost treatment response in PTSD. Human fMRI studies indicate that intranasal OT attenuates amygdala (hyper)activity and enhances connectivity of the amygdala with the vmPFC and hippocampus, resulting in increased top-down control over the fear response. In addition, intranasal OT was found to attenuate amygdala–brainstem connectivity and to change activity and connectivity in nodes of the salience network (i.e. AI and dACC). Furthermore, OT administration may modulate hypothalamus–pituitary–adrenal (HPA) axis and autonomic nervous system (ANS) function and may enhance social behaviour, which could be beneficial in the therapeutic alliance. We also discuss contextual and interindividual factors (e.g. gender and social context) which may influence the effectiveness of OT in MEP. In all, we propose that intranasal OT given prior to each psychotherapy session may be an effective additive treatment to boost treatment response in PTSD.
    Psychoneuroendocrinology 01/2014; 40:242–256. · 5.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Emotional memory consolidation has been associated with rapid eye movement (REM) sleep, and recent evidence suggests that increased electroencephalogram spectral power in the theta (4-8 Hz) frequency range indexes this activity. REM sleep has been implicated in posttraumatic stress disorder (PTSD) as well as in emotional adaption. In this cross-sectional study, thirty young healthy African American adults with trauma exposure were assessed for PTSD status using the Clinician Administered PTSD Scale. Two consecutive night polysomnographic (PSG) recordings were performed and data scored for sleep stages. Quantitative electroencephalographic spectral analysis was used to measure theta frequency components sampled from REM sleep periods of the second-night PSG recordings. Our objective was to compare relative theta power between trauma-exposed participants who were either resilient or had developed PTSD. Results indicated higher right prefrontal theta power during the first and last REM periods in resilient participants compared with participants with PTSD. Right hemisphere prefrontal theta power during REM sleep may serve as a biomarker of the capacity for adaptive emotional memory processing among trauma-exposed individuals.
    Experimental Brain Research 02/2014; · 2.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Premenstrual dysphoric disorder (PMDD), characterized by luteal phase-induced negative affect and loss of impulse control, often results in compromised social interactions. Although amygdala activation is generally linked to negative affect, increased amygdala reactivity to aversive stimuli in the luteal phase has not been consistently reported in PMDD. We tested the hypothesis that amygdala hyper-reactivity in PMDD is symptom specific, rather than generalized, and linked to socially relevant stimuli. Blood oxygenation level dependent signal changes during exposure to negative images with social and non-social content were evaluated in the mid-follicular and late luteal phase of the menstrual cycle. Fourteen women with PMDD and 13 healthy controls participated. When compared with healthy controls, women with PMDD in the luteal phase had enhanced reactivity to social stimuli compared to non-social stimuli in the amygdala and insula, but attenuated reactivity in the anterior cingulate cortex. Functional couplings between emotion processing and controlling areas were significantly different, being positive in women with PMDD and negative in healthy controls. Changes in progesterone levels in women with PMDD correlated positively with altered amygdala reactivity. Socially relevant aversive stimulation elicited enhanced activity in affective processing brain regions that were functionally coupled to compromised activity in cognitive control areas. Because increased reactivity correlated positively with alterations in ovarian steroid levels, data preliminary support the hypothesis that enhanced progesterone sensitivity in PMDD affects corticolimbic processing of social emotions.
    Biology of mood & anxiety disorders. 02/2014; 4(1):3.

Full-text

View
47 Downloads
Available from
May 21, 2014