Functional MRI of sustained attention in bipolar mania (original) (raw)
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Brain functional changes across the different phases of bipolar disorder
The British journal of psychiatry : the journal of mental science, 2015
Little is known about how functional imaging changes in bipolar disorder relate to different phases of the illness. To compare cognitive task activation in participants with bipolar disorder examined in different phases of illness. Participants with bipolar disorder in mania (n = 38), depression (n = 38) and euthymia (n = 38), as well as healthy controls (n = 38), underwent functional magnetic resonance imaging during performance of the n-back working memory task. Activations and de-activations were compared between the bipolar subgroups and the controls, and among the bipolar subgroups. All participants were also entered into a linear mixed-effects model. Compared with the controls, the mania and depression subgroups, but not the euthymia subgroup, showed reduced activation in the dorsolateral prefrontal cortex, the parietal cortex and other areas. Compared with the euthymia subgroup, the mania and depression subgroups showed hypoactivation in the parietal cortex. All three bipolar...
Evidence for deficient modulation of amygdala response by prefrontal cortex in bipolar mania
Psychiatry Research: Neuroimaging, 2008
Several studies have implicated the involvement of two major components of emotion regulatory networks, the ventrolateral prefrontal cortex (VLPFC) and amygdala, in the pathophysiology of bipolar disorder. In healthy subjects, the VLPFC has been shown to negatively modulate amygdala response when subjects cognitively evaluate an emotional face by identifying and labeling the emotion it expresses. The current study used such a paradigm to assess whether the strength of this modulation was altered in bipolar subjects when manic. During fMR imaging, 9 manic subjects with bipolar I disorder and 9 healthy subjects either named the emotion shown in a face by identifying one of two words that correctly expressed the emotion (emotion labeling task) or matched the emotion shown in a face to one of two other faces (emotion perception task). The degree to which VLPFC regulated amygdala response during these tasks was assessed using a psychophysiological interaction (PPI) analysis. Compared to healthy subjects, manic patients had a significantly reduced VLPFC regulation of amygdala response during the emotion labeling task. These findings, taken in context with previous fMRI studies of bipolar mania suggest that reductions in inhibitory frontal activity in these patients may lead to an increased reactivity of the amygdala.
State- and trait-related deficits in sustained attention in bipolar disorder
European archives of psychiatry and clinical neuroscience, 2004
Investigation of neuropsychological functioning in bipolar disorder provides a potential link from the prominent cognitive symptoms of the disorder to the underlying neural mechanisms. Continuous performance measures of sustained attention have yielded consistent findings in bipolar disorder patients. There are impairments that appear to be both state- and trait-related. Impaired target detection may represent one of the most sensitive markers of illness course in bipolardisorder. It is unrelated to residual mood symptomatology and medication status, and is present in patients with good functional recovery. The impairment in target detection is exacerbated in the manic state, and is accompanied by an increased rate of false responding. Sustained attention deficit is present early in the course of the disorder, but becomes more pronounced with repeated episodes. This cognitive profile, of an early-onset, state-modulated, trait marker, is distinct from the profile of attentional disru...
NeuroImage, 2012
Functional neuroimaging studies have implicated the involvement of the amygdala and ventrolateral prefrontal cortex (vlPFC) in the pathophysiology of bipolar disorder. Hyperactivity in the amygdala and hypoactivity in the vlPFC have been reported in manic bipolar patients scanned during the performance of an affective faces task. Whether this pattern of dysfunction persists during euthymia is unclear. Using functional magnetic resonance imaging (fMRI), 24 euthymic bipolar and 26 demographically matched healthy control subjects were scanned while performing an affective task paradigm involving the matching and labeling of emotional facial expressions. Neuroimaging results showed that, while amygdala activation did not differ significantly between groups, euthymic patients showed a significant decrease in activation of the right vlPFC (BA47) compared to healthy controls during emotion labeling. Additionally, significant decreases in activation of the right insula, putamen, thalamus and lingual gyrus were observed in euthymic bipolar relative to healthy control subjects during the emotion labeling condition. These data, taken in context with prior studies of bipolar mania using the same emotion recognition task, could suggest that amygdala dysfunction may be a state-related abnormality in bipolar disorder, whereas vlPFC dysfunction may represent a trait-related abnormality of the illness. Characterizing these patterns of activation is likely to help in understanding the neural changes related to the different mood states in bipolar disorder, as well as changes that represent more sustained abnormalities. Future studies that assess mood-state related changes in brain activation in longitudinal bipolar samples would be of interest. Published by Elsevier Inc.
Decreased activation of the anterior cingulate in bipolar patients: an fMRI study
Journal of Affective Disorders, 2004
Background: Previous neuroimaging investigations of patients with bipolar disorder have reported abnormalities of the frontal subcortical network. The role of the anterior cingulate cortex (ACC) and the dorsolateral prefrontal cortex (DLPFC) in bipolar disorder are not clear, although both regions have been shown to be components of a neural network which plays a critical role in the completion of tasks requiring self-monitoring and inhibition, functions often noted to be altered in bipolar patients. fMRI studies have helped clarify the role of specific subdivisions of the ACC and the DLPFC during the performance of cognitive challenges, including the Stroop color word test. To date, studies that have examined ACC function in bipolar patients have not differentiated subregions within this area, nor have they examined changes in these subregions in relation with DLPFC activation. Methods: To help clarify the specific roles of these regions in bipolar patients, we examined stable patients and control subjects during performance of the Stroop test using BOLD fMRI techniques. We hypothesized that bipolar patients would demonstrate reduced activation of two subdivisions of the ACC (AAA and VOA), as well as altered activation of the DLPFC, during the interference condition. Results: Results indicate that relative to controls, bipolar patients demonstrated significantly reduced signal intensity within the right AAA subdivision (p = 0.011), which accompanied an increase in the DLPFC (p = 0.049) during the task. Limitations: The study sample was somewhat small (11 patients, 10 controls) which limits the generalizability of the study findings, however, the patient sample consisted of well-diagnosed, stable, chronic individuals with bipolar disorder and the sample size provided enough power to detect between-group differences. Conclusions: These findings suggest differential processing strategies of bipolar patients and support the theory of altered frontal systems in these patients during the performance of cognitive tasks.
Neuropsychologia, 2010
Objective: To identify neurocognitive measures that could be used as objective markers of bipolar disorder. Methods: We examined executive function, sustained attention and short-term memory as neurocognitive domains in 18 participants with bipolar disorder in euthymic state (Beuth), 14 in depressed state (Bdep), 20 with unipolar depression (Udep) and 28 healthy control participants (HC). We conducted four-group comparisons followed by relevant post hoc analyses. Results: Udep and Bdep, but not Beuth showed impaired executive function (p = 0.045 and p = 0.046, respectively). Both Bdep and Beuth, but not Udep, showed impaired sustained attention (p = 0.001 and p = 0.045, respectively). The four groups did not differ significantly on short-term memory. Impaired sustained attention and executive dysfunction were not associated with depression severity, duration of illness and age of illness onset. Only a small number of abnormal neurocognitive measures were associated with medication in Bdep and Beuth. Conclusion: Impaired sustained attention appears specific to bipolar disorder and present in both Beuth and Bdep; it may represent an objective marker of bipolar disorder. Executive dysfunction by contrast, appears to be present in Udep and Bdep and likely represents a marker of depression.
Early Intervention in Psychiatry, 2009
Aim: To identify differential patterns of brain activation between adolescents with bipolar disorder and adolescents with attention-deficit hyperactivity disorder (ADHD) to better understand the neurophysiology of both disorders. We hypothesized that subjects with ADHD would show altered activation in brain regions involved in executive and sustained attention. In contrast, we hypothesized that bipolar subjects would show altered brain activation in regions responsible for emotionally homeostasis, including the striatum and amygdala.
Journal of Affective Disorders, 2013
Background: The inferior frontal cortical (IFC)-striatal network plays an integral role in response inhibition and is compromised in patients with Bipolar Disorder (BP) or Attention-Deficit/Hyperactivity Disorder (ADHD). Prior BP functional neuroimaging studies have not accounted for ADHD comorbidity despite its high prevalence. Methods: The authors conducted an fMRI study using a response inhibition task (Go-NoGo) in 32 euthymic adults with BP, half with comorbid ADHD (BP/ADHD); 16 adults with ADHD alone; and 30 healthy controls. Within-and between-group whole-brain analyses were performed to assess for significant neural function differences. Results: All groups activated frontal and striatal regions involved in response inhibition. ANOVA results demonstrated significant interaction effects of BP and ADHD in the anterior and posterior cingulate, left superior and middle frontal gyri and left inferior parietal lobule. Follow-up comparisons showed significant differences between BP subjects with and without ADHD. Other regions demonstrated main effects of BP (left inferior frontal gyrus, left middle frontal gyrus, right superior frontal gyrus and left insula) and ADHD (left inferior frontal gyrus, left precentral gyrus and right anterior cingulate). Limitations: This study, as the first of its kind, requires replication using large sample sizes and controlling for potential effects of medication. Conclusions: Euthymic bipolar adults with comorbid ADHD have significantly different neural activation patterns from BP patients without this comorbidity. If understanding of the neurobiology of bipolar disorder is to be achieved, it is critical to control for this potential confound, something not done by most prior fMRI studies of adults with BP.