title: Failure of de-activation in the medial frontal cortex in mania: evidence for default mode network dysfunction in the disorder.
abstract: OBJECTIVE
  Manic patients have been found to show reduced activation in the prefrontal cortex and other regions during performance of cognitive tasks. However, little is known about de-activations associated with the disorder. This study aimed to examine, at the whole-brain level, abnormal patterns of task-related activation and de-activation during performance of a working memory task.
  
  
  METHODS
  Twenty-nine DSM-IV bipolar patients and 46 healthy controls underwent fMRI during performance of the n-back task. The patients were scanned while they were in a manic episode. Linear models were used to obtain maps of within-group activations and areas of differential activation between the groups.
  
  
  RESULTS
  The manic patients showed reduced activation compared to the controls in the bilateral dorsolateral prefrontal cortex and the right parietal cortex. They also showed failure of de-activation in the medial frontal cortex, extending to the temporal poles and parts of the limbic system bilaterally. The failure of activation in the dorsolateral prefrontal cortex disappeared when differences in task performance were controlled for in the analysis. However, the medial frontal failure of de-activation survived controlling for this.
  
  
  CONCLUSIONS
  This study suggests that, in addition to reduced prefrontal activation, failure of de-activation is an important functional imaging abnormality in mania. This, together with its location in the medial prefrontal cortex, implies default mode network dysfunction in the disorder.
authors: FIDMAG, Germanes Hospitalàries ,  Barcelona ,  Spain.
authors: Edith
authors: E
authors: Pomarol-Clotet
authors: Noemi
authors: N
authors: Moro
authors: Salvador
authors: S
authors: Sarró
authors: José M
authors: JM
authors: Goikolea
authors: Eduard
authors: E
authors: Vieta
authors: Benedikt
authors: B
authors: Amann
authors: Paloma
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authors: Fernandez-Corcuera
authors: Bibiana
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authors: Sans-Sansa
authors: Gemma C
authors: GC
authors: Monté
authors: Antoni
authors: A
authors: Capdevila
authors: Peter J
authors: PJ
authors: McKenna
authors: Raymond
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authors: Salvador