Physiological basis of default mode network and its implications in severe disorders of consciousness

Abstract

The Default Mode Network (DMN) is a highly complex system composed by midline cerebral areas. Its importance lies to the fact that it is considered to support consciousness and other superior mental functions. The activity of the DMN predominates over other regions in the so-called resting state conditions, in which the subject remains peacefully laid without performing any mental task. In this state, it has been compared, by the use of functional magnetic resonance imagining (fMRI), the activation of the DMN in healthy subjects to that obtained in patients with disorders of consciousness. The results have been extraordinary, since it has been demonstrated that the different level of activation of the DMN is intrinsically associated to the prognosis of altered states of consciousness. This discovery supposes a turning point and might represent a revolutionary change in the whole management of severe disorders of consciousness.