The instability of functional connectivity in patients with schizophrenia and their siblings: A dynamic connectivity study

Schizophr Res. 2018 May:195:183-189. doi: 10.1016/j.schres.2017.09.035. Epub 2017 Nov 15.

Abstract

Background: The distributed connectivity among brain regions is in a constant state of flux, even when a subject is at rest. This instability (temporal variability), when optimal, may contribute to efficient cross-network communications. We investigate the role of this variability in the genetic diathesis and symptom expression of schizophrenia.

Methods: Resting state functional MRI data acquired from 116 subjects (28 patients with schizophrenia, 28 siblings and 60 matched healthy controls). Using a sliding-window dynamic connectivity approach, we quantified the variability of whole-brain connectivity (dynamic functional connectivity or dFC) of each of the 90 brain regions obtained using a parcellation scheme that covered all contiguous brain regions of the cerebral cortex.

Results: We noted a high degree of instability anchored on the precuneus in patients with schizophrenia compared to both healthy controls (t=3.60, p=0.0005) and unaffected siblings (t=3.61, p=0.001) indicating a role for dFC of precuneus in the clinical expression of schizophrenia. Compared to patients, siblings also showed an increase in medial orbitofrontal but reduced putaminal instability; these latter changes were not seen in patients when compared to controls, indicating a lack of specificity for diathesis or expression related effects.

Conclusions: Instability in the intrinsic connectivity of precuneus, a functional core hub with a major role in task-free self-processing, is likely to be a core substrate of the clinical expression of schizophrenia.

Keywords: Dynamic functional connectivity; Genetic risk; Precuneus; Schizophrenia; Sibling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Case-Control Studies
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging*
  • Male
  • Neural Pathways / diagnostic imaging*
  • Neural Pathways / pathology
  • Nonlinear Dynamics
  • Oxygen / blood
  • Rest
  • Schizophrenia / diagnostic imaging*
  • Siblings*
  • Statistics as Topic
  • Young Adult

Substances

  • Oxygen

Grants and funding