The relationship between delirium duration, white matter integrity, and cognitive impairment in intensive care unit survivors as determined by diffusion tensor imaging: The VISIONS prospective cohort magnetic resonance imaging study
Critical Care Medicine, 06/29/2012
Morandi A et al. – In this pilot investigation, delirium duration in the intensive care unit was associated with white matter disruption at both discharge and 3months. Similarly, white matter disruption was associated with worse cognitive scores up to 12months later. This hypothesis–generating investigation may help design future studies to explore these complex relationships in greater depth.Methods
- Delirium was evaluated with the Confusion Assessment Method for the Intensive Care Unit and cognitive outcomes were tested at 3 and 12–month follow–up.
- Following the intensive care unit stay, fractional anisotropy, a measure of white matter integrity, was calculated quantitatively using diffusion tensor imaging with a 3–T magnetic resonance imaging scanner at hospital discharge and 3–month follow–up.
- The authors examined associations between delirium duration and fractional anisotropy and fractional anisotropy and cognitive outcomes using linear regression adjusted for age and sepsis.
- A total of 47 patients with a median age of 50yrs completed the diffusion tensor imaging–magnetic resonance imaging protocol.
- Greater duration of delirium (3 vs. 0days) was associated with lower fractional anisotropy (i.e., reduced fractional anisotropy=white matter disruption) in the genu (–0.02; p=.04) and splenium (–0.01; p=.02) of the corpus callosum and anterior limb of the internal capsule (–0.02; p=.01) at hospital discharge.
- These associations persisted at 3months for the genu (–0.02; p=.02) and splenium (–0.01; p=.004).
- Lower fractional anisotropy in the anterior limb of internal capsule at discharge and in genu of corpus callosum at three months was associated with worse cognitive scores at 3 and 12months.