Article

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

Center for Quality of Aging, Vanderbilt University Medical Center, Department of Medicine, Division of Allergy, Vanderbilt University School of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
Critical care medicine (Impact Factor: 6.15). 05/2012; 40(7):2182-9. DOI: 10.1097/CCM.0b013e318250acdc
Source: PubMed

ABSTRACT Evidence is emerging that delirium duration is a predictor of long-term cognitive impairment in intensive care unit survivors. Relationships between 1) delirium duration and brain white matter integrity, and 2) white matter integrity and long-term cognitive impairment are poorly understood and could be explored using magnetic resonance imaging.
A two-center, prospective cohort study incorporating delirium monitoring, neuroimaging, and cognitive testing in intensive care unit survivors.
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. We examined associations between 1) delirium duration and fractional anisotropy and 2) fractional anisotropy and cognitive outcomes using linear regression adjusted for age and sepsis.
A total of 47 patients with a median age of 50 yrs completed the diffusion tensor imaging-magnetic resonance imaging protocol. Greater duration of delirium (3 vs. 0 days) 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 3 months 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 12 months.
In this pilot investigation, delirium duration in the intensive care unit was associated with white matter disruption at both discharge and 3 months. Similarly, white matter disruption was associated with worse cognitive scores up to 12 months later. This hypothesis-generating investigation may help design future studies to explore these complex relationships in greater depth.

1 Follower
 · 
187 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Survivors of critical illness frequently have severe and long-lasting cognitive impairments and psychiatric disorders, which adversely affect functional outcomes including return to work, and quality of life. While data regarding cognitive outcomes has increased over the last 15 years, neuroimaging data in medical and surgical critical populations is extremely limited. The abrupt development of new significant cognitive impairments after critical illness along with abnormalities on neuroimaging suggest that critical illness results in new acquired brain injury, similar to that observed in other acquired brain injuries. Abnormalities on neuroimaging including cortical and subcortical lesions, brain atrophy, and white matter hyperintensities (WMH) which occur in widely distributed brain regions. Patients admitted to neurorehabilitation who received critical care related to their primary diagnosis may have sustained neurological injury from the nonspecific effects of their critical illness and as demonstrated in this review, generalized, non-specific neuroimaging findings may be observed and quantified. Given the high prevalence rate of cognitive impairments in this population, neuroimaging is important to help elucidate neuropathology of critical illness acquired brain injury and may be beneficial in guiding rehabilitation outcomes in this population.
    Neurorehabilitation 01/2012; 31(3):311-8. DOI:10.3233/NRE-2012-0798 · 1.74 Impact Factor
  • Critical care medicine 07/2012; 40(7):2259-60. DOI:10.1097/CCM.0b013e318256b987 · 6.15 Impact Factor
  • Brain 09/2012; 135(Pt 9):2582-4. DOI:10.1093/brain/aws235 · 10.23 Impact Factor
Show more