TY - JOUR
T1 - Default Mode Network Perfusion in Aneurysmal Subarachnoid Hemorrhage
AU - Nelson, Sarah
AU - Edlow, Brian L.
AU - Wu, Ona
AU - Rosenthal, Eric S.
AU - Westover, M. Brandon
AU - Rordorf, Guy
N1 - Funding Information:
Dr. Westover is supported by the following grants: NIH-NINDS 1K23NS090900, The Rappaport Foundation, and the Andrew David Heitman Neuroendovascular Research Fund. Drs. Nelson, Edlow, Wu, Rosenthal, and Rordorf have no conflict of interest.
Funding Information:
This work was conducted with support from Harvard Catalyst and financial contributions from Harvard University and its affiliated academic healthcare centers. The content is solely the responsibility of the authors and does not necessarily represent the official views of Harvard Catalyst, Harvard University and its affiliated academic healthcare centers, or the National Institutes of Health. The authors also acknowledge Ms. Camille A. Spencer, who assisted with the statistical analyses.
Publisher Copyright:
© 2016, Springer Science+Business Media New York.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Background: The etiology of altered consciousness in patients with high-grade aneurysmal subarachnoid hemorrhage (SAH) is not thoroughly understood. We hypothesized that decreased cerebral blood flow (CBF) in brain regions critical to consciousness may contribute. Methods: We retrospectively evaluated arterial-spin labeled (ASL) perfusion magnetic resonance imaging (MRI) measurements of CBF in 12 patients with aneurysmal SAH admitted to our neurocritical care unit. CBF values were analyzed within gray matter nodes of the default mode network (DMN), whose functional integrity has been shown to be necessary for consciousness. DMN nodes studied were the bilateral medial prefrontal cortices, thalami, and posterior cingulate cortices. Correlations between nodal CBF and admission Glasgow Coma Scale (GCS) score, admission Hunt and Hess (HH) class, and GCS score at the time of MRI (MRI GCS) were tested. Results: Spearman’s correlation coefficients were not significant when comparing admission GCS, admission HH, and MRI GCS versus nodal CBF (p > 0.05). However, inter-rater reliability for nodal CBF was high (r = 0.71, p = 0.01). Conclusions: In this retrospective pilot study, we did not identify significant correlations between CBF and admission GCS, admission HH class, or MRI GCS for any DMN node. Potential explanations for these findings include small sample size, ASL data acquisition at variable times after SAH onset, and CBF analysis in DMN nodes that may not reflect the functional integrity of the entire network. High inter-rater reliability suggests ASL measurements of CBF within DMN nodes are reproducible. Larger prospective studies are needed to elucidate whether decreased cerebral perfusion contributes to altered consciousness in SAH.
AB - Background: The etiology of altered consciousness in patients with high-grade aneurysmal subarachnoid hemorrhage (SAH) is not thoroughly understood. We hypothesized that decreased cerebral blood flow (CBF) in brain regions critical to consciousness may contribute. Methods: We retrospectively evaluated arterial-spin labeled (ASL) perfusion magnetic resonance imaging (MRI) measurements of CBF in 12 patients with aneurysmal SAH admitted to our neurocritical care unit. CBF values were analyzed within gray matter nodes of the default mode network (DMN), whose functional integrity has been shown to be necessary for consciousness. DMN nodes studied were the bilateral medial prefrontal cortices, thalami, and posterior cingulate cortices. Correlations between nodal CBF and admission Glasgow Coma Scale (GCS) score, admission Hunt and Hess (HH) class, and GCS score at the time of MRI (MRI GCS) were tested. Results: Spearman’s correlation coefficients were not significant when comparing admission GCS, admission HH, and MRI GCS versus nodal CBF (p > 0.05). However, inter-rater reliability for nodal CBF was high (r = 0.71, p = 0.01). Conclusions: In this retrospective pilot study, we did not identify significant correlations between CBF and admission GCS, admission HH class, or MRI GCS for any DMN node. Potential explanations for these findings include small sample size, ASL data acquisition at variable times after SAH onset, and CBF analysis in DMN nodes that may not reflect the functional integrity of the entire network. High inter-rater reliability suggests ASL measurements of CBF within DMN nodes are reproducible. Larger prospective studies are needed to elucidate whether decreased cerebral perfusion contributes to altered consciousness in SAH.
KW - Arterial-spin labeling (ASL)
KW - Cerebral blood flow
KW - Default mode network
KW - Disorders of consciousness
KW - Magnetic resonance imaging
KW - Subarachnoid hemorrhage
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U2 - 10.1007/s12028-016-0244-z
DO - 10.1007/s12028-016-0244-z
M3 - Article
C2 - 26800697
AN - SCOPUS:84955304635
VL - 25
SP - 237
EP - 242
JO - Neurocritical Care
JF - Neurocritical Care
SN - 1541-6933
IS - 2
ER -