MRI default mode network connectivity is associated with functional outcome after cardiopulmonary arrest.
BACKGROUND
We hypothesized that the degree of preserved functional connectivity within the DMN during the first week after cardiopulmonary arrest (CPA) would be associated with functional outcome at hospital discharge.


METHODS
Initially comatose CPA survivors with indeterminate prognosis at 72 h were enrolled. Seventeen CPA subjects between 4 and 7 days after CPA and 17 matched controls were studied with task-free fMRI. Independent component analysis was performed to delineate the DMN. Connectivity strength in the DMN was compared between CPA subjects and controls, as well as between CPA subjects with good outcome (discharge Cerebral Performance Category or CPC 1-2) and those with bad outcome (CPC 3-5). The relationship between connectivity strength in the posterior cingulate cortex (PCC) and precuneus (PC) within the DMN with discharge CPC was evaluated using linear regression.


RESULTS
Compared to controls, CPA subjects had significantly lower connectivity strength in subregions of the DMN, the PCC and PC (p < 0.0001). Furthermore, connectivity strength in the PCC and PC was greater in CPA subjects with good outcome (n = 8) than those with bad outcome (n = 9) (p < 0.003). Among CPA subjects, the connectivity strength in the PCC and PC showed strong linear correlations with the discharge CPC (p < 0.005).


CONCLUSIONS
Among initially comatose CPA survivors with indeterminate prognosis, task-free fMRI demonstrated graded disruption of DMN connectivity, especially in those with bad outcomes. If confirmed, connectivity strength in the PC/PCC may provide a clinically useful prognostic marker for functional recovery after CPA.
The Queen's Medical Center, Neuroscience Institute, QET5, 1301 Punchbowl Street, Honolulu, HI, 96813, USA, mkoenig95@gmail.com.
Matthew A
MA
Koenig
John L
JL
Holt
Thomas
T
Ernst
Steven D
SD
Buchthal
Kazuma
K
Nakagawa
Victor A
VA
Stenger
Linda
L
Chang
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation; D003128:Coma / Q000209:etiology* / Q000503:physiopathology*; D063132:Connectome / Q000379:methods*; D005260:Female; D006323:Heart Arrest / Q000150:complications*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D011237:Predictive Value of Tests; D011379:Prognosis; D020127:Recovery of Function / Q000502:physiology*; D017741:Survivors; D055815:Young Adult