RT Journal Article
SR Electronic
T1 Efficacy Assessment of Cerebral Perfusion Augmentation through Functional Connectivity in an Acute Canine Stroke Model
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1214
OP 1219
DO 10.3174/ajnr.A8320
VO 45
IS 9
A1 Warioba, Chisondi S.
A1 Liu, Mira
A1 Peñano, Sagada
A1 Carroll, Timothy J.
A1 Foxley, Sean
A1 Christoforidis, Gregory
YR 2024
UL http://www.ajnr.org/content/45/9/1214.abstract
AB BACKGROUND AND PURPOSE: Ischemic stroke disrupts functional connectivity within the brain's resting-state networks (RSNs), impacting recovery. This study evaluates the effects of norepinephrine and hydralazine (NEH), a cerebral perfusion augmentation therapy, on RSN integrity in a hyperacute canine stroke model.MATERIALS AND METHODS: Fifteen adult purpose-bred mongrel canines, divided into treatment and control (natural history) groups, underwent endovascular induction of acute middle cerebral artery occlusion (MCAO). Postocclusion, the treatment group received intra-arterial norepinephrine (0.1–1.52 µg/kg/min, adjusted for 25–45 mm Hg above baseline mean arterial pressure) and hydralazine (20 mg). Resting-state fMRI (rs-fMRI) data were acquired with a 3T scanner by using a blood oxygen level dependent-EPI sequence (TR/TE = 1400 ms/20 ms, 2.5 mm slices, 300 temporal positions). Preprocessing included motion correction, spatial smoothing (2.5 mm full width at half maximum), and high-pass filtering (0.01 Hz cutoff). Functional connectivity within RSNs were analyzed through group-level independent component analysis and weighted whole-brain ROI-to-ROI connectome, pre- and post-MCAO.RESULTS: NEH therapy significantly maintained connectivity post-MCAO in the higher-order visual and parietal RSNs, as evidenced by thresholded statistical mapping (threshold-free cluster enhancement Pcorr > .95). However, this preservation was network-dependent, with no significant (Pcorr < .95) changes in the primary visual and sensorimotor networks.CONCLUSIONS: NEH demonstrates potential as a proof-of-concept therapy for maintaining RSN functional connectivity after ischemic stroke, emphasizing the therapeutic promise of perfusion augmentation. These insights reinforce the role of functional connectivity as a measurable end point for stroke intervention efficacy, suggesting clinical translatability for patients with insufficient collateral circulation.FWEfamily-wise errorICAindependent component analysisMCAOmiddle cerebral artery occlusionNEHnorepinephrine and hydralaziners-fMRIresting-state fMRIRSNresting-state networkTFCEthreshold-free cluster enhancement