Changes in Brain Resting-state Functional Connectivity Associated with Peripheral Nerve Block: A Pilot Study.
Limited information exists on the effects of temporary functional deafferentation (TFD) on brain activity after peripheral nerve block (PNB) in healthy humans. Increasingly, resting-state functional connectivity (RSFC) is being used to study brain activity and organization. The purpose of this study was to test the hypothesis that TFD through PNB will influence changes in RSFC plasticity in central sensorimotor functional brain networks in healthy human participants.



The authors achieved TFD using a supraclavicular PNB model with 10 healthy human participants undergoing functional connectivity magnetic resonance imaging before PNB, during active PNB, and during PNB recovery. RSFC differences among study conditions were determined by multiple-comparison-corrected (false discovery rate-corrected P value less than 0.05) random-effects, between-condition, and seed-to-voxel analyses using the left and right manual motor regions.



The results of this pilot study demonstrated disruption of interhemispheric left-to-right manual motor region RSFC (e.g., mean Fisher-transformed z [effect size] at pre-PNB 1.05 vs. 0.55 during PNB) but preservation of intrahemispheric RSFC of these regions during PNB. Additionally, there was increased RSFC between the left motor region of interest (PNB-affected area) and bilateral higher order visual cortex regions after clinical PNB resolution (e.g., Fisher z between left motor region of interest and right and left lingual gyrus regions during PNB, -0.1 and -0.6 vs. 0.22 and 0.18 after PNB resolution, respectively).



This pilot study provides evidence that PNB has features consistent with other models of deafferentation, making it a potentially useful approach to investigate brain plasticity. The findings provide insight into RSFC of sensorimotor functional brain networks during PNB and PNB recovery and support modulation of the sensory-motor integration feedback loop as a mechanism for explaining the behavioral correlates of peripherally induced TFD through PNB.
From the Department of Anesthesiology (M.S.M., K.C.N., S.M.K.), Geriatric Behavioral Health Division, Department of Psychiatry and Behavioral Sciences, (J.N.B., D.J.M.), Department of Radiology, (T.B.H.), and Duke Brain Imaging and Analysis Center, Duke University Medical Center, Durham, North Carolina (J.N.B., T.B.H., D.J.M.).
M Stephen
MS
Melton
Jeffrey N
JN
Browndyke
Todd B
TB
Harshbarger
David J
DJ
Madden
Karen C
KC
Nielsen
Stephen M
SM
Klein
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects*; D005260:Female; D007839:Functional Laterality / Q000187:drug effects; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000000981:diagnostic imaging / Q000187:drug effects; D009407:Nerve Block; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000187:drug effects*; D059906:Neuroimaging / Q000379:methods; D009473:Neuronal Plasticity / Q000187:drug effects; D010525:Peripheral Nerves / Q000187:drug effects*; D010865:Pilot Projects; D012146:Rest; D066191:Sensorimotor Cortex / Q000000981:diagnostic imaging / Q000187:drug effects; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000187:drug effects; D055815:Young Adult