title: Investigation of Multiple Frequency Ranges Using Discrete Wavelet Decomposition of Resting-State Functional Connectivity in Mild Traumatic Brain Injury Patients.
abstract: The aim of this study was to investigate if discrete wavelet decomposition provides additional insight into resting-state processes through the analysis of functional connectivity within specific frequency ranges within the default mode network (DMN) that may be affected by mild traumatic brain injury (mTBI). Participants included 32 mTBI patients (15 with postconcussive syndrome [PCS+] and 17 without [PCS-]). mTBI patients received resting-state functional magnetic resonance imaging (rs-fMRI) at acute (within 10 days of injury) and chronic (6 months postinjury) time points and were compared with 31 controls (healthy control [HC]). The wavelet decomposition divides the time series into multiple frequency ranges based on four scaling factors (SF1: 0.125-0.250 Hz, SF2: 0.060-0.125 Hz, SF3: 0.030-0.060 Hz, SF4: 0.015-0.030 Hz). Within each SF, wavelet connectivity matrices for nodes of the DMN were created for each group (HC, PCS+, PCS-), and bivariate measures of strength and diversity were calculated. The results demonstrate reduced strength of connectivity in PCS+ patients compared with PCS- patients within SF1 during both the acute and chronic stages of injury, as well as recovery of connectivity within SF1 across the two time points. Furthermore, the PCS- group demonstrated greater network strength compared with controls at both time points, suggesting a potential compensatory or protective mechanism in these patients. These findings stress the importance of investigating resting-state connectivity within multiple frequency ranges; however, many of our findings are within SF1, which may overlap with frequencies associated with cardiac and respiratory activities.
authors: 1 Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine , Baltimore, Maryland.|2 Magnetic Resonance Research Center (MRRC) , Baltimore, Maryland.
authors: Chandler
authors: C
authors: Sours
authors: 3 University of Maryland School of Medicine , Baltimore, Maryland.
authors: Haoxing
authors: H
authors: Chen
authors: 1 Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine , Baltimore, Maryland.|2 Magnetic Resonance Research Center (MRRC) , Baltimore, Maryland.
authors: Steven
authors: S
authors: Roys
authors: 1 Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine , Baltimore, Maryland.|2 Magnetic Resonance Research Center (MRRC) , Baltimore, Maryland.
authors: Jiachen
authors: J
authors: Zhuo
authors: 4 Department of Computer Science, Institute for Advanced Computer Studies, University of Maryland College Park , College Park, Maryland.
authors: Amitabh
authors: A
authors: Varshney
authors: 1 Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine , Baltimore, Maryland.|2 Magnetic Resonance Research Center (MRRC) , Baltimore, Maryland.
authors: Rao P
authors: RP
authors: Gullapalli
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001930:Brain Injuries / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D009434:Neural Pathways / Q000503:physiopathology*; D009483:Neuropsychological Tests
keywords: discrete wavelet; mild traumatic brain injury; postconcussive syndrome; resting state fMRI