Resting‐state functional magnetic resonance imaging with independent component analysis for presurgical seizure onset zone localization: A systematic review and meta‐analysis

Abstract

Objective: One of the greatest challenges of achieving successful surgical outcomes in patients with epilepsy is the ability to properly localize the seizure onset zone (SOZ). Many techniques exist for localizing the SOZ, including intracranial electroencephalography, magnetoencephalography, and stereoelectroencephalography. Recently, resting-state functional magnetic resonance imaging (rs-fMRI) in conjunction with independent component analysis (ICA) has been utilized for presurgical planning of SOZ resection, with varying results. In this meta-analysis, we analyze the current role of rs-fMRI in identifying the SOZ for presurgical planning for patients with drug-resistant epilepsy. Specifically, we seek to demonstrate its current effectiveness compared to other methods of SOZ localization. Methods: A literature review was conducted using the PubMed, MEDLINE, and Embase databases up to May of 2020. A total of 253 articles were screened, and seven studies were chosen for analysis. Each study was analyzed for SOZ localization by ground truth, SOZ localization by rs-fMRI with ICA, principal component analysis, or intrinsic connectivity contrast, and outcomes of surgery. A meta-analysis was performed to analyze how ground truth compares to rs-fMRI in SOZ localization. Results: The odds ratio comparing ground truth to rs-fMRI was 2.63 (95% confidence interval = 0.66-10.56). Average concordance of rs-fMRI SOZ localization compared with ground truth localization across studies was 71.3%. Significance: In the hunt for less invasive presurgical planning for epilepsy surgery, rs-fMRI with ICA provides a promising avenue for future standard practice. Our preliminary results show no significant difference in surgical outcomes between traditional standards of SOZ localization and rs-fMRI with ICA. We believe that rs-fMRI could be a step forward in this search. Further investigation comparing rs-fMRI to traditional methods of SOZ localization should be conducted, with the hope of moving toward relying solely on noninvasive screening methods.

Association of Network Connectivity via Resting State Functional MRI with Consciousness, Mortality, and Outcomes in Neonatal Acute Brain Injury

“…Similarly, in children with DRE, findings by RS seemingly consistent with a seizure onset zone are acquired almost entirely during the interictal period and are thus thought to indicate ongoing abnormal network activity that occurs at sub-clinical seizure threshold. Ultimately, these findings have shown to be reliable to direct neurosurgical intervention leading to improved surgical outcomes ( Chakraborty et al, 2020;Boerwinkle et al, 2019a;Boerwinkle et al, 2017). However, being that this population does not have the diagnosis of DRE, the meaning of RS SOZ after ABI in those with largely resolved seizures may have more to do with the neuroplastic changes of the injury, rather than correlation with a resolved seizure or prediction of epileptogenicity.…”

“…In neonates with ABI, network pathology localization is not well-characterized and data-driven approaches, such as ICA may best be suited for localization of network pathology. ICA has level 1 evidence for diagnostic testing (OCEBM Levels of Evidence Working Group) in children and adults for characterizing normal and pathological networks in drug resistant epilepsy and improving outcomes (Chakraborty et al, 2020), however, method comparison may be of value.…”

“…RSN requires interpretation, prompting the blinded study design. Further means of minimizing bias by developing automated RSN categorization may help (Chakraborty et al, 2020;Griffanti et al, 2017;Griffanti et al, 2014).…”

Dynamic Resting State Motor Network Connectivity of Neurotypical Children, the Groundwork for Network-Guided Therapy in Childhood Movement Disorders

“…In children with drug resistant epilepsy, non-invasive means of informing the sEEG placement by resting-state functional MRI (rs-fMRI) localizes the seizure onset zone with 90% correlation with sEEG, improves surgical outcomes, and increases surgical candidacy, thus may similarly inform DBS placement in MD (Boerwinkle et al, 2019b; oerwinkle, Foldes, et al, 2018; Boerwinkle et al, 2020; Boerwinkle et al, 2017; Chakraborty et al, 2020).…”

Presurgical Evaluation of Epilepsy Using Resting-State MEG Functional Connectivity

“…Advances in neuroimaging have generated multimodal technologies to analyze the resting-state functional networks (Figure 1). Of these imaging modalities, functional magnetic resonance imaging (fMRI) has been widely employed to investigate the functional connectivity during the resting state (Biswal et al, 1995;Palacios et al, 2013;Tracy and Doucet, 2015;Chakraborty et al, 2020;Courtiol et al, 2020). However, fMRI is an indirect measure of neural activity with a delay that detects the changes in blood oxygenation using bloodoxygen-level-dependent (BOLD) contrast (Scarapicchia et al, 2017).…”