Abnormal Profiles of Local Functional Connectivity Proximal to Focal Cortical Dysplasias

• Published in: PloS one Vol. 11; no. 11; p. e0166022
• Main Authors: Besseling, René M. H., Jansen, Jacobus F. A., de Louw, Anton J. A., Vlooswijk, Mariëlle C. G., Hoeberigs, M. Christianne, Aldenkamp, Albert P., Backes, Walter H., Hofman, Paul A. M.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 18.11.2016; Public Library of Science (PLoS)
• Subjects: Aberration; Adult; Attention Deficit Hyperactivity Disorder; Biology and Life Sciences; Birth defects; Brain - pathology; Brain Mapping; Brain research; Case-Control Studies; Congenital defects; Connectome; Cortex; Dysplasia; Electroencephalography; Epilepsy; Female; Functional magnetic resonance imaging; Genetic disorders; Humans; Image Interpretation, Computer-Assisted; Image Processing, Computer-Assisted; Lesions; Magnetic Resonance Imaging - methods; Male; Males; Malformations of Cortical Development - diagnostic imaging; Malformations of Cortical Development - physiopathology; Medical imaging; Medicine and Health Sciences; Mental health; Neuroimaging; Neurology; Neurosciences; NMR; Nuclear magnetic resonance; Patients; Physical Sciences; Research and Analysis Methods; Rest; Structure-function relationships; Young Adult; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0166022

Focal cortical dysplasia (FCD) is a congenital malformation of cortical development that often leads to medically refractory epilepsy. Focal resection can be an effective treatment, but is challenging as the surgically relevant abnormality may exceed the MR-visible lesion. The aim of the current study is to develop methodology to characterize the profile of functional connectivity around FCDs using resting-state functional MRI and in the individual patient. The detection of aberrant connectivity may provide a means to more completely delineate the clinically relevant lesion. Fifteen FCD patients (age, mean±SD: 31±11 years; 11 males) and 16 matched healthy controls (35±9 years; 7 males) underwent structural and functional imaging at 3 Tesla. The cortical surface was reconstructed from the T1-weighted scan and the registered functional MRI data was spatially normalized to a common anatomical standard space employing the gyral pattern. Seed-based functional connectivity was determined in all subjects for all dysplasia locations. A single patient was excluded based on an aberrant FCD seed time series. Functional connectivity as a function of geodesic distance (along the cortical surface) was compared between the individual patients and the homotopic normative connectivity profiles derived from the controls. In 12/14 patients, aberrant profiles of functional connectivity were found, which demonstrated both hyper- and hypoconnectivity as well as combinations. Abnormal functional connectivity was typically found (also) beyond the lesion visible on structural MRI, while functional connectivity profiles not related to a lesion appeared normal in patients. This novel functional MRI technique has potential for delineating functionally aberrant from normal cortex beyond the structural lesion in FCD, which remains to be confirmed in future research.