Molecular and diffusion tensor imaging of epileptic networks.
Several studies have shown that seizure-induced cellular and molecular changes associated with chronic epilepsy can lead to functional and structural alterations in the brain. Chronic epilepsy, when medically refractory, may be associated with an expansion of the epileptic circuitry to involve complex interactions between cortical and subcortical neuroanatomical substrates. Progress in neuroimaging has led not only to successful identification of epileptic foci for surgical resection, but also to an improved understanding of the functional and microstructural changes in long-standing epilepsy. Positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) are all promising tools that can assist in elucidating the underlying pathophysiology in chronic epilepsy. Studies using PET scanning have demonstrated dynamic changes associated with the evolution from acute to chronic intractable epilepsy. Among these changes are data to support the existence of secondary epileptogenesis in humans. MRI with DTI is a powerful tool which has the ability to characterize microstructural abnormalities in epileptic foci, and to demonstrate the white matter fibers and tracts participating in the epileptic network. In this review, we illustrate how PET and DTI can be applied to depict the functional and microstructural alterations associated with chronic epilepsy.
Luat
Aimee F
AF
Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Wayne State University, Detroit, Michigan, USA.
Chugani
Harry T
HT
D000293:Adolescent; D000367:Age Factors; D001931:Brain Mapping / Q000379:methods*; D002250:Carbon Radioisotopes; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002648:Child; D002908:Chronic Disease; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004827:Epilepsy / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D005442:Flumazenil; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology; D049268:Positron-Emission Tomography / Q000379:methods; D011300:Preoperative Care
D002250:Carbon Radioisotopes; D019788:Fluorodeoxyglucose F18; D005442:Flumazenil