Functional neuroimaging abnormalities in idiopathic generalized epilepsy.
Magnetic resonance imaging (MRI) techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE) is characterized by bilateral synchronous spike-wave discharges on electroencephalography (EEG) but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray-white blurring, fractional anisotropy (FA) measures from diffusion tensor imaging (DTI) and fractional amplitude of low frequency fluctuations (fALFF) in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray-white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC) subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE.
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Megan L
ML
McGill
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Orrin
O
Devinsky
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Xiuyuan
X
Wang
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Brian T
BT
Quinn
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Heath
H
Pardoe
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Chad
C
Carlson
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Tracy
T
Butler
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Ruben
R
Kuzniecky
Comprehensive Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, NY 10016, USA.
Thomas
T
Thesen
D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D004829:Epilepsy, Generalized / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D017397:Prefrontal Cortex / Q000473:pathology / Q000503:physiopathology; D013788:Thalamus / Q000473:pathology / Q000503:physiopathology; D055815:Young Adult
DTI (diffusion tensor imaging); IGE (idiopathic generalized epilepsy); fALFF (fractional amplitude of low frequency fluctuations); quantitative morphometry