Impaired Functional Connectivity and Language in Non-Symptomatic Localization-Related Epilepsy

Jacobus F.A. Jansen¹, Marielle C. Vlooswijk², H J. Majoie², Paul A. Hofman², Marc C. de Krom², Albert P. Aldenkamp², Walter H. Backes²

To investigate the neuronal mechanisms underlying neuropsychological language dysfunction, activation maps and functional connectivity networks were studied by fMRI of language. 34 patients with non-symptomatic localization-related epilepsy and 20 healthy controls were included for this study. They all underwent neuropsychological assessment of IQ, word fluency, and text reading. Additionally, fMRI was performed with a standard covert word generation and text reading paradigm. Functional connectivity analysis comprised cross-correlation of signal time-series of the characteristic and most strongly activated regions involved in the language tasks. A relation between reduced functional connectivity and performance on word fluency and text reading tests was demonstrated in the patients. Impaired performance on language assessment in epilepsy patients could be attributed to loss of functional connectivity in the language networks.