title: Interictal epileptic discharge correlates with global and frontal cognitive dysfunction in temporal lobe epilepsy.
abstract: Temporal lobe epilepsy (TLE) with hippocampal sclerosis has widespread effects on structural and functional connectivity and often entails cognitive dysfunction. EEG is mandatory to disentangle interactions in epileptic and physiological networks which underlie these cognitive comorbidities. Here, we examined how interictal epileptic discharges (IEDs) affect cognitive performance.
  
  
  
  Thirty-four patients (right TLE=17, left TLE=17) were examined with 24-hour video-EEG and a battery of neuropsychological tests to measure intelligence quotient and separate frontal and temporal lobe functions. Hippocampal segmentation of high-resolution T1-weighted imaging was performed with FreeSurfer. Partial correlations were used to compare the number and distribution of clinical interictal spikes and sharp waves with data from imagery and psychological tests.
  
  
  
  The number of IEDs was negatively correlated with executive functions, including verbal fluency and intelligence quotient (IQ). Interictal epileptic discharge affected cognitive function in patients with left and right TLE differentially, with verbal fluency strongly related to temporofrontal spiking. In contrast, IEDs had no clear effects on memory functions after corrections with partial correlations for age, age at disease onset, disease duration, and hippocampal volume.
  
  
  
  In patients with TLE of long duration, IED occurrence was strongly related to cognitive deficits, most pronounced for frontal lobe function. These data suggest that IEDs reflect dysfunctional brain circuitry and may serve as an independent biomarker for cognitive comorbidity.
authors: Epilepsy Unit, Pitié-Salpêtrière Hospital, APHP, Paris, France; Brain and Spine Institute, (Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, ICM), Paris, France; Rothschild Foundation, Paris, France. Electronic address: v.dinkelacker@gmail.com.
authors: Vera
authors: V
authors: Dinkelacker
authors: Epilepsy Unit, Pitié-Salpêtrière Hospital, APHP, Paris, France; Affiliated Teaching Hospital of Tsinghua University, Beijing, China.
authors: Xu
authors: X
authors: Xin
authors: Epilepsy Unit, Pitié-Salpêtrière Hospital, APHP, Paris, France.
authors: Michel
authors: M
authors: Baulac
authors: Epilepsy Unit, Pitié-Salpêtrière Hospital, APHP, Paris, France; Psitec Laboratory (EA 4072), University of Lille, France.
authors: Séverine
authors: S
authors: Samson
authors: Epilepsy Unit, Pitié-Salpêtrière Hospital, APHP, Paris, France; Brain and Spine Institute, (Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, ICM), Paris, France.
authors: Sophie
authors: S
authors: Dupont
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003071:Cognition / Q000502:physiology*; D060825:Cognitive Dysfunction / Q000503:physiopathology* / Q000523:psychology; D004569:Electroencephalography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology* / Q000523:psychology; D056344:Executive Function / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D013702:Temporal Lobe / Q000503:physiopathology*; D055815:Young Adult
keywords: Epilepsy; Executive function; Hippocampal sclerosis; Interictal activity; Neuropsychology