title: Recent seizure activity alters motor organization in frontal lobe epilepsy as revealed by task-based fMRI.
abstract: OBJECTIVE
  Patients with frontal lobe epilepsy (FLE) commonly demonstrate motor impairments, suggesting that frontal lobe seizures affect motor function. However, the underlying mechanisms of these deficits are not known, nor has any study systematically examined motor organization in these patients. We therefore examined cortical motor organization in a group of adult patients with FLE, using task-based fMRI.
  
  
  METHODS
  Eleven right FLE patients, six left FLE patients, and ten control subjects underwent task-based fMRI. Two tasks were performed using the right and left hands separately, and both hands together. The first task was a finger-tapping task and the second task was a more complex coordination task. Functional MR data were compared between patient groups and controls. A laterality index of brain activation was also calculated between the epileptic and healthy hemisphere to determine hemispheric dominance during task performance to explore its relationship with a variety of patient-specific epilepsy factors.
  
  
  RESULTS
  Overall, right FLE patients demonstrated decreased BOLD activity in the epileptic hemisphere and increased BOLD activity in the healthy hemisphere compared to controls (p<0.05). The comparison of left FLE patients to controls provided less conclusive differences, possibly due to the low number of left FLE patients studied. Laterality indices of the coordination task were positively correlated to the number of months since the last seizure in both patient groups (right FLE: rs=0.779, left FLE: rs=0.943). Patients that had experienced a recent seizure relied more on the sensorimotor cortex of the healthy hemisphere during task performance, compared to those that were relatively seizure free (p<0.05).
  
  
  CONCLUSIONS
  Patients with FLE exhibited changes in motor BOLD activity that was dependent on the duration of seizure freedom. These results demonstrate the presence of seizure-related alteration of cortical motor organization in FLE, which may underlie the motor deficits seen in these patients.
authors: Department of Neuroscience, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Hotchkiss Brain Institute, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Seaman Family MR Research Center, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4. Electronic address: kwoodwar@ucalgary.ca.
authors: Kristine E
authors: KE
authors: Woodward
authors: Hotchkiss Brain Institute, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Seaman Family MR Research Center, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4. Electronic address: igaxiola@ucalgary.ca.
authors: Ismael
authors: I
authors: Gaxiola-Valdez
authors: Seaman Family MR Research Center, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4. Electronic address: dgmainpr@gmail.com.
authors: David
authors: D
authors: Mainprize
authors: Seaman Family MR Research Center, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4. Electronic address: mvgrossi@ucalgary.ca.
authors: Matthew
authors: M
authors: Grossi
authors: Department of Radiology, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Department of Psychiatry, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Hotchkiss Brain Institute, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Seaman Family MR Research Center, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4. Electronic address: goodyear@ucalgary.ca.
authors: Bradley G
authors: BG
authors: Goodyear
authors: Department of Neuroscience, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Department of Clinical Neuroscience, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Department of Radiology, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Hotchkiss Brain Institute, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4; Seaman Family MR Research Center, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4. Electronic address: pfederic@ucalgary.ca.
authors: Paolo
authors: P
authors: Federico
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D012640:Seizures / Q000175:diagnosis / Q000503:physiopathology*; D055815:Young Adult
keywords: BOLD; Connectivity; Frontal lobe epilepsy; Motor coordination; fMRI