title: Young patients with focal seizures may have the primary motor area for the hand in the postcentral gyrus.
abstract: OBJECTIVE
  We determined whether the primary motor hand area was most frequently located in the precentral gyrus in young patients with intractable focal seizures.
  
  
  METHODS
  Sixty-five patients with focal seizures aged between 5 months and 20 years who underwent a two-stage epilepsy surgery using chronic subdural-EEG monitoring were studied. Pairs of subdural electrodes were electrically stimulated, and the brain region with contralateral hand movement induced by the lowest-intense stimulus was defined as the primary motor hand area.
  
  
  RESULTS
  Contralateral hand movement was induced without afterdischarges in 50 children but not in the remaining 15 children. The unpaired t-test revealed that failure to induce contralateral hand motor movement was associated with younger age of subjects. Among the 50 patients with a positive motor response, the primary motor hand area was confined to the precentral gyrus in 9 patients, confined to the postcentral gyrus in 24, and located in both the pre- and post-central gyri in the remaining 17. The McNemar's test revealed that the observed frequency of 24 patients showing the primary motor hand area confined to the postcentral gyrus was larger than chance frequency. Logistic regression analysis failed to demonstrate that the observation of the primary motor hand area confined to the postcentral gyrus was associated with the age, the presence of dysplastic lesion or the seizure onset involving the frontal lobe.
  
  
  CONCLUSIONS
  Our study failed to support the traditionally-accepted notion that the primary motor hand area is most frequently located in the precentral gyrus but rather demonstrated that a substantial proportion of young patients had the primary motor hand area in the postcentral gyrus.
authors.affiliation: Department of Pediatrics, Children's Hospital of Michigan, Wayne State University, Detroit, MI 48201, USA.
authors.forename: Ateeq
authors.initials: A
authors.lastname: Haseeb
authors.forename: Eishi
authors.initials: E
authors.lastname: Asano
authors.forename: Csaba
authors.initials: C
authors.lastname: Juhász
authors.forename: Aashit
authors.initials: A
authors.lastname: Shah
authors.forename: Sandeep
authors.initials: S
authors.lastname: Sood
authors.forename: Harry T
authors.initials: HT
authors.lastname: Chugani
mesh_terms: D002540:Cerebral Cortex / Q000503:physiopathology; D002648:Child; D004558:Electric Stimulation; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000503:physiopathology*; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D006225:Hand / Q000294:innervation*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008032:Limbic System / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D012984:Software