Jerk-locked back averaging and dipole source localization of magnetoencephalographic transients in a patient with epilepsia partialis continua

Electroencephalogr Clin Neurophysiol. 1997 Oct;103(4):440-4. doi: 10.1016/s0013-4694(97)00040-0.


In order to localize the generator site of epileptiform discharges, we applied the techniques of jerk-locked back averaging (JBA) of magnetoencephalographic (MEG) activities and dipole source localization in a patient with epilepsia partialis continua (EPC), who showed continuous, focal myoclonic jerks in the right arm. The myoclonic discharges in the right thenar muscle were used as a trigger pulse. JBA revealed consistent EEG and MEG transients that coincided consistently and constantly preceded the myoclonic jerks. The estimated dipoles of MEG were localized in a restricted area in the left precentral area, which closely correlated with the area of epileptic discharges recorded in electrocorticography. Therefore, JBA of MEG is considered to be a useful non-invasive method for localizing the epileptogenic area in EPC.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Cerebral Cortex / physiopathology
  • Electrocardiography
  • Electroencephalography
  • Electromyography
  • Epilepsies, Partial / physiopathology*
  • Humans
  • Magnetic Resonance Imaging
  • Magnetoencephalography / methods*
  • Male