RT Book, Section
A1 Chung, Steve S.
A1 Horne, Kent
A2 Sirven, Joseph I.
A2 Stern, John M.
SR Print(0)
ID 1103049178
T1 Secondarily Generalized Seizures
T2 Atlas of Video-EEG Monitoring
YR 2011
FD 2011
PB McGraw-Hill Education
PP New York, NY
SN 9780071597425
LK neurology.mhmedical.com/content.aspx?aid=1103049178
RD 2024/04/25
AB In  clinical  practice,  epileptic  seizures  with  focal  onset  and  subsequent  generalized  motor  involvement  are  referred  to  as  secondarily  generalized  seizures.1,2  However,  generalized  motor  manifestations  do  not  necessarily  imply  that  the  entire  or  even  bilateral  cerebral  cortex  is  producing  the  epileptic  discharges.3  Focal  seizures  arising  from  the  supplementary  motor  cortex  or  basal  ganglia  also  can  produce  clinical  signs  of  generalized  motor  activity.4  Conversely,  bilateral  and  widely  spread  ictal  electroencephalographic  (EEG)  patterns  can  be  found  in  patients  with  minimal  or  subtle  motor  activity  during  a  secondarily  generalized  seizure  (Case  11-1).5  Thus,  the  operational  definition  of  secondary  generalization  in  the  era  of  video-EEG  monitoring  (VEM)  should  be  focal  onset  of  an  epileptic  seizure  with  generalized  or  bilateral  ictal  electrographic  propagation.6  According  to  the  classification  by  the  International  League  Against  Epilepsy  (ILAE),  there  are  three  different  types  of  secondarily  generalized  seizures:  tonic-clonic  seizures,  absence  seizures,  and  epileptic  spasms  (Table  11-1).1,7,8  Differences  in  clinical  presentation  and  EEG  findings  of  these  seizure  types  are  compared  in  Table  11-2.  Although  partial  onset  seizures  do  not  commonly  progress  to  secondarily  generalized  seizures,  more  than  60%  of  patients  with  partial  seizures  may  experience  tonic-clonic  seizures.9  Not  all  secondarily  generalized  convulsions  progress  from  complex  partial  seizures,  and  up  to  20  to25%  of  them  are  directly  evolved  from  simple  partial  seizures,  which  suggests  multiple  cortical  and  subcortical  routes  of  spread  are  possible  for  secondary  generalization.10