PMID- 18318414
OWN - NLM
STAT- MEDLINE
DCOM- 20080410
LR  - 20170214
IS  - 1550-0594 (Print)
IS  - 1550-0594 (Linking)
VI  - 39
IP  - 1
DP  - 2008 Jan
TI  - EEG infraslow activity in absence and partial seizures.
PG  - 12-9
AB  - It is currently assumed that for recording of infraslow activity (ISA) DC-coupled 
      amplifiers are required. This report will demonstrate that this may not be the 
      case and presents some data about its potential clinical usefulness. Archived 
      EEGs of 29 seizures from 6 children with absence attacks, accompanied by 3 Hz 
      classical spike-wave discharges (SW), were compared with 20 partial seizures from 
      10 adult patients. The data from the children were acquired on a Bio-logic 
      system, those from the adults on a Grass-Telefactor instrument. In the children 
      the original 30-minute routine EEG was used while in the adults stored 
      videomonitored data were excerpted to provide 20-minute segments which included 
      the preictal, ictal and postictal state. All data were analyzed with the BESA 
      software package. The seizures were evaluated separately on conventional filter 
      settings, full band of 0.01-to the upper limit of the instrument, and 0.01-0.1 Hz 
      (infraslow activity, ISA). Filter settings of 0.01-0.1 Hz provided a better 
      assessment of ISA than when the full band was evaluated. Absence seizures showed 
      bilateral essentially synchronous ISA with a negative positive sequence in the 
      frontal areas and opposite polarity in the posterior head regions. In partial 
      seizures when seizure onset was clearly lateralizeable from conventional 
      frequency settings ISA corresponded to that hemisphere, but the electrode 
      position could be displaced to a neighboring one from the one which was maximally 
      involved on conventional settings. Topographic analysis showed two types of ISA: 
      one with focal spread only and the other where there was in addition an element 
      of synchrony especially in the frontal areas. It is concluded that ISA can be 
      recovered from conventional EEG recordings and may be helpful not only in 
      determining the area(s) of seizure onset but can also differentiate truly focal 
      seizures from those where an additional generalized seizure tendency is present. 
      This is likely to be important when epilepsy surgery is performed in absence of a 
      demonstrable structural lesion.
FAU - Rodin, E
AU  - Rodin E
AD  - Department of Neurology, University of Utah, Salt Lake City, Utah, USA. 
      erodin@pcu.net
FAU - Constantino, T
AU  - Constantino T
FAU - van Orman, C
AU  - van Orman C
FAU - House, P
AU  - House P
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Clin EEG Neurosci
JT  - Clinical EEG and neuroscience
JID - 101213033
SB  - IM
MH  - Adult
MH  - Case-Control Studies
MH  - Child
MH  - Child, Preschool
MH  - *Electroencephalography
MH  - Epilepsies, Partial/*physiopathology
MH  - Epilepsy, Absence/*physiopathology
MH  - Female
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Photic Stimulation
MH  - Seizures/*physiopathology
EDAT- 2008/03/06 09:00
MHDA- 2008/04/11 09:00
CRDT- 2008/03/06 09:00
PHST- 2008/03/06 09:00 [pubmed]
PHST- 2008/04/11 09:00 [medline]
PHST- 2008/03/06 09:00 [entrez]
AID - 10.1177/155005940803900108 [doi]
PST - ppublish
SO  - Clin EEG Neurosci. 2008 Jan;39(1):12-9. doi: 10.1177/155005940803900108.