Role and limitations of routine and ambulatory scalp electroencephalography in diagnosing and managing seizures.
The scalp electroencephalogram (EEG) is the cornerstone in the diagnosis and treatment of seizure disorders. The EEG, with its excellent temporal resolution, provides a direct measurement of cortical electrophysiology, revealing, for example, the presence of interictal epileptiform discharges that identify regions of an epileptogenic brain. We define the EEG characteristics of focal and generalized epileptiform discharges and provide evidence for their varying diagnostic importance in different patient populations. Identification of nonepileptiform EEG transients, such as wicket waves, small sharp spikes,rhythmic temporal theta activity, and 14- and 6-Hz positive bursts, that can be confused for epileptiform transients is emphasized. A final point is that the clinician must interpret EEG findings within the overall clinical context.
Worrell
Gregory A
GA
Department of Neurology, Mayo Clinic, Rochester, Minn 55905, USA.
Lagerlund
Terrence D
TD
Buchhalter
Jeffrey R
JR
D000513:Alpha Rhythm; D001611:Beta Rhythm; D001921:Brain / Q000503:physiopathology; D003700:Delta Rhythm; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods / Q000592:standards; D004827:Epilepsy / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D018670:Monitoring, Ambulatory; D011237:Predictive Value of Tests; D012640:Seizures / Q000175:diagnosis / Q000503:physiopathology*; D012894:Sleep Stages