The electroencephalogram in patients with epilepsy.

Area of Science:

• Neurology
• Clinical Neurophysiology

Background:

• Epilepsy diagnosis relies on clinical presentation and electrophysiological findings.
• Electroencephalography (EEG) is a key tool in evaluating suspected seizure disorders.

Purpose of the Study:

• To outline the utility and limitations of EEG in diagnosing seizure disorders.
• To emphasize the importance of interpreting EEG within the broader clinical context.

Main Methods:

• Review of EEG's role in diagnosis, localization, and differentiation of seizure types.
• Discussion of activating procedures (hyperventilation, photic stimulation, sleep recording) to enhance diagnostic yield.
• Consideration of epileptiform activity in the absence of seizures.

Main Results:

• EEG can confirm seizure disorder diagnosis, determine seizure type and origin, and distinguish epileptic from non-epileptic events.
• Focal slowing on EEG may indicate underlying pathology.
• A negative EEG does not exclude epilepsy; repeated or prolonged recordings may be necessary.

Conclusions:

• EEG is valuable but not solely diagnostic for epilepsy.
• Epileptiform activity on EEG can occur without a seizure disorder.
• EEG interpretation must be integrated with the overall clinical picture for accurate epilepsy diagnosis.