An EEG supports a seizure diagnosis but rarely settles it alone. A normal EEG does not rule out epilepsy, and an abnormal one does not by itself prove it. The diagnosis rests on the description of the episodes, with the EEG as supporting evidence.
An EEG supports a seizure diagnosis but rarely settles it alone. A normal EEG does not rule out epilepsy, and an abnormal one does not by itself prove it. The diagnosis rests on the description of the episodes, with the EEG as supporting evidence.
Epilepsy is diagnosed clinically. What the EEG adds is evidence about the electrical tendency underlying the episodes, and information about seizure type and where seizures may be starting, both of which influence which medication is chosen. It is a supporting investigation rather than the arbiter, which is why a neurologist will spend more of the appointment on what happened than on the tracing.
A routine EEG records a short window while you are awake and between episodes. Many people with epilepsy have entirely normal recordings in that window, because the abnormality is intermittent. So a normal result narrows nothing on its own. If the clinical suspicion is high and the routine study is normal, the next step is usually a longer recording: an ambulatory EEG runs for days and substantially raises the chance of capturing something.
Some abnormal-looking patterns occur in people who never have seizures, and other findings are non-specific, meaning they indicate something is different without saying what. Interictal discharges, the abnormal patterns seen between episodes, do support a diagnosis of epilepsy in the right clinical context, but the phrase in the right clinical context is doing real work in that sentence. Treating a tracing without a matching history is how people end up on anti-seizure medication they never needed.
Clinical Neurology Specialists has been physician-owned since 1998, when Leo Germin, M.D., FAANEM founded it. Five board-certified neurologists and four advanced practice providers see patients at the Las Vegas and Henderson offices, each with its own AANEM-accredited electrodiagnostic laboratory.
Clinical Neurology Specialists is an adult outpatient neurology practice for patients 18 and older. The practice performs no surgery and operates no imaging suite, infusion suite or interventional pain programme, and provides no emergency or inpatient care.
Physician-reviewed. Reviewed by the physicians of Clinical Neurology Specialists — board-certified neurologists, AANEM-accredited electrodiagnostic laboratories, physician-owned since 1998. Reviewed 1 August 2026. This article is general education for adults 18 and older and is not a substitute for a consultation.
Sources and further reading: MedlinePlus: epilepsy; MedlinePlus: electroencephalogram (EEG); American Academy of Neurology.
Adults 18 and older, at the Las Vegas and Henderson offices. Call 702-804-1212 or request an appointment online.