Why 24-Hour EEG Is Our New Standard

(And When a Routine EEG Still Makes Sense)

For decades, EEG testing has followed a fairly minimal standard. In many hospitals and outpatient facilities, a “routine EEG” is often as short as 20–30 minutes — just enough time to place electrodes, record briefly, and move on to the next patient.

While that model works for efficiency, it doesn’t always work for answers.

At our practice, we made a different decision early on.

Our routine EEGs are a minimum of one full hour.

And now, based on clinical data, patient outcomes, and current neurological science, we often recommend 24-hour EEG monitoring when symptoms warrant it.

Why Length Matters in EEG Testing

EEG is a snapshot of brain activity in time. The shorter the recording, the smaller the snapshot.

A 20–21 minute EEG may be enough to detect abnormalities in certain well-established epilepsy types — but for many patients, it simply isn’t long enough to capture meaningful data.

That’s why we don’t perform abbreviated studies.

Our 1-hour routine EEG allows time for:

• A more stable baseline

• Activation procedures

• Observation beyond a brief resting state

• Increased likelihood of detecting abnormalities

Even so, one hour still has limits.

When a Routine EEG Can Be Enough

There are specific epilepsy types where abnormal activity may appear quickly — even during a routine study.

These can include:

• Generalized epilepsies, where discharges are widespread

• Absence epilepsy, with classic spike-and-wave patterns

• Juvenile myoclonic epilepsy (JME)

• Certain frequent or well-established focal epilepsies

In these situations, a routine EEG — especially one that is a full hour — may provide answers right away. This is why routine EEGs still have a role and are appropriate for patients with a single event or when abnormalities are likely to be captured quickly.

Where routine EEGs Fall Short

Many neurological symptoms don’t happen on command.

Events may be:

• Infrequent

• Triggered by fatigue or stress

• Occurring only during sleep

• Unpredictable

If abnormal activity doesn’t occur during a brief recording window, the EEG may appear normal even when symptoms persist.

A normal short EEG does not always rule out an underlying condition.

Why We Now Encourage 24-Hour EEG Based on Data and Science

As EEG technology and clinical understanding have evolved, the data has been clear:

Longer monitoring increases diagnostic yield.

For patients with recurring symptoms or nocturnal events, a 24-hour EEG allows us to:

• Capture natural sleep cycles

• Evaluate brain activity across wake, rest, and sleep

• Identify abnormalities that may only occur overnight

• Correlate symptoms with EEG changes in real time

Many seizure types and abnormal discharges are more likely to occur during sleep, making overnight data critical — not optional.

This isn’t about doing more testing.

It’s about doing the right test, for the right patient, at the right time.

A More Thoughtful Standard of Care

• Many facilities perform EEGs as short as 20–30 minutes

• Our routine EEGs are a minimum of one hour

• We now recommend 24-hour EEG monitoring for patients with recurring symptoms or nighttime events

• This shift is guided by science, data, and real patient outcomes

We tailor EEG length based on symptom pattern, frequency, and timing, not convenience.

More context leads to clearer answers and clearer answers lead to Better Brain Health.