SEEG

Stereo‑EEG

What is an SEEG examination?

SEEG (stereo‑EEG) is an invasive epilepsy investigation in which thin intracerebral electrodes are placed inside the brain.
This is only done when earlier, non‑invasive tests (such as MRI, PET, SPECT/SISCOM, or video‑EEG) do not yet provide sufficient clarity about where the epilepsy originates.

The purpose of SEEG is to identify the epileptogenic zone with great precision, so the team can determine whether epilepsy surgery is possible and meaningful.

Careful preparation

Several specialists are involved in planning a SEEG procedure, including neurosurgeons, epileptologists and neuroradiologists.

The electrode trajectories are carefully planned using advanced neuroimaging and computer‑based navigation.
The plan is fully tailored to your child’s brain, ensuring that electrodes are placed safely and accurately.

The operation

The procedure is performed under general anaesthesia. Your child sleeps deeply and feels nothing.
The neurosurgeon places the thin electrodes through small openings in the skull, positioning them precisely in the brain.
Afterwards, your child is admitted to a monitoring unit for observation and further recording.

Hospitalisation typically lasts 1 to 2 weeks, depending on how much information is needed.

The registration phase: what happens next?

Once the electrodes are in place, a period of continuous EEG recording begins.

During this phase:

spontaneous seizures are recorded, and sometimes
seizures are safely and carefully induced (for example, by temporarily reducing medication, only if medically justified).

Because the electrodes measure directly inside the brain, the doctors can see with great precision:

where seizures begin,
how they spread,
and which brain regions are involved.

Your child is monitored 24/7, both clinically and via video and EEG.
Parents may remain with their child, except in specific medical situations where this is not possible. The team will always inform you clearly.

Why SEEG can be important

Information from SEEG is essential to determine:

whether epilepsy surgery is an option,
which part of the brain could be safely treated,
and which surgical strategy would offer the best and safest outcome.

SEEG is only used when truly necessary, but it can provide crucial insights into the epilepsy and possible treatment options.

After the examination

When enough information has been collected:

the electrodes are removed during a short procedure,
your child gradually recovers,
and all collected data are discussed within the multidisciplinary epilepsy team.

You will then receive extensive feedback about the findings and the possible next steps in treatment.