EEG (Electroencephalogram)
A focused scan for Brain waves, Seizures, Epilepsy.
Overview
Examines Brain waves, Seizures, Epilepsy. Performed at an NABL-accredited Meridian Health centre with a same-day report and a free doctor review.
The full panel
3 areas across 1 groupEvery parameter, grouped by body system — no clicking to expand.
What this scan measures
The brain's electrical rhythms, recorded painlessly from electrodes placed on the scalp. It shows the background rhythm and its symmetry, and looks for the specific abnormal discharges — spikes and sharp waves — associated with a tendency to seizures. Activation procedures such as deep breathing, flashing lights and, where possible, sleep are used to bring out abnormalities that a quiet resting record can hide.
It is ordered after a first seizure to help classify the seizure type and estimate recurrence risk, in known epilepsy where the pattern is changing, in unexplained episodes of altered awareness, and in encephalopathy or coma to assess brain function.
Symptoms that lead to this scan
- A first seizure or convulsion
- Recurrent blank spells or episodes of unresponsiveness
- Unexplained jerking movements, especially in the morning
- Known epilepsy with a change in seizure pattern
- Unexplained confusion or altered consciousness
Understanding your results
A normal EEG does NOT exclude epilepsy — a routine recording captures only a short window of time, and many people with epilepsy have a normal trace between seizures, which is why a sleep-deprived or repeat study is sometimes requested. Conversely, minor non-specific abnormalities occur in people who have never had a seizure, so an abnormal EEG alone does not make the diagnosis. Epilepsy is diagnosed clinically, from the description of the events, with the EEG and MRI supporting classification and treatment choice.
Why the preparation matters
Wash your hair the night before or that morning and use no oil, gel, serum or conditioner — the electrodes need direct contact with clean scalp, and oil is the usual reason a recording has to be repeated. Eat normally and do not skip meals; low blood sugar alters the trace. If a sleep-deprived study has been requested, follow the exact instructions given, and arrange for someone to drive you. Take your usual medication unless your neurologist has specifically said otherwise — stopping anti-epileptic drugs to 'improve' the test can provoke a seizure and must never be done without instruction.
Neuro — safety and who should not be scanned
Full Neuro guideNo ionising radiation and no magnetic field. An EEG only records what your brain is already producing, and a nerve conduction study delivers pulses far below any level that could injure a nerve. There is nothing to recover from and no restriction afterwards. Two specific points are worth knowing. The flashing light used during an EEG can provoke a seizure in the small number of people with photosensitive epilepsy — that is a recognised, deliberately supervised part of the test, done with staff present who stop it immediately, and you should say beforehand if flashing lights have ever triggered an episode. And where the neurological workup includes an MRI, the whole of the MRI safety set applies to that scan, not to the electrical tests.
- Implants and metal, where the workup includes an MRI
- An EEG or nerve conduction study has no magnet, but a brain or spine MRI ordered alongside it does — and the magnet is always on. A cardiac pacemaker or defibrillator, any implanted electronic device, a ferromagnetic aneurysm clip or coil, a cochlear implant, a neurostimulator, a programmable shunt valve or a metallic foreign body in the eye must all be declared before that scan is booked. Bring the device card. The full screening list is on the MRI page and it is not a formality.
- Claustrophobia, or an inability to lie still
- This applies to the MRI part of a neurological workup rather than to the electrical tests, where you sit or lie on an open couch. Say so in advance: a wide-bore scanner, a different position, music, a companion in the room or medication arranged with your doctor all work better than an abandoned scan.
- Children, and sedation
- A young child who cannot stay still for an MRI, or cooperate with an EEG, may need sedation or a general anaesthetic, or a sleep-deprived protocol timed around a nap. That is arranged in advance with a paediatrician or anaesthetist, and the fasting instructions given for it must be followed exactly. Never plan a sedated study on the day.
- Implanted electrical devices, for a nerve conduction study
- Pacemakers, defibrillators and implanted stimulators need declaring before a nerve conduction study so that stimulation is kept away from the device and its leads and the study is done under the appropriate protocol. External cardiac pacing wires and indwelling central lines matter for the same reason. This is a matter of how the test is performed, not usually a reason to refuse it.
- Blood thinners, if a needle muscle study is planned
- A needle EMG puts a fine electrode into muscle, so warfarin, the newer oral anticoagulants, aspirin, other antiplatelet drugs, a known bleeding disorder or a low platelet count all need declaring in advance. Do not stop any of them yourself — the neurologist decides, and often the study goes ahead unchanged.
- Preparation that decides whether the test works at all
- For an EEG, come with clean, dry hair and no oil, gel, serum or spray — electrodes cannot make electrical contact through a product film, and the appointment is wasted. Recent scalp surgery, an open wound or an active scalp infection should be mentioned before booking. For a nerve conduction study, skip moisturiser and lotion on the arms and legs that day and keep the limbs warm on the way in, because cold skin genuinely slows conduction and can make a healthy nerve look abnormal. And never stop anti-epileptic medication before an EEG unless the neurologist who requested it has specifically told you to.
Who should consider this scan
- Anyone after a first unexplained seizure
- People with known epilepsy under review
- Anyone with recurrent unexplained blank or staring spells
- Patients with unexplained encephalopathy
- Children with suspected absence seizures
Conditions it helps detect
How it works
Patient stories
96% recommend“The phlebotomist arrived exactly on time and was gentle. My report came in five hours with a doctor’s note.”
“Booked at night, sample collected next morning. The parameter breakdown is genuinely thorough.”
“Loved the free doctor review — she walked me through my vitamin D and thyroid results clearly.”