top of page
  • Dr Ashleigh Bhanjan

The EEG, in Epilepsy, and Neurological Practice

Updated: Feb 5

An electroencephalogram (EEG) is a test that measures electrical activity in the brain using small, metal discs (electrodes) attached to the scalp.

EEG is an essential tool that studies the brain's electrical activity and remains an essential paraclinical tool for seizure evaluation.

EEG can also play a role in diagnosing other brain disorders.


Here are some clinical indications of EEG :

  • Seizure disorders : EEG is used to evaluate seizures and epilepsy.

It can help diagnose the type of seizure, determine the location of the seizure focus, and monitor the effectiveness of treatment.

  • Brain injury : EEG can help diagnose brain damage from head injury, stroke, or other conditions that affect blood flow to the brain.

  • Sleep disorders : EEG can help diagnose sleep disorders such as sleep apnea, narcolepsy, and insomnia.

  • Encephalopathy : EEG can help diagnose encephalopathy, a condition that causes confusion, memory loss, and other cognitive problems.

Normal EEG recording

EEG demontrating generalized cerebral slowing (encephalopathy)


Who performs the EEG ?

EEG is performed by an EEG technician/technologist, who is a trained professional with appropriate undergraduate education and training. They undergo rigorous training and certification process.

Once a study is completed, the recordings are reviewed, and a report is generated by the Neurologist who undergoes additional subspecialty training in EEG/epilepsy

However, EEG can be a useful tool in predicting clinical outcomes in patients with disorders of consciousness after severe acquired brain injury.

EEG continues to play a central role in the diagnosis and management of patients with seizure disorders.


The EEG, and Epilepsy

Here are some ways EEG is used in the diagnosis and management of epilepsy

  • Diagnosis of epilepsy : EEG is used to diagnose epilepsy by detecting changes in the typical pattern of brain waves, even when a person is not having a seizure. EEG helps determine seizure type and epilepsy syndrome in patients with epilepsy, and thereby choice of antiepileptic medication and prediction of prognosis.

The recently published National Institute for Clinical Excellence (NICE) guidelines for diagnosis and management of the epilepsies in adults and children recommend that an EEG should be performed to support a diagnosis of epilepsy in adults in whom the clinical history suggests the seizure is likely to be epileptic in origin.

  • Localization of seizure focus : EEG can help determine the location of the seizure focus in the brain, which is important for surgical planning. Once identified, that location is fitted onto an MRI scan of the brain.

  • Monitoring of treatment: EEG can be used to monitor the effectiveness of treatment for epilepsy. Your Neurologist may monitor you on video during an EEG to detect and record any seizures you experience.

  • Classification of epilepsy : EEG helps determine the type of epilepsy a person has, which is important for choosing the right treatment

EEG demonstrating continous seizure activity

The diagnostic accuracy of EEG varies depending on the condition being evaluated.

EEG is the only available investigation for recording and evaluating the paroxysmal discharges of cerebral neurons causing seizures
EEG is an integral part of the diagnostic process in epilepsies and should not be underrated.


How long does an EEG test take and is it painful ?

  • Duration: A routine EEG recording usually takes from 20 to 60 minutes to complete.

Sometimes, a sleep recording is also required, which can take longer. Long-term EEG tests can last anywhere from 3 days to as long as 10 days, depending on what your doctor recommends.

  • Pain : An EEG test is a completely painless procedure.

The electrodes don't transmit any sensations, and no electricity is put into your body while it's carried out. You will be asked to lie quietly to avoid any electrical interference from muscle contractions, and sometimes you may be asked to open and close your eyes and to breathe heavily. Lights may be flashed before your eyes, but this does not cause any pain.


What should I wear for an EEG test ?

When preparing for an EEG test, it is recommended to wear comfortable clothing.

It is also recommended to AVOID using sprays, gels, or oils on your hair before the test, and to avoid braids or intricate hair designs.

You can wear jewelry, but large or dangling earrings could get in the way of the test, depending on where the electrodes are placed.



Contact us, for your EEG booking now !


bottom of page