EEG – Electroencephalogram Test – EEG Test – Neurology Services

What is EEG?

The EEG test studies the electrical activity in the brain to detect any sort of abnormalities. Electrodes with small metal discs and wires are used to connect patient’s scalp to the EEG system. The brain wave patterns are carefully tracked and recorded to assess the health or diseased status of the brain.

What happens during an EEG test?

  • You have to lied down and relax by reclining backwards.
  • The scalp is prepared by the technician and measurements are taken to find the exact positions for electrodes.
  • The patient’ scalp will be stuck with small metal discs and the wires from these discs are connected to the EEG system.
  • The movement of neurons in the brain produces electrical current.
  • EEG detects and records these pulses between 250 to 2000 times every second.
  • The EEG uses this recorded data to display graphs known as brain waves.
  • You will be asked by the technician to perform some actions such as breathing, looking at lights, closing and opening eyes, etc.,
  • The recorded data can be stored in digital form or printed on special paper for review and evaluation.


What are the advantages of EEG?

  • It is a non-invasive procedure although invasive electrodes may be used under specific conditions.
  • It is useful to detect brain disorders and prepare brainwave profiles for mental illness research.
  • Modern EEG systems use advanced algorithms and they can be transported easily.
  • EEG research and advanced systems makes it possible to monitor patient’s brain in a more convenient and comfortable manner.


What are the applications of EEG?

  • 70% of EEG applications are in diagnosing epilepsy or seizure or fits.
  • Sleep patterns and disorders in patients can also be studied.
  • Head injuries, brain tumors, brain stroke, encephalopathy or brain dysfunction can also be detected using EEG.
  • Amnesia, Dementia, and other aging related brain problems, etc.,
  • Brain activity of comatose patients or those who already had surgery.
  • Neuroscience research for relating brain activity with speech, vision, taste, smell, hearing, etc.,
  • EEG metrics are also used in Neurotechnology research to understand brain’s ability to handle workload, get engaged or focused, or distracted.


EEG Risks

  • There are no visible risks associated with a clinical EEG as it is non-invasive
  • The exam is also painless and safe without any side effects.
  • The trained technician can handle seizure patients if they react to test stimuli such as a flashing light.



  • You will have to sign a consent form after understanding the terms and conditions of EEG.
  • Consult the doctor regarding prescription drugs intake before the test.
  • Inform the technologist about your medical condition and the drugs you are taking for current diseases.
  • Do not take food, coffee, or other caffeinated drinks for a minimum of 8 hours before the test.
  • Wash the hair on the night before the exam, but avoid hair gel or other cosmetic sprays.
  • For EEG during sleep – Avoid sleeping the night before the test or a sedative may be given during the test to induce rest and sleep.


Post-EEG Instructions

  • You can begin routine daily work immediately after leaving the centre.
  • Patients who had EEG during sleep have to rest for the sedative to wear off.
  • Avoid driving and bring along a friend to take you back home.