EEG Test in Ranchi
Electroencephalogram (EEG) — a painless, non-invasive test recording brain electrical activity — performed and interpreted by Dr. Yuvraj Lahre, DM Neurology (AIIMS), at Neurovision Clinic.
What is EEG (Electroencephalogram)?
An EEG (electroencephalogram) is a non-invasive diagnostic test that records the electrical activity of the brain. Small metal discs called electrodes are placed on the scalp using a conductive paste. These electrodes detect the tiny electrical impulses generated by brain cells (neurons) as they communicate. The signals are amplified and recorded as wavy lines on a computer, creating a real-time map of brain activity. EEG is one of the most important tools in neurology for diagnosing epilepsy and seizure disorders, but it also provides valuable information about sleep disorders, brain infections, encephalopathy (brain dysfunction), and altered states of consciousness.
Why is EEG (Electroencephalogram) Done?
- •Diagnose epilepsy and classify seizure types based on characteristic brain wave patterns
- •Evaluate unexplained episodes of confusion, staring spells, or loss of awareness
- •Assess sleep disorders including sleep apnea-related brain activity changes
- •Monitor brain function in patients with encephalopathy, coma, or altered consciousness
- •Evaluate brain involvement in metabolic disorders, infections (encephalitis), or degenerative conditions
- •Determine brain death in critically ill patients
- •Differentiate between epileptic seizures and non-epileptic (psychogenic) events
How EEG (Electroencephalogram) is Performed
Preparation
You'll be seated comfortably or lie down. A technician measures your head and marks electrode positions. Your scalp is gently cleaned at each spot.
Electrode Placement
20–25 small electrodes are attached to your scalp using a water-soluble conductive paste. The process takes about 20–30 minutes and is completely painless.
Recording
You'll be asked to relax with your eyes closed. The recording typically lasts 20–40 minutes. You may be asked to open/close your eyes, breathe deeply (hyperventilate), or look at a flashing light (photic stimulation) — these are standard activation procedures that help reveal abnormalities.
Sleep Recording (if needed)
For some patients, a sleep recording is obtained. You may be asked to sleep naturally or, in a sleep-deprived EEG, you'll have been asked to sleep less the night before to facilitate sleep during the test.
Completion & Cleanup
The electrodes are removed and any remaining paste is cleaned from your scalp. You can resume normal activities immediately. The recording is analyzed by Dr. Yuvraj Lahre, and results are discussed with you at a follow-up appointment.
How to Prepare
- •Wash your hair thoroughly the night before the test with shampoo only — no conditioner, hair oil, gel, or styling products
- •Avoid caffeine (tea, coffee, cola, energy drinks) for at least 8 hours before the test
- •Take your regular medications as prescribed unless your doctor specifically tells you otherwise — bring a list of all medications
- •If a sleep-deprived EEG is ordered, follow the sleep restriction instructions provided (typically sleep only 4–5 hours the night before)
- •Eat a normal meal before the test to prevent low blood sugar, which can affect brain activity
- •Inform the technician if you have any skin allergies or scalp conditions
Related Conditions
EEG (Electroencephalogram) helps diagnose and monitor these conditions. Explore our condition pages for more detailed information about each.