What an EEG can and cannot tell you
An EEG shows whether the brain's electrical rhythms are normal in waking, drowsiness and sleep. It can support a diagnosis of epilepsy, help classify seizure type, identify a focal area of abnormal activity, and detect non-convulsive seizures or encephalopathy in a patient who is confused.
An EEG is not a brain scan and does not show most structural causes of headache. A normal EEG does not exclude epilepsy, especially when the recording is short and no event occurs. An abnormal EEG does not by itself prove epilepsy either; the tracing has to be interpreted with the clinical story, examination and imaging.
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When an EEG is useful
EEG is considered after a first seizure, for recurrent unexplained blackouts or staring spells, for suspected absence or focal seizures, and when medication decisions depend on whether the events are epileptic. It is also used in status epilepticus, after brain injury or infection, and during pre-surgical epilepsy evaluation.
The request should answer a specific question. Ordering an EEG for every headache, dizziness or memory complaint adds cost without changing care. Dr. Yadav reviews the events, witness account and video where available before deciding whether routine, sleep-deprived or longer monitoring is appropriate.
- First seizure or recurrent unprovoked events
- Suspected absence, focal or nocturnal seizures
- Unexplained confusion, drowsiness or behavioural change
- Epilepsy medication review and treatment monitoring
- Pre-surgical epilepsy assessment or second opinion
How to prepare and what to expect
Routine EEG takes about 20 to 40 minutes. The technician measures the head and attaches flat electrodes with a gentle paste. You may be asked to breathe deeply, look at a flashing light, or sleep briefly. Sleep-deprived EEG requires reduced sleep the night before, as advised by the treating team.
Eat normally and take regular medicines unless told otherwise. Wash the hair and avoid oil, gel or sprays. Bring a seizure diary, witness descriptions, prior EEG reports, MRI or CT discs and a medication list. Results are explained with the limitations of the test and a plan for what happens next.
| Test | Typical duration | Main purpose |
|---|---|---|
| Routine EEG | 20–40 minutes | Seizure classification, background activity |
| Sleep-deprived EEG | 40–60 minutes | Increase yield when routine EEG is inconclusive |
| Ambulatory or video EEG | Hours to days | Capture events, clarify diagnosis, pre-surgical work-up |
Access and booking
Appointments are at Kathmandu Neurology Clinic & Cognitive Center, 117 Lal Durbar Marg, Kathmandu, opposite Yak & Yeti Hotel. Call +977-9747736624 or use /book-appointment. Bring prior reports, imaging, seizure or symptom records and a medication list. Neurophysiology tests are arranged at an affiliated laboratory or hospital when indicated; the consultation confirms whether the test is appropriate and explains the result.