An electroencephalogram (EEG) is a diagnostic test utilized to identify abnormalities in the electrical activity of the brain. During this procedure, brain wave patterns are tracked and recorded. Thin wires connected to small metal discs, known as electrodes, are positioned on the scalp, transmitting signals to a computer to capture the findings. Normal brain function generates distinctive electrical patterns, which are recognizable on the EEG. By analyzing the recorded data, doctors can detect abnormal patterns indicative of seizures and other neurological issues.
Why is an EEG Done
The EEG serves as a diagnostic tool for various brain disorders. In cases of epilepsy, seizure activity manifests as rapid spiking waves on the EEG. Patients with brain lesions resulting from conditions like tumors or stroke may exhibit unusually slow EEG waves, influenced by the lesion’s size and location.
Beyond epilepsy and lesions, the EEG aids in diagnosing other conditions affecting brain activity, including Alzheimer’s disease, certain psychoses, and narcolepsy. Additionally, it can assess overall brain electrical activity, aiding in the evaluation of trauma, drug intoxication, or the extent of brain damage in comatose patients. During surgical procedures, the EEG may also monitor blood flow in the brain.
Your doctor may recommend an EEG for various other reasons, depending on your specific medical circumstances.
Results of EEG
Abnormal findings on an EEG test may arise from various factors, including:
- Abnormal bleeding (hemorrhage)
- Structural abnormalities in the brain (e.g., brain tumors)
- Tissue death due to blocked blood flow (cerebral infarction)
- Substance abuse (e.g., drugs or alcohol)
- Head injuries
- Migraines (in certain cases)
- Seizure disorders (e.g., epilepsy)
- Sleep disorders (e.g., narcolepsy)
- Brain swelling (edema)
The EEG, a long-standing diagnostic tool, is generally considered safe and non-invasive. The procedure is comfortable, as the electrodes solely record brain activity without causing any sensation. Additionally, there’s no risk of electric shock during the test.