Electroencephalography (EEG)

Patterns

1. Electrocerebral silence
2. Alpha rhythm
3. Burst suppression. Burst suppression occurs during states of general anesthesia or coma. Burst suppression is an on/off pattern of EEG activity characterized by periods of high cortical electrical activity followed by periods of low electrical activity. The periods of hyperexcitability are variable but can last 0.5–10 seconds in duration. The periods of low electrical activity or suppression may be due to transient increases in GABAergic inhibition of cortical activity, whereas cortical hyperexcitability may arise from ongoing glutamatergic transmission. An absence of burst suppression does not necessarily indicate that a patient is not under deep anesthesia.
4. Ischemia
5. Hyper-hypothermia
6. Changes in ventilation
7. Artifact

Processing Methods

1. Fourier series analysis
2. Bispectral array
3. Mapping techniques

Intraoperative Monitoring

1. Carotid Endarterectomy
2. Seizure Surgery
3. Cardiac Surgery
4. Deliberate Hypotension
5. Deliberate Hypothermia
6. Barbiturate Coma
7. Intracranial Vascular Procedures