Intracranial EEG - Clinical Applications

Clinical Applications

Since its development in the 1950s, ECoG has been used to localize epileptogenic zones during presurgical planning, map out cortical functions, and to predict the success of epileptic surgical resectioning. ECoG offers several advantages over alternative diagnostic modalities:

• Flexible placement of recording and stimulating electrodes

• Can be performed at any stage before, during, and after a surgery
• Allows for direct electrical stimulation of the brain, identifying critical regions of the cortex to be avoided during surgery
• Greater precision and sensitivity than an EEG scalp recording - spatial resolution is higher and signal-to-noise ratio is superior due to greater proximity to neural activity

Limitations of ECoG include:

• Limited sampling time – seizures (ictal events) may not be recorded during the ECoG recording period
• Limited field of view – electrode placement is limited by the area of exposed cortex and surgery time, sampling errors may occur
• Recording is subject to the influence of anesthetics, narcotic analgesics, and the surgery itself