[Monitoring of brain damage in patients with head injuries]

Early detection of impending cerebral ischemia in comatose patients is most important to avoid secondary insults to the injured brain.

Whilst the computer tomography scan provides a static picture primarily concerned with details of structure, the electroencephalogram (EEG) is the objective source par excellence of information about brain function. The EEG represents the only biological activity suitable for continuous non-invasive monitoring of brain function. In this context, the cerebral function monitor (CFM) of Maynard and Prior (1969) provides a compressed array of amplitude variations and has benefited many critical patients. Among the invasive methods, direct monitoring of cerebral white matter oxygenation (tissular pressure of oxygen) is a promising new technique that has attracted considerable interest over the past four years. Recent studies on multimodal hemodynamic monitoring (intracranial pressure, cerebral perfusion pressure, PtiO2), place this latter technique as a primary basis for management decisions in the ICUs. We have studied four young injured patients, to compare early digital EEG recordings with tissular pressure of oxygen data.

In general, there was agreement between EEG findings and tissular pressure of oxygen levels. The EEG helped with urgent data, though barbiturate therapy interfered in two cases.