Really interesting article in the latest issue of JAMA Neurology: Specific EEG changes, known as periodic discharges (PDs), seem to be of value in predicting brain tissue hypoxia in vulnerable patients with acute brain injury.

In this investigation, Witsch and colleagues included 90 patients with high-grade subarachnoid haemorrhage and monitored them with continuous EEG in addition to an array of other modalities, most importantly: brain tissue oximetry and regional cerebral blood flow measurements. They found that certain EEG patterns, specifically higher frequency PDs, puts the patient at risk of hypoxia, due to increased metabolic demand not necessarily compensated for by increased oxygen delivery via increased CBF.

Periodic discharges as a phenomenon is likely to receive a lot more attention after this publication. It may be another step in the right direction towards a non-invasive modality for identifying incipient hypoxia and secondary brain damage.