What is CNS oxygen toxicity?
Central nervous system (CNS) toxicity, aka acute oxygen toxicity or the Paul Bert Effect (who researched this problem in the 1870s), manifests itself as convulsions, often with very little in the way of warning signs. The cause of these convulsions is attributed to oxidants and the resulting compounds produced in our body at elevated PO2. At some point our body will fail to cope and it reacts by convulsing. The phases before, during and following convulsions may be characterised by the steps below. 1. Pre-tonic build-up or pre-tonic premonition. This is the lead up to convulsions and may or may not be present or noticed. The symptoms are very similar to DCS and may include muscle twitching, nausea, hearing problems, tunnel vision, light headedness and breathing problems. If the symptoms do appear they may be followed so quickly by the next phase that the victim has no time to deal with the problem. It is also unlikely that the buddy will notice them either with all that diving gear (co
