DCS can manifest with dysexecutive syndromes in which the diver complains of difficulties with concentration, memory, mood and other cognitive functions. These manifestations are frequently noticed ‘late’ when the diver returns home or to work. As described in Chapter 10, it seems most likely that such symptoms arise from exposure of the brain to VGE that have arterialized across a right-to-left shunt such as a PFO. It seems unlikely that these small VGE can cause the focal stroke-like manifestations typically associated with larger bubbles that may be introduced to the cerebral arterial circulation after pulmonary barotrauma. The latter type of presentation is described in Chapter 6. The natural history of cerebral DCS is poorly characterized, although the authors are aware of cases in which permanent cognitive sequelae have been reported.