The creation of new brain cells, or neurogenesis, is thought to be dependent on a spike of blood flow to the brain. In fact, running and other aerobic exercises have been shown to increase neuron production in the areas of the brain associated with memory and thinking in both mice and humans. However, this was thought not to apply to resistance training. That is changing.
This is from an article on research on the effect of weight-lifting on the brain. But I haven't heard that neurogenesis is dependent on a spike of blood flow to the brain. Nor do I understand what exactly is meant by that - how much blood flow is needed? It does however fit into the CCSVI picture. People with CCSVI have slow perfusion. We might not be able to 'spike' our blood flow if inflow needs to be in correlation to outflow and the outflow is limited due to outflow obstructions in the veins. By improving outflow through CCSVI venoplasty, it might give our brains the breathing room to begin to heal. If neurogenesis is impaired in people with CCSVI, then it could be a factor in our neurodegeneration.