I don't think it's useful to consider a rare (0.2%) neurological disorder in this discussion, unless you're suggesting that Neanderthals had voids in their brai

I don't think it's useful to consider a rare (0.2%) neurological disorder in this discussion, unless you're suggesting that Neanderthals had voids in their brain matter. This would be an extraordinary claim, being unlike any other primate or mammal.