“When you are stunned or knocked unconscious, it is from your brain essentially splashing against the inside of your skull,” Dr Stephen Mendel told me. “If your brain smashes up against one side, it will in most cases splash back, injuring the opposite side to a lesser degree.
Unconsciousness can also result from your brain twisting, even ever-so-slightly-inside your cranium. At times with this twist, connectors can stretch or even rip free. It has absolutely nothing to with what part of your skull is thicker or harder and everything to do with the force that moves the brain inside the skull.”
Another neurosurgeon, Dr Kenneth Chen reports, "Sometimes the simplest bump on the head or a ding from a fall could take away your sense of taste for life, or your sense of smell, depending upon where the injury occurs. You don't want to risk these injuries.”
"A blow to the head that at first seems minor and does not result in immediate pain or other symptoms can in fact turn out to be a life-threatening brain injury.
It's very common for someone to appear perfectly lucid just after the impact but then to suddenly, rapidly deteriorate," warns Dr. Carmelo Graffagnino, director of Duke University Medical Center's Neurosciences Critical Care Unit, in a March, 2009 CNN interview.
"The nerves surrounding the bruise can begin to stretch, causing what is known as an axonal injury. "The brain is like Jell-O. Imagine if you dropped a bowl of Jell-O on the floor and it looks intact at first but when you examine it really close, you can see it has teeny tiny cracks all in it."