Many brain injuries are the result of bruising, bleeding, twisting or tearing of brain tissue.
Damage to the brain may occur at the time of the accident, or develop over time as tissues swell and bleed within the head. The brain is several pounds of a jelly-like substance containing millions of microscopic fibers suspended in cerebrospinal fluid. When brain tissue is disturbed in an injury, these axonal-dendric connections can be disturbed or broken. The cortex is the center where most thinking takes place. The left hemisphere is often the dominant structure and controls verbal functions such as speaking, writing, reading and calculating.