Complex sentence: While research has demonstrated that thinking and behavior may be altered in virtually all forms of ABI, brain injury is itself a very complex phenomenon having dramatically varied effects, and no two people can expect the same outcome or resulting difficulties.
Split into simpler sentences: While research has demonstrated that thinking and behavior may be altered in virtually all forms of ABI, brain injury is itself a very complex phenomenon having dramatically varied effects. No two people can expect the same outcome or resulting difficulties.