Final answer:
Traumatic Encephalopathy is the term commonly used to describe the condition where a mother experiences brain damage due to a car crash and becomes mentally different since she didn't seek medical attention.
Step-by-step explanation:
The term commonly used to describe the condition where a mother experiences brain damage due to a car crash and becomes mentally different since she didn't seek medical attention is Traumatic Encephalopathy. Traumatic encephalopathy refers to brain damage caused by a traumatic injury to the head. In this case, the car crash would be the traumatic event that led to the brain damage.