Chronic traumatic encephalopathy could involve two distinct symptom patterns, according to a new study released Wednesday.
The research, published in the Neurology journal showed that early signs of destructive brain disease due to head blows may include mood changes in younger athletes and eventual mental decline later on in life.
The researchers believe that this type of disease can include two distinct patterns of symptoms which they found after athletes have died.
"The study is the largest report of a series of cases involving autopsy-confirmed chronic traumatic encephalopathy or CTE," said lead author Robert Stern, a neurology professor at Boston University's medical school.
The research involved 36 former athletes - mostly professional football players - who experienced repeated head blows throughout their play years.
The brains of these athletes were donated by their respective families for the purpose of the research.
The results of the study showed that mood and behavior changes like depression and explosive tempers began appearing at the age of 35 for young players.
In older players, mental decline that begins at the age of 59 was the first reported symptom.
Results of the study echoed research in former boxers with "punch drunk" symptoms, but that evidence did not include brain imagine, Stern said.
The researchers acknowledged the limitations of the study and said that larger studies may bring about different results.
