Thank you for posting your query.
First of all, let me reassure you that you do not have dementia
or Alzheimer's disease (AD).
The most important criteria for diagnosis of dementia and AD is clinical examination by a doctor and not an MRI
Also, there is no correlation between size of brain and brain functions. So, your brain finding (mild diffuse volume loss) could be a normal incidental finding.
If your brain functions are within normal limits, there is no need to worry. I have noted that you do have memory and concentration issues. But is that seriously interfering with your daily life?
For a person to qualify for dementia, he should have severe memory loss
and loss of at least one other brain function, which interferes with day-to-day functioning.
I hope it clarifies.
Dr Sudhir Kumar MD DM (Neurology)
Senior consultant Neurologist
Apollo Hospitals, Hyderabad