Mrs. J is a 69-year-old Caucasian woman who presents with symptoms of forgetfulness. She has trouble remembering names and the location of certain keys on her keyboard. Her past medical history includes uncomplicated shingles and treatment with prednisone for temporal arteritis between the ages of 65 to 67. Consequently, she has been taking calcium supplements as well as low doses of thyroid replacement therapy. Twenty months later, she is reassessed and reports that her memory impairment has worsened and is now embarrassing her. She has stopped working in an office and her husband has observed her to be more irritable as well as nervous.

Diagnosis is early Alzheimers but i need help with the explaination of that diagnosis?