Case 78

An 86-year-old previously healthy female patient complains of memory problem, attention deficit, slowness of thought and drowsiness in the last 4 months. She reports problems in handling activities of daily living, such as bathing herself. She is normotensive and has no recent history of falling or any other accident. She does not report use of any medication.

Question:
Based on the clinical data and neuroimaging presented, which is the patient's diagnosis