Question category: Psychiatry
A man is brought to the GP by his wife. Over the previous 4 months he has been aggressive, rude to strangers and has noticeable memory loss. He is not on any medication, does not smoke or drink and takes no recreational drugs. On examination his BP is 145/9 mmHg, bloods are normal including thyroid function, and there is nothing else to note. An MRI shows increased T2 signal in the frontal lobe white matter and frontal lobe atrophy. A PET scan demonstrates hypometabolism in the front and temporal areas. What is the most likely diagnosis?