1st August 2023

A 58-year-old man attends a memory clinic. He has a background of HIV, which was diagnosed ten years ago.

A 58-year-old man attends a memory clinic. He has a background of HIV, which was diagnosed ten years ago. He has generally been well-compliant with his antiretroviral therapy (ART). Still, his partner –who attends with him –reports that for the past eighteen months, he has occasionally been forgetting to take his medication, which is happening more frequently. He has also been having difficulty remembering certain words. He has been demonstrating odd behaviours, such as getting up in the middle of the night and moving things around in the kitchen. He seems more irritable than usual and more impulsive, such as booking a round-the-world cruise “on a whim” two weeks ago. On examination, he appears slightly ataxic in his upper limbs, past-pointing bilaterally, and demonstrates horizontal gaze nystagmus.

What is the most likely diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.