Dr diagnosed OH with young onset dementia, but after taking him off certain meds the sleep clinic had him on he improved loads & wasn't as mixed up. After attending memory clinic they said he has no dementia on pet scan & it's MCI your husband has. I am applying for power of attorney & now neurologist thinks it's Functional cognitive disorder & are going to see him in August. Anyone else had the same situation? My husband also has sleep apnea. Just don't know what to say to any family or friends as its changed again on diagnosis.