Risk of dementia after fluctuating mild cognitive impairment: when the yo-yoing stops.

Friends, family members, and medical caretakers notice that sometimes we have good days and sometimes we have bad days. If we are older, the bad days may involve making poor judgments, acting impulsively, forgetting information we just heard, or repeating ourselves in conversations. If these oscillations persist, then someone we know well may suggest consulting a physician because our bad days are interfering with our daily activities. Presented with variable symptoms on different occasions, physicians legitimately may diagnose us with mild cognitive impairment (MCI) on one occasion and then equally legitimately retract the diagnosis on another occasion. Many in the field have observed that patients and study participants may yo-yo between normal cognitive performance and MCI, but until now, the import of these diagnostic fluctuations was unclear.