Have you ever lost your train of thought? Stared into space? Experienced daytime sleepiness? Had disorganized or illogical thoughts? Of course, we all have these experiences. There are days when I am not as focused and days where I am very focused and I’m never at my best by 4:00 in the afternoon as I am in the morning. The clinical term for these lapses is fluctuating consciousness. It should come as no surprise that fluctuating consciousness is more pronounced in dementias. It is startling how lucid a person with Alzheimer’s or Lewy body disease can be one minute and how confused the next.

Fluctuating confusion is a hallmark diagnostic sign of Lewy body disease as it is characteristic of nearly 90% of those with this form of cognitive decline – even before it progresses to the point of dementia. But fluctuating confusion can also be found in a substantial percentage of those with cognitive decline from cerebrovascular disease (e.g., TIAs or strokes) or Alzheimer’s disease, about 40% and 20% of cases, respectively. Early on this symptom appears infrequently but as the decline progresses the inconsistency becomes more frequent.

This is not to say that we should be alarmed at every mental lapse. It is to say that if these lapses are frequent or severe, they deserve appropriate medical and cognitive assessment. If these changes have happened to you or to someone you love, ask two questions. First, do they ever have spontaneous episodes where they appear drowsy but awake or look dazed and are not aware of what is going on? Second, has the level of confusion varied from day to day or week to week with at least two incidents over the past month? How frequent are the episodes (daily, weekly, monthly)? How long do they last (seconds, minutes, or hours)? If answering these questions makes you concerned, seek assessment. Start with a medical evaluation. If there is no medical reason (e.g., sleep apnea, drug or medication use, metabolic disorder, etc.), be sure to get a thorough cognitive assessment.

To put this in another perspective, a recent study of 500 older adults demonstrated that 12% experienced cognitive fluctuations such as daytime somnolence, sleeping more than 2 hours during the day, illogical or disorganized thinking and/or staring spells. Those with mild cognitive decline were nearly five times as likely to report significant episodes of cognitive fluctuations as those with no cognitive decline.

There are early signs that should alert us to the need for memory assessment such as worrying about your memory, a family history of dementia, a past head injury, late life depression, and significant cognitive fluctuations. And for caregivers, these cognitive fluctuations are a part of the reality of a dementia. Take advantage of the lucid moments and try to go with the flow when the confusion is substantial.

Dr. Beckwith is a neuropsychologist, speaker, and author of Managing Your Memory: Practical Solutions for Forgetting. He has an office in Naples and can be reached at memoryseminars@aol.com or (239)851-1968.