Dementia Diagnosis: Keeping an open mind

Written on the 25 May 2022 by Dr Kailas Roberts

Over the last ten+ years of seeing patients in my private practice, I have seen a number of people who have erroneously been diagnosed with a form of dementia. Many have radically changed their lives – say, by resigning from their job, or moving house – because they have been told their cognition and ability to function day to day will inevitably deteriorate. Others have unduly gone through considerable angst and grief as they adjust to the idea of having what is a terminal illness.

But there is a positive of course. If the problems are not related to dementia, they may be completely reversible. A recent example of this was a man I reviewed in a nursing home who was bed-bound and losing weight. He was very frail and reliant on care staff to look after him, and with his poor oral intake, I felt he was unlikely to last much longer.

He had been sent to the facility directly from the hospital, where he had been diagnosed with a type of dementia, but something didn’t fit. As I spoke to him, it became apparent that the most obvious problem was his profound level of depression. Yes, he had some problems with memory, but these seemed mild compared to his low mood. I organised for him to be admitted to another hospital for re-evaluation. My colleagues agreed that he was clinically depressed, and he underwent robust treatment for this. After a period, his mood lifted, and with it, so did his cognitive ability. Ultimately, he was discharged a different man – independent, happy, and cognitively intact.

This is of course an extreme example of misdiagnosis and is unusual in its dramatic nature, but it is not uncommon for people to come and see me in my clinic thinking they have dementia when in fact something else is causing their memory problems. Or they may have dementia, but it is not as severe as it appears – another reversible problem has exacerbated the cognitive impairment.

For all these reasons, it is important not to conclude dementia is present before investigating what else might be going on.

So, what sort of things should you look out for that might indicate that dementia is not the problem, or at least not the only problem?

Firstly, the timeframe is relevant – a sudden change in thinking and memory is not usual for dementia (except perhaps that which happens after a stroke) and warrants an urgent medical review.

Next, any change in medication that immediately precedes the cognitive problem should be considered a possible contributing factor, especially in the elderly. Medications for allergies, incontinence, depression and pain can all addle the brain, and for some, it is the combination of medications that causes problems.

Then there are physical health problems that can mimic dementia. Sleep apnoea is a classic but under-recognised cause, so if you notice snoring, daytime tiredness, or periods of choking, gasping or not breathing overnight, this needs evaluation. Any infection has the potential to induce confusion, as does cardiac disease and changes in thyroid, kidney, and liver function. Blood tests can be greatly helpful in identifying some of these things.

Finally, just like our man above, psychological illness is a major cause of cognitive impairment, especially in the elderly. Obvious signs of anxiety or distress, persistently low mood, lack of interest and motivation and certainly expressed feelings of hopelessness or suicide are all red flags.

Many professionals in my field lament the length of time it takes for people to be diagnosed with a form of dementia, and this is certainly understandable, but we should equally avoid reaching a diagnostic decision too soon.

*As published in Inside Aging May 2022