Question

I know that cognitive dysfunction/’brain fog’ is one of the key symptoms of ME/CFS and that it can vary in severity – just like most other ME/CFS symptoms. But I’m concerned about what seems to be a slow and progressive worsening in the problems I have with memory, concentration, mixing up words and the ability to process information. I’ve also noticed that my memory for events in the past is now being affected. Otherwise, most of my other ME/CFS symptoms are fairly stable. But the frustration with not being able to properly function mentally is starting to make me feel depressed.

I went to see my GP a few months ago, and he felt that my cognitive problems were probably ‘just another part of having ME/CFS’. So is this sort of progressive decline in mental functioning something that other people with ME/CFS report and just have to live with?

Answer

You are quite right to be concerned because while this may be part of the natural course of your ME/CFS, it’s also possible that this progressive deterioration in mental function is being caused by another medical or neurological problem – such as low thyroid function/hypothyroidism or even early dementia, or by depression, or (in the case of women) the menopause. It’s also worth noting that cognitive dysfunction in ME/CFS does not normally cause problems with intellect, IQ or memory for past events.

So, you must go back to your GP and ask for a proper mental function assessment, and some blood tests – especially thyroid function. You may also need to question whether you should be referred to a memory clinic at the local hospital where they can check your cognitive function in more detail, and you might require some hospital-based investigations.

While dementia becomes increasingly common over the age of 65, it can also occur in younger age groups and there are now over 40,000 people with dementia below the age of 65. However, there is no evidence that cognitive dysfunction in ME/CFS increases a person's risk of developing dementia in later life – even when this is severe.

More information

• The ME Association has a detailed information covering the causation and management of cognitive dysfunction in ME/CFS available to download from the Free Literature.