Up to 50% of people with MND will experience mild cognitive change and, of these, a further 5 to 10% will develop frontotemporal dementia (FTD) which is more severe. This is a small but significant minority of people. FTD is an increasingly recognised form of dementia, with different signs and symptoms to the more common Alzheimer’s disease.
‘Cognition’ refers to a range of high-level brain functions, for example:
- executive functioning – e.g. ability to plan
- social cognition.
For people living with MND, the most prominent impairment is in executive functioning; but some will also show changes in language and behaviour. Memory is not usually affected, and problems with perception are rarely seen. Changes in social cognition, which affect the person with MND’s ability to empathise with other people’s feelings and beliefs, may be challenging for carers/family of people with MND.
A full description of the indicators of cognitive change can be found in the MND Association resource ‘Cognitive change, frontotemporal dementia and MND‘.
Behavioural changes may include egocentric or selfish behaviour, loss of interest, apathy, disinhibition, irritability, aggression and absence of insight into these changes. People with MND may also find it difficult to recognise emotions in others and have altered sensitivity to social and emotional cues.
It is important to note that people with no cognitive changes can have profound behavioural abnormalities and it is unlikely that someone experiencing these changes will know this is happening or can acknowledge the change.
People with MND may experience cognitive and/or behavioural changes not classified as dementia, ranging from mild to moderate or more severe in some cases. Changes can be subtle and may be masked by movement and speech problems; some may be part of the normal ageing process.
Fronto-temporal dementia and MND
The following explanation defines MND-FTD and the combination of symptoms that may indicate frontotemporal dementia.
Cognitive change in MND-FTD could include:
- marked executive dysfunction (difficulties with higher order cognitive abilities such as planning, decision making, problem solving and poor attention span)
- a change in language – expressive (problems communicating what they are trying to say)
- a change in language – receptive (problems understanding what is communicated to them)
- memory difficulties. Although this isn’t a primary symptom, someone may experience difficulties due to executive dysfunction and ‘taking in’ information, rather than the memory problems associated with Alzheimer’s, for example visuospatial functions are preserved.
Behaviour change in MND-FTD could include:
- significant personality change
- disinhibition and impulsivity (socially inappropriate behaviour)
- perseveration (continuing to conduct an activity that is no longer appropriate)
- change in eating behaviour (sweet food preference)
- loss of emotional understanding (appearing egocentric/selfish)
- being withdrawn (apathy/failure to initiate)
- stereotyped/ritualistic behaviour.
Behaviour change often occurs before cognitive impairment.
Support you can give
Listen to carers when monitoring for change. For example, if a carer says, “My partner is different, he just doesn’t love me anymore” this may well be a change in the relationship since diagnosis, but it could also indicate something deeper in terms of behaviour and lack of empathy.
A carer whose husband had MND-FTD
Family members may be the first to notice early signs of change, such as the ability to process information, or difficulties with language. It is important that you listen carefully to what they are saying as you may recognise alterations as potential indicators of cognitive change.
If you suspect or recognise any of the symptoms of cognitive change in the person you are caring for it is advisable to discuss them with the person with MND and their carer/family (where relevant and appropriate) to see if they are aware of any changes and to explore their thoughts. It is important to rule out other causes. Any changes should be discussed with the person’s neurologist and the wider multidisciplinary team.
You could make use of tools such as the Edinburgh Cognitive and Behavioural ALS Screen (ECAS), MiND-B or M-ACE to screen for potential signs of cognitive or behaviour change. If the result indicates some evidence of impairment, then advice should be sought from local clinical neuropsychology services.
Timely assessment by professionals is important. Understanding the cognition level of the person with MND is crucial to help them and their family cope with what may lie ahead which includes being able to make timely decisions about treatment and care.