Everyone associates dementia and Alzheimer’s disease with memory problems but the other common problem – spatial disorientation is far less known, despite it having potentially fatal consequences.
A new study sheds light on why people with dementia get lost and points towards new solutions.
Memory problems are the key symptom of Alzheimer’s disease, even in the earliest stages of the disease. However, similarly common but rarely mentioned are spatial disorientation symptoms.
What is spatial disorientation?
Spatial disorientation refers to being unsure of where we are. We all can feel at times disoriented and unsure where we are. The perfect example is when we are travelling and are in a town which we do not know. In that town, we can get easily disorientated or lost, in particular without the help of any map or GPS help. The difference in Alzheimer’s disease is that people with the disease get also spatially disoriented in familiar space, such as places they have been living a long time or even within their own house.
How is this spatial disorientation explained?
The reason why people with Alzheimer’s disease are more vulnerable to spatial disorientation is that the same brain area which is important for our memories – the hippocampus (from Latin hippocampus = ‘seahorse’) – is also very important for our spatial orientation and navigation.
The discovery that the hippocampus is important for spatial orientation and navigation was actually awarded the Nobel Prize in Medicine in 2014, as it had such a fundamental impact on our understanding of the brain. For the first time, we understand how the ‘GPS system in our brain’ works and helps us to find our way around.
Since the hippocampus is one of the earliest brain region affected by Alzheimer’s disease, it should come therefore not as a surprise that people with the disease have memory problems as well as spatial disorientation.
How come then that the spatial disorientation problems are less noted?
There are several reasons why this might be the case. For example, the memory problems are simply more prominent and ‘overshadow’ any other symptoms, such as spatial disorientation. Spatial disorientation is also a more ‘private’ symptom, as the person with the disease might experience it but the people around the person might not notice the disorientation if it is not blatantly obvious.
Finally, a reason why those spatial disorientation symptoms are less noted, is that our brain can compensate for them for quite a long time. We can use other spatial orientation functions in the brain, which do not rely as much on the hippocampus to still find our way around – at least at the beginning stages of the disease.
Spatial disorientation often therefore only ’emerges’ to others when the disease is more advanced, as we cannot compensate anymore those deficits. It is therefore important to remember that spatial disorientation is an early symptom in Alzheimer’s disease but only ’emerges’ to others in the subsequence disease stages.
Once a person struggles to know where they are and to find their way around, they are more vulnerable to get lost as the navigation and orientation system is not working anymore correctly. Scientific evidence shows that ~70% of people with dementia have at least one getting lost episode throughout the disease, showing again how spatial disorientation is such an integral part of the disease.
Unfortunately, the first episode of getting lost comes ‘out of the blue’ for most people with dementia and their families. For example, they do no return from a routine outing with their dog or getting the newspaper from the local shop. This unexpectedness makes these events very stressful not only to the person with dementia but also their families.
Not surprisingly, after the first such episode people with dementia are often only reluctantly let go on their own out by their families. Some families opt for GPS trackers to know the person’s location at any time and provide peace of mind but for some, this is a clear intrusion into their privacy and instead, they keep ‘a close eye on the person with dementia.
Regardless of the measures families put in place, it is clear that such getting lost episodes lead to a reduced autonomy of the person with dementia. But not only have these getting lost episodes an impact on the person with dementia but also their carer and families. The scientific evidence shows that carers of people with dementia who go repeated times missing have much higher stress and care burden levels compared to other carers. Repeated getting lost episodes also lead to a seven-time increase in care home placement of the person with dementia, further reducing their autonomy and independence.
Does this mean that carers and families overreact for such getting lost episodes?
They actually do not overreact as in the worst cases the person with dementia actually comes to harm or even dies due to dehydration or exposure when getting lost. Fortunately, this is a rare occurrence but clearly should not happen at all for the ~40,000 people with dementia going missing in the UK every year.
It is therefore important to strike a balance between the safety and the autonomy of the person with dementia for getting lost episodes. It is also of importance to understand much better which factors make people with dementia at higher risk of getting lost. Such risks can be either associated with the person themselves, such as their disease stage, however, the other risk is the environment they live in, which might make them more at risk than other people with dementia.
Our recent study* investigated whether the environment affects people with dementia to get lost. More specifically, we investigated whether the complexity of the road network and intersections puts a person with dementia at a higher risk of getting lost.
The rationale behind looking at the complexity of the street network is that each crossing is a decision point for our navigation. The more spatial decision points we have, such as a complex road intersection, the more likely it is that we take a wrong turn.
We hypothesised therefore that people with dementia would be more at risk of getting lost when the road network is more complex and intersections have more streets coming of them.
We were fortunate enough to work with the police and obtain their de-identified records of missing reports for people with dementia over a 3 year period. The data indeed showed that the more complex the street network and the more complex street intersections, the more likely people with dementia would get lost.
What do these findings mean?
The results show that the environment plays a clear role in the risk for people with dementia getting lost. Clearly, we cannot change our environment easily, however people with dementia and their families can – based on these findings – plan routes for the person with dementia to take which are less complex and have fewer crossings through areas which they are very familiar with.
For the future, the findings will also inform urban planning for dementia-friendly towns and cities, as we know now that road complexity is a clear factor in make people getting lost when having dementia.
What else can people do to prepare for such getting lost episodes, since they are coming often ‘out of the blue’?
The key message is to keep calm in the first instance. The vast majority of people with dementia are found within a 3km/1.8miles radius of their residence and within one hour. The police and Search & Rescue services call this the ‘golden hour’, as people found within the first hour of going missing are less likely to come to harm.
We need to act therefore fast if someone is missing and should always contact the police, even if the person might be found within 5 minutes, for example in a neighbour’s garden. The police have also different systems and mechanisms in different countries to deal with missing people with dementia.
In the US for example, there is the Silver Alert system across all states, allowing to inform a large number of services and people when a person with dementia is missing. A similar system – called Purple Alert – based on social media networks is currently piloted in Scotland. (see links below)
For the UK, many police forces offer the Herbert Protocol (see link below) to people with dementia and their carers. The Herbert Protocol (named after George Herbert, a person with dementia who got lost and sadly died) is a form the person with dementia and their family can complete and entails information on themselves as well as routes they commonly have taken and places they often went to (such as former place of work). In case of the person with dementia getting lost, the family gives the Herbert Protocol forms to the attending police or Search & Rescue services, which will facilitate the finding of the person with dementia.
Spatial disorientation in dementia is a serious symptom but often overlooked until people with dementia go missing, with sometimes fatally consequences. Being aware of this danger and being prepared for its occurrence will not only give people with dementia the confidence to stay longer independent but also peace of mind to their carers and families.
Links:
- Silver Alert information: https://en.wikipedia.org/wiki/Silver_Alert
- Purple Alert information: https://www.alzscot.org/purplealert
- Herbert Protocol (The link is for the Metropolitan police in London but you can find the same form for your local police force on the internet): https://www.met.police.uk/herbertprotocol
Impact of road network structure on dementia-related missing incidents: a spatial buffer approach. Puthusseryppady V, Manley E, Lowry E, Patel M, Hornberger M. Sci Rep. 2020 Oct 29;10(1):18574. doi: 10.1038/s41598-020-74915-y.
