Forgetfulness is the thing that most people in general associate with dementia. Memory problems are also some of the earliest symptoms to appear. However, there are various memory systems, and some of them deteriorate more quickly than others.
The hippocampus can be found in the temporal lobes of the brain and is used to form new memories. When people with dementia forget that they ate lunch an hour ago, this is because the hippocampus has been damaged. In Alzheimer’s disease this occurs at an early stage.
The same person who forgot they had eaten lunch can nonetheless give a detailed account of their honeymoon 50 years ago. In both cases, the person is looking for information in their episodic memory, the brain’s storage area for episodes and events that the person was actively involved in. However, as dementia first affects the ability to form new memories, it is above all the events that occurred from the time the person became ill that are forgotten. The episodic memory is no longer being filled.
In moderate dementia, episodic memory deteriorates further. The patient finds it more and more difficult to retrieve even old memories. Memory images from the period when the person was aged 20–30 tend to survive the longest.
While the episodic memory is affected at an early stage, other memory systems fare better. The short-term memory often deteriorates later as the dementia progresses. The semantic memory, too, works fairly well for a long time. This is a sort of knowledge memory and is used to remember the names of the days of the week, the capital of Sweden, and where the cutlery goes on the dining table.
For a long time, deficiencies in the semantic memory can be compensated for with a little help from those around. A simple clue – such as pointing to the fork when laying the table – can put the patient back on track and ensure that they can carry out a task. As the dementia progresses further, there is a more pronounced deterioration of both the short-term memory and the semantic memory.
One family carer said of her husband with dementia, “It’s as though he only sometimes wants to remember.” The explanation may lie in the environment. The ability to learn and recall memories is greater when there is peace and quiet, which would mean that the patient is relaxed and does not feel under pressure. The damage to the brain places an absolute limit on memory capacity, but with various aids and knowledge of how memory works, families and nursing staff can provide vital support to the person affected.
Good advice for handling memory difficulties:
- Do not say, “Do you remember…?”; instead, provide clues that may activate the person’s memory.
- Listen and be patient.
- Try not to offend the person by becoming irritated. Remember that, even if this is the tenth time you have heard something, as far as the person is concerned it is the first time they have said it.
Memory difficulties can occur, for example, with Alzheimer’s, Lewy body, Parkinson’s, vascular and fronto-temporal dementia. To find out more about the diseases, click bellow.