Amnesia describes the partial or total loss of memory. It can be temporary or permanent. What forms can it take? How to detect it? Are there any treatments for memory recovery? The point with Pr Emmanuelle Duron, neurologist-geriatrician.
Partial or total loss of memoryamnesia can be of two types:
- anterograde amnesia : concerning recent events
- retrograde amnesia : if the affected person no longer remembers his earlier acquisitions.
Amnesia is said to be anterograde when subject fails to recall recent events and finds it difficult to acquire new knowledge. This is particularly the case in post-traumatic stress disorder.
Retrograde amnesia refers to the failure to remember old facts.
Lacunar or selective amnesia refers to the loss of memory of a specific event. Very often, it lasts only a few hours.
Dissociative, or psychogenic, amnesia is a form of retrograde amnesia that usually occurs following a traumatic event.
Amnesia is qualified as partial when the loss of memory is not total. We remember some memories but hide others.
Infantile amnesia means having no memories before the age of 3 and very little until the age of 6 years.
Amnesia can have various origins. It may have been triggered by an organic pathology (brain injury, head trauma, neurological disease, etc.) or functional (psychological disorders, post-traumatic stress, psychiatric illness, etc.).
Amnesia is manifested by a memory loss that varies depending on the type of amnesia. “For example, if the subject does not remember their childhood, this is suggestive of retrograde amnesia. Conversely, in anterograde amnesia, the person remembers old events but forgets more recent or new information. The subject also tends to repeat himself, lose track of time and space and may end up in a state of confusion”, says Professor Emmanuelle Duron, neurologist-geriatrician at the Paul Brousse hospital and researcher at INSERM within the MOODS unit.
Memory loss is assessed using very comprehensive tests which also allow a study of language and attention. They last 2 hours.
→ The Mini-Mental State Examination (MMS) or Folstein test: lasting 15 minutes, this test allows you to study orientation, language, learning, attention to calculation, recovery of calculation, knowing how to form a phrasing. It is not a diagnostic test but screening.
→ The test of 5 words from Dubois : This test assesses episodic memory. It consists in making the patient learn 5 words with a clue by pointing out to which semantic category he belongs. “For example, eggplant is a vegetable, we will hide the list and ask him for the 5 words again. If any are missing, we can help him by citing the semantics of the missing word (vegetable). After an interfering task, we will ask him again for the learned words”, specifies the neuro-geriatrician.
→ The test of Grober and Buschke : it tests verbal episodic memory. The test includes 16 words belonging to 16 different semantic categories. The patient must find the words after giving him clues.
→ The test of DO80 language : this test consists in showing 80 images to the patient who must name them.
“These tests must be accompanied by a complete clinical examination, of one brain imaging (MRI) and a complete blood count with assays that may indicate memory impairment (e.g. hypothyroidism)”, adds the specialist.
The treatment will depend on the cause of the amnesia. “In certain degenerative pathologies such as Alzheimer’s disease or Parkinson’s disease, memory impairments are irreversiblealthough there are treatments to slow down their development, explains Professor Emmanuelle Duron. On the other hand, any disease that can be cured must be treated. For example, if it is hypothyroidism, depression, treating the cause will improve the symptoms and therefore restore the memory.
Thanks to Pr Emmanuelle Duron, neurologist-geriatrician at Paul Brousse hospital and researcher at INSERM within the MOODS unit.