“Every morning when I wake up I am perfectly capable of remembering the main European capitals and rivers, or the names of the presidents of my country and the different events that have marked contemporary history; and yet I feel totally lost when I have to face the fact that girls consider me a bore, because I always try to flirt with them forgetting that I have been previously rejected on several occasions. I am not able to store in my memory the day-to-day experiences that forge my character, although I am the owner of some distant memories”.
What is developmental amnesia?
In 1997, Vargha-Khadem described a rare condition known as developmental amnesia, in which children with a normal level of intelligence who had suffered a hypoxic-ischemic pathology in the perinatal period (between birth and 28 days of life), suffered from a memory disorder (especially episodic or autobiographical memory), with preservation of semantic memory (which is related to the acquisition, retention and use of knowledge about the world, in a broader sense).
In other words, these were children whose brains were not able to record all the events or experiences that happened to them on a daily basis in a given place and time. Instead, they were able to acquire, retain and use general knowledge about the world (facts, concepts and vocabulary), because this type of memory has no connotations of time and space. And to the surprise of parents and educators, they learned a poem, the multiplication tables or the lesson of natural sciences with relative normality. However, they were unable to remember that they had gone on a field trip the day before.
As a common denominator, all these children had suffered some kind of serious incident in their first weeks of life (e.g., open heart surgery, delivery with severe fetal distress, sepsis with multiorgan failure or cardiac arrest at 48 hours of life), and had survived the episode without apparent neurological sequelae and with normal psychomotor development.
As a result, there was a low level of oxygen supply to the brain, resulting in specific damage to the hippocampus, which is a structure involved in the consolidation of memories and their storage, and an area of the central nervous system that is very vulnerable to damage at very early stages of development. The lack of oxygen supply to the brain in these cases was sufficient to produce selective damage to the hippocampus, but not to cause more severe and widespread brain damage leading to motor or cognitive neurological deficits.
Why is it an underdiagnosed pathology?
The lack of knowledge of this recently described disorder makes it an underdiagnosed pathology, so that the follow-up of all newborns at neurological risk beyond the age of 4-6 years (the age at which the control of these children usually ends in our environment), and the systematic assessment of memory in the neuropsychological study, are of fundamental importance for the earliest possible diagnosis.
This will undoubtedly allow a greater and better knowledge of this entity, as well as the implementation of the corresponding psychoeducational and cognitive rehabilitation measures, which will result in a better prognosis and adaptation of the child and his family to this disorder.