Two main clinical features differentiate
early-onset Alzheimer's disease (AD) from late-onset AD: the frequency of
atypical phenotypes and the rapidity of clinical decline. Young AD is defined
by an age of onset before 65 years. In this study, the authors sought to
retrospectively characterize the initial complaint (onset of the first
symptoms) and course of care of young AD patients, with or without work
activity, and to compare their neuropsychological profiles at the time of
diagnosis with those of elderly patients. In
order to take into account the age of retirement, they focused their work on
patients under 62 years old.
When the initial main complaint did not correspond to cognitive neurological
symptoms such as language or memory disorders, the diagnosis made was that of
burnout leading to psychiatric follow-up and this atypical profile was observed
in 32% of young ADs in the cohort. Thus, in young subjects, the use of a psychiatrist
before the neurological consultation was more frequent than in elderly
subjects.
Regarding the other "classic" inaugural symptoms, the initial
cognitive complaint in young AD subjects differed from that of elderly subjects
by a lesser predominance of memory deficits (38% versus 87%) and a greater
frequency of cortical symptoms (language, visuo-spatial functions, behavior). The diagnosis of young AD was made more than 2
years after the first symptoms and at a more severe stage than in elderly patients.
In conclusion, the inaugural clinical signs of young AD can be misleading and
are often identified in the professional context. The researchers hypothesize an early dysfunction
of the parietal-frontal networks responsible for a deficit of the working
memory at the origin of a pseudo-burnout. Several
studies have indeed demonstrated a preferential lesional involvement of the
parietal cortex in young AD compared to old AD. A training effort for health and information professionals
is absolutely necessary in order to improve the diagnosis of early-onset AD and
allow patients to have access to specialized care and the possibility of being
included in therapeutic trials.
Contacts : p.olivieri@ghu-paris.fr m.sarazin@ghu-paris.fr