Occupational burnout‐like syndrome in early‐onset Alzheimer’s disease

Abstract

Background and aims: Early-onset Alzheimer's disease (EOAD) differentiates from late-onset AD by a predominant and early involvement of the parietal neocortex with hippocampal sparing, leading to non-amnesic syndromes. We aimed to identify the inaugural symptoms leading to a medical consultation in EOAD patients. Method(s): We retrospectively collected the clinical history of patients younger than 62 years referred to our memory clinic for cognitive dysfunction during the last year. Among 91 patients, 31 were diagnosed with AD based on clinical and biological criteria (cerebrospinal fluid biomarkers). Their mean age was 55+/-3.8 years. Result(s): 11 EOAD patients (35%) were initially diagnosed with an occupational burnout syndrome, while logopenic aphasia or visuo-spatial deficit were observed in the remaining 20 patients (65%). In the burnout syndrome subgroup, the delay between the 1st symptoms and neurological examination was 2.6+/-1.1 years and the initial Mini-Mental State Examination score was 19.6+/-4.6/30. The neuropsychological assessment showed a severe working memory deficit, associated with mild cognitive cortical parietal syndrome. Visual inspection of brain MRI and FDG-PET showed bilateral parietal atrophy and a severe focal hypometabolism of associative parietal cortices. Conclusion(s): We describe for the 1st time a new clinical presentation of EOAD mimicking an occupational burnout syndrome. The severe inaugural working memory deficit due to early cortical parietal damage leads to an inability to carry out concurrent professional tasks, and to severe anxiety, in the absence of overt aphasia or episodic memory deficit. It is crucial to consider this clinical phenotype in the definition of EOAD to avoid delayed diagnosis.