Amyloid positron emission tomography and cognitive reserve.

Alzheimer's disease (AD) is characterized by a non-linear progressive course and several aspects influence the relationship between cerebral amount of AD pathology and the clinical expression of the disease. Brain cognitive reserve (CR) refers to the hypothesized capacity of an adult brain to cope with brain damage in order to minimize symptomatology. CR phenomenon contributed to explain the disjunction between the degree of neurodegeneration and the clinical phenotype of AD. The possibility to track brain amyloidosis (Aβ) in vivo has huge relevance for AD diagnosis and new therapeutic approaches. The clinical repercussions of positron emission tomography (PET)-assessed Aβ load are certainly mediated by CR thus potentially hampering the prognostic meaning of amyloid PET in selected groups of patients. Similarly, amyloid PET and cerebrospinal fluid amyloidosis biomarkers have recently provided new evidence for CR. The present review discusses the concept of CR in the framework of available neuroimaging studies and specifically deals with the reciprocal influences between amyloid PET and CR in AD patients and with the potential consequent interventional strategies for AD.