Amyloid PET scan diagnosis of Alzheimer's disease in patients with multiple sclerosis: a scoping review study

BackgroundMultiple sclerosis (MS) is an autoimmune disease affecting the central nervous system. This study aimed to evaluate the advantages and disadvantages of a positron emission tomography (PET) scan method for diagnosing Alzheimer's disease (AD) in MS patients with no clinical symptoms or early-onset AD.Main textTo identify potentially relevant documents, we systematically searched international databases from 2000 to 2021. We abstracted data on article characteristics, ID/country, study, design, population, type of tracer, and outcomes. The primary outcomes were mean amyloid tracer standardized uptake value relative (SUVr), AD diagnosis in MS patients, and the tracer's uptake. Secondary outcomes were the megabecquerel amount of tracer and tracer side effects. Nine studies were finally entered into our research for review. Among the studies included, two studies used 18F-florbetaben, six of these used 11C-Pittsburgh compound B (11C-PiB), and in two studies (18)F-florbetapir (18F-AV1451) was used for imaging. Data from 236 participants were included in this study (145 MS patients, 17 AD patients, 12 mild cognitive impairment patients, and 62 healthy controls).ConclusionsPET scan, especially florbetapir-based radio traces in helping to diagnose early AD, is imperative to use an age-specific cutoff in MS patients to support AD diagnosis.