%0 Journal Article %J J Alzheimers Dis %D 2016 %T Clinical Impact of a Second FDG-PET in Atypical/Unclear Dementia Syndromes. %A Bergeron, David %A Beauregard, Jean-Mathieu %A Guimond, Jean %A Fortin, Marie-Pierre %A Houde, Michèle %A Poulin, Stéphane %A Verret, Louis %A Bouchard, Rémi W %A Laforce, Robert %K Adult %K Brain %K Dementia %K Diagnosis, Differential %K Female %K Fluorodeoxyglucose F18 %K Humans %K Male %K Middle Aged %K Positron-Emission Tomography %K Radiopharmaceuticals %K Retrospective Studies %X

Diagnosis of atypical/unclear dementia is often difficult and this delays treatment initiation. Several authors have shown that beyond standard dementia workup, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) reduces the number of unclear diagnoses, leads to earlier treatment, and has a beneficial impact on families. However, it is not uncommon that the FDG-PET findings are equivocal in this setting. For those cases, a repeat FDG-PET may clarify the diagnosis and prevent treatment delay. We retrospectively assessed the clinical impact of a repeat FDG-PET in 59 patients with atypical/unclear dementia syndromes and inconclusive initial FDG-PET. Changes in primary diagnosis, diagnostic confidence, and management following the second FDG-PET were examined. Conducting a second FDG-PET reduced the number of unclear diagnoses from 80% to 34% , led to diagnostic change in 24% of cases, and treatment modification in 22% of patients. Overall, the clinical impact was higher when initial diagnostic confidence was low and the second FDG-PET repeated ≥12 months after the first one. In tertiary care memory clinic settings, when diagnostic incertitude persists despite extensive evaluation and an equivocal FDG-PET, repeating the FDG-PET 12 months later can greatly clarify the diagnosis and improve management.

%B J Alzheimers Dis %V 49 %P 695-705 %8 2016 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/26484904?dopt=Abstract %R 10.3233/JAD-150302