<scp>FDG‐PET</scp> Patterns Predict Amyloid Deposition and Clinical Profile in Corticobasal Syndrome
Jacy Bezerra Parmera, Artur Martins Coutinho, Mateus Rozalem Aranha, Adalberto Studart‐Neto, Camila de Godoi Carneiro, Isabel Junqueira de Almeida, Davi Jorge Fontoura Solla, Carla Rachel Ono, Egberto Reis Barbosa, Ricardo Nitríni, Carlos Alberto Buchpiguel, Sônia Maria Dozzi Brucki
Abstract
BACKGROUND: Corticobasal syndrome (CBS) is an atypical parkinsonian syndrome related to multiple underlying pathologies. OBJECTIVE: C]Pittsburgh Compound-B (PIB)-PET. METHODS: Forty-five patients with probable CBS were prospectively evaluated regarding cognitive and movement disorders profile. They underwent FDG-PET and were distributed into groups: likely related to AD (CBS FDG-AD) or likely non-AD (CBS FDG-nonAD) pathology. Thirty patients underwent PIB-PET on a hybrid PET-magnetic resonance imaging equipment to assess their amyloid status. FDG and PIB-PET images were classified individually based on visual and semi-quantitative analysis, blinded to each other. Quantitative group analyses were also performed. RESULTS: CBS FDG-AD group demonstrated worse cognitive performances, mostly concerning attention, memory, visuospatial domains, and displayed more myoclonus and hallucinations. The non-AD metabolic group presented more often limb dystonia, ocular motor dysfunction, motor perseveration, and dysarthria. All patients classified as CBS FDG-AD tested positive at PIB-PET compared to 3 of 20 in the non-AD group. The individual FDG-PET classification demonstrated 76.92% of sensitivity, 100% of specificity and positive predictive value and 88.5% of balanced accuracy to detect positive PIB-PET scans. Individuals with positive and negative PIB-PET showed hypometabolism in posterior temporoparietal areas and in thalamus and brainstem, respectively, mainly contralateral to most affected side, disclosing possible metabolic signatures of CBS variants. CONCLUSION: FDG-PET was useful to predict AD and non-AD CBS variants depicting their specific degeneration patterns, different clinical features, and brain amyloid deposition. © 2020 International Parkinson and Movement Disorder Society.