[11 C]PBB3 binding in Aß(-) or Aß(+) corticobasal syndrome.

ABSTRACT

Corticobasal syndrome (CBS) is associated with 4-repeat tauopathy and/or Alzheimer's disease pathologies. To examine tau and amyloid-ß (Aß) deposits in CBS patients using positron emission tomography (PET). Eight CBS patients and three healthy individuals lacking amyloid pathology underwent PET with [11 C]PBB3 for tau imaging, and [11 C]AZD2184 for Aß. Subcortical and cortical binding of [11 C]PBB3 was compared between Aß(-) and Aß(+) CBS patients and reference group. Postmortem analysis was done in one CBS patient. Three CBS patients were considered Aß(+). Total binding was higher in all patients compared to the reference group. Similar regional binding profiles of [11 C]PBB3 in Aß(+) and Aß(-) CBS patients were found. Elevated [11 C]PBB3 binding in pallidum was observed in all CBS patients. Cortical [11 C]PBB3 binding was higher in Aß(+) compared to Aß(-) patients. Postmortem analysis of a CBS patient revealed corticobasal degeneration neuropathology and [11 C]PBB3 autofluorescence in some tau-positive structures. [11 C]PBB3 is elevated in CBS patients with binding in relevant areas capturing some, but not all, 4-repeat tauopathy in CBS.