Citations

This study examined the rate of producing alternating motion rates, sequential motion rates (SMRs), and repeated words in 27 individuals with the semantic variant of Primary Progressive Aphasia (svPPA). Only the rate of producing SMRs was significantly elevated in svPPA compared to controls. This may be associated with concomitant neuropsychiatric symptoms in svPPA, as correlation analysis showed a relationship between increased SMR rate and the Neuropsychiatric Inventory Questionnaire, which documented anxiety and disinhibition. Future studies will assess these findings in a larger cohort and work to better understand if this phenomenon is a manifestation of behavioral and/or motor changes.

AbstractBackgroundElevated uptake of the [18F]AV‐1451 tau‐PET ligand has been observed cross‐sectionally in subjects with progressive supranuclear palsy (PSP). However, it is unknown how the ligand performs longitudinally in PSP. We aimed to determine how regional measures of change on [18F]AV‐1451 PET perform as longitudinal biomarkers of PSP compared with the more established biomarker of rate of midbrain atrophy.MethodsSixteen subjects with PSP underwent 2 serial [18F]AV‐1451 tau‐PET scans and 3‐Tesla MRI over 12 months and were age‐ and sex‐matched to 39 healthy controls with longitudinal [18F]AV‐1451 PET. Median [18F]AV‐1451 uptake was calculated for each scan for regions of interest across the brain and divided by uptake in cerebellar crus to create standard uptake value ratios. Midbrain volume on MRI was also calculated for each scan. Sample sizes required to power placebo‐controlled treatment trials were calculated.ResultsRate of midbrain atrophy was significantly increased in PSP compared with controls. [18F]AV‐1451 regional change measures were significantly increased in PSP compared with controls in the pallidum, precentral cortex, dentate nucleus of the cerebellum, and midbrain. Change over time in the PSP Rating Scale correlated with change in midbrain volume but did not correlate with change in the [18F]AV‐1451 measures. Smallest sample‐size estimates were obtained with rate of midbrain atrophy, followed by the PSP Rating Scale, with both outperforming [18F]AV‐1451 measures.Conclusions[18F]AV‐1451 tau‐PET measures increase over time in subjects with PSP, but longitudinal [18F]AV‐1451 measures may not perform as well as rate of midbrain atrophy as biomarkers for PSP clinical trials. © 2018 International Parkinson and Movement Disorder Society

Background and purposeThe non‐fluent/agrammatic variant of primary progressive aphasia (agPPA) is a heterogeneous diagnosis wherein some individuals have apraxia of speech (AOS). When agPPA includes AOS, a tauopathy is the likely underlying pathology. Recently, [18F]AV‐1451 was developed for the in‐vivo assessment of tau. In this study, we compared patterns of tau tracer uptake in patients with agPPA with and without AOS.MethodsNine patients with agPPA (four without AOS) underwent tau positron emission tomography imaging with [18F]AV‐1451. Uptake of [18F]AV‐1451 was assessed as cortical to cerebellar crus ratio (standard uptake value ratio) in cortical regions of interest measured using the MCALT atlas and compared voxel‐wise in SPM12. Each patient was age‐ and sex‐matched to three controls.ResultsThe agPPA without AOS showed uptake in the left frontal and temporal lobes, whereas agPPA with AOS showed uptake in the bilateral supplementary motor areas, frontal lobes, precuneus and precentral gyrus relative to controls. The left precentral gyrus had uptake in agPPA with AOS relative to those without AOS.ConclusionsThis cross‐sectional study suggests that [18F]AV‐1451 uptake in the precentral gyrus is implicated in AOS in agPPA.