Glial activation measured by in vivo [11C]‐PBR28 positron emission tomography (PET) is increased in pathologically relevant regions in people with amyotrophic lateral sclerosis (ALS) and correlates with clinical measures, according to a recent study. 85 participants—including 53 ALS, 11 primary lateral sclerosis (PLS), and 21 healthy controls—underwent integrated [11C]‐PBR28 PET‐MR brain imaging. Patients were clinically assessed using the upper motor neuron burden (UMNB), and the revised ALS functional rating scale (ALSFRS‐R). [11C]‐PBR28 uptake was quantified as standardized uptake value ratio (SUVR), and compared between groups. Cortical thickness and fractional anisotropy were compared between groups and correlated with SUVR and the clinical data. Researchers found:
- Whole brain voxel‐wise, surface‐based, and region of interest analyses revealed increased [11C]‐PBR28 uptake in the precentral and paracentral gyri in ALS, and in the sub‐cortical white matter for the same regions in PLS, compared to controls.
- The increase in [11C]‐PBR28 uptake co‐localized and correlated with cortical thinning, reduced fractional anisotropy, increased mean diffusivity, and correlated with higher UMNB score.
- No significant changes were detected in [11C]‐PBR28 uptake over 6 months despite clinical progression.
Alshikho MJ, Zürcher NR, Loggia ML, et al. Integrated MRI and [11C]‐PBR28 PET imaging in amyotrophic lateral sclerosis. [Published online ahead of print May 8, 2018]. Ann Neurol. doi:10.1002/ana.25251.