TSPO and Primary lateral sclerosis: We have previously shown that with [11C]PBR28 whole-brain normalizations, we were able to detect significant increases in TSPO activation in chronic pain [35, 77], primary lateral sclerosis [38], and ALS [33, 40], with strong regional overlap between [11C]PBR28 SUVR60–90 and VT and/or VT ratio (DVR) [32, 77].