GFAP and amyotrophic lateral sclerosis: Plasma GFAP did not statistically differ among ALS patients belonging to different Strong’s Categories (p = 0.16) but was higher in ALS patients with associated FTD (230.7 (154–317.9) vs. 157.8 (116.6–225.25), p = 0.042) as compared to pure motor ALS.