C9orf72 and amyotrophic lateral sclerosis: Despite pioneering spinal papers [47,67,96,103,107] and ample examples from brain imaging [70], pre-symptomatic spinal imaging has a strikingly limited literature despite the fact that many motor neuron and neurodegenerative diseases are genetic (HSP, SCA, SOD1-ALS, C9orf72-ALS, etc.)With very few exceptions [140], in the absence of complementary post-mortem data, the histopathological correlates of in vivo spinal signal alterations are not described.