The neuroradiology of upper motor neuron degeneration: PLS, HSP, ALS.

While correlations between CST metrics and motor disability are confounded by co-existing lower motor neuron degeneration in ALS ([8]), these are pertinent to upper motor neuron predominant disorders such as PLS and HSP ([9]). In this edition of Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, Navas-Sánchez et al. present an intriguing study of motor cortex and corticospinal tract (CST) degeneration in hereditary spastic paraparesis type 4 (SPG4) ([7]). Curr Opin Neurol. 2018; 31: 431 - 8. 16 Schuster C, Elamin M, Hardiman O, Bede P. The segmental diffusivity profile of amyotrophic lateral sclerosis associated white matter degeneration. The neuroimaging literature of motor neuron diseases is dominated by studies in ALS ([1],[2]). [Extracted from the article]