Metabolic brain changes across different levels of cognitive impairment in ALS: a

To identify the metabolic changes related to the various levels of cognitive deficits in amyotrophic lateral sclerosis (ALS) using274 ALS patients underwent neuropsychological assessment and brainWe identified frontal lobe relative hypometabolism in cognitively impaired patients that resulted more extensive and significant across the continuum from ALS-Ci, through ALS-Cbi, to ALS-FTD. ALS-FTD patients also showed cerebellar relative hypermetabolism. ALS-Bi patients did not show any difference compared with ALS-Cn.These data support the concept that patients with cognitive impairment have a more widespread neurodegenerative process compared with patients with a pure motor disease: the more severe the cognitive impairment, the more diffuse the metabolic changes. Otherwise, metabolic changes related to pure behavioural impairment need further characterisation.