Summary

We report a case of a typical MRI from a patient with bulbar-onset sporadic amyotrophic lateral sclerosis associated with Chiari type 1 malformation. Our report reinforces the conventional neuroimaging appearance associated with each condition and the associated abnormalities on a clinical and advanced imaging techniques basis. The MRI signal intensity was useful for detecting upper motor neuron degeneration based on corticospinal tract signal intensity, while diffusion tensor imaging parameters were limited to this purpose. Our description reinforces the relevance of the T1 magnetisation transfer sequence to demonstrate corticospinal tract degeneration and corroborate an amyotrophic lateral sclerosis diagnosis in an individual participant, when there is a potential concurrent ‘amyotrophic lateral sclerosis mimic syndrome’. To our knowledge, this is the first description of the non-conventional MR techniques applicability to distinguish the impact of amyotrophic lateral sclerosis from Chiari 1 malformation.