Case of familial amyotrophic lateral sclerosis showing gadolinium‐enhanced cranial nerves on magnetic resonance imaging associated with rapid progression of facial nerve palsy

The evaluation of cranial nerves in magnetic resonance imaging (MRI) at early developmental stage has not been established in amyotrophic lateral sclerosis (ALS). A 23‐year‐old man with familial ALS developed peripheral facial nerve palsy, and showed the striking gadolinium enhancement on MRI in those nerves at an early stage. His symptoms progressed rapidly and he died approximately 3 months after onset. We identified a missense mutation in exon 1 of the Cu/Zn superoxide dismutase gene (SOD‐1), resulting in a Cys6Gly (C6G) amino acid substitution. Based on the rapid progression and neurotoxicity resulting from SOD‐1 protein aggregation, the gadolinium enhancement of facial nerves might be caused by the rapid Wallerian degeneration and blood–brain barrier disruption at the early phase of progression.