Supranuclear gaze palsy in glycine receptor antibody-positive progressive encephalomyelitis with rigidity and myoclonus

摘要

Hexanucleotide expansions"withfrrtfte" first iiitron of the C9ORF72 gene are a significant cause of familial frontotem-poral dementia (FTD) and amyotrophic lateral sclerosis (ALS), alone or in combination, as well as sporadic ALS worldwide. Several recent reports have described cases that broaden the clinical phenotype to include behavioral-variant FTD with or without early psychiatric presentations and parkinsonian features and primary progressive aphasia.6 There is also a report of a patient with a family history of ALS and cerebellar ataxia, an intriguing finding as neu-roimaging of C9ORF72 patients shows cerebellar atrophy, which is not typically observed with other FTD-related mutations such as MAPT or GRN.7 Cerebellar neuronal cytoplasmic inclusions have also been observed in multiple studies, yet clinical cerebellar ataxia has not been detected in any large cohorts of C9ORF72 patients with FTD and/or ALS. Because a majority of adult-onset ataxia cases are of unknown etiology, these observations raise the possibility that C9ORF72 may contribute to the development of sporadic spinocerebellar ataxia.