Characterization of Dysphagia and Longitudinal Changes in Swallowing Function in Adults with Niemann-Pick Disease Type C Treated with Miglustat

Niemann-Pick disease type C (NPC) is a rare, autosomal recessive neurodegenerative disease, characterized by progressive psychiatric and neurological deficits. Neurological symptoms include cognitive decline and dysphagia. Aspiration pneumonia secondary to dysphagia is a leading cause of death in NPC. Miglustat is currently the only approved disease-specific treatment shown to be effective in stabilizing neurological symptoms. Miglustat has previously been reported to halt or improve early dysphagia and cognitive symptoms. Here we examine the characteristics of dysphagia, the relationship between dysphagia and the presence of cognitive impairment, and longitudinal changes in swallowing function during miglustat treatment in adult-and-adolescent-onset NPC. Retrospective analysis of videofluoroscopic swallow studies (VFSS) was completed for ten adults with NPC (mean age 28.44 years ± 9.34 years). Participants were recruited through the Royal Melbourne Hospital in Australia between 2008 and 2015. The Bethlehem Swallowing Scale and the Penetration-Aspiration Scale were used to quantify VFSS data. Dysphagia was present in 90% of participants at baseline with reduced lingual function and a delayed swallowing reflex as the most common symptoms. Swallow impairment appeared to stabilize during miglustat therapy for periods up to 66 months, with no significant changes in scores (p > 0.05). Data were in accordance with the literature and support the use of miglustat as an efficacious treatment for reducing swallowing impairment and stabilizing cognitive function. Findings provide detailed information on the impairments experienced by patients, give context to events leading to aspiration in NPC and, importantly, inform how management of dysphagia can complement pharmaceutical treatment.