Characterization of dysphagia in a canine model of late infantile neuronal ceroid lipofuscinosis

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Late Infantile Neuronal Ceroid Lipofuscinosis, also known as CLN2, is the most common form of Batten disease in children. Nearly all children with CLN2 develop dysphagia that necessitates feeding tube placement. Pneumonia is the most common cause of death, typically occurring by 15 years of age. Despite the prevalence and the devastating outcome of dysphagia in CLN2-affected children, limited research exists. The purpose of this study was to characterize dysphagia in CLN2 using a naturally occurring canine model that develops neurological symptoms ~6 months of age and dies ~11 months of age. Eleven dachshunds (5 CLN2-affected and 6 healthy, age-matched controls) were tested using a freely behaving videofluoroscopic swallow study (VFSS) protocol established in our lab. Affected dogs were tested between one and three times and unaffected dogs were tested between one and five times from 6 to 10 months of age. VFSS recordings were analyzed to quantify 5 swallow parameters: time to maximal pharyngeal constriction, time to proximal esophageal sphincter closure, inter-swallow interval, pharyngeal constriction ratio, and penetration-aspiration. Only videos for 10-month-old dogs have been analyzed to date. Compared to age-matched controls, inter-swallow interval was significantly longer for CLN2-affected dogs (p<0.05) when drinking thin liquid, indicative of oral stage dysphagia. One of the affected dogs aspirated thin liquids during the swallow, indicative of pharyngeal dysphagia. No significant differences were identified for the other three swallow parameters. This study provides novel evidence that CLN2-affected dogs develop dysphagia and are therefore suitable for further dysphagia research.