Dysphagia is prevalent in patients with CPEO and single, large-scale deletions in mtDNA

Background: The aim of this study was to assess the frequency of subjective and objective dysphagia in patients with chronic progressive external ophthalmoplegia (CPEO) due to single, large-scale deletions (LSDs) of mitochondrial DNA (mtDNA). Methods: Sixteen patients with CPEO and single LSDs of mtDNA were included in the study and compared to a control group of 12 patients with the m.3243A > G mtDNA mutation. Patients had to drink 80 ml of water at 4 degrees C as fast as they could (cold-water test) and fill out a standardized questionnaire about dysphagia. Results: Eight patients (50%) with CPEO and single LSDs of mtDNA had a prolonged cold-water test, including one with a PEG-tube, who was unable to perform the test, and nine patients reported subjective swallowing problems (56.3%). All mitochondrial myopathy patients in the control group had a normal duration of the cold-water test. Conclusions: The study shows that dysphagia is a common problem in patients with CPEO and LSDs of mtDNA. Dysphagia seems to be progressive with age as abnormal swallowing occurred preferentially in persons >= 45 years. The study shows that increased awareness of this symptom should be given to address appropriate treatment interventions and avoid complications such as social isolation, malnutrition and aspiration pneumonia. (C) 2016 Elsevier B.V. and Mitochondria Research Society. All rights reserved.