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 °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.