Periodic breathing and dysphagia associated with a localized lateral medullary infarction.

A 77-year-old man experienced sudden onset of dysphagia. An MRI revealed a left lateral medullary infarction. Portable polysomnography showed Cheyne-Stokes-like breathing with marked desaturation (lowest SaO(2) 74%) associated with apnoea. Oxygen administration reduced the apnoea-hypopnoea index from 30.1 to 20.0 per hour. Sustained periodic breathing under normoxaemia suggested that the brainstem lesion, rather than peripheral factors such as prolonged lung-chemoreceptor circulatory delay, was responsible for the abnormal breathing. Polysomnography or overnight SaO(2) monitoring should be considered for patients with dysphagia due to a brainstem lesion, to investigate the possible presence of abnormal breathing.