Chronic dyspnea and hyperventilation in an awake patient with small subcortical infarcts

A 79-year-old woman presented with chronic dyspnea and hyperventilation. Th ere was no evidence of pulmonary disease. Hyperventilation persisted during sleep and after high-dose administration of a narcotic. A head MRI reveale d bilateral medial thalamic infarctions. Central neurogenic hyperventilatio n was diagnosed in this alert patient. The case may illustrate a role for t he thalamus in regulating ventilation, but another small infarct not visibl e on MRI also could be responsible.