The authors describe a patient who experienced stereotypical episodes of dyspnea and presyncopal sensation without loss of consciousness during a 4-month period. Further evaluation established intermittent arterial O 2 desaturations associated with this dyspnea. After an extensive cardiopulmonary workup was performed for presumptive diagnosis of pulmonary embolism, a brain magnetic resonance image revealed a right medial temporal lobe lesion. The patient's dyspnea was then suspected to be a symptom of a seizure. His shortness of breath and O2 desaturation resolved with administration of phenytoin. This case, to the authors' knowledge, is the first documented example of simple partial seizures presenting with episodic autonomic cardiopulmonary symptoms in the absence of other ictal behavior. This case may also illustrate one specific limbic autonomic network.