Autonomic function and motility in intestinal pseudoobstruction caused by paraneoplastic syndrome.

This report documents the occurrence of chronic intestinal pseudoobstruction in association with a small cell carcinoma of the lung with evidence of pre- and postganglionic sympathetic dysfunction in one patient with brain metastases, and with sympathetic and parasympathetic postganglionic dysfunction in a second patient. A strategy is outlined for the identification and characterization of disordered neural control of gut motility. This strategy utilizes gastrointestinal motility studies to confirm gut neuropathy, autonomic function tests, and plasma norepinephrine responses to intravenous edrophonium to identify the level of dysfunction. These cases are compared with others in the literature, and the occult nature of these cancers, the spectrum of symptoms suggesting autonomic dysfunction on presentation, and the occasional response of the neurologic deficit to treatment of the malignancy are highlighted.