Studies of circulatory changes during cough syncope by Sharpey-Schafer1 and by McIntosh et al.2 imply that the mechanism of this syndrome has been satisfactorily explained. Their explanations seem unsuitable in instances of certain patients studied recently. Our results indicate that the term cough concussion may be preferable to cough syncope in certain instances.
Eighteen patients presenting the typical features of cough syncope3 have been observed. Voluntary coughing could produce syncope at will in 5 patients, and 21 episodes were studied in these. In addition to the usual clinical observations made on patients with syncope, electroencephalograms* have been recorded in 11 patients; intra-arterial pressures have been recorded in 10 instances, and an antigravity suit has been used with one subject. Peripheral arterial pressures were recorded from an indwelling Cournand needle in the brachial artery. Central aortic pressures were recorded through a polyvinyl catheter 24 cm. long with