Psychophysiologic correlates of nocturnal penile tumescence in normal males.

Despite increasing clinical reliance on nocturnal penile tumescence (NPT) testing for the differential diagnosis of male impotence, little is known at present about the relationship between NPT and other aspects of sleep and waking psychophysiology. This study investigated patterns of NPT, sleep, and EEG hemispheric asymmetry in 20 male subjects, using standard polysomnographic laboratory procedures for the assessment of sleep and NPT, and a method of EEG amplitude integration developed by Goldstein. Additionally, the effects of daytime sexual activity and mood state on the duration and amplitude of NPT were studied. Overall, the results of this study confirmed the well-documented relationship between NPT and stage REM, as well as demonstrating a strong association between NPT phase and nondominant hemisphere activation. Furthermore, this association appeared to strengthen over the course of the night. Hemispheric asymmetry and stage REM were also closely linked throughout. On the other hand, no significant correlations were found between daytime sexual activity or mood state and NPT. It is suggested that concurrent assessment of hemispheric asymmetry may strengthen the diagnostic power of NPT testing in impotence cases involving central organic etiology.

Evaluating control of breathing utilizing an on-line microcomputer.

This paper describes a system that was designed to evaluate ventilatory responses to hypercapnia, airway occlusion pressure (P100), as well as measuring ventilatory drive and timing. Parameters measured include minute ventilation (VE), breathing rate (f), tidal volume (VT), inspiratory time (TI), fractional inspiratory time (TI/TTot), mean inspiratory flow (VT/TI), and end tidal partial pressure of carbon dioxide (PETCO2). These measurements allow for a thorough analysis of abnormalities of neural and neuromuscular ventilatory drive. The system's architecture was based primarily on currently available microcomputer components designed for the IEEE 696 bus.

Endorphins and the control of breathing. Ability of naloxone to restore flow-resistive load compensation in chronic obstructive pulmonary disease.

Since narcotic drugs profoundly depress breathing, we tested whether endogenous opioids influenced control of breathing in chronic obstructive pulmonary disease (COPD), reasoning that the stress of chronic dyspnea might cause elaboration of "endorphins." In 14 patients with COPD (but without respiratory failure) and eight normal controls, we measured ventilation, mechanical lung function, respiratory sensitivity to carbon dioxide, and the increase in respiratory effort elicited by an increase in resistance to breathing; each measurement was performed before and after administration of the opiate antagonist naloxone. Before naloxone, increased resistance to breathing enhanced respiratory effort in all controls, but seven of 14 patients with COPD had no response. After naloxone, these seven patients had load responses. Furthermore, the respiratory effort elicited by the resistance also increased after the drug was given to the patients who had had a response. These data suggest that endorphin elaboration minimizes the stress of chronic airway obstruction.