“Primary Spontaneous Pneumomediastinum” [article in Japanese], K. Togashi and Y. Hosaka, Kyobu Geka, vol. 60, no. 13, December 2007, pp. 1163–6. The authors, at Nagaoka Red Cross Hospital in Japan, explain [AIR 16:1]:
“We report 5 cases of spontaneous pneumomediastinum [air in the space between the lungs]…. 1 patient had a karaoke-related condition. Primary spontaneous pneumomediasinum is a rare condition…. there is no previous report describing karaoke-related spontaneous pneumomediastinum.”