In Reply.—It was an intellectual pleasure to follow the erudite speculations of Dr Backon, who has been pioneering a systematic approach to the biochemistry of behavior since his early work as medical research director of the Addiction Studies Foundation of
Mount Pleasant Hospital. Indeed, we also saw a connection between the sudden fear of dying, the sensation of impending doom so prevalent in patients with Hoigne's syndrome, and the panic attack syndrome.1,2
It is quite plausible that procaine could inhibit PGE1, elevating levels of PGE2 and TXA2. In panic attacks, anxiety, depression, and seizure, the TXA2 level may be elevated. The confusional state that is a central feature of Hoigne's syndrome could indeed be understood as resulting from transient ischemia due to increased TXA2 synthesis. The tachycardia and elevation of blood pressure seen in all of our patients may also be due to the effect