Showing papers by "Patrick D. Wall published in 1947"

An ensheathed rotating knife for causing brain lesions.

Abstract: When studying the effects of coagulation lesions caused by high-frequency alternating current passing through electrodes in the brain of monkeys, we often noticed that the injury was not confined to the needle tip, but extended along the needle. This additional damage was caused by gas bubbles arising from the point of coagulation from the high temperature of the needle, even when the current was passed for only 10 sec., and from the irregular distribution of the current. The use of direct current often avoids this trouble but has other disadvantages. To avoid the use of electrodes altogether we found the following purely mechanical cutting instrument useful.