Intracranial lesions for the relief of intractable pain or neurologic disease have been produced in 12 patients by a new method developed at the Johns Hopkins University School of Medicine.
A stainless steel "electroseed" measuring 1 mm in diameter and 8 mm in length is implanted subcortically by a stereotactic apparatus. It then can be heated by placing the target area within a radiofrequency electromagnetic field.
The size of the lesion needed for alleviation of symptoms can be determined by judging the amount of relief noted by the patient during the heating procedure, Earl A. Walker, MD, said.
"Using a radiofrequency of 380 kc/sec, this method is apparently safe, and tissue that is not directly associated with the pin is not affected," Dr. Walker said.
In a convention exhibit, Dr. Walker and Charles Burton, MD, showed how the technique was used for disorders causing involuntary motion such as Parkinsonism, as