Deep Brain Stimulation Shape and Surface Characteristics: Electrical and Mechanical Design Goals

Abstract

O ne of the many risks associated with deep brain stimulation (3, 14) is the possibility of lead migration. Although typically this is defined as a large shift in lectrode position from the original placement (i.e., as identified y a change from immediate fluoroscopy to later imaging), there ould also be a more subtle shift in position due to normal brain ovement within the skull as a result of body posture and brain ulsation, replacement of cerebrospinal fluid postoperatively (i.e., s the air that enters during the procedure is later slowly emoved), or pathologically, such as with development of subural fluid or hematoma (6). The Parittotokkaporn et al. article ntroduces the concept of “microtexturing” the electrode to revent small scale shifts, with small “barbs” microfabricated on he surface of the semiconductor electrode so that the electrode s more stable within the brain over time. It is not clear whether echanically this would prevent large postoperative shifts in lectrode position (e.g., due to tugging or pulling while tunneling), ut the force required to displace or pull out the electrode ncreased significantly in the study, both within the brain as well s particularly when the burr hole cover was modified, when the lot for the electrode exit was microtextured. It is not clear hether this type of surface treatment could be performed on xisting materials (i.e., the Pt/Ir metal used for deep brain timulation [DBS] electrodes), but this type of microtexturing ertainly could be added to the exit slot on various forms of burr ole covers to prevent movement of the DBS electrode within he cover itself. Possible deleterious side effects of the microexturing of the DBS electrode itself include increased damage to he brain when purposefully retrieving the electrode, as opposed o the current, smooth DBS electrode, which typically pulls out ery easily when needed, and causes minor brain damage (13).