Intraoperative recording with microelectrodes: risks and benefits. It's worth it?

Abstract

The use of electrophysiological mapping techniques for stereotactic targeting has been commonly used in movement disorders surgery. In fact, it has been considered as one of the important surgical aspects for a good clinical outcome, as suggested by neurosurgeons across several basic Functional Neurosurgery Centers. All different mapping techniques provide important information about the basal ganglia structures. Yet, the majority of the functional groups use one of the following neurophysiological techniques: Microrecording mapping or macrostimulation alone.

Microrecording mapping allows the recording of the single-cell action potential and provides important information that facilitates the choice of the best location for placement of Deep Brain Stimulation Electrodes or to make a lesion. As an example: the delimitation of the shape of nucleus, the appreciation of it’s intrinsic somatotopy, receptive fields, and somato-sensorial representations are all possible with the use of microrecording mapping.

The analysis of the comparison between Microrecording and Macrostimulation is difficult because there are no Class I randomized studies addressing this issue. The best evidence comes form the great number of papers published on pallidotomy studies. There seems to be no differences in outcome in patients that underwent pallidotomy with microrecording versus macrostimulation. Similar results are seen in patients treated with STN DBS or subthalamotomy. The literature also shows that there is a tendency for a higher incidence of brain hemorrage with the use of microrecordings. Despite these considerations, more definitive answers as to whether different techniques are associated with differences in the incidence of bleeding will only be provided by Class I evidence studies.