The purpose of this study was to investigate the relative effects of unilateral (left-sided) versus bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) on verbal fluency. To do this, 10 Parkinson's disease patients with predominantly bilateral motor symptoms who received bilateral STN DBS were compared with 6 patients suffering from predominantly unilateral symptoms who received STN DBS on the left side only. The results suggest that unilateral STN DBS of the speech dominant hemisphere is associated with significantly less declines in measures of verbal fluency as compared to bilateral stimulation. (JINS, 2012, 18, 606–611)

The ISG viewing wand is an intra-operative guidance system with a proprioceptive robotic-like jointed arm. It provides surgeons with almost instantaneously reconstructed computer-generated CT or MRI images in two or three dimensions and can correlate any point within the operative field to its corresponding locus on the reformatted scan images. In addition to having been used in over 400 neurosurgical patients in Bristol, 14 patients with skull-base, cerebello-pontine angle or temporal bone lesions have also undergone wand-guided resections. The wand has proved to be particularly useful in pre-operative planning, allowing minimally-invasive incisions, providing per-operative navigation, identifying the relationship and proximity of important anatomical structures and in assessing the extent of lesion resection. We illustrate the advantages of intra-operative image-guidance by discussing four cases. The potential applications of this form of imaging technology to other otolaryngological procedures are discussed.