Pallidotomy: A survey of current practice in North America

TWENTY-EIGHT CENTERS COMPLETED a survey about their current practice of pallidotomy. This sample represents a non-exhaustive survey of the current practice of pallidotomy in North America and is not a study of outcomes. 1015 patients underwent 1219 pallidotomies: 811 (80%) unilateral, 72 (7%) staged bilateral, and 132 (13%) simultaneous bilateral. Pallidotomy has long been an accepted procedure and the indications for this surgery, in the opinion of the responding centers, were rated on a scale of 1 (poor) to 4 (excellent) and demonstrated dyskinesia as the best indication (median=4); on-off fluctuations, dystonia, rigidity, and bradykinesia as good indications (median=3); and freezing, tremor and gait disturbances as fair indications (median=2). Most centers used MRI alone (50%) or in combination with CT scan (n=6) or ventriculography (n=5) to localize the target. The median values of pallidal coordinates were: 2 mm anterior to the midcommissural point, 21 mm lateral to the midsagittal plane and 5 mm below the intercommissural line. Microrecording was performed by half of the centers (n=14) and half of the remaining centers were considering starting it (n=7). Main criteria used to define the target included the firing pattern of spontaneous neuronal discharges (n=13) and the response to joint movement (n=10). Most centers performed motor (n=26) and visual (n=23) macrostimulation. Twenty four centers performed test lesions using median values of 55 degrees C temperatures for 30 s. Final lesions consisted of 3 permanent lesions placed 2 mm apart, each lesion created with median values of 75 degrees C temperatures for 1 minute. Median hospital stay was 2 days.