Comparison of actual pallidotomy lesion location with expected stereotactic location

Document Type

Article

Abstract

Accuracy of pallidotomy lesion placement was assessed by comparing actual lesion locations with expected pallidotomy lesion locations based on stereotaxy. Actual and expected lesions were compared in anteroposterior, dorsoventral and lateral axes. In 22 pallidotomies, actual lesion locations were determined using axial MR images. Expected lesion locations were calculated using a starting point derived from preoperative computerized tomography, displacements from the starting point based on microelectrode- driven electrophysiological refinement, and the trajectory angle of the lesioning tract relative to the anterior-posterior commissural plane. On average, actual lesion locations were found 2.91 ± 2.23 mm posterior, 3.22 ± 2.49 mm ventral, and 0.05 ± 1.80 mm lateral compared to the expected lesion location. Discrepancies between the actual lesion and expected lesion locations may be mostly accounted for by posterior and ventral lesion spread from the exposed electrode tip, in-plane and volume averaging effects associated with MR images, and possible brain shifting during surgery. However, despite the remaining small differences between actual and expected lesion location, good clinical outcome of reduced dyskinesias and 'off' time along with UPDRS-based improvement in mentation, motor and activity of daily living measures was observed.

Publication Date

12-1-1998

Publication Title

Stereotactic and Functional Neurosurgery

ISSN

10116125

Volume

71

Issue

1

First Page

1

Last Page

19

PubMed ID

10072669

Digital Object Identifier (DOI)

10.1159/000029642

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