Magnetic resonance imaging and anatomic atlas mapping for thalamotomy.

A computerized anatomic atlas mapping technique has been developed and used to determine target sites for stereotactic thalamotomies. The digitized stereotactic atlases of Schaltenbrand and Bailey, Van Buren and Borke, and Schaltenbrand and Wahren are used in conjunction with an associated electrophysiological data base to determine the intended target site on MR images of the diencephalon. This mapping technique uses the 'Brierley and Beck' proportional hypothesis for thalamic nuclear determination. Target site determination by this method was found to be very accurate, and frequently the mere placement of the probe in the target site resulted in tremor cessation.