Thalamotomy In The Infirm Patient

Robert Plunkett1, Kimberly Trinidad2, Steve deBoer1, Matthew Podgorsak1, Dheerendra Prasad1

1Roswell Park Cancer Institute 2 Buffalo General Hospital

Keywords: gamma knife, tremor, thalamotomy, outcome, deep brain stimulation

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Abstract

     Many elderly or chronically ill patients with disabling tremor are not considered candidates for DBS or RF Thalamotomy. 
     Since Gamma Knife Thalamotomy is an option, we reviewed our experience with GK Thalamotomy in the infirm.
     Retrospective review of ten infirm patients with disabling tremor. In seven patients (Group 1: 4 with Essential Tremor, 3 with Multiple Sclerosis) the intent was to restore one functional upper extremity to allow eating, writing, and dressing. The other three patients (Group 2: all with MS) had one functional hand, but the severity of their tremor on the contralateral side rendered the “good” hand useless. The four ET patients ranged in age from 85-90. Co-morbidities for the group included pro-coagulant defects, deep vein thrombosis, atrial fibrillation, poorly compensated congestive heart failure, and paraplegia. 7/10 were on Coumadin.
     Gamma Knife Thalamotomy was done with local anesthesia and minimal sedation. Coordinates were based on the commissures, and we developed a system for internal verification. AP: 1/4 AC-PC plus 1 mm in front of PC. Lateral: 1/2 width of IIIrd ventricle plus 11 mm. Vertical: 2mm above AC-PC plane. 130 Gray was delivered at the 100% isodose line.
     Tremor reduction was noted 4-8 weeks after GK Thalamotomy in 8/10 patients. In Group 1, 5/7 patients had a significant reduction in tremor, but only 4/7 were functionally improved. In Group 1 ET patients, 3/4 achieved a functional reduction in tremor (eating/writing), allowing several to remain at home. Only 1 of 3 MS patients had a functional tremor reduction in Group 1. All three patients in Group 2 had MS with extremely coarse tremor; all three were functionally better after GK Thalamotomy. Improvement was sustained for at least one year. One patient (Group 1, MS) developed mild new leg weakness after thalamotomy.
     This is a retrospective study.
     Gamma Knife Thalamotomy can reduce tremor and restore function in some of the most challenging patients seen by Movement Disorder Neurologists.
     The procedure is well tolerated, even in infirm or elderly patients, and the rate of complications was acceptable. GK Thalamotomy should be in the armamentarium of Comprehensive Movement Disorder Centers.


Acknowledgements

Project Roles:

R. Plunkett (), K. Trinidad (), S. deBoer (), M. Podgorsak (), D. Prasad ()