ABSTRACT
I. Introduction 162
II. Pathophysiology of Tremor 162
III. Surgical Options and Indications 164
IV. Thalamotomy 164
V. Thalamic Stimulation 165
VI. Subthalamic Stimulation 166
VII. Methodology 166
A. Selection of Patients and Surgical Types 166
B. Operative Methodology 167
VIII. Follow-Up Care 170
IX. Outcome 171
A. Thalamotomy 171
B. Thalamic Stimulation 172
C. Thalamotomy vs. Thalamic Stimulation 176
D. Subthalamic Stimulation 177
X. Conclusion 177
References 177
I. INTRODUCTION
Tremor is a common involuntary movement disorder, and can arise from various
etiologies (1), with essential tremor being the most common (prevalence between
0.05% and 5.5%) (2). Many patients with tremor syndromes live with substantial
inconvenience before eventually seeking medical advice. The management of
tremor was fairly nihilistic until the 1950-60s at which time both pharmacologi-
cal treatments and stereotactic neurosurgeries were first commonly employed. In
the late 1950s, the ventrolateral thalamus replaced the globus pallidus as a main
surgical target for tremor of various types (3,4). In the 1960s, microelectrode
recording techniques, employed during the course of functional stereotactic
surgery in order to better delineate surgical targets, were introduced by
Albe-Fessard et al. (5) and others. These electrophysiologic studies helped to
determine the ventral intermediate (VIM) nucleus of the thalamus as the
optimal lesioning target for treatment of tremor. Such techniques were commonly
used and thousands of thalamotomies were carried out during the 1950-60s for
tremor from Parkinson’s disease (PD) and essential tremor (6-8). Major limit-
ations encountered with surgical treatments in the first half of the 20th century
included inconsistent targeting and surgical complications.
