ABSTRACT
I. Introduction 195
II. Clinical Features of PD 196
III. Etiology of Tremor 198
A. Pathological Data 198
B. Functional Imaging 198
IV. Central vs. Peripheral Tremor Generators 201
A. Peripheral Generator 201
B. Central Generator 201
1. Possible Locations of the Central Oscillator 202
V. Animal Models 205
VI. Therapy 206
A. Medical 206
B. Surgical Therapy 210
VII. Conclusion 211
References 211
I. INTRODUCTION
In 1817, James Parkinson described what is now known as Parkinson’s disease
(PD) in a monograph entitled “An Essay on the Shaking Palsy (1).” In it he
commented on “involuntary tremulous motion, with lessened muscular power, in
parts not in action and even when supported.” This is now recognized as the
classic resting tremor of PD. Resting tremor is one of the cardinal symptoms of
PD along with bradykinesia, rigidity, and postural instability and can often be
the presenting feature of PD. When looking at large series of patients with
autopsy proven PD, it is the most specific sign of idiopathic PD compared to the
other cardinal symptoms (2). Though rest tremor may be absent in patients with
idiopathic PD, it is much more often lacking in the “Parkinson-plus” syndromes.
