ABSTRACT
Essential tremor is one of the most common adult movement disorders (1). The
reported prevalence of essential tremor varies from 1% to 22% (2) though based
on the most recent data of a door-to-door survey it is estimated to be 4% (3). The
incidence of essential tremor increases with age (4). The etiology of essential
tremor remains unknown though genetic factors play a clear role (2). The patho-
physiology of essential tremor is also not completely understood though it is
believed that essential tremor is a centrally mediated disease with the disturbance
of olivocerebellar pathways implicated as the cause of the clinical symptoms (5).
Essential tremor is characterized by postural and action tremor that typically
involves the upper extremities but also can affect the voice and head. The
success of available pharmacological treatments of essential tremor ranges
between 40% and 65% (6). Frequently use of pharmacological agents can be
limited by the low tolerance of the medications or presence of comorbidity
especially in elderly patients restricting use of the medications. Surgical treat-
ments of essential tremor either by ablative lesioning procedures like thalamot-
omy, or by placing a deep brain stimulator (DBS) in the ventral intermediate
nucleus (VIM) of the thalamus are very effective and provide on average 80%
tremor suppression (7).
