ABSTRACT
University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
I. Introduction 118
II. The Impact of Essential Tremor on Activities of Daily Living 119
III. Quality of Life in Essential Tremor 120
IV. Neuropsychological Functioning in Patients with Essential Tremor 121
V. Impact of Medical and Surgical Treatments on Neuropsychological
Functioning, ADLs, and QOL 124
A. Pharmacotherapy of Essential Tremor 124
B. Surgical Intervention for Treatment of Essential Tremor 124
1. Thalamotomy 124
2. Changes in Neuropsychological Functioning and ADLs
Associated with Thalamotomy 125
3. Thalamic Deep Brain Stimulation 125
4. Changes in Activities of Daily Living and Quality of
Life Following DBS 126
5. Neuropsychological Changes Associated with
Thalamic DBS 126
VI. Conclusions 127
References 128
I. INTRODUCTION
Essential tremor, one of the most common movement disorders associated with
advanced age, has traditionally been considered benign. However, symptoms
of essential tremor may range from mild tremor that does not warrant medical
treatment, to more severe forms that result in disability and handicap. Severe
tremor is hardly “benign” as it may affect not only the ability to carry out activi-
ties of daily living (ADLs), but social and emotional well being. Patients may
withdraw from social activities due to fear of embarrassment related to such
difficulties as speaking indistinctly and spilling food and beverages, potentially
resulting in worsening of depressive symptoms. Recent research has also
revealed cognitive changes in essential tremor that may further impair an individ-
ual’s ability to function in daily life. Most theoretical models suggest a strong
relationship between functional status and quality of life (QOL). For example,
the model of Wilson and Cleary (1) (Fig. 8.1), which has been used to conceptu-
alize QOL determinants in Parkinson’s disease (2) posits that functional status is
a function of, among other factors, physical and emotional symptoms, and that
functional status is a more proximal determinant of QOL than symptoms or bio-
logical disease variables. It is reasonable to assume then that essential tremor, via
its impact on cognition, emotion, and ADLs, has the potential to exert a signifi-
cant and detrimental impact on QOL. By logical extension, it is probable that suc-
cessful treatments of essential tremor, even if symptomatic rather than curative,
would positively impact QOL. The impact of essential tremor on QOL and its
treatments has been difficult to capture, probably in large part due to the lack
of a disease-specific QOL instrument for essential tremor, and the only very
recent and sparse use of generic QOL measures. This chapter discusses the
Figure 8.1 Model linking clinical variables with health-related QOL. [From Wilson and Cleary (1).]
changes in ADLs, cognitive functioning, and QOL that patients experience as a
consequence of essential tremor and its treatment.
