Prevalence of Essential Tremor (ET)
Essential tremor (ET) affects approximately 0.9% of the general population, with an estimated prevalence of 134,000 cases in the United States. 1
Epidemiology of Essential Tremor
Essential tremor is one of the most common neurological movement disorders. According to the National Comprehensive Cancer Network (NCCN) guidelines, the prevalence of ET in the United States is estimated to be approximately 134,000 cases 1. This makes ET significantly more common than myelofibrosis (13,000 cases) but less common than polycythemia vera (148,000 cases).
Age-Related Factors
ET prevalence increases with age, with important clinical implications:
- ET rarely presents with head tremor before the age of 36 2
- Younger patients (<40 years) with long-duration tremor (≥10 years) rarely develop head tremor (7.4%) compared to older patients (>60 years) with similar tremor duration (42.8%) 2
- The appearance of head tremor depends more on the patient's biological age than on disease duration 2
Disease Progression
ET is a chronic and progressive neurological disease with significant impact on patients' quality of life:
- ET is characterized by a 4-12Hz kinetic tremor that occurs during voluntary movements 3
- The disease is progressive, with most patients experiencing worsening symptoms over time
- In longitudinal studies, approximately two-thirds (63.4%) of ET patients report worsening symptoms at half or more of their follow-up evaluations 4
- One in four patients (26.8%) report worsening at every follow-up evaluation, suggesting consistent deterioration 4
Treatment Considerations
For patients diagnosed with ET, treatment options should be considered when tremor causes functional disability:
- Current medications can improve tremor in approximately 50% of patients 5
- First-line pharmacological treatments include primidone and propranolol 5
- More than 30% of patients are completely unresponsive to current pharmacotherapies 6
- Deep brain stimulation of the motor thalamus is the most effective treatment for medication-resistant cases 6
Clinical Implications
The high prevalence of ET and its progressive nature have important clinical implications:
- ET is not a static or benign condition but rather a progressive disorder that patients experience as consistently worsening 4
- The disease appears to be neurodegenerative, with research increasingly identifying the cerebellum as the primary site of pathology 3
- ET may represent not a single disease but a family of diseases with kinetic tremor as the central defining feature 3
- ET appears to be a risk factor for other neurodegenerative conditions including Alzheimer's disease and Parkinson's disease 3
Understanding the prevalence and progressive nature of ET is essential for proper patient education, treatment planning, and long-term management of this common neurological disorder.