Related Experiment Videos
Clinical subtypes of essential tremor
E D Louis1, B Ford, L F Barnes
1Neurological Institute, Unit 198, 710 W 168th St, New York, NY 10032, USA.
Archives of Neurology
|August 6, 2000
Summary
Essential tremor (ET) is not a single condition. This study found distinct clinical subtypes of ET based on age of onset, tremor distribution, and progression rate, suggesting varied etiologies and treatment responses.
Area of Science:
- Neurology
- Clinical Neuroscience
Background:
- Essential tremor (ET) exhibits significant clinical variability.
- The existence of distinct ET subtypes with differing etiologies, progression rates, or treatment responses remains unclear.
Purpose of the Study:
- To investigate age of onset, tremor distribution, and progression rate in ET cases.
- To identify associations between these clinical factors in essential tremor.
Main Methods:
- Ascertained ET cases from community (n=60) and referral (n=55) settings.
- Conducted interviews and videotaped tremor examinations.
- Estimated tremor progression rate based on severity and disease duration.
Main Results:
- Age of onset showed a bimodal distribution in clinic-based cases.
- Observed variations in tremor distribution (arm, head, or both).
- Identified an association between older age of onset (>60 years) and more rapid progression; concomitant head tremor slowed upper limb tremor progression.
Conclusions:
- Essential tremor is a heterogeneous condition, not a single entity.
- Identified potential distinct clinical subtypes of ET, particularly those with later onset or without head tremor.
- These subtypes warrant further investigation for etiologic, genetic, and therapeutic heterogeneity.