ET cases that progress to Parkinsons disease are less likely to have had cerebellar problems. Recent neuroimaging studies have suggested that the efficiency of the overall brain functional network in ET is disrupted. Recent post mortem studies have evidenced alterations in (leucine-rich repeat and Ig domain containing 1 (LINGO1) gene and GABA receptors in the cerebellum of people with essential tremor. HAPT1 mutations have also been linked to ET, as well as to Parkinsons disease, multiple system atrophy, and progressive supranuclear palsy.In 2012, the National Toxicology Program concluded that sufficient evidence exists of an association between blood lead exposure at levels >10 μg/dl and essential tremor in adults, and limited evidence at blood lead levels >5 μg/dl. Diagnosis
Usually, the diagnosis is established on clinical grounds. Tremors can start at any age, from birth through advanced ages (senile tremor). Any voluntary muscle in the body may be affected, although the tremor is most commonly seen in the hands and arms and slightly less commonly in the neck (causing the persons head to shake), tongue, and legs. A resting tremor of the hands is sometimes present. Tremor occurring in the legs might be diagnosable as orthostatic tremor. ET occurs within multiple neurological disorders besides Parkinsons disease. This includes migraine disorders, where co-occurrences between ET and migraines have been examined. Treatment
General measures
Not all individuals with ET require treatment, but  many treatment options are available depending on symptom severity. Caffeine and stress should be avoided, and adequate good-quality sleep is recommended.
ET is generally progressive in most cases (sometimes rapidly, sometimes very slowly), and can be disabling in severe cases. Epidemiology
ET is one of the most common neurological diseases, with a prevalence around 4% in persons age 40 and older and considerably higher among persons in their 60s, 70s, and 80s, with an estimated 20% of individuals in their 90s and over. Aside from enhanced physiological tremor, it is the most common type of tremor and one of the most commonly observed movement disorders. Society and culture
Actress Katharine Hepburn (1907–2003) had an essential tremor, possibly inherited from her grandfather, that caused her head—and sometimes her hands—to shake. The tremor was noticeable by the time of her performance in the 1979 film The Corn Is Green, when critics mentioned the "palsy that kept her head trembling". Hepburns tremor worsened in her later life.Charles M. Schulz, American cartoonist and creator of the Peanuts comic strip, was affected during the last two decades of his life. West Virginia Senator Robert Byrd also had essential tremor. In 2010, musician Daryl Dragon of The Captain and Tennille was diagnosed with essential tremor, with the condition becoming so severe that Dragon was no longer able to play the keyboards.Director-writer-producer-comedian Adam McKay was diagnosed with essential tremor.Downton Abbey creator Julian Fellowes has the condition, as does the shows character Charlie Carson.In 2022, Matthew Caws of Nada Surf and his son made a PSA called "Living with a Mild Essential Tremor". Research
Harmaline is a widely used model of essential tremor (ET) in rodents.