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.
A focal lung pneumatosis,  is an enclosed pocket of air or gas in the lung and includes blebs, bullae, pulmonary cysts, and lung cavities. Blebs and bullae can be classified by their wall thickness. A bleb has a wall thickness of less than 1 mm. By radiology definition, it is up to 1 cm in total size. By pathology definition, it originates in the pleurae (rather than in the lung parenchyma). A bulla has a wall thickness of less than 1 mm. By radiology definition, it has a total size of greater than 1 cm. By pathology definition, it originates in the lung parenchyma (rather than in the pleurae). A lung cyst has a wall thickness of up to 4 mm. A minimum wall thickness of 1 mm has been suggested, but thin-walled pockets may be included in the definition as well. A cavity has a wall thickness of more than 4 mm.The terms above, when referring to sites other than the lungs, often imply fluid content. Lung cysts are seen in about 8% of the general population, with an increased prevalence in older people, and are not associated with emphysema. They may be part of the aging changes of the lungs, and cause a slight decrease in their diffusing capacity. The presence of multiple pulmonary cysts may indicate a need to evaluate the possibility of bullous or cystic lung diseases. Cavitation indicates workup for serious infection or lung cancer.