Current Insight for the Etiology and Pathogenesis of Essential Tremor

Essential tremor (ET) is one of the most common neurological disorders. The main manifestation of the ET is upper-limb action tremor, often accompanied by other motor as well as non-motor symptoms. Modern therapeutic options for the treatment of ET are limited due to a limited understanding of the etiology, pathomorphology and pathogenesis of ET. There are several risk factors for ET: elderly age, family history, genetic predisposition, environmental factors (organochlorine pesticides, ethanol, lead and mercury compounds, beta-carboline alkaloids). At the pathomorphological level, degenerative changes of the cerebellum and, less often, pathological changes in the locus coeruleus, substantia innominata, dorsal nucleus of the vagus nerve, substantia nigra and other parts of the brain are detected in ET. The inferior olive, cerebellum, nucleus ruber, thalamus and cerebral cortex, combined into a single cerebello-thalamo-frontal system, are involved in the pathogenesis of ET. There are several different hypotheses of the mechanisms of tremor occurrence: the neurodegenerative hypothesis, the hypothesis of the central oscillatory network, the GABAergic hypothesis and the hypothesis of the effects of β-carboline alkaloids