News and controversies regarding essential tremor.

Essential tremor is the most common movement disorder in adults. It is characterized by a postural and kinetic tremor affecting the arms, but it can also affect other body parts. It evolves gradually and can be responsible for a functional impairment in activities of daily living. Its pathophysiology remains poorly understood and effective therapeutic options are limited. There are significant semiological variations between patients, and the term "essential tremor" seems to encompass a wide range of heterogeneous clinical phenotypes. The diagnostic criteria presented in 1998 are now challenged. Furthermore, there is a current debate concerning the etiology of this affection, as to whether essential tremor is a complex degenerative disorder or a functional reversible disorder of neuronal oscillation. In this review, we summarize some aspects of clinical, etiologic and therapeutic news, to better address the questioning on unravelling the clinical presentation and examine the current pathophysiological controversy in this disorder.