Tremor.

INTRODUCTION OR
BACKGROUND: Tremor is one of the commonest movement disorders and can be disabling. There are many causes and treatment options include medications, adaptations, botulinum toxin injections and functional neurosurgery. SOURCES OF DATA: Pubmed.gov peer-reviewed journal articles and reviews. AREAS OF AGREEMENT: A new tremor classification has been published. Axis 1 of this classification highlights the clinical characteristics of tremor and axis 2 is dedicated to aetiology. The cerebello-thalamo-cortical network and connections to other brain areas is emerging as pivotal to many types of tremor. AREAS OF CONTROVERSY: There has been ongoing debate around the clinical entity of essential tremor and its pathophysiological basis. GROWING POINTS: Increasing understanding of the pathophysiology underpinning tremor is helping to improve classification and is pushing forward trials of new treatment options, particularly surgical options. AREAS TIMELY FOR DEVELOPING RESEARCH: With deeper phenotyping from the new classification, genetics of common forms of tremor are ripe for discovery. New pharmacological therapeutic options are needed to complement the better understanding of the basis of tremor.