Holmes tremor: an updated review.

Holmes tremor is a rare movement disorder with rest, intention and postural components, characterized by high amplitude and low frequency. It occurs mainly as a result of impairment of dopaminergic nigrostriatal system and cerebellothalamocortical or dentato-rubro-olivary pathways. The aetiologies of this tremor vary widely, including cerebrovascular events, tumours, demyelination and infections. Diagnosis is based on clinical examination, neurophysiological and neuroimaging studies. Magnetic resonance imaging (MRI) scan of the brain is the gold standard method for revealing the location and potential cause of the lesion, whereas dopamine transporter single photon emission with the use of 123I-FP CIT is useful in assessing the functional integrity of the nigrostriatal pathway. Although various treatment options are available, including pharmacological agents, deep brain stimulation and regional surgical techniques, its treatment remains challenging. Our deeper understanding of the disruption of associated neural brain circuits combined with recent genetic and molecular evidence will drastically improve its clinical evaluation and management.