Essential tremor: Update of therapeutic strategies (medical treatment and gamma knife thalamotomy).

Tremor is a highly prevalent movement disorder that markedly reduces quality of life. The management of severe tremor is particularly challenging. Pharmacological treatment is available, but no real breakthrough has emerged recently. Propranolol and primidone are still the two most recommended agents, followed by topiramate. However, surgical treatments for medically refractory tremors are expanding. Gamma knife (GK) thalamotomy is an option particularly suitable for patients who are not candidates for deep brain stimulation. Owing to the fact that it is a non-invasive procedure without craniotomy, GK radiosurgery has almost no contraindications. Since the late 1990s, more than 250 case reports and patient series have been published. Most of these studies show that unilateral GK thalamotomy is well tolerated and reduces tremor disability. A recent study with prospective blinded assessment has confirmed its safety, together with significant improvements in tremor scores and activities of daily living.