Surgical Treatment of Tremor

Abstract

Tremor can be a disabling movement disorder that interferes with activities of daily living and lowers quality of life. About one half of all patients with essential tremor (ET) fail to respond to pharmacologic therapy, and other forms of tremor are also difficult to control. 1 When pharmacologic treatment of tremor fails, surgery often is a good option for the properly selected patient. Surgical treatment for ET using deep brain stimulation (DBS) of the ventrolateral thalamus typically improves limb tremor by 60-70% and activities of daily living by over 50%, with relatively minimal side effects. 1 This overview examines the history of tremor surgery, describes the different types of surgeries, discusses selection and clinical management of surgical patients, and reviews outcome studies of tremor surgery. Historical Evolution of the Surgical Treatment of Tremor Before the modern pharmacologic era, surgical treatment of tremor and other movement disorders was the only option available to patients. During the 20th century, many different surgical procedures were attempted to reduce disabling tremor of various etiologies, primarily Parkinson’s disease (PD). The schematic in Fig 1 illustrates these numerous anatomical targets for surgical treatment of tremor. In their review of the history of surgery for PD, Speelman and Bosch 2 describe 2 eras of surgery for movement disorders—“open” (1912-1947) and “closed” (1947 to today). The difference between the 2 is that “open” surgery involved removal of overlying structures to allow access to deeper structures, whereas “closed” surgery involved the use of stereotactic techniques developed by Spiegel and Wycis to access deeper structures. Surgical techniques have improved over time, resulting in better relief of tremor and less morbidity from more restricted, focal intervention. What began as a crude removal of motor cortex or cutting of