Since Laitinen’s report of pallidotomy for the treatment of advanced Parkinson’s disease less than a decade ago, there has been a resurgence of interest in functional neurosurgery for movement disorders. The convergence of several paths, including the clinical problem of levodopa induced dyskinesias and motor fluctuations, increased understanding of cellular pathophysiology, improved brain imaging and microelectrode recording techniques, and the development of deep brain stimulation (DBS), have paved the way for novel therapeutic strategies and major advances in the field. The neurologist must work in partnership with the neurosurgeon in a multidisciplinary team, helping to optimise patient selection, assess patients interoperatively, and supervise drug treatment and stimulation parameters postoperatively. c HISTORY OF MOVEMENT DISORDER SURGERY

Surgery for movement disorders is not new (fig 1). Before 1975, 75 000 thalamotomies had been performed worldwide. The breakthrough in the development of human stereotactic surgery came in 1947 when Speigel and Wycis decided to use landmarks within the brain, rather than the skull. Their first patient had a pallidal lesion for Huntington’s chorea. Parkinsonism (including many postencephalitic cases) was treated with lesions in the thalamus, ansa lenticularis. and pallidum. In 1952, Cooper inadvertently interrupted the anterior choroidal artery in a patient with Parkinson’s disease, and the patient awoke with resolution of tremor and no deficit despite infarction of the globus pallidus. This led to the practice of injecting alcohol into this area. Lesions in the thalamus more reliably abolished tremor, so that by the late 1950s this had become the preferred target, and particularly the ventrointermediate (Vim) nucleus. Following the introduction of levodopa in 1968, stereotactic surgery for Parkinson’s disease was hardly performed and interest in the field waned.