Deep brain stimulation and the treatment of movement disorders

Deep brain stimulation (DBS) is an effective surgical treatment in ameliorating symptoms of Parkinson's disease (PD), dystonia and tremor. DBS involves the surgical insertion of electrode(s) to stimulate either the subthalamic nucleus, globus pallidum interna or ventral intermediate nucleus of the thalamus, depending on the condition being treated. These structures play a critical role in the relay of electrical signals within the basal ganglia to facilitate movement. The mechanism by which DBS improves symptoms is not clearly understood. However, one notion is that the local effects of stimulation cause neuromodulation resulting in subsequent distant effects within connecting neural networks. Important factors to be considered when selecting patients for DBS include establishing a diagnosis, assessment of the patient's levodopa responsiveness if diagnosed with PD, neuropsychological and psychiatric evaluations, and a pre-DBS magnetic resonance imaging scan. Rare complications, such as intracranial haemorrhage, and common complications, such as infection, can occur. On balance, DBS is a highly effective and safe treatment for movement disorders; although, careful patient selection is critical.