Deep-brain stimulation

Deep-brain stimulation (DBS) is a clinical intervention that has provided remarkable therapeutic benefits for otherwise treatment-resistant movement and affective disorders. The resulting direct causal manipulation of both local and distributed brain networks is not only clinically helpful but can also help to provide novel fundamental insights into brain function. In particular, DBS can be used in conjunction with methods such as local field potentials and magnetoencephalography to map the underlying mechanisms of normal and abnormal oscillatory synchronization in the brain. The precise mechanisms of action for DBS remain uncertain but here we present an overview of the clinical efficacy of DBS, its neural mechanisms and potential future applications. Deep-brain stimulation (DBS) in select brain regions has become the basis of highly successful therapies for treating otherwise treatment-resistant movement and affective disorders such as chronic pain, Parkinson's disease, tremor and dystonia [1]. Yet, despite the long history of DBS, its underlying principles and mechanisms are still not clear. DBS directly changes brain activity in a controlled manner , its effects are reversible (unlike those of lesion-ing techniques) and it is one of only a few neurosurgical methods that allows blinded studies. Here we first review the proven clinical efficacy of DBS for movement, affective and non-movement disorders, as well as the safety and potential complications of DBS. We then show how translational research has led to novel DBS targets for Parkinson's disease, specifically addressing the recent promising development of a new target in the brainstem nucleus, the pedunculopontine nucleus (PPN). We then review some of the relevant experimental evidence for the underlying mechanisms for DBS. This forms the basis of the proposed model for how DBS might work. Finally, we review some of the future perspectives for refining and expanding DBS. DBS is not, however, only a remarkably useful clinical intervention but the causal, interventional nature of DBS also has great potential to help us unravel the fundamental mechanisms of human brain function. This potential can be harnessed by combining DBS with noninvasive neuroimaging methods, such as magnetoencephalography (MEG), which offer the possibility of mapping the spatio-temporal unfolding of DBS-elicited whole-brain activity, including the normal and abnormal oscillatory synchronizations. DBS for movement disorders Modulation of brain activity by way of direct electrical stimulation of the brain has been in use at least since 1870, when Fritsch and Hirtzig demonstrated that stimulation of the motor cortex of the dog can elicit limb …