Deep brain stimulation for the treatment of movement disorders

Aim: To explore the principles behind deep brain stimulation (DBS), its efficacy and future uses. Method: Research for this paper was carried out using Medline, Google Scholar and UBC’s e-library. Search phrases included: deep brain stimulation, movement disorders, Parkinson’s disease (PD), essential tremor (ET), dystonia and adenosine hyperpolarisation. Papers were limited to those published in English between the years 1995 and 2011, except for adenosine-related articles. Overview: DBS has been approved to treat PD, ET and dystonia. It is an alternative to medication and has replaced ablative surgery. DBS sends electrical impulses to brain nuclei via electrodes. This causes functional inhibition, thus eliminating tremors. The mechanism of action is not known but theories include: hyperpolarisation of overactive neurons; modification of malfunctioning feedback loops; and, down-regulation of hormones and neurotransmitters. These mechanisms are target independent; thus, DBS is being studied to treat non-movement disorders. Conclusion: Despite not understanding DBS’s mechanism of action, its effectiveness is replicable and it has provided patients with clinical improvement. It is currently being studied for use in non-movement disorders. DBS is becoming safer and more effective as patient selection criteria are refined, surgical techniques are improved and patient care evolves. It is expected to become a more common intervention for ET, PD and dystonia.