Implantation of deep brain stimulators

Deep brain stimulation (DBS) involves the implantation of electrodes into select regions of the brain, allowing for electrical stimulation of the area to modulate brain activity, resulting in attenuation, if not elimination, of the symptoms and signs of a number of disease states (Table 133-1). The specific site of electrode implantation depends on the disorder for which the patient requires treatment (Figure 133-1). Despite the use of DBS for many decades, the exact mechanism or mechanisms accounting for its clinical efficacy are not well understood, but the electric current is believed to somehow modulate abnormal neuronal function, either by acting directly on neuronal action potentials or altering neurotransmitter release. Use of DBS has generally replaced ablative procedures, such as pallidotomy or thalamotomy (i.e., thermal, mechanical, or electrical destruction of a region of the globus pallidus or thalamus, respectively), for the treatment of Parkinson disease. Unlike these earlier procedures, DBS is reversible.