Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus interna (GPi) is considered an essential therapy in the management paradigm of Parkinson's disease (PD). Its success stems essentially from its remarkable efficacy and, compared to the lesions created with thalamotomy and pallidotomy, its flexibility through programming that allows modification of the stimulation delivered to the precise brain targets, thereby obtaining maximal benefit with minimal side effects. In light of the impressive pace of advances in DBS technology, relentless exploration of new targets, development of programming paradigms, and continued controversy on patient selection and timing of DBS surgery, a special issue on this fascinating topic is pertinent and timely.e choice of the DBS target between STN and GPi is driven by the constellation of motor and nonmotor symptoms which are key determinants to quality of life. U. Yazdani et al. discuss the pros and cons of each target and emphasize the need for these considerations while determining the final choice in a given individual. A widely accepted notion is that GPi DBS causes less cognitive decline than STN DBS and can be considered as the preferred target in PD patients with preoperative cognitive impairment. R. Mehanna et al. reevaluate this issue in a review of 72 studies totaling 2,410 STN DBS patients and 702 GPi DBS patients and draw a set of recommendations regarding the cognitive impact of DBS in PD patients.While STN and GPi are the main targets of DBS in PD patients as they alleviate a broader spectrum of motor symptoms, in contrast to Vim which helps primarily with tremors [1], the benefit of their stimulation on axial and nonmotor symptoms is limited [2]. D. Anderson et al. describe the role of emerging alternative DBS targets such as the pedunculopontine nucleus, caudal zona incerta, substantia nigra pars reticulata, and the motor cortex for control of axial symptoms such as freezing, postural instability, gait, speech, and swallowing and nonmotor symptoms such as memory impairment, attention decline, and sleep disturbances in PD patients. Although initial reports are promising, carefully designed and larger controlled studies are required to verify the efficacy of these alternative DBS targets.In addition to appropriate patient screening and target selection, careful programming is critical for a positive clinical outcome. Although general guidelines for DBS programming are available, a systematic protocol is lacking. Programming can thus be challenging, time-consuming, and laborintensive. Nevertheless, with the advent of technological improvements, programming algorithms are expected to become more effective and less frustrating. A. Wagle Shukla et al. review the current approaches to DBS programming and summarize the most recent advances in the DBS field, including interleaving of DBS pulses, fractionated current, directional steering of current, use of biphasic DBS pulses, and closed-loop stimulation. e authors also discuss the role of comput...