In 2020, the Guidelines Task Force conducted another systematic review of the relevant literature on deep brain stimulation (DBS) for obsessive-compulsive disorder (OCD) to update the original 2014 guidelines to ensure timeliness and accuracy for clinical practice.
To conduct a systematic review of the literature and update the evidence-based guidelines on DBS for OCD.
The Guidelines Task Force conducted another systematic review of the relevant literature, using the same search terms and strategies as used to search PubMed and Embase for relevant literature. The updated search included studies published between 1966 and December 2019. The same inclusion/exclusion criteria as the original guideline were also applied. Abstracts were reviewed and relevant full-text articles were retrieved and graded. Of 864 articles, 10 were retrieved for full-text review and analysis. Recommendations were updated according to new evidence yielded by this update.
Seven studies were included in the original guideline, reporting the use of bilateral DBS as more effective in improving OCD symptoms than sham treatment. An additional 10 studies were included in this update: 1 class II and 9 class III.
Based on the data published in the literature, the following recommendations can be made: (1) It is recommended that clinicians utilize bilateral subthalamic nucleus DBS over best medical management for the treatment of patients with medically refractory OCD (level I). (2) Clinicians may use bilateral nucleus accumbens or bed nucleus of stria terminalis DBS for the treatment of patients with medically refractory OCD (level II). There is insufficient evidence to make a recommendation for the identification of the most effective target.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/deep-brain-stimulation-obsessive-compulsive-disord.

Is bilateral subthalamic nucleus deep brain stimulation (STN DBS) more, less, or as effective as bilateral globus pallidus internus deep brain stimulation (GPi DBS) in treating motor symptoms of Parkinson\'s disease, as measured by improvements in Unified Parkinson\'s Disease Rating Scale, part III (UPDRS-III) scores?
Given that bilateral STN DBS is at least as effective as bilateral GPi DBS in treating motor symptoms of Parkinson\'s disease (as measured by improvements in UPDRS-III scores), consideration can be given to the selection of either target in patients undergoing surgery to treat motor symptoms. (Level I).
Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in allowing reduction of dopaminergic medication in Parkinson\'s disease?
When the main goal of surgery is reduction of dopaminergic medications in a patient with Parkinson\'s disease, then bilateral STN DBS should be performed instead of GPi DBS. (Level I).
Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in treating dyskinesias associated with Parkinson\'s disease?
There is insufficient evidence to make a generalizable recommendation regarding the target selection for reduction of dyskinesias. However, when the reduction of medication is not anticipated and there is a goal to reduce the severity of \"on\" medication dyskinesias, the GPi should be targeted. (Level I).
Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in improving quality of life measures in Parkinson\'s disease?
When considering improvements in quality of life in a patient undergoing DBS for Parkinson\'s disease, there is no basis to recommend bilateral DBS in 1 target over the other. (Level I).
Is bilateral STN DBS associated with greater, lesser, or a similar impact on neurocognitive function than bilateral GPi DBS in Parkinson disease?
If there is significant concern about cognitive decline, particularly in regards to processing speed and working memory in a patient undergoing DBS, then the clinician should consider using GPi DBS rather than STN DBS, while taking into consideration other goals of surgery. (Level I).
Is bilateral STN DBS associated with a higher, lower, or similar risk of mood disturbance than GPi DBS in Parkinson\'s disease?
If there is significant concern about the risk of depression in a patient undergoing DBS, then the clinician should consider using pallidal rather than STN stimulation, while taking into consideration other goals of surgery. (Level I).
Is bilateral STN DBS associated with a higher, lower, or similar risk of adverse events compared to GPi DBS in Parkinson\'s disease?
There is insufficient evidence to recommend bilateral DBS in 1 target over the other in order to minimize the risk of surgical adverse events.  The full guideline can be found at: https://www.cns.org/guidelines/deep-brain-stimulation-parkinsons-disease.

OBJECTIVE: To provide recommendations to patients, physicians, and other health care providers on several issues involving deep brain stimulation (DBS) for Parkinson disease (PD).
METHODS: An international consortium of experts organized, reviewed the literature, and attended the workshop. Topics were introduced at the workshop, followed by group discussion.
METHODS: A draft of a consensus statement was presented and further edited after plenary debate. The final statements were agreed on by all members.
CONCLUSIONS: (1) Patients with PD without significant active cognitive or psychiatric problems who have medically intractable motor fluctuations, intractable tremor, or intolerance of medication adverse effects are good candidates for DBS. (2) Deep brain stimulation surgery is best performed by an experienced neurosurgeon with expertise in stereotactic neurosurgery who is working as part of a interprofessional team. (3) Surgical complication rates are extremely variable, with infection being the most commonly reported complication of DBS. (4) Deep brain stimulation programming is best accomplished by a highly trained clinician and can take 3 to 6 months to obtain optimal results. (5) Deep brain stimulation improves levodopa-responsive symptoms, dyskinesia, and tremor; benefits seem to be long-lasting in many motor domains. (6) Subthalamic nuclei DBS may be complicated by increased depression, apathy, impulsivity, worsened verbal fluency, and executive dysfunction in a subset of patients. (7) Both globus pallidus pars interna and subthalamic nuclei DBS have been shown to be effective in addressing the motor symptoms of PD. (8) Ablative therapy is still an effective alternative and should be considered in a select group of appropriate patients.

The advent of deep brain stimulation (DBS) has been an important advance in the treatment of Parkinson\'s disease (PD). DBS may be employed in the management of medication-refractory tremor or treatment-related motor complications, and may benefit between 4.5% and 20% of patients at some stage of their disease course. In Australia, patients with PD are reviewed by specialised DBS teams who assess the likely benefits and risks associated with DBS for each individual. The aim of these guidelines is to assist neurologists and general physicians identify patients who may benefit from referral to a DBS team. Common indications for referral are motor fluctuations and/or dyskinesias that are not adequately controlled with optimised medical therapy, medication-refractory tremor, and intolerance to medical therapy. Early referral for consideration of DBS is recommended as soon as optimised medical therapy fails to offer satisfactory motor control.