Deep brain stimulation in the treatment of severe dystonia

A retrospective study of a consecutive series of 19 patients with medically intractable dystonia treated with uni- or bilateral deep brain stimulation (DBS) is reported. A minimal follow-up of 6 months was available, up to eleven years in one patient. The first twelve consecutive patients (4 with primary and 8 with secondary dystonia) were treated with chronic stimulation of the posterior part of the ventrolateral thalamic nucleus (VLp). In this group global functional outcome was improved in 8 patients, although dystonia movement and disability scale scores did not show significant improvement. Of the 12 patients treated first by VLp DBS, three (1 primary and 2 secondary dystonia) underwent pallidal (GPi) DBS after the VLp DBS failed to improve their symptoms. The last seven consecutive patients (5 primary and 2 secondary dystonia) were treated directly with GPi DBS. Extracranial infection prevented chronic GPi DBS in one patient. In another GPi patient, preliminary negative tests with the electrodes discouraged implantation of the stimulators, and the patient was not treated with chronic DBS. In the remaining group of eight patients including those previously treated with VLp DBS, chronic GPi DBS resulted in a significant improvement in the dystonia movement scale and disability scores. Although this is a retrospective study dealing with dystonia of heterogeneous etiology, the results strongly suggest that GPi DBS has a better outcome than VLp DBS Received: 22 January 2001 / Received in revised form: 28 February 2001 / Accepted: 1 March 2001     

Surgical targets for dystonic tremor: Considerations between the globus pallidus and ventral intermediate thalamic nucleus

Dystonic tremor (DT) is characterized by coexisting tremor and abnormal dystonic posturing in the same segment. DT is often medically refractory and DBS is an important therapeutic option. However, the optimal surgical target for DT remains uncertain with Vim, GPi and zona incerta previously reported as effective. We retrospectively reviewed the outcome data from all patients with DT involving at least one upper extremity who underwent DBS at Vanderbilt University from July 2006 to July 2010. We evaluated the improvement of tremor and dystonia after their response to DBS was judged to be maximal. Ten patients met the inclusion criteria. Vim was targeted in four patients and three had unilateral procedure and one bilateral Vim DBS. GPi was targeted in four patients with bilateral DBS procedure in every patient from this subgroup. A combined bilateral GPi and unilateral Vim DBS was performed in two patients. The best results for tremor control were observed in patients with Vim DBS but they had persisting mild dystonia. Patients with GPi DBS had average DT improvement by approximately 50% but their dystonia symptoms were markedly improved. We propose that the patients with DT with a mild dystonia should be considered for Vim DBS procedure and the coexistence of severe DT and dystonia may be successfully controlled by combined GPi and Vim DBS surgeries.     

Utility of Deep Brain Stimulation Telemedicine for Patients With Movement Disorders During the COVID-19 Outbreak in China

ObjectiveTo explore the utility of deep brain stimulation (DBS) telemedicine in the management of patients with movement disorders from January 2019 to March 2020, covering the main period of the COVID-19 outbreak in China.Materials and MethodsWe obtained data from 40 hospitals around China that employed DBS tele-programming for their outpatients with Parkinson’s disease or dystonia from January 2019 to March 2020. Data were obtained on the number and nature of patients’ DBS health care service requests, reasons for their requests, the number of DBS telemedicine sessions subsequently completed, safety issues, and the patients’ satisfaction with the DBS tele-programing parameter adjustments made.ResultsThere were 909 DBS tele-programming health service requests (from 196 patients) completed during the study period. The results showed: 1) the number of DBS telemedicine sessions requested and the number of patients examined increased during the COVID-19 outbreak in February and March 2020 when compared with the monthly numbers in 2019; 2) the most common reason for the patients’ health service requests was poor symptom control; 3) the most common DBS tele-programming adjustment made was voltage change; 4) overall, most (89%) DBS tele-programming adjustment sessions were experienced by the patients as satisfactory; and 5) significant adverse events and unexpected treatment interruptions caused by connection failure or other hardware- or software-related problems did not occur.ConclusionsDBS telemedicine could have a unique role to play in maintaining the delivery of DBS treatment and medical care to outpatients with movement disorders during the COVID-19 pandemic.     

Deep-brain stimulation in the subthalamic nuclei improves balance performance in patients with Parkinson's disease, when tested without anti-parkinsonian medication

OBJECTIVE: To evaluate the effect of bilateral deep-brain stimulation (DBS) in the subthalamic nucleus (STN) on balance performance in patients with severe Parkinson's disease (PD), when tested without anti-parkinsonian medication. MATERIAL AND METHODS: Thirty-one patients (median age 65 years, range 50-77) were included. Assessments were made after 10-12 h withdrawal of medication, before and 6 and 12 months after surgery. Postoperative evaluations were performed with DBS on and off. Balance performance was evaluated with the Berg Balance Scale (BBS). Motor symptoms and postural stability (item 30) were assessed with the Unified Parkinson's Disease Rating Scale (UPDRS III). RESULTS: DBS in STN improved balance performance as well as postural stability and motor symptoms significantly (P 相似文献   

Deep brain stimulation and cognitive functions in Parkinson's disease: A three‐year controlled study

There is debate over the cognitive and behavioral effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD). To evaluate these effects, we performed a prospective, naturalistic controlled, 3‐year follow‐up study. A total of 65 PD patients were enrolled, of whom 32 underwent STN‐DBS (PD‐DBS) and 33, even though eligible for this treatment, declined surgery and chose other therapeutic procedures (PD‐control). Motor and neuropsychological functions were assessed in all the subjects at baseline (T0) and 36 months (T36). The PD‐DBS patients were also evaluated at 1, 6, 12, and 24 months after surgery (T1, T6, T12, and T24). At T1, compared with T0, the PD‐DBS patients recorded worse logical executive function task and verbal fluency (FAS) scores, whereas their performance of memory tasks remained stable. At T12, their cognitive profile had returned within the pre‐DBS range, thereafter remaining stable until T36. FAS scores at T36 were significantly worse in the PD‐DBS compared with the PD‐control patients. This is the first long‐term naturalistic controlled study of cognitive functions in PD patients submitted to STN‐DBS. Our results confirm previous reports of a worsening of verbal fluency after DBS, but show that STN‐DBS seems to be relatively safe from a cognitive standpoint, as the short‐term worsening of frontal‐executive functions was found to be transient. © 2009 Movement Disorder Society     

Me, Myself and My Brain Implant: Deep Brain Stimulation Raises Questions of Personal Authenticity and Alienation

In this article, I explore select case studies of Parkinson patients treated with deep brain stimulation (DBS) in light of the notions of alienation and authenticity. While the literature on DBS has so far neglected the issues of authenticity and alienation, I argue that interpreting these cases in terms of these concepts raises new issues for not only the philosophical discussion of neuro-ethics of DBS, but also for the psychological and medical approach to patients under DBS. In particular, I suggest that the experience of alienation and authenticity varies from patient to patient with DBS. For some, alienation can be brought about by neurointerventions because patients no longer feel like themselves. But, on the other hand, it seems alienation can also be cured by DBS as other patients experience their state of mind as authentic under treatment and retrospectively regard their former lives without stimulation as alienated. I argue that we must do further research on the relevance of authenticity and alienation to patients treated with DBS in order to gain a deeper philosophical understanding, and to develop the best evaluative criterion for the behavior of DBS patients.     

Subthalamic deep brain stimulation in patients with a previous pallidotomy.

The safety and efficacy of subthalamic nucleus (STN) deep brain stimulation (DBS) in patients who have had a previous unilateral pallidotomy is not clear. We identified 10 patients (9 male) at the Baylor College of Medicine Parkinson's Disease Center who underwent STN DBS after prior unilateral pallidotomy. Demographics, efficacy as determined by off Unified Parkinson's Disease Rating Scale (UPDRS) part III scores, and levodopa equivalent dosing were analyzed. We then compared these to an age- and sex-matched group of 25 DBS patients who had no prior pallidotomy. After their initial pallidotomy (mean age, 51.8 +/- 10.8 years), the mean UPDRS motor off medicine scores improved from 51.3 +/- 14.3 to 34.9 +/- 12.8, and the UPDRS dyskinesia score improved from 1.8 +/- 1.0 to 0.8 +/- 0.7. Their STN DBS off UPDRS motor scores (mean age, 56.0 +/- 10.2 years) improved by 16.0% from 53.1 +/- 9.7 (range, 42-68) to 44.6 +/- 11.1 (range, 25-67). In contrast, the UPDRS off motor scores in a control group of 25 DBS patients improved by 49.9%, from 49.7 +/- 11.1 to 25.7 +/- 18.9, (16.0% vs. 49.9%; P < 0.001). Changes in UPDRS dyskinesia scores were similar in both groups. AE thought to be related to the STN DBS following pallidotomy included worse dysarthria (three) and worse balance (two). STN DBS patients with prior pallidotomy had less improvement in UPDRS off motor score compared to other STN DBS patients, despite relatively good outcomes immediately after their pallidotomy. This may be partially due to a selection bias, but it may also indicate that prior pallidotomy is a negative predictor of outcome of STN DBS and should be considered in patient selection.     

On-demand deep brain stimulation for essential tremor: a report on four cases.

Deep brain stimulation (DBS) is an established therapy for essential tremor (ET), but loss of efficacy due to tolerance can occur. Our objective was to evaluate if it is feasible to use DBS only on-demand and if this would prevent tolerance. We report on the effects of left-side thalamic DBS in 4 ET patients who were instructed to switch on stimulation only when using their right hand for motor tasks and were followed-up to 30 months after surgery. The patients were capable of using DBS only on-demand (DBS use of 22.0+/-13.5%/day). DBS led to a stable suppression of right arm tremor throughout the follow-up. No problems associated with tolerance such as tremor rebound or late therapy failure occurred. In comparison to publications stating that ET patients had been using DBS continuously during the daytime, the use of on-demand DBS saves battery life, which delays surgical replacement of the stimulator. Thus, on-demand DBS saves money, may help to prevent tolerance, and should be adopted for the long-term treatment of ET patients.     

Antibiotic impregnated catheter coverage of deep brain stimulation leads facilitates lead preservation after hardware infection

Deep brain stimulation (DBS) has become a reliable and effective treatment for many disorders. However, the risk of long-term hardware-related complications is notable, and most concerning is hardware-related infections. Given the risk of hardware removal in the setting of infection, we retrospectively examined the implementation of a novel technique using antibiotic covered catheter protection of DBS leads after infection. The effect on hardware salvage and ease of reimplantation of the DBS extension and implantable pulse generator (IPG) was examined. A total of nine (9%) out of 100 DBS patients met the inclusion criteria with 11 DBS hardware-related infections at either the frontal, parietal, or IPG sites, from June 2003 to November 2010, at our institution. Subsequent to the initial patient in the series, a total of eight patients had placement of a short segment (approx. 4 cm long) of antibiotic impregnated catheter (Bactiseal, Codman, Johnson & Johnson, Raynham, MA, USA) over the distal end of the DBS leads at the parietal incision. Seven of these eight patients presented with pus and deep tissue infections around the hardware at either the frontal, parietal, or chest incisions. In seven of these eight patients (87.5%) we were able to protect and salvage their DBS leads without need for removal. In conclusion, this novel technique provides a simple reimplantation operation, with a decreased risk of DBS lead damage. It may improve the preservation of DBS leads when hardware infection occurs, is inexpensive, and confers no additional risks to patients.     

Does subthalamic nucleus deep brain stimulation really improve quality of life in Parkinson's disease?

We investigated the impact of subthalamic nucleus (STN) deep brain stimulation (DBS) on quality of life (QOL) in patients with advanced Parkinson's disease, as self-assessed before and after surgery by completing the Parkinson's Disease Questionnaire (PDQ39). In addition to this prospective evaluation, we asked patients postoperatively to evaluate their preoperative QOL. In the prospective assessment, results showed that patients perceived a general improvement of QOL after the STN DBS. However, when evaluated retrospectively, they tended to overestimate their preoperative functioning, therefore obscuring the improvement found prospectively. This observation highlights the impact of the method used on obtained results when assessing the effects of STN DBS.     

Management of referred deep brain stimulation failures: a retrospective analysis from 2 movement disorders centers

BACKGROUND: Since the Food and Drug Administration approved DBS, there has been a surge in the number of centers providing the procedure. There is currently no consensus regarding appropriate screening procedures, necessary training of individuals providing the therapy, the need for an interdisciplinary team, or guidelines for the management of complications. An increasing number of patients come to experienced DBS centers after unsatisfactory results from DBS surgery. An attempt is made herein to evaluate the reasons for DBS failure in a series of such patients and to make recommendations to improve overall DBS outcomes. OBJECTIVE: To improve outcomes of deep brain stimulation (DBS) surgery by analyzing a series of patients who had suboptimal results from DBS. METHODS: Forty-one consecutive patients complaining of suboptimal results from DBS surgery came to the University of Florida Movement Disorders Center, or to Beth Israel Movement Disorders Center, over a 24-month period. All patients had undergone implantation of DBS devices at outside medical centers. Each patient was evaluated by a movement disorders neurologist, and the complete medical record was reviewed. The DBS device for each patient was interrogated for adverse effects and programmed for maximal benefit. Postoperative imaging studies were evaluated whenever possible. RESULTS: The average age of patients was 63.4 years (range, 49-84 years). The indication for surgery (by record review) included 9 patients with essential tremor, 31 with Parkinson disease, and 1 with dystonia. The diagnoses after referral examination included 5 with essential tremor, 26 with Parkinson disease, 3 with Parkinson disease and dementia, 1 with Parkinson disease and essential tremor, 1 with corticobasal degeneration, 1 with dystonia, 2 with multiple system atrophy, 1 with progressive supranuclear palsy, and 1 with myoclonus. Issues related to inadequate preoperative screening: Thirty (73%) of 41 patients saw a movement disorders specialist prior to DBS implantation. Fourteen (34%) patients had neuropsychological testing, 4 (10%) did not have testing, and in 23 cases (56%), it could not be determined whether or not they were tested. Five (12%) of 41 patients had an inadequate medication trial, and 5 patients (12%) had significant cognitive dysfunction prior to their DBS implantation. Surgical and device-related complications: Nineteen (46%) of 41 patients had suboptimally placed electrodes. Seven electrodes (17%) were replaced with improvement. Three patients' devices had failed due to end of battery life, 2 had infections, and 1 had a fractured lead. Programming and medication adjustments: Seven (17%) of 41 patients had no or poor access to programming. Two patients (5%) moved, and 2 physicians (5%) moved, creating issues with access to care. Eight patients (20%) required local follow-up (they flew to remote centers to have the surgery performed). Fifteen patients (37%) were inadequately programmed and improved significantly with reprogramming. Six patients (15%) experienced partial improvement with reprogramming, and 21 patients (51%) failed to improve despite extensive reprogramming. Thirty patients (73%) benefited from medication changes, 4 (10%) had antidepressants added to their regimens, and 1 (2%) had donepezil hydrochloride added. One patient's carbidopa/levodopa (2%) was restarted after complete discontinuation. Outcomes: With the various postoperative interventions described, 21 (51%) of 41 patients had good outcomes, 6 (15%) had modest clinical improvement, and 14 (34%) did not improve. CONCLUSIONS: With appropriate intervention, 51% of patients who complained of "failed" DBS procedures ultimately had good outcomes. Thirty-four percent of these patients had persistently poor outcomes despite maximal intervention. This case series provides important insights into reasons for "DBS failure" and proposes strategies to manage patients with DBS more effectively.     

Restless legs syndrome in Parkinson's disease patients may improve with subthalamic stimulation.

We report on 6 advanced Parkinson's disease (PD) patients who underwent bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) surgery whose restless legs syndrome (RLS) improved postoperatively. Despite a mean 56% decrease in their levodopa equivalents postoperatively, their RLS scores dropped by a mean of 84% (100% in three). Our findings suggest that bilateral STN DBS surgery can improve RLS in patients with advanced PD.     

The Influence of Deep Brain Stimulation Intensity and Duration on Symptoms Evolution in an OFF Stimulation Dystonia Study

BackgroundDeep brain stimulation (DBS) of the internal globus pallidus (GPi) is an established therapy for primary generalized dystonia. However, the evolution of dystonia symptoms after DBS discontinuation after years of therapy has only rarely been reported. We therefore longitudinally studied the main physiological measurements known to be impaired in dystonia, with DBS ON and then again after termination of DBS, after at least five years of continuous DBS.ObjectiveWe studied whether dystonia evolution after DBS discontinuation in patients benefiting from long-term GPi DBS is different from that observed in earlier stages of the therapy.MethodsIn eleven DYT1 patients treated with bilateral GPi DBS for at least 5 years, dystonia was assessed ON-DBS, immediately after switch-off (OFF-DBS1) and 48 h after DBS termination (OFF-DBS2). We studied the influence of DBS intensity on dystonia when DBS was discontinued.ResultsOn average a significant difference in symptoms was measured only between ON-DBS and OFF-DBS1 conditions. Importantly, none of the patients returned to their preoperative dystonia severity, even 48 h after discontinuation. The amount of clinical deterioration in the OFF conditions positively correlated with higher stimulation current in the chronic ON-DBS condition.ConclusionsThe duration of DBS application influences symptom evolution after DBS termination. DBS intensity seems to have a prominent role on evolution of dystonic symptoms when DBS is discontinued. In conclusion, DBS induces changing modulation of the motor network with less worsening of symptoms after long term stimulation, when DBS is stopped.     

Deep brain stimulation for Parkinson’s disease: Australian referral guidelines

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.     

Thalamic Deep Brain Stimulation May Improve Restless Legs Syndrome in Patients With Essential Tremor

ObjectivesTo determine change in restless legs syndrome (RLS) symptoms in essential tremor (ET) patients undergoing bilateral thalamic ventral intermedius (VIM) deep brain stimulation (DBS) surgery.Materials and MethodsWe retrospectively reviewed our database of ET patients with RLS who had undergone VIM DBS for tremor from 2012 to 2020. We reviewed the patients with available International Restless Leg Syndrome Study Group RLS scale scores before and after DBS. Percentage of responders, defined as proportion of patients experiencing three or more point improvement of RLS scores post-DBS, was calculated. We performed two-tailed t-test of pre-DBS and post-DBS RLS scores.ResultsWe identified 13 patients with ET and RLS who had undergone bilateral VIM DBS, of whom nine (69%) were responders post-DBS. Five of 13 patients (38%) had complete resolution of RLS post-DBS. For all patients, mean pre-DBS RLS score was 15.8 ± 7.9 which improved by 46% post-DBS to a mean of 8.5 ± 8.8 (p = 0.007). Four patients rated their RLS scale one night with the stimulator OFF and another night with the stimulator ON. The mean RLS score with stimulator ON was 15.5 ± 7.6 which improved by 53% to a mean of 6.25 ± 7.8 (p = 0.008), with two having complete resolution of RLS with stimulator ON. Of the nine responders, six preferred to keep their stimulator ON at night due to relief of RLS and better subjective quality of sleep.ConclusionsWe report for the first time improvement of RLS in patients with ET after bilateral thalamic DBS. Although many ET patients with nonrechargeable DBS systems switch off their stimulator at night to conserve battery life, those with RLS may potentially benefit from keeping their stimulator ON at night to relieve their RLS.     

Reducing hardware-related complications of deep brain stimulation

BACKGROUND: Deep brain stimulation (DBS) is used increasingly worldwide for the treatment of Parkinson's disease, dystonia, tremor and pain. As with any implanted system, however, DBS introduces a new series of problems related to its hardware. Infection, malfunction and lead migration or fracture may increase patient morbidity and should be considered when evaluating the risk/benefit ratio of this therapy. This work highlights several factors felt to increase DBS hardware complications. METHODS: The authors undertook a prospective analysis of their patients receiving this therapy in two Canadian centres, over a four-year period. RESULTS: One hundred and forty-four patients received 204 permanent electrode implants. The average follow-up duration was 24 months. Complications related to the DBS hardware were seen in 11 patients (7.6%). There were two lead fractures (1.4%) and nine infections (6.2%) including two erosions (1.4%). There was a significantly greater risk of infection in patients who underwent staged procedures with externalization. In patients with straight scalp incisions, the rate of infection was higher than that seen with curved incisions. CONCLUSION: Hardware complications were not common. A period of externalization of the electrodes for a stimulation trial was associated with an increased infection rate. It is also possible that a straight scalp incision instead of curvilinear incision may lead to an increase in the rate of infection. With a clear understanding of the accepted DBS device indications and their potential complications, patients may make a truly informed decision about DBS technology.     

The number and nature of emergency department encounters in patients with deep brain stimulators

Deep brain stimulation (DBS) has become an increasingly common modality for control of several neurological disorders such as Parkinson’s disease, dystonia, essential tremor (ET), and others. Our experience has demonstrated the need for emergency physicians to familiarize themselves with the potential complications of the DBS device as well as the device itself. Therefore, our aim in this paper was to elucidate the number and nature of DBS and non-DBS presentations to the emergency department (ED) and to educate and familiarize ED physicians about DBS devices and their potential complications. We also aimed to devise a simple protocol for DBS management so that all ED physicians would have access to the knowledge or referral capabilities when managing a DBS patient. The objective of the present study was to review the number and nature of ED encounters in patients with deep brain stimulation (DBS) devices implanted for movement and neuropsychiatric disorders. Methods: The series of encounters reviewed included 215 unique patients with DBS implantation who were identified using an IRB approved database and a paper chart review. Patients in the study included those implanted at University of Florida (UF), as well as those implanted at outside institutions, so long as they were followed at UF. The cohort included n = 215 DBS patients. 25.6% of all 215 patients presented to the ED at least once, with the most common presentation occurring as a result of a decline in mental status when taking into account all visits (6%). Reasons for presentation to the ED included neurological (54.6%), infections/hardware issues (27.9%), orthopedic/focal problems (10.5%), and medical issues (7%). In total, 29 patients arrived at the ED for DBS related issues (23.2%). Of those who presented to the ED (n = 55), the average age was 53.1 (range 10–80 years). Headache was the most common complaint within the neurological category (22.1%), followed by change in mental status (15.1%), and syncope (9.3%). When examining the data by ED diagnosis, change in mental status occurred most commonly in Parkinson’s disease (19.6%). Falls were most common in essential tremor (27.2%), and headache occurred most commonly in the dystonia group (52.1%). Across all diseases, mental status change was the most common indication for an ED encounter (6%). Parkinson disease patients most commonly presented with altered mental status (8%), essential tremor patients revealed a high preponderance of falls (6.5%), and dystonia patients tended to present with headache (7.1%). It was concluded that a large number of patients with DBS will present to the ED for many reasons, the majority of which will not be direct complications of their DBS device. Neurological issues were the most common chief complaint, with individual differences depending on the underlying disease. It is important for ED physicians to consider non-DBS related complaints in the presentation of these unique patients since these issues comprise the majority of the ED visits. However, when properly evaluating these patients, management of their DBS device, or referrals to neurosurgery and neurology, if necessary, are imperative. In addition to device management, regular ED standards of care should apply to this special cohort of patients.     

Deep brain stimulation in the treatment of Parkinson's disease: a review and update

Deep brain stimulation (DBS) is a neurosurgical treatment of severe forms of Parkinson's disease, already applied to three targets, the thalamus, the internal pallidum (GPi) and the subthalamic nucleus (STN). Thalamic DBS mainly improves contralateral tremor and is therefore restricted to a small group of patients with tremor dominant disease. STN and GPi DBS improve off-motor periods and dyskinesias. The magnitude of the improvement seems more constant with STN DBS than with GPi, but there is very little comparative data between these procedures. The DBS procedure has the unique advantage of reversibility and adjustability over time. Most authors agree that bilateral DBS is reasonably safe, which is not the case of ablation. In any event, surgery is restricted to patients disabled by their condition but still responding well at times to levodopa, who are generally fit with no behavioural, mood or cognitive impairment. DBS can have side effects. Side effects more specific to the DBS procedure are infection, disconnection and hardware failure. DBS, like ablative surgery can induce an intracranial lesion like a hematoma or a stroke. There are side effects more specific to the target like postural instability, dysarthria or paresthesia in the thalamus and dyskinesias or eyelid opening apraxia in the STN. The mechanism by which high frequency DBS mimics the effect of ablation is not fully understood.     

Globus pallidus internus deep brain stimulation for dystonic conditions: a prospective audit.

In the current era of functional surgery for movement disorders, deep brain stimulation (DBS) of the globus pallidus internus (GPi) is emerging as the favoured target in the treatment of patients with dystonia. The results of 25 consecutive patients with medically intractable dystonia (12 with generalised dystonia, 7 with spasmodic torticollis, and 6 with other types of dystonia) treated with GPi stimulation are reported. Although comparisons were limited by differences in their respective neurological rating scales, chronic DBS benefited all groups, resulting in clear and progressive improvements in their condition. This study clearly demonstrates that DBS of the GPi provides amelioration of intractable dystonia.     

Long-term comparative effectiveness of deep brain stimulation in severe obsessive-compulsive disorder

BackgroundTwenty years after the first use of Deep Brain Stimulation (DBS) in obsessive-compulsive disorder (OCD), our knowledge of the long-term effects of this therapeutic option remains very limited.ObjectiveOur study aims to assess the long-term effectiveness and tolerability of DBS in OCD patients and to look for possible predictors of long-term response to this treatment.MethodsWe studied the course of 25 patients with severe refractory OCD treated with DBS over an average follow-up period of 6.4 years (±3.2) and compared them with a control group of 25 patients with severe OCD who refused DBS and maintained their usual treatment. DBS was implanted at the ventral anterior limb of the internal capsule and nucleus accumbens (vALIC-Nacc) in the first six patients and later at the bed nucleus of stria terminalis (BNST) in the rest of patients. Main outcome was change in Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score between the two groups assessed using mixed models. Secondary effectiveness outcomes included Hamilton Depression Rating Scale (HDRS) and Global Assessment of Functioning (GAF) scores.ResultsObsessive symptoms fell by 42.5% (Y-BOCS score) in patients treated with DBS and by 4.8% in the control group. Fifty-six per cent of DBS-treated patients could be considered responders at the end of follow-up and 28% partial responders. Two patients among those who rejected DBS were partial responders (8%), but none of the non-DBS group achieved criteria for complete response. HDRS and GAF scores improved significantly in 39.2% and 43.6% among DBS-treated patients, while did not significantly change in those who rejected DBS (improvement limited to 6.2% in HDRS and 4.2% in GAF scores). No statistically significant predictors of response were found. Mixed models presented very large comparative effect sizes for DBS (4.29 for Y-BOCS, 1.15 for HDRS and 2.54 for GAF). Few patients experienced adverse effects and most of these effects were mild and transitory.ConclusionsThe long-term comparative effectiveness and safety of DBS confirm it as a valid option for the treatment of severe refractory OCD.