The neurosurgical treatment of addiction

Deep brain stimulation for substance use disorder: a systematic review and meta-analysis

Objective

Substance use disorder (SUD) is a significant public health issue with a high mortality rate. Deep brain stimulation (DBS) has shown promising results in treating SUD in certain cases. In this study, we conducted a meta-analysis to evaluate the efficacy of DBS in the treatment of SUD and reduction of relapse rates.

Methods

We performed a thorough and methodical search of the existing scientific literature, adhering to the PRISMA guidelines, to identify 16 original studies that fulfilled our inclusion criteria. We used the evidence levels recommended by the Oxford Centre for Evidence-Based Medicine to assess bias. The R version 4.2.3 software was utilized to calculate the mean effect size. We estimated study heterogeneity by employing tau2 and I2 indices and conducting Cochran's Q test.

Results

The results showed that DBS treatment resulted in a significant improvement in the clinical SUD scales of patients, with an average improvement of 59.6%. The observed relapse rate was 8%. The meta-analysis estimated a mean effect size of 55.9 [40.4; 71.4]. Heterogeneity analysis showed a large degree of heterogeneity among the included studies. Subgroup and meta-regression analysis based on age and SUD type suggested that DBS may be more effective for patients above 45 years of age, and for alcohol and opioid addiction compared to nicotine addiction.

Conclusion

The current literature suggests that DBS has a moderate effect on SUD symptoms. However, the limited number of studies and small sample size indicate that more research is needed to better understand the factors that influence its effectiveness.

A transdiagnostic network for psychiatric illness derived from atrophy and lesions

Psychiatric disorders share neurobiology and frequently co-occur. This neurobiological and clinical overlap highlights opportunities for transdiagnostic treatments. In this study, we used coordinate and lesion network mapping to test for a shared brain network across psychiatric disorders. In our meta-analysis of 193 studies, atrophy coordinates across six psychiatric disorders mapped to a common brain network defined by positive connectivity to anterior cingulate and insula, and by negative connectivity to posterior parietal and lateral occipital cortex. This network was robust to leave-one-diagnosis-out cross-validation and specific to atrophy coordinates from psychiatric versus neurodegenerative disorders (72 studies). In 194 patients with penetrating head trauma, lesion damage to this network correlated with the number of post-lesion psychiatric diagnoses. Neurosurgical ablation targets for psychiatric illness (four targets) also aligned with the network. This convergent brain network for psychiatric illness may partially explain high rates of psychiatric comorbidity and could highlight neuromodulation targets for patients with more than one psychiatric disorder.

Is Deep Brain Stimulation an Effective Treatment for Psychostimulant Dependency? A Preclinical and Clinical Systematic Review

Addiction to psychostimulants significantly affects public health. Standard medical therapy is often not curative. Deep brain stimulation (DBS) is a promising treatment that has attracted much attention for addiction treatment in recent years. The present review aimed to systematically identify the positive and adverse effects of DBS in human and animal models to evaluate the feasibility of DBS as a treatment for psychostimulant abuse. The current study also examined the possible mechanisms underlying the therapeutic effects of DBS. In February 2022, a comprehensive search of four databases, including Web of Science, PubMed, Cochrane, and Scopus, was carried out to identify all reports that DBS was a treatment for psychostimulant addiction. The selected studies were extracted, summarized, and evaluated using the appropriate methodological quality assessment tools. The results indicated that DBS could reduce relapse and the desire for the drug in human and animal subjects without any severe side effects. The underlying mechanisms of DBS are complex and likely vary from region to region in terms of stimulation parameters and patterns. DBS seems a promising therapeutic option. However, clinical experiences are currently limited to several uncontrolled case reports. Further studies with controlled, double-blind designs are needed. In addition, more research on animals and humans is required to investigate the precise role of DBS and its mechanisms to achieve optimal stimulation parameters and develop new, less invasive methods.

Anterior Cingulate Cortex in Addiction: New Insights for Neuromodulation

OBJECTIVES

Substance use disorder (SUD) is characterized by compulsive use of addictive substances with considerable impact on both the medical system and society as a whole. The craving of substances leads to relapse in the majority of patients within one year of traditional treatments. In recent decades, neuromodulation approaches have emerged as potential novel treatments of SUD, but the ideal neural target remains contentious.

MATERIALS AND METHODS

In this review, we discuss new insights on the anterior cingulate cortex (ACC) as a neuromodulation target for SUD.

RESULTS AND CONCLUSION

First, we illustrate that the ACC serves as a central "hub" in addiction-related neural networks of cognitive functions, including, but not limited to, decision-making, cognitive inhibition, emotion, and motivation. Then, we summarize the literature targeting the ACC to treat SUDs via available neuromodulation approaches. Finally, we propose potential directions to improve the effect of stimulating the ACC in SUD treatment. We emphasize that the ACC can be divided into at least four sub-regions, which have distinctive functions and connections. Studies focusing on these sub-regions may help to develop more precise and effective ACC stimulation according to patients' symptom profiles and cognitive deficits.

Neurosurgical treatment for addiction: lessons from an untold story in China and a path forward

Addiction is a major public-health crisis associated with significant disability and mortality. Although various pharmacological and behavioral treatments are currently available, the clinical efficacy of these treatments is limited. Given this situation, there is a growing interest in finding an effective neurosurgical treatment for addiction. First, we discuss the use of ablative surgery in treating addiction. We focus on the rise and fall of nucleus accumbens ablation for addiction in China. Subsequently, we review recent studies that have explored the efficacy and safety of deep-brain-stimulation treatment for addiction. We conclude that neurosurgical procedures, particularly deep-brain stimulation, have a potentially valuable role in the management of otherwise intractable addictive disorders. Larger well-controlled clinical trials, however, are needed to assess clinical efficacy and safety. We end by discussing several key issues involved in this clinical field and identifying some areas of progress.

Deep brain stimulation for the treatment of drug addiction

Drug addiction represents a significant public health concern that has high rates of relapse despite optimal medical therapy and rehabilitation support. New therapies are needed, and deep brain stimulation (DBS) may be an effective treatment. The past 15 years have seen numerous animal DBS studies for addiction to various drugs of abuse, with most reporting decreases in drug-seeking behavior with stimulation. The most common target for stimulation has been the nucleus accumbens, a key structure in the mesolimbic reward pathway. In addiction, the mesolimbic reward pathway undergoes a series of neuroplastic changes. Chief among them is a relative hypofunctioning of the prefrontal cortex, which is thought to lead to the diminished impulse control that is characteristic of drug addiction. The prefrontal cortex, as well as other targets involved in drug addiction such as the lateral habenula, hypothalamus, insula, and subthalamic nucleus have also been stimulated in animals, with encouraging results. Although animal studies have largely shown promising results, current DBS studies for drug addiction primarily use stimulation during active drug use. More data are needed on the effect of DBS during withdrawal in preventing future relapse. The published human experience for DBS for drug addiction is currently limited to several promising case series or case reports that are not controlled. Further animal and human work is needed to determine what role DBS can play in the treatment of drug addiction.

Effects of Non-invasive Brain Stimulation on Stimulant Craving in Users of Cocaine, Amphetamine, or Methamphetamine: A Systematic Review and Meta-Analysis

Dopamine system plays a pivotal role in specific kinds of substance use disorders (SUD, i. e., cocaine and methamphetamine use disorders). Many studies addressed whether dopamine-involved craving could be alleviated by non-invasive brain stimulation (NIBS) techniques. Nevertheless, the outcomes were highly inconsistent and the stimulating parameters were highly variable. In the current study, we ran a meta-analysis to identify an overall effect size of NIBS and try to find stimulating parameters of special note. We primarily find 2,530 unduplicated studies in PubMed, Psychology and Behavioral Sciences Collection, PsycARTICLES, PsycINFO, and Google Scholar database involving “Cocaine”/“Amphetamine”/“Methamphetamine” binded with “TMS”/“tDCS”/“non-invasive stimulation” in either field. After visual screening, 26 studies remained. While 16 studies were further excluded due to the lack of data, invalid craving scoring or the absence of sham condition. At last, 16 units of analysis in 12 eligible studies were coded and forwarded to a random-effect analysis. The results showed a large positive main effect of stimulation (Hedge's g = 1.116, CI = [0.597, 1.634]). Further subgroup analysis found that only high-frequency repetitive transcranial magnetic stimulation (rTMS) could elicit a significant decrease in craving, while the outcome of low-frequency stimulation was relatively controversial. Moreover, univariate meta regression revealed that the number of pulses per session could impose negative moderation toward the intervention. No significant moderation effect was found in types of abuse, overall days of stimulation and other variables of stimulating protocol. In conclusion, this meta-analysis offered a persuasive evidence for the feasibility of using NIBS to remit substance addictive behavior directly based on dopamine system. We also give clear methodological guidance that researchers are expected to use high-frequency, sufficiently segmented rTMS to improve the efficacy in future treatments.

Efficacy of Invasive and Non-Invasive Brain Modulation Interventions for Addiction

It is important to find new treatments for addiction due to high relapse rates despite current interventions and due to expansion of the field with non-substance related addictive behaviors. Neuromodulation may provide a new type of treatment for addiction since it can directly target abnormalities in neurocircuits. We review literature on five neuromodulation techniques investigated for efficacy in substance related and behavioral addictions: transcranial direct current stimulation (tDCS), (repetitive) transcranial magnetic stimulation (rTMS), EEG, fMRI neurofeedback and deep brain stimulation (DBS) and additionally report on effects of these interventions on addiction-related cognitive processes. While rTMS and tDCS, mostly applied at the dorsolateral prefrontal cortex, show reductions in immediate craving for various addictive substances, placebo-responses are high and long-term outcomes are understudied. The lack in well-designed EEG-neurofeedback studies despite decades of investigation impedes conclusions about its efficacy. Studies investigating fMRI neurofeedback are new and show initial promising effects on craving, but future trials are needed to investigate long-term and behavioral effects. Case studies report prolonged abstinence of opioids or alcohol with ventral striatal DBS but difficulties with patient inclusion may hinder larger, controlled trials. DBS in neuropsychiatric patients modulates brain circuits involved in reward processing, extinction and negative-reinforcement that are also relevant for addiction. To establish the potential of neuromodulation for addiction, more randomized controlled trials are needed that also investigate treatment duration required for long-term abstinence and potential synergy with other addiction interventions. Finally, future advancement may be expected from tailoring neuromodulation techniques to specific patient (neurocognitive) profiles.

State of the Art: Novel Applications for Cortical Stimulation

OBJECTIVE

Electrical stimulation via implanted electrodes that overlie the cortex of the brain is an upcoming neurosurgical technique that was hindered for a long time by insufficient knowledge of how the brain functions in a dynamic, physiological, and pathological way, as well as by technological limitations of the implantable stimulation devices.

METHODS

This paper provides an overview of cortex stimulation via implantable devices and introduces future possibilities to improve cortex stimulation.

RESULTS

Cortex stimulation was initially used preoperatively as a technique to localize functions in the brain and only later evolved into a treatment technique. It was first used for pain, but more recently a multitude of pathologies are being targeted by cortex stimulation. These disorders are being treated by stimulating different cortical areas of the brain. Risks and complications are essentially similar to those related to deep brain stimulation and predominantly include haemorrhage, seizures, infection, and hardware failures. For cortex stimulation to fully mature, further technological development is required to predict its outcomes and improve stimulation designs. This includes the development of network science-based functional connectivity approaches, genetic analyses, development of navigated high definition transcranial alternating current stimulation, and development of pseudorandom stimulation designs for preventing habituation.

CONCLUSION

In conclusion, cortex stimulation is a nascent but very promising approach to treating a variety of diseases, but requires further technological development for predicting outcomes, such as network science based functional connectivity approaches, genetic analyses, development of navigated transcranial electrical stimulation, and development of pseudorandom stimulation designs for preventing habituation.

Posttraumatic Stress Disorder: Perspectives for the Use of Deep Brain Stimulation

OBJECTIVES

Deep Brain Stimulation (DBS) has been either approved or is currently under investigation for a number of psychiatric disorders.

MATERIALS AND METHODS

We review clinical and preclinical concepts as well as the neurocircuitry that may be of relevance for the implementation of DBS in posttraumatic stress disorder (PTSD).

RESULTS

PTSD is a chronic and debilitating illness associated with dysfunction in well-established neural circuits, including the amygdala and prefrontal cortex. Although most patients often improve with medications and/or psychotherapy, approximately 20-30% are considered to be refractory to conventional treatments. In other psychiatric disorders, DBS has been investigated in treatment-refractory patients. To date, preclinical work suggests that stimulation at high frequency delivered at particular timeframes to different targets, including the amygdala, ventral striatum, hippocampus, and prefrontal cortex may improve fear extinction and anxiety-like behavior in rodents. In the only clinical report published so far, a patient implanted with electrodes in the amygdala has shown striking improvements in PTSD symptoms.

CONCLUSIONS

Neuroimaging, preclinical, and preliminary clinical data suggest that the use of DBS for the treatment of PTSD may be practical but the field requires further investigation.

Deep brain stimulation improves behavior and modulates neural circuits in a rodent model of schizophrenia

Schizophrenia is a debilitating psychiatric disorder with a significant number of patients not adequately responding to treatment. Deep brain stimulation (DBS) is a surgical technique currently investigated for medically-refractory psychiatric disorders. Here, we use the poly I:C rat model of schizophrenia to study the effects of medial prefrontal cortex (mPFC) and nucleus accumbens (Nacc) DBS on two behavioral schizophrenia-like deficits, i.e. sensorimotor gating, as reflected by disrupted prepulse inhibition (PPI), and attentional selectivity, as reflected by disrupted latent inhibition (LI). In addition, the neurocircuitry influenced by DBS was studied using FDG PET. We found that mPFC- and Nacc-DBS alleviated PPI and LI abnormalities in poly I:C offspring, whereas Nacc- but not mPFC-DBS disrupted PPI and LI in saline offspring. In saline offspring, mPFC-DBS increased metabolism in the parietal cortex, striatum, ventral hippocampus and Nacc, while reducing it in the brainstem, cerebellum, hypothalamus and periaqueductal gray. Nacc-DBS, on the other hand, increased activity in the ventral hippocampus and olfactory bulb and reduced it in the septal area, brainstem, periaqueductal gray and hypothalamus. In poly I:C offspring changes in metabolism following mPFC-DBS were similar to those recorded in saline offspring, except for a reduced activity in the brainstem and hypothalamus. In contrast, Nacc-DBS did not induce any statistical changes in brain metabolism in poly I:C offspring. Our study shows that mPFC- or Nacc-DBS delivered to the adult progeny of poly I:C treated dams improves deficits in PPI and LI. Despite common behavioral responses, stimulation in the two targets induced different metabolic effects.

Low Current-driven Micro-electroporation Allows Efficient In Vivo Delivery of Nonviral DNA into the Adult Mouse Brain

Viral gene transfer or transgenic animals are commonly used technologies to alter gene expression in the adult brain, although these approaches lack spatial specificity and are time consuming. We delivered plasmid DNA locally into the brain of adult C57BL/6 mice in vivo by voltage- and current-controlled electroporation. The low current-controlled delivery of unipolar square wave pulses of 125 µA with microstimulation electrodes at the injection site gave 16 times higher transfection rates than a voltage-controlled electroporation protocol with plate electrodes resulting in currents of about 400 mA. Transfection was restricted to the target region and no damage due to the electric pulses was found. Our current-controlled electroporation protocol indicated that the use of very low currents resulting in applied voltages within the physiological range of the membrane potential, allows efficient transfection of nonviral plasmid DNA. In conclusion, low current-controlled electroporation is an excellent approach for electroporation in the adult brain, i.e., gene function can be influenced locally at a high level with no mortality and minimal tissue damage.

[Surgical strategy to rescue the addicts]

Since its successful application for the treatment of neurological disorders, deep brain stimulation (DBS) is currently also applied for the treatment of psychiatric disorders such as obsessive compulsive disorders or depression. DBS is being considered, or even applied, as a treatment for certain forms of addiction. We review here the cerebral structures aimed for such a strategy and discuss their respective positive and negative aspects.

Limbic neuromodulation: implications for addiction, posttraumatic stress disorder, and memory

Deep brain stimulation, a technique whereby electrodes are implanted into specific brain regions to modulate their activity, has been mainly used to treat movement disorders. More recently this technique has been proposed for the treatment of drug addiction, posttraumatic stress disorder (PTSD), and dementia. The nucleus accumbens, amygdala, and hippocampus, central nuclei within the limbic system, have been studied as potential targets for neuromodulation for the treatment of drug addiction, PTSD, and dementia, respectively. As the scope of neuromodulation grows to include disorders of mood and thought, new ethical and philosophic challenges that require multidisciplinary discussion and cooperation are emerging.

Ethical Considerations in Deep Brain Stimulation for the Treatment of Addiction and Overeating Associated With Obesity

The success of deep brain stimulation (DBS) for movement disorders and the improved understanding of the neurobiologic and neuroanatomic bases of psychiatric diseases have led to proposals to expand current DBS applications. Recent preclinical and clinical work with Alzheimer's disease and obsessive-compulsive disorder, for example, supports the safety of stimulating regions in the hypothalamus and nucleus accumbens in humans. These regions are known to be involved in addiction and overeating associated with obesity. However, the use of DBS targeting these areas as a treatment modality raises common ethical considerations, which include informed consent, coercion, enhancement, threat to personhood, and manipulation of the reward center. Pilot studies for both of these conditions are currently investigational. If these studies show promise, then there is a need to address the ethical concerns related to the initiation of clinical trials including the reliability of preclinical evidence, patient selection, study design, compensation for participation and injury, cost-effectiveness, and the need for long-term follow-up. Multidisciplinary teams are necessary for the ethical execution of such studies. In addition to establishing safety and efficacy, the consideration of these ethical issues is vital to the adoption of DBS as a treatment for these conditions. We offer suggestions about the pursuit of future clinical trials of DBS for the treatment of addiction and overeating associated with obesity and provide a framework for addressing ethical concerns related to treatment.

The ventral portion of the CA1 region of the hippocampus and the prefrontal cortex as candidate regions for neuromodulation in schizophrenia

Existing antipsychotic drugs are most effective in the treatment of the positive symptoms of schizophrenia. However, they are associated with considerable side effects and have relatively low efficacy. Diminished inhibitory control in the hippocampus has been suggested to lead to hyperactivation of the dopamine system thus underpinning the dopamine-dependent psychosis associated with schizophrenia. Similarly, diminished inhibitory control is thought to underpin the cortical disruption associated with the cognitive dysfunctions. Impairment of a specific class of parvalbumin-positive inhibitory interneuron has been consistently identified in the prefrontal cortex and hippocampus of schizophrenics. Thus, this impairment common to both regions, may subserve these distinct symptom domains. Deep brain stimulation has been suggested to act, at least in part, through the modulation of interneuron function and here we propose the prefrontal cortex and hippocampus as potential targets for neuromodulatory intervention in the treatment of schizophrenia. Further, we specifically consider whether multiple targets and multiple neuromodulatory approaches may be necessary in the treatment of this multi-faceted disease. Finally we propose that deep brain stimulation of the ventral protion of the CA1 region of the hippocampus may be the most promising single target for neuromodulation in schizophrenia.

Ethical implications of research on craving

Cravings, intense desires to experience the effects of a drug, are widely regarded as significant impediments to overcoming addiction, although their role in relapse may be overstated. Scientists and clinicians wish to better understand the neurobiological and cognitive basis of craving so that they may develop psychotherapeutic, pharmacological and other medical methods to reduce craving and thereby drug use. The conduct of such research raises significant ethical issues. When recruiting individuals and conducting this research, scientists need to ensure that substance dependent participants have the capacity to provide free and uncoerced consent. This is especially the case in studies in which dependent participants are given their drug of addiction or provided with other inducements to participate (e.g. financial incentives) that may undermine their ability to fully consider the risks of participation. Treatments for addiction that seek to reduce cravings may also carry risks. This includes psychotherapeutic approaches, as well as pharmacological and medical treatments. Clinicians need to consider the risks and benefits of treatment and carefully communicate these to patients. The desire to reduce urges to use drugs should not be employed to justify potentially harmful and ineffective treatments. The safety and effectiveness of emerging treatments should be assessed by well conducted randomized controlled clinical trials.

Deep brain stimulation of the nucleus accumbens for the treatment of addiction

Despite novel medications and other therapeutic strategies, addiction to psychotropic substances remains one of the most serious public health problems worldwide. In this review, beginning with an introduction of deep brain stimulation (DBS), we highlight the importance of the nucleus accumbens (NAc) in the context of the reward circuitry and addictive behavior. We will provide a short historic overview of other neurosurgical approaches to treat addiction and describe the experimental and preclinical data on DBS in addiction. Finally, we call attention to key ethical issues related to using DBS to treat addiction that are important for future research and the design of clinical trials.

Brain stimulation methods to treat tobacco addiction

BACKGROUND

Tobacco smoking is the leading cause of preventable deaths worldwide, but many smokers are simply unable to quit. Psychosocial and pharmaceutical treatments have shown modest results on smoking cessation rates, but there is an urgent need to develop treatments with greater efficacy. Brain stimulation methods are gaining increasing interest as possible addiction therapeutics.

OBJECTIVES

The purpose of this paper is to review the studies that have evaluated brain stimulation techniques on tobacco addiction, and discuss future directions for research in this novel area of addiction interventions.

METHODS

Electronic and manual literature searches identified fifteen studies that administered repetitive transcranial magnetic stimulation (rTMS), cranial electrostimulation (CES), transcranial direct current stimulation (tDCS) or deep brain stimulation (DBS).

RESULTS

rTMS was found to be the most well studied method with respect to tobacco addiction. Results indicate that rTMS and tDCS targeted to the dorsolateral prefrontal cortex (DLPFC) were the most efficacious in reducing tobacco cravings, an effect that may be mediated through the brain reward system involved in tobacco addiction. While rTMS was shown to reduce consumption of cigarettes, as yet no brain stimulation technique has been shown to significantly increase abstinence rates. It is possible that the therapeutic effects of rTMS and tDCS may be improved by optimization of stimulation parameters and increasing the duration of treatment.

CONCLUSION

Although further studies are needed to confirm the ability of brain stimulation methods to treat tobacco addiction, this review indicates that rTMS and tDCS both represent potentially novel treatment modalities.

Voluntary exercise ameliorates cognitive deficits in morphine dependent rats: the role of hippocampal brain-derived neurotrophic factor

Chronic exposure to opiates impairs spatial learning and memory. Given the well-known beneficial effects of voluntary exercise on cognitive functions, we investigated whether voluntary exercise would ameliorate the cognitive deficits that are induced by morphine dependence. If an effect of exercise was observed, we aimed to investigate the possible role of hippocampal brain-derived neurotrophic factor (BDNF) in the exercise-induced enhancement of learning and memory in morphine-dependent rats. The rats were injected with bi-daily doses (10mg/kg, at 12h intervals) of morphine over a period of 10 days of voluntary exercise. Following these injections, a water maze task was performed twice a day for five consecutive days, followed by a probe trial 2 days later. A specific BDNF inhibitor (TrkB-IgG chimera) was used to block the hippocampal BDNF action during the 10 days of voluntary exercise. We found that voluntary exercise blocked the ability of chronic morphine to impair spatial memory retention. A blockade of the BDNF action blunted the exercise-induced improvement of spatial memory in the dependent rats. Moreover, the voluntary exercise diminished the severity of the rats' dependency on morphine. This study demonstrates that voluntary exercise ameliorates, via a TrkB-mediated mechanism, the cognitive deficits that are induced by chronic morphine. Thus, voluntary exercise might be a potential method to ameliorate some of the deleterious behavioral consequences of the abuse of morphine and other opiates.

Local pretreatment with the cannabinoid CB1 receptor antagonist AM251 attenuates methamphetamine intra-accumbens self-administration

The endocannabinoid system is a potential target for therapeutic intervention of substance abuse. Cannabinoid CB1 receptor antagonist decreases intravenous methamphetamine self-administration in animal models. This study examined whether the nucleus accumbens (NAcc) is a site of interaction between methamphetamine and the CB1 receptor antagonist AM251. Male Sprague-Dawley rats were trained to lever press and then were surgically implanted with a guide cannula into the right NAcc. Rats were allowed one week to recover and then AM251 (0.1 or 1.0 μg/μL) was reverse dialyzed directly into the NAcc prior to methamphetamine (10 μg/μL) intra-accumbens self-administration. AM251 (1.0 μg/μL) reduced methamphetamine self-administration while AM251 (0.1 μg/μL) had an intermediary effect. The mechanism of self-administration attenuation is not known but could be mediated by AM251 affecting the negative feedback from the NAcc to the ventral tegmental area (VTA). This study provides evidence that the endocannabinoid system is involved with rewarding effects of methamphetamine and suggests a possible therapeutic intervention for methamphetamine abuse.

Deep brain stimulation between 1947 and 1987: the untold story

Deep brain stimulation (DBS) is the most rapidly expanding field in neurosurgery. Movement disorders are well-established indications for DBS, and a number of other neurological and psychiatric indications are currently being investigated. Numerous contemporary opinions, reviews, and viewpoints on DBS fail to provide a comprehensive account of how this method came into being. Misconceptions in the narrative history of DBS conveyed by the wealth of literature published over the last 2 decades can be summarized as follows: Deep brain stimulation was invented in 1987. The utility of high-frequency stimulation was also discovered in 1987. Lesional surgery preceded DBS. Deep brain stimulation was first used in the treatment of movement disorders and was subsequently used in the treatment of psychiatric and behavioral disorders. Reports of nonmotor effects of subthalamic nucleus DBS prompted its use in psychiatric illness. Early surgical interventions for psychiatric illness failed to adopt a multidisciplinary approach; neurosurgeons often worked "in isolation" from other medical specialists. The involvement of neuro-ethicists and multidisciplinary teams are novel standards introduced in the modern practice of DBS for mental illness that are essential in avoiding the unethical behavior of bygone eras. In this paper, the authors examined each of these messages in the light of literature published since 1947 and formed the following conclusions. Chronic stimulation of subcortical structures was first used in the early 1950s, very soon after the introduction of human stereotaxy. Studies and debate on the stimulation frequency most likely to achieve desirable results and avoid side effects date back to the early days of DBS; several authors advocated the use of "high" frequency, although the exact frequency was not always specified. Ablative surgery and electrical stimulation developed in parallel, practically since the introduction of human stereotactic surgery. The first applications of both ablative surgery and chronic subcortical stimulation were in psychiatry, not in movement disorders. The renaissance of DBS in surgical treatment of psychiatric illness in 1999 had little to do with nonmotor effects of subthalamic nucleus DBS but involved high-frequency stimulation of the very same brain targets previously used in ablative surgery. Pioneers in functional neurosurgery mostly worked in multidisciplinary groups, including when treating psychiatric illness; those "acting in isolation" were not neurosurgeons. Ethical concerns have indeed been addressed in the past, by neurosurgeons and others. Some of the questionable behavior in surgery for psychiatric illness, including the bygone era of DBS, was at the hands of nonneurosurgeons. These practices have been deemed as "dubious and precarious by yesterday's standards."

Deep brain stimulation: from neurology to psychiatry?

Functional stereotaxy was introduced in the late 1940s to reduce the morbidity of lobotomy in psychiatric disease by using more focal lesions. The advent of neuroleptics led to a drastic decline in psychosurgery for several decades. Functional stereotactic neurosurgery has recently been revitalized, starting with treatment of Parkinson's disease, in which deep brain stimulation (DBS) facilitates reversible focal neuromodulation of altered basal ganglia circuits. DBS is now being extended to treatment of neuropsychiatric conditions such as Gilles de la Tourette syndrome, obsessive-compulsive disorder, depression and addiction. In this review, we discuss the concept that dysfunction of motor, limbic and associative cortico-basal ganglia-thalamocortical loops underlies these various disorders, which might now be amenable to DBS treatment.

Disruption of cigarette smoking addiction after posterior cingulate damage

The authors describe the case of a 35-year-old woman with a history of an addiction to cigarette smoking who presented with an intracerebral hemorrhage from a ruptured arteriovenous malformation. The patient reported an immediate and complete disruption of her addiction to cigarette smoking following her stroke. Structural MR imaging revealed a lesion of the posterior cingulate cortex. Neuropsychological tests showed intact cognitive functioning. This observation suggests that the posterior cingulate cortex may play a role in the addiction to cigarette smoking.

Heroin-assisted treatment in the Netherlands: History, findings, and international context

This monograph describes the history, findings and international context of heroin-assisted treatment (HAT) in the Netherlands. The monograph consists of (1) a short introduction and seven paragraphs describing the following aspects of HAT in the Netherlands: (2) history of HAT studies and implementation of routine HAT in the Netherlands; (3) main findings on efficacy, safety and cost-effectiveness from the two randomized controlled HAT trials in the Netherlands; (4) new findings from a large cohort study on the effectiveness of HAT in routine clinical practice in the Netherlands; (5) unique data on the patient's perspective of HAT; (6) data on the pharmacological and pharmaceutical basis for HAT in the Netherlands; (7) description of the registration process; and (8) account of the international context of HAT. Together, these data show that HAT can now be considered a safe and proven-effective intervention for the treatment of chronic, treatment-resistant heroin dependent patients.

Counteracting incentive sensitization in severe alcohol dependence using deep brain stimulation of the nucleus accumbens: clinical and basic science aspects

The ventral striatum/nucleus accumbens (NAcc) has been implicated in the craving for drugs and alcohol which is a major reason for relapse of addicted people. Craving might be induced by drug-related cues. This suggests that disruption of craving-related neural activity in the NAcc may significantly reduce craving in alcohol-dependent patients. Here we report on preliminary clinical and neurophysiological evidence in three male patients who were treated with high frequency deep brain stimulation of the NAcc bilaterally. All three had been alcohol-dependent for many years, unable to abstain from drinking, and had experienced repeated relapses prior to the stimulation. After the operation, craving was greatly reduced and all three patients were able to abstain from drinking for extended periods of time. Immediately after the operation but prior to connection of the stimulation electrodes to the stimulator, local field potentials were obtained from the externalized cables in two patients while they performed cognitive tasks addressing action monitoring and incentive salience of drug-related cues. LFPs in the action monitoring task provided further evidence for a role of the NAcc in goal-directed behaviors. Importantly, alcohol-related cue stimuli in the incentive salience task modulated LFPs even though these cues were presented outside of the attentional focus. This implies that cue-related craving involves the NAcc and is highly automatic.

Deep brain stimulation: current and future perspectives

Deep brain stimulation (DBS) has been used to treat various neurological and psychiatric disorders. Over the years, the most suitable surgical candidates and targets for some of these conditions have been characterized and the benefits of DBS well demonstrated in double-blinded randomized trials. This review will discuss some of the areas of current investigation and potential new applications of DBS.

Neurosurgical treatment of mood disorders: traditional psychosurgery and the advent of deep brain stimulation

PURPOSE OF REVIEW

From its peak in the 1940s and 1950s, psychosurgery (or, neurosurgery for psychiatric disorders) has had a gradual decline, with only a few centers around the world continuing with the procedure into the 1980s and 1990s. With recent developments in brain stimulation techniques, the continuing relevance of psychosurgery in the treatment of psychiatric disorders is worthy of examination.

RECENT FINDINGS

A review of databases (PubMed, Medline, Current Contents and Embase) suggests that psychosurgery in the form of stereotactic focal ablation is still practiced in a few centers, although the number has decreased further from the 1990s. Procedures have not changed substantively, although modern imaging and stereotaxy have made them more precise. No good predictors of treatment response have been identified. There is a major shift in interest to deep brain stimulation (DBS) instead of ablative surgery. Studies of DBS in resistant depression and obsessive-compulsive disorder have been few and have involved small numbers, but this field is growing rapidly.

SUMMARY

Although ablative psychosurgery using stereotactic procedures continues to be used to a small extent, psychiatrists remain ambivalent about this procedure. The baton of psychosurgery, however, appears to have been passed on to DBS, but more data are needed on technical details and outcomes before the possible therapeutic role of DBS can be established.