Long-term results of a multicenter study on subthalamic and pallidal stimulation in Parkinson's disease

Surgical approach to l-dopa-induced dyskinesias

Many patients treated chronically with l-dopa for Parkinson disease (PD) become functionally disabled by l-dopa-induced dyskinesias (LID). Evolved from early empirical procedures, modern stereotactic surgical lesioning techniques and deep brain stimulation (DBS) can effectively treat LID while simultaneously improving the cardinal motor symptoms of PD. Here we review the common surgical targets used to treat LID, and compare their relative efficacy. We explain the anti-dyskinetic action of surgery at each of these targets based on evolving models of basal ganglia function. Finally, we discuss the appropriate selection of patients with LID for surgery and address relevant technical and management issues in these patients.

Ethical Issues in Deep Brain Stimulation Research for Treatment-Resistant Depression: Focus on Risk and Consent

Deep brain stimulation (DBS) is currently in pivotal trials as an intervention for treatment-resistant depression (TRD). Although offering hope for TRD, DBS also provokes ethical concerns-particularly about decision-making capacity of people with depression-among bioethicists, investigators, institutional review boards, and the public. Here, we examine this critical issue of informed consent for DBS research using available evidence regarding decision-making capacity and depression. Further, we explore the implications of the nature of TRD as well as that of the intervention (invasive brain surgery) for informed consent. Based on these analyses, we argue that additional safeguards specific to DBS research for TRD, beyond those that might be used in any higher risk study, are not supported by available empirical evidence. We nevertheless underscore the limited data on such invasive procedures in severely ill psychiatric patients and advocate a research agenda for the systematic study of ethical issues raised by these research endeavors.

High frequency deep brain stimulation of the subthalamic nucleus versus continuous subcutaneous apomorphine infusion therapy: a review

In advanced Parkinson's disease, several therapeutical option including not only lesional surgery (VIM, GPi) and deep brain stimulation (STN, GPi, VIM) but also continuous subcutaneous apomorphine infusion therapy can be proposed to the patient. The choice depends on the hope of the patient, patient's general health condition and the experience and choice of the neurosurgical and neurologist team. Here we report our experience based on 400 STN-DBS cases and we discuss, on the basis of our experience and on the literature, the advantage and disadvantage of DBS strategy as compared with non-surgical option such as continuous subcutaneous apomorphine infusion therapy.

Stuck in a rut: rethinking depression and its treatment

The current definition of major depressive disorder (MDD) emerged from efforts to create reliable diagnostic criteria for clinical and research use. However, despite decades of research, the neurobiology of MDD is largely unknown, and treatments are no more effective today than they were 50-70 years ago. Here, we propose that the current conception of depression is misguiding basic and clinical research. Redefinition is necessary and could include a focus on a more narrowly defined set of core symptoms. However, we conclude that depression is better defined as the tendency to enter into, and inability to disengage from, a negative mood state rather than the mood state per se. We also discuss the implications of this revised definition for future clinical and basic research.

Recent advances in the assessment and treatment of falls in Parkinson's disease

Falls are among the most incapacitating features of Parkinson's disease. Prevention of falls requires a systematic assessment of all contributing factors (with emphasis on freezing of gait and frontal executive dysfunction), and a multidisciplinary treatment approach tailored to the specific pathophysiology of falls for each individual patient.

Pathological considerations in the treatment of Parkinson's disease: more than just a wiring diagram

Parkinson's disease (PD) represents a common but challenging condition in which an increasing number of therapeutic options have evolved over the course of the last 50 years. The introduction of dopaminergic therapies has dramatically improved outcomes but life expectancies remain significantly curtailed. Currently, all available treatment options are directed towards the amelioration of symptoms. However, it is hoped that a greater understanding of the distinctive pathology underlying PD might offer some novel therapeutic approaches. The identification of degeneration within the nigrostriatal tract as the most prominent pathological process in PD has led to the development of a number of therapies. However, despite initially good symptomatic control it has become clear that the longer-term use of these medications is associated with a number of debilitating motor complications. The management of these drug-related issues has necessitated a further tier of therapeutic options based largely on a greater understanding of the basal ganglia circuitry involved. Indeed, surgical interventions targeting these neural circuits have provided increased control of motor symptoms in patients with advanced disease, however, such techniques still fail to slow or reverse the disease. To this end, a number of novel approaches focussed on restoration or repair of the diseased brain have received increasing attention. Nevertheless, there are multiple symptoms that are unresponsive to any of these therapies, highlighting the involvement of other neurotransmitter systems and the complexities of the disease beyond the basal ganglia circuitry. An appreciation of the ongoing neurodegenerative processes at the core of PD and the burden of disease associated with them, emphasises the need for increased research into more effective and comprehensive treatment methodologies.