1,744,069 research outputs found
Current DBS programming
No full textDeep brain stimulation is an established treatment option for various neurological and psychiatric disorders. Throughout its journey as a confirmed long-term efficacious therapeutic option for movement disorders such as Parkinson’ s disease, essential tremor and dystonia over the last three decades, programming strategies continuously improved to due to the development of DBS technologies. The aim of this review is to take a glance into current programming strategies in the era of movement disorders particularly with an updated review of the literature for current and emerging DBS technologies
Pulse-width modulated temporal interference (PWM-TI) brain stimulation
No full textBACKGROUND: Electrical stimulation involving temporal interference of two different kHz frequency sinusoidal electric fields (temporal interference (TI)) enables non-invasive deep brain stimulation by creating an electric field that is amplitude modulated at the slow difference frequency within the neural range at the target brain region. OBJECTIVE: Here, we investigate temporal interference neural stimulation using square, rather sinusoidal, electric fields that create an electric field that is pulse-width, but not amplitude, modulated at the difference frequency (pulse-width modulated temporal interference, (PWM-TI)). METHODS/RESULTS: We show, using ex-vivo single-cell recordings and in-vivo calcium imaging, that PWM-TI effectively stimulates neural activity at the difference frequency at a similar efficiency to traditional TI. We then demonstrate, using computational modelling, that the PWM stimulation waveform induces amplitude-modulated membrane potential depolarization due to the membrane's intrinsic low-pass filtering property. CONCLUSIONS: PWM-TI can effectively drive neural activity at the difference frequency. The PWM-TI mechanism involves converting an amplitude-fixed PWM field to an amplitude-modulated membrane potential via the low-pass filtering of the passive neural membrane. Unveiling the biophysics underpinning the neural response to complex electric fields may facilitate the development of new brain stimulation strategies with improved precision and efficiency
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Deep Brain Stimulation for Disabling “Outflow” Tremors
No full text“Outflow” tremors, sometimes referred to in the literature by a variety of terms (outflow, rubral, midbrain, Holmes), are frequently associated with significant disability and are notoriously unresponsive or only partially responsive to medical treatment. Deep brain stimulation (DBS) has been successfully used in patients with outflow tremors; however, longterm outcomes are not welldocumented because large case series are hard to assemble. This chapter describes a patient with disabling outflow tremors secondary to multiple sclerosis, treated with unilateral thalamic DBS, who achieved excellent tremor control with initial programming but shortly afterward developed rebound tremor. Intensive programming involved alternating the site of stimulation by using different combinations of contacts; this was a successful strategy for maintaining a clinically significant reduction in tremor. Disease progression, worsening of tremor, habituation, and loss of efficacy are known problems with some tremors, and their management can be challenging. The pathophysiology of worsening tremor after DBS is discussed in the chapter, as are potential programming strategies to manage this problem
Functional MRI with active, fully implanted, deep brain stimulation systems: Safety and experimental confounds
No full textWe investigated safety issues and potential experimental confounds when performing functional magnetic resonance imaging (fMRI) investigations in human subjects with fully implanted, active, deep brain stimulation (DBS) systems. Measurements of temperature and induced voltage were performed in an in vitro arrangement simulating bilateral DBS during magnetic resonance imaging (MRI) using head transmit coils in both 1.5 and 3.0 T MRI systems. For MRI sequences typical of an fMRI study with coil-averaged specific absorption rates (SARs) less than 0.4 W/kg, no MRI-induced temperature change greater than the measurement sensitivity (0.1 °C) was detected at 1.5 T, and at 3 T temperature elevations were less than 0.5 °C, i.e. within safe limits. For the purposes of demonstration, MRI pulse sequences with SARs of 1.45 W/kg and 2.34 W/kg (at 1.5 T and 3 T, respectively) were prescribed and elicited temperature increases (> 1 °C) greater than those considered safe for human subjects. Temperature increases were independent of the presence or absence of active stimulator pulsing. At both field strengths during echo planar MRI, the perturbations of DBS equipment performance were sufficiently slight, and temperature increases sufficiently low to suggest that thermal or electromagnetically mediated experimental confounds to fMRI with DBS are unlikely. We conclude that fMRI studies performed in subjects with subcutaneously implanted DBS units can be both safe and free from DBS-specific experimental confounds. Furthermore, fMRI in subjects with fully implanted rather than externalised DBS stimulator units may offer a significant safety advantage. Further studies are required to determine the safety of MRI with DBS for other MRI systems, transmit coil configurations and DBS arrangements
Deep-Brain stimulation of the subthalamic nucleus or the pars interna of the globus pallidus in Parkinson's disease.
No full textEffects of single-session versus multi-session non-invasive brain stimulation on craving and consumption in individuals with drug addiction, eating disorders or obesity: A meta-analysis
No full textBackground: Brain stimulation interventions are increasingly used to reduce craving and consumption in individuals with drug addiction or excessive eating behavior. However, the efficacy of these novel treatments and whether effect sizes are affected by the length of the intervention has not been comprehensively evaluated.
Objective: A meta-analytical approach was employed to evaluate the effectiveness of non-invasive excitatory brain stimulation [transcranial Direct Current Stimulation (tDCS) and high-frequency repetitive Transcranial Magnetic Stimulation (rTMS)] targeted at dorsolateral prefrontal cortex (dlPFC) for reducing craving and consumption levels in drug and eating addiction, including both single- and multi-session protocols.
Methods: After a comprehensive literature search, 48 peer-reviewed studies (1095 participants in total) were included in the current meta-analysis. We computed Hedge's g as a conservative measure for evaluating effect sizes.
Results: Random effects analyses revealed a small effect of neuromodulation interventions on craving and a medium effect on consumption, favoring active over sham stimulation. These effects did not differ across the different populations investigated (alcohol, nicotine, illicit drugs, eating addictions) or by the used technique (rTMS/tDCS, left/right hemisphere). Multi-session protocols showed a larger effect size for reducing craving and consumption than single-session protocols, with a positive linear association between the number of sessions or administered pulses and craving reduction, indicating a dose-response effect.
Conclusions: Our results provide compelling evidence that novel non-invasive brain stimulation targeted at dlPFC reduces craving and consumption levels (providing the first meta-analytical evidence for the latter effect in drug addiction), with larger effects in multi-session as compared to single-session interventions. (C) 2018 Elsevier Inc. All rights reserved
Trends in Clinical Deep Brain Stimulation
No full textThis book covers the current trends in clinical deep brain stimulation (DBS) research. This collection of papers from experts in the field provides state of the art knowledge and future perspectives in clinical DBS research. A range of topics involved in DBS is presented, ranging from high resolution imaging, electrophysiology and personalized medicine, in a broad range of brain disorders
Trends in Clinical Deep Brain Stimulation
Get PDFThis book covers the current trends in clinical deep brain stimulation (DBS) research. This collection of papers from experts in the field provides state of the art knowledge and future perspectives in clinical DBS research. A range of topics involved in DBS is presented, ranging from high resolution imaging, electrophysiology and personalized medicine, in a broad range of brain disorders
Deep brain stimulation and tics
No full textWhen patients with Tourettes syndrome (TS) are refractory to behavioral, pharmacological and invasive nonsurgical treatment (botulinum toxin injection), a viable emerging option is deep brain stimulation (DBS)
Deep brain stimulation for disorders of consciousness: Systematic review of cases and ethics
No full textBackground: A treatment for patients suffering from prolonged severely altered consciousness is not available. The success of Deep Brain Stimulation (DBS) in diseases such as Parkinson's, dystonia and essential tremor provided a renewed impetus for its application in Disorders of Consciousness (DoC). Objective: To evaluate the rationale for DBS in patients with DoC, through systematic review of literature containing clinical data and ethical considerations. Methods: Articles from PubMed, Embase, Medline and Web of Science were systematically reviewed. Results: The outcomes of 78 individual patients reported in 19 articles from 1968 onwards were pooled and elements of ethical discussions were compared. There is no clear clinical evidence that DBS is a treatment for DoC that can restore both consciousness and the ability to communicate. In patients who benefitted, the outcome of DBS is often confounded by the time frame of spontaneous recovery from DoC. Difficult ethical considerations remain, such as the risk of increasing self-awareness of own limitations, without improving overall wellbeing, and the issues of proxy consent. Conclusion: DBS is far from being evident as a possible future therapeutic avenue for patients with DoC. Double-blind studies are lacking, and many clinical and ethical issues have to be addressed. In the rare cases when DBS for patients with DoC is considered, this needs to be evaluated meticulously on a case by case basis, with comprehensive overall outcome measures including psychological and quality-of-life assessments, and with the guidance of an ethical and interdisciplinary panel, especially in relation to proxy consent. </p
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