Brain Stimulation Therapies
Bahman Zohuri, Patrick J. McDaniel in Electrical Brain Stimulation for the Treatment of Neurological Disorders, 2019
Brain stimulation therapies can play a role in treating certain mental disorders. Brain stimulation therapies involve activating or inhibiting the brain directly with electricity. This chapter reviews the understanding of the physiologic effects and presumed mechanism of effect of transcranial magnetic stimulation (TMS) as an antidepressant. Standard TMS procedure usually implies that the subject remains conscious and is comfortably sitting. The cap is worn during the stimulation that enables marking of the coil position on the surface of the head. Several methods for the localization of stimulation site can be applied regarding the region of interest. TMS is extensively used for investigation of the excitability of the human brain. Together, computational models of TES play a critical role in visualizing the electrical field distribution, understanding the mechanistic action of TES on neuronal network dynamics, and optimizing stimulation parameters to guide the design of the next generation of TES.
Electrical Stimulation of Excitable Tissue
Joseph D. Bronzino, Donald R. Peterson in Biomedical Engineering Fundamentals, 2014
Electrical stimulation of cardiac tissue has been particularly successful to restore the function in the heart with implanted pacemakers, and functional electrical stimulation of the nervous system can provide functional restoration to neurologically impaired individuals. Biological volume conductors are highly inhomogenous and the complexity of the volume conductors requires in most cases numerical solutions using nite element or nite boundary methods. Corrosion of the electrode is a major concern since it can cause pitting, metal dissolution, and tissue damage. Corrosion occurs at the anodic phase of the stimulation during oxidation. A successful restoration of function with electrical stimulation requires that the activation of the excitable tissue be carried out without causing damage. Stimulation of the cardiac tissue diers in several respects from the stimulation of the nervous system. Electrical stimulation of an excitable tissue has been highly successful as indicated by the broad application of devices such as the cardiac pacemaker and cochlear prostheses.
NEUROMODULATION – SPINAL CORD, PERIPHERAL NERVE AND BRAIN STIMULATION
Kate M. Grady, Andrew M. Severn, Andrew M. Severn in Key Topics in Pain Management, 2006
Methods and sites The commonest site for stimulation for pain is the spinal cord. Stimulation can also be delivered to sites within the brain (such as the thalamus) or occasionally over the motor cortex of the brain. Stimulation can be used for control of conditions other than pain, such as spasticity, bladder control in multiple sclerosis (MS), peripheral vascular disease (PVD) and angina. There is increasing interest in peripheral nerve stimulation for pain – sacral nerve stimulation for incontinence is well evidenced and more recently occipital nerve stimulation is gaining acceptance for occipital neuralgia, cluster headache and even migraine. This growth reflects in part improvements in technology – hitherto, systems able to deliver peripheral nerve stimulation have been unreliable.
Desynchronizing the abnormally synchronized neural activity in the subthalamic nucleus: a modeling study
Published in Expert Review of Medical Devices, 2007
Christian Hauptmann, Oleksandr Popovych, Peter A Tass
A mathematical model of a target area for deep brain stimulation was used to investigate the effects of electrical stimulation on pathologically synchronized clusters of neurons. In total, three newly developed stimulation techniques based on multisite coordinated reset and delayed feedback were tested and compared with a high-frequency stimulation method that is currently used as a standard stimulation protocol for deep brain stimulation. By modeling both excitatory and inhibitory actions of the electrical stimulation, we revealed the desynchronization impacts of the novel stimulation techniques. This contrasts with standard high-frequency stimulation, which failed to desynchronize the target population and whose inhibitory effects blocked all neuronal activity. We also explored the demand-controlled character of the proposed methods, and demonstrated that the amount of stimulation current required was considerably smaller than that for high-frequency stimulation. These novel stimulation methods appear to be superior to standard high-frequency stimulation techniques, and we propose the methods now be used for deep brain stimulation.
Visions on the future of medical devices in spinal cord stimulation: what medical device is needed?
Published in Expert Review of Medical Devices, 2016
SUMMARY Recently burst stimulation and 10 kHz stimulation have been developed as novel stimulation designs. Both appear to be superior to classical tonic stimulation in the amount of responders and the amount of pain suppression and have as an extra advantage that they are paresthesia-free. This evolution is very important as it shifts the focus of research from better targeting by developing new lead configurations to better communication with the nervous system. It can be envisioned that this is only the start of a new trend in spinal cord, brain, and peripheral nerve stimulation and that more new stimulation designs will be developed in the near future such as pseudorandom burst stimulation, pleasure stimulation, noise stimulation and reconditioning stimulation. This evolution mandates a new approach in the development of internal pulse generators, and the most obvious approach is to develop an upgradable stimulator, on which new stimulation designs can be downloaded, analogous to the apps people download on their smartphones. This will create a shift from hardware driven products to software driven stimulators.
Activation of sensory cortex by imagined genital stimulation: an fMRI analysis
Published in Socioaffective Neuroscience & Psychology, 2016
Nan J. Wise, Eleni Frangos, Barry R. Komisaruk
BackgroundDuring the course of a previous study, our laboratory made a serendipitous finding that just thinking about genital stimulation resulted in brain activations that overlapped with, and differed from, those generated by physical genital stimulation. ObjectiveThis study extends our previous findings by further characterizing how the brain differentially processes physical ‘touch’ stimulation and ‘imagined’ stimulation. DesignEleven healthy women (age range 29–74) participated in an fMRI study of the brain response to imagined or actual tactile stimulation of the nipple and clitoris. Two additional conditions – imagined dildo self-stimulation and imagined speculum stimulation – were included to characterize the effects of erotic versus non-erotic imagery. ResultsImagined and tactile self-stimulation of the nipple and clitoris each activated the paracentral lobule (the genital region of the primary sensory cortex) and the secondary somatosensory cortex. Imagined self-stimulation of the clitoris and nipple resulted in greater activation of the frontal pole and orbital frontal cortex compared to tactile self-stimulation of these two bodily regions. Tactile self-stimulation of the clitoris and nipple activated the cerebellum, primary somatosensory cortex (hand region), and premotor cortex more than the imagined stimulation of these body regions. Imagining dildo stimulation generated extensive brain activation in the genital sensory cortex, secondary somatosensory cortex, hippocampus, amygdala, insula, nucleus accumbens, and medial prefrontal cortex, whereas imagining speculum stimulation generated only minimal activation. ConclusionThe present findings provide evidence of the potency of imagined stimulation of the genitals and that the following brain regions may participate in erogenous experience: primary and secondary sensory cortices, sensory-motor integration areas, limbic structures, and components of the ‘reward system’. In addition, these results suggest a mechanism by which some individuals may be able to generate orgasm by imagery in the absence of physical stimulation.