Experimental Nondestructive Electrical Stimulation of the Brain and Spinal Cord
01 May 1970-Journal of Neurosurgery (Journal of Neurosurgery Publishing Group)-Vol. 32, Iss: 5, pp 553-559
TL;DR: The basic requirements for standardization of a safe stimulating current are studied and several factors that theoretically influence the safe stimulation critical value are theoretically influenced.
Abstract: HE shortcomings of destructive lesions used as treatment for neurological disorders ~,6 have triggered a search for new techniques. Electrical stimulation of the nervous system has been an attractive possibility because undesirable side effects of the stimulus may be eliminated when the electrical current is stoppedY We have studied the basic requirements for standardization of a safe stimulating current. Electricity has long been used for destruction of tissue, either as direct or radiofrequency current; both will lead to destruction of brain or spinal cord, but each is partially uncontrollable and the results are irreversible. Even alternating current will damage the nervous system if its parameters are not rigidly controlled. Since electrical stimulation of the nervous system offers attractive possibilities for treatment of some neurological disorders, 2,11,12 standardization of safety factors is essential. Several factors that theoretically influence the safe stimulation critical value (r) are: Voltage across the electrodes, V Current delivered to the load, I Pulse repetition rate, f Pulse duration, d Contact area of the electrode, A Type of metal, M.
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TL;DR: The physical basis for electrical stimulation of excitable tissue, as used by electrophysiological researchers and clinicians in functional electrical stimulation, is presented with emphasis on the fundamental mechanisms of charge injection at the electrode/tissue interface.
1,875 citations
TL;DR: Results show that charge density (as measured at the surface of the stimulating electrode) and charge per phase interact in a synergistic manner to determine the threshold of stimulation-induced neural injury.
Abstract: Stimulating electrodes of various sizes were used to investigate the interactions of two stimulus parameters, charge density and charge per phase, in determining the threshold of neural injury induced by electrical stimulation. Platinum electrodes ranging in size from 0.002 to 0.5 cm/sup 2/ were implanted over the parietal cortex of adult cats. Ten days after implantation, the electrodes were pulsed continuously for 7 h using charge-balanced, current-regulated, symmetric pulse pairs 400 mu s per phase in duration and at a repetition rate of 50 Hz. The results show that charge density (as measured at the surface of the stimulating electrode) and charge per phase interact in a synergistic manner to determine the threshold of stimulation-induced neural injury. This interaction occurs over a wide range of both parameters: for charge density from at least 10 to 800 mu C/cm/sup 2/, and for charge per phase from at least 0.05 to 5.0 mu C per phase. The significance of these findings in elucidating the mechanisms underlying stimulation-induced injury is discussed. >
752 citations
TL;DR: In this article, the authors review recent efforts to design stimulus waveforms for selective electrical stimulation of the nervous system and present the fundamental principles governing the response of excitable nerve fibers to imposed stimuli are reviewed and used to design waveforms.
Abstract: The authors review recent efforts to design stimulus waveforms for selective electrical stimulation of the nervous system. Two types of selectivity are considered. Fiber diameter selectivity refers to the ability to activate one group of nerve fibers having a common diameter without activating nerve fibers having different diameters. Spatial selectivity refers to the ability to activate nerve fibers in a localized region without activating nerve fibers in neighboring regions. The fundamental principles governing the response of excitable nerve fibers to imposed stimuli are reviewed and used to design waveforms. The emphasis of the presentation is on excitation of peripheral myelinated nerve fibers, The underlying principles, however, are broadly applicable to all excitable membranes. >
355 citations
TL;DR: Facial anesthesia dolorosa following retrogasserian rhizotomy was treated by stimulation of the contralateral thalamic sensory nucleus (posterior ventralis medialis) through stereotaxically placed, chronically implanted electrodes in five patients and facial pain was masked by electrically induced paresthesia.
Abstract: Facial anesthesia dolorosa following retrogasserian rhizotomy was treated by stimulation of the contralateral thalamic sensory nucleus (posterior ventralis medialis) through stereotaxically placed, chronically implanted electrodes in five patients. In four patients, facial pain was masked by electrically induced paresthesia. One patient continued to experience her pain through the induced paresthesia. The mechanism of pain control in these cases can be postulated as suppression at the thalamic level of neuronal hyperactivity projected from the deafferented trigeminal system.
343 citations
TL;DR: This pilot project demonstrated the feasibility of controlled study of thalamic stimulation in epilepsy, but further study will be needed to demonstrate efficacy.
Abstract: Stimulation of centromedian (CM) thalamic nuclei has been proposed as a treatment for seizures. We implanted programmable subcutaneous (s.c.) stimulators into CM bilaterally in 7 patients with intractable epilepsy to test feasibility and safety. Stimulation was on or off in 3-month blocks, with a 3-month washout period in a double-blind, cross-over protocol. Stimuli were delivered as 90-microseconds pulses at 65 pulses/s, 1 min of each 5 min for 2 h/day, with voltage set to half the sensory threshold. Stimulation was safe and well-tolerated, with a mean reduction of tonic-clonic seizure frequency of 30% with respect to baseline when stimulator was on versus a decrease of 8% when the stimulator was off. There was no improvement in total number of generalized seizures with stimulation, and treatment differences were not statistically significant. Stimulation at low intensity did not alter the EEG acutely, but high-intensity stimulation induced slow waves or 2-3 Hz spike-waves with ipsilateral frontal maximum. In an open-label follow-up segment with stimulator trains continuing for 24 h/day, 3 of 6 patients reported at least a 50% decrease in seizure frequency. There were no side effects. This pilot project demonstrated the feasibility of controlled study of thalamic stimulation in epilepsy, but further study will be needed to demonstrate efficacy.
338 citations
References
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TL;DR: Electrical Inhibition of Pain by Stimulation of the Dorsal Columns: Preliminary Clinical Report
Abstract: Electrical Inhibition of Pain by Stimulation of the Dorsal Columns: Preliminary Clinical Report C. SHEALY;J. MORTIMER;JAMES RESWICK; Anesthesia & Analgesia
1,227 citations
TL;DR: It is demonstrated that activity in large peripheral sensory nerve fibers carrying nonpainful impulses inhibits in the spinal cord subsequent activity from the smallest fibers considered essential to pain conduction.
Abstract: ECENT neurophysiologic s tudies have R raised the possibility of electrical inhibition of pain. Electronarcosis has been widely investigatedl-12 but no previous attempts are known of application of inhibiting currents to the spinal cord. Wal113 demonstrated that activity in large peripheral sensory nerve fibers carrying nonpainful impulses inhibits in the spinal cord subsequent activity from the smallest fibers considered essential to pain conduction. Melzack and Wall14 suggested using this knowledge to suppress pain. Mechanical surface activation of the noripainful large fibers, such as rubbing or vibration, however, is not practical for prolonged use. Furthermore, it is probable that such stimuli must be applied to a wide area to block pain effectively from even a small focus.
167 citations
TL;DR: The extent of capillary damage and its possible role in the development of a lesion are important from the point of view of the physiological effect of ultrasound.
Abstract: It has been demonstrated in recent years * that focused ultrasound of frequencies ranging from 0.9 to 2.5 megacycles (mc), and at intensities of from 200 to 1500 watts per square centimeter, may be used to produce circumscribed small lesions in the central nervous system. Histological examination of the tissue damaged by focused ultrasound does not reveal the mechanism of destruction, although the morphological appearance of ultrasonic lesions differs specifically from other types of lesions.2 A cardinal point in understanding the effect of ultrasound on central nervous tissue is knowledge of the reaction of the cerebral capillaries to this type of injury. Both the absence of gross hemorrhage and the existence of edema have been reported by some investigators.† Thus, the extent of capillary damage and its possible role in the development of a lesion are important from the point of view of the physiological effect of ultrasound. For this
131 citations
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TL;DR: The bipolar catheter pacemaker was used as a temporary measure in 58 patients with complete heart block and failure to pace was usually caused by malposition or breakage of the catheter, poor electrical connections, or run-down batteries.
Abstract: The bipolar catheter pacemaker was used as a temporary measure in 58 patients with complete heart block The external jugular veins were the preferred sites of passage, and a fluoroscopic image intensifier was almost a necessity Complications were frequent including two deaths during catheterization and two later deaths Failure to pace was usually caused by malposition or breakage of the catheter, poor electrical connections, or run-down batteries Investigation of such failure should include a survey of the pacemaker artifact in the standard electrocardiogram and the recording of endocardial leads from the catheter, in addition to x-ray studies
30 citations