Tissue reactions to long-term electrical stimulation of the cerebellum in monkeys

1977 ◽  
Vol 47 (3) ◽  
pp. 366-379 ◽  
Author(s):  
W. Jann Brown ◽  
Thomas L. Babb ◽  
Henry V. Soper ◽  
Jeffrey P. Lieb ◽  
Carlos A. Ottino ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Charge Density ◽  
Purkinje Cells ◽  
Molecular Layer ◽  
Electrode Array ◽  
Electrode Arrays ◽  
Human Cerebellum ◽  
A Charge ◽  
Tissue Reactions ◽  
Stimulation Of

✓ Light and electron microscopic analyses were carried out on the stimulated and unstimulated paravermal cortices of six rhesus monkeys that had electrodes implanted on their cerebella for 2 months. The electrodes and the stimulation regime (10 p.p.s.: 8 min on, 8 min off) were similar to those used to stimulate the human cerebellum for treatment of certain neurological disorders. Mere presence of the electrode array in the posterior fossa for 2 months resulted in some meningeal thickening, attenuation of the molecular layer, and loss of Purkinje cells immediately beneath the electrode array. There was no evidence of scarring. After 205 hours of stimulation (7.38 × 106 pulses) over 18 days, a charge of 0.5 µC/ph or estimated charge density of 7.4 µC/sq cm/ph resulted in no damage to the cerebellum attributable to electrical stimulation per se. Such a charge/phase is about five times the threshold for evocation of cerebellar efferent activity, and might be considered “safe” for stimulation of human cerebellum. Charge density/phase and charge/phase were directly related to increased cerebellar injury in the six other cerebellar cortices stimulated. Leptomeningeal thickening increased with increased charge density. Injury included severe molecular layer attenuation, ongoing destruction of Purkinje cells, gliosis, ongoing degeneration of myelinated axons, collagen intrusion, and increased levels of local polysaccharides. In all cases, even with damage that destroyed all conducting elements beneath the electrodes, there was no damage further than 1 to 2 mm from the edges of the electrode arrays.

scholarly journals Sensory and motor electrophysiological mapping of the cerebellum in humans

2020 ◽  
Author(s):  
Reiko Ashida ◽  
Peter Walsh ◽  
Jonathan C.W. Brooks ◽  
Richard J. Edwards ◽  
Nadia L. Cerminara ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Evoked Potentials ◽  
Posterior Fossa ◽  
Posterior Lobe ◽  
Posterior Fossa Surgery ◽  
Motor Mapping ◽  
Human Cerebellum ◽  
Limb Muscles ◽  
The Right ◽  
Stimulation Of

AbstractDamage to the cerebellum during posterior fossa surgery can lead to ataxia and in paediatric cases, the risk of cerebellar mutism syndrome. Animal electrophysiological and human imaging studies have shown compartmentalisation of sensorimotor and cognitive functions within the cerebellum. In the present study, electrophysiological monitoring of sensory and motor pathways was carried out to assess the location of limb sensorimotor representation within the human cerebellum, as a potential approach for real time assessment of neurophysiological integrity to reduce the incidence of cerebellar surgical morbidities.Thirteen adult and paediatric patients undergoing posterior fossa surgery were recruited. For sensory mapping (n=8), electrical stimulation was applied to the median nerves, the posterior tibial nerves, or proximal and distal limb muscles and evoked field potential responses were sought on the cerebellar surface. For motor mapping (n=5), electrical stimulation was applied to the surface of the cerebellum and evoked EMG responses were sought in facial and limb muscles.Evoked potentials on the cerebellar surface were found in two patients (25% of cases). In one patient, the evoked response was located on the surface of the right inferior posterior cerebellum in response to stimulation of the right leg. In the second patient, stimulation of the extensor digitorum muscle in the left forearm evoked a response on the surface of the left inferior posterior lobe. In the motor mapping cases no evoked EMG responses could be found.Intraoperative electrophysiological mapping, therefore, indicates it is possible to record evoked potentials on the surface of the human cerebellum in response to peripheral stimulation.

Functional Electrical Stimulation of the Larynx with a Flexible Ribbon Electrode Array

2014 ◽  
Vol 151 (1_suppl) ◽  
pp. P71-P72
Author(s):  
Morgan R. Bliss ◽  
Heather Wark ◽  
Daniel McDonnall ◽  
Marshall E. Smith
Keyword(s):  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Electrode Array ◽  
Stimulation Of

Electrical Cochlear Stimulation in the Deaf Cat: Comparisons Between Psychophysical and Central Auditory Neuronal Thresholds

2000 ◽  
Vol 83 (4) ◽  
pp. 2145-2162 ◽  
Author(s):  
Ralph E. Beitel ◽  
Russell L. Snyder ◽  
Christoph E. Schreiner ◽  
Marcia W. Raggio ◽  
Patricia A. Leake
Keyword(s):  
Electrical Stimulation ◽  
Auditory System ◽  
Pulse Rate ◽  
Auditory Nerve ◽  
Round Window ◽  
Electrode Array ◽  
Scala Tympani ◽  
Behavioral Thresholds ◽  
Current Pulses ◽  
Stimulation Of

Cochlear prostheses for electrical stimulation of the auditory nerve (“electrical hearing”) can provide auditory capacity for profoundly deaf adults and children, including in many cases a restored ability to perceive speech without visual cues. A fundamental challenge in auditory neuroscience is to understand the neural and perceptual mechanisms that make rehabilitation of hearing possible in these deaf humans. We have developed a feline behavioral model that allows us to study behavioral and physiological variables in the same deaf animals. Cats deafened by injection of ototoxic antibiotics were implanted with either a monopolar round window electrode or a multichannel scala tympani electrode array. To evaluate the effects of perceptually significant electrical stimulation of the auditory nerve on the central auditory system, an animal was trained to avoid a mild electrocutaneous shock when biphasic current pulses (0.2 ms/phase) were delivered to its implanted cochlea. Psychophysical detection thresholds and electrical auditory brain stem response (EABR) thresholds were estimated in each cat. At the conclusion of behavioral testing, acute physiological experiments were conducted, and threshold responses were recorded for single neurons and multineuronal clusters in the central nucleus of the inferior colliculus (ICC) and the primary auditory cortex (A1). Behavioral and neurophysiological thresholds were evaluated with reference to cochlear histopathology in the same deaf cats. The results of the present study include: 1) in the cats implanted with a scala tympani electrode array, the lowest ICC and A1 neural thresholds were virtually identical to the behavioral thresholds for intracochlear bipolar stimulation; 2) behavioral thresholds were lower than ICC and A1 neural thresholds in each of the cats implanted with a monopolar round window electrode; 3) EABR thresholds were higher than behavioral thresholds in all of the cats (mean difference = 6.5 dB); and 4) the cumulative number of action potentials for a sample of ICC neurons increased monotonically as a function of the amplitude and the number of stimulating biphasic pulses. This physiological result suggests that the output from the ICC may be integrated spatially across neurons and temporally integrated across pulses when the auditory nerve array is stimulated with a train of biphasic current pulses. Because behavioral thresholds were lower and reaction times were faster at a pulse rate of 30 pps compared with a pulse rate of 2 pps, spatial-temporal integration in the central auditory system was presumably reflected in psychophysical performance.

scholarly journals Acute electrical stimulation of the human retina with an epiretinal electrode array

2011 ◽  
Vol 90 (1) ◽  
pp. e1-e8 ◽  
Author(s):  
Matthias Keserü ◽  
Matthias Feucht ◽  
Norbert Bornfeld ◽  
Thomas Laube ◽  
Peter Walter ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Electrode Array ◽  
Human Retina ◽  
Stimulation Of

scholarly journals Sensory and motor electrophysiological mapping of the cerebellum in humans

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Reiko Ashida ◽  
Peter Walsh ◽  
Jonathan C. W. Brooks ◽  
Nadia L. Cerminara ◽  
Richard Apps ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Posterior Fossa ◽  
Functional Organization ◽  
Posterior Lobe ◽  
Posterior Fossa Surgery ◽  
Motor Mapping ◽  
Human Cerebellum ◽  
The Right ◽  
Sensory Evoked ◽  
Stimulation Of

AbstractCerebellar damage during posterior fossa surgery in children can lead to ataxia and risk of cerebellar mutism syndrome. Compartmentalisation of sensorimotor and cognitive functions within the cerebellum have been demonstrated in animal electrophysiology and human imaging studies. Electrophysiological monitoring was carried out under general anaesthesia to assess the limb sensorimotor representation within the human cerebellum for assessment of neurophysiological integrity to reduce the incidence of surgical morbidities. Thirteen adult and paediatric patients undergoing posterior fossa surgery were recruited. Sensory evoked field potentials were recorded in response to mapping (n = 8) to electrical stimulation of limb nerves or muscles. For motor mapping (n = 5), electrical stimulation was applied to the surface of the cerebellum and evoked EMG responses were sought in facial and limb muscles. Sensory evoked potentials were found in two patients (25%). Responses were located on the surface of the right inferior posterior cerebellum to stimulation of the right leg in one patient, and on the left inferior posterior lobe in another patient to stimulation of left forearm. No evoked EMG responses were found for the motor mapping. The present study identifies challenges with using neurophysiological methods to map functional organization within the human cerebellum and considers ways to improve success.

scholarly journals Binocular 3D otolith-ocular reflexes: responses of chinchillas to prosthetic electrical stimulation targeting the utricle and saccule

2020 ◽  
Vol 123 (1) ◽  
pp. 259-276 ◽  
Author(s):  
Kristin N. Hageman ◽  
Margaret R. Chow ◽  
Dale Roberts ◽  
Peter J. Boutros ◽  
Angela Tooker ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Hair Cells ◽  
Temporal Dynamics ◽  
Semicircular Canals ◽  
Bipolar Electrode ◽  
Electrode Arrays ◽  
Reflex Responses ◽  
Ocular Reflex ◽  
Postural Responses ◽  
Stimulation Of

From animal experiments by Cohen and Suzuki et al. in the 1960s to the first-in-human clinical trials now in progress, prosthetic electrical stimulation targeting semicircular canal branches of the vestibular nerve has proven effective at driving directionally appropriate vestibulo-ocular reflex eye movements, postural responses, and perception. That work was considerably facilitated by the fact that all hair cells and primary afferent neurons in each canal have the same directional sensitivity to head rotation, the three canals’ ampullary nerves are geometrically distinct from one another, and electrically evoked three-dimensional (3D) canal-ocular reflex responses approximate a simple vector sum of linearly independent components representing relative excitation of each of the three canals. In contrast, selective prosthetic stimulation of the utricle and saccule has been difficult to achieve, because hair cells and afferents with many different directional sensitivities are densely packed in those endorgans and the relationship between 3D otolith-ocular reflex responses and the natural and/or prosthetic stimuli that elicit them is more complex. As a result, controversy exists regarding whether selective, controllable stimulation of electrically evoked otolith-ocular reflexes (eeOOR) is possible. Using micromachined, planar arrays of electrodes implanted in the labyrinth, we quantified 3D, binocular eeOOR responses to prosthetic electrical stimulation targeting the utricle, saccule, and semicircular canals of alert chinchillas. Stimuli delivered via near-bipolar electrode pairs near the maculae elicited sustained ocular countertilt responses that grew reliably with pulse rate and pulse amplitude, varied in direction according to which stimulating electrode was employed, and exhibited temporal dynamics consistent with responses expected for isolated macular stimulation. NEW & NOTEWORTHY As the second in a pair of papers on Binocular 3D Otolith-Ocular Reflexes, this paper describes new planar electrode arrays and vestibular prosthesis architecture designed to target the three semicircular canals and the utricle and saccule. With this technological advancement, electrically evoked otolith-ocular reflexes due to stimulation via utricle- and saccule-targeted electrodes were recorded in chinchillas. Results demonstrate advances toward achieving selective stimulation of the utricle and saccule.

Technical Approach for Reanimation of the Chronically Denervated Larynx by Means of Functional Electrical Stimulation

1994 ◽  
Vol 103 (9) ◽  
pp. 705-712 ◽  
Author(s):  
David L. Zealear ◽  
Cheryl L. Rainey ◽  
Tetsuya Tanabe ◽  
Matthew L. Jerles ◽  
Garrett D. Herzon
Keyword(s):  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Vocal Fold ◽  
Hot Spot ◽  
Electrode Array ◽  
Electrode Arrays ◽  
Denervated Muscle ◽  
Alternative Approach ◽  
Bilateral Vocal Fold Paralysis ◽  
Posterior Cricoarytenoid

Functional electrical stimulation (FES) of the posterior cricoarytenoid (PCA) muscle to produce vocal fold abduction offers an alternative approach to current surgical therapies for bilateral vocal fold paralysis. The purpose of this study was to characterize the application of FES to chronically denervated PCA muscles. Specific goals were to develop a stimulus delivery system for the PCA muscle, determine a practical means of implantation, and identify stimulus parameters effective in activating chronically denervated muscle. Seventeen dogs were implanted with planar electrode arrays 3 months after unilateral recurrent laryngeal nerve resection. A nail-bed electrode array allowed discrete activation of the PCA muscle and gave the greatest abductions, with minimal charge dissipation. Muscle mapping revealed hot-spot regions on the PCA muscle surface, in which stimulation produced maximum abduction. A conservative stimulus paradigm effective in activating chronically denervated muscle was a 1-second pulse train of 2-millisecond-duration pulses, delivered at a tetanizing frequency of 30 Hz and an amplitude of 4 to 14 mA.

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