Mapping of sensory responses to epidural stimulation of the intraspinal neural structures in man

1993 ◽  
Vol 78 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Giancarlo Barolat ◽  
Fulvio Massaro ◽  
Jiping He ◽  
Sergio Zeme ◽  
Beth Ketcik
Keyword(s):  
Electrode Array ◽  
Electrode Arrays ◽  
Content Type ◽  
Implanted Electrodes ◽  
Root Entry Zone ◽  
Dorsal Columns ◽  
Epidural Spinal Cord Stimulation ◽  
Sensory Responses ◽  
Stimulation Of

✓ A database is presented of sensory responses to electrical stimulation of the dorsal neural structures at various spine levels in 106 subjects subjected to epidural spinal cord stimulation. All patients were implanted for chronic pain management and were able to perceive stimulation in the area of pain. All patients entered in this study were able to reliably report their stimulation pattern. Several patients were implanted with more than one electrode array. The electrode arrays were placed in the dorsal epidural space at levels between C-1 and L-1. The structures that were likely involved include the dorsal roots, dorsal root entry zone, dorsal horn, and dorsal columns. At the present time, exact characterization of the structure being stimulated is possible only in limited instances. Various body areas are presented with the correspondent spine levels where implanted electrodes generate paresthesias. Areas that are relatively easy targets for stimulation are the median aspect of the hand, the abdominal wall, the anterior aspect of the thigh, and the foot. Some areas are particularly difficult to cover with stimulation-induced paresthesias; these include the C-2 distribution, the neck, the low back, and the perineum.

Intraoperative evoked potentials recorded in man directly from dorsal roots and spinal cord

1985 ◽  
Vol 62 (5) ◽  
pp. 680-693 ◽  
Author(s):  
Blaine S. Nashold ◽  
Janice Ovelmen-Levitt ◽  
Robbin Sharpe ◽  
Alfred C. Higgins
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Mean Amplitude ◽  
Dorsal Column ◽  
Intractable Pain ◽  
Neurosurgical Procedures ◽  
Negative Wave ◽  
Content Type ◽  
Root Entry Zone ◽  
Dorsal Columns

✓ Direct spinal cord surface recordings of evoked spinal cord potentials have been made in 26 patients during neurosurgical procedures for intractable pain. Monopolar recordings at the dorsal root entry zone after peripheral nerve stimulation have been made at multiple levels for segmental localization and to monitor the state of the afferent path and dorsal horn. Dorsal root and dorsal column conduction has been tested on diseased and intact sides. Normal afferent conduction velocity was found to have an overall mean of 61.33 m/sec for cervicothoracic and lumbosacral peripheral nerves, and 50 m/sec for the dorsal columns. The normal mean amplitude for the slow negative wave (N1) recorded at the root entry was 52.54 µV, while that for the dorsal column conducted response recorded within 4 cm of the stimulus point on the dorsal columns was 347.5 µV. Several different placements of stimulating and recording electrodes are described, as well as their application. An interpretation of the resulting data is proposed.

Generator sites of early scalp potentials evoked from the three trigeminal branches

1998 ◽  
Vol 88 (4) ◽  
pp. 718-725 ◽  
Author(s):  
Massimo Leandri
Keyword(s):  
Direct Evidence ◽  
Foramen Ovale ◽  
Superior Orbital Fissure ◽  
Entry Zone ◽  
Content Type ◽  
Maxillary Nerve ◽  
Root Entry Zone ◽  
Foramen Rotundum ◽  
Fine Print ◽  
Stimulation Of

Object. The aim of this study was to seek evidence about the generators of the first three components of the scalp's early trigeminal evoked potentials (TEPs) obtained by stimulation of the supraorbital (SW1, SW2, and SW3), infraorbital (W1, W2, and W3) and mental (MW1, MW2, and MW3) nerves. Methods. Simultaneous scalp and depth recordings were measured during surgical procedures in which thermorhizotomy and microvascular decompression were performed. Conclusions. Direct evidence was found that the origin of MW1 lies in the mandibular nerve at the foramen ovale, whereas the origin of W1 in the maxillary nerve at the foramen rotundum and the origin of SW1 in the ophthalmic nerve at the superior orbital fissure could only be inferred. The generators of SW2, W2, and MW2 were found to be on the nerve root at a distance of 10 mm from the pons. Calculations based on conduction velocity suggested that the generators of SW3, W3, and MW3 were inside the brainstem, at distances between 16 mm and 20 mm from the root entry zone. Recordings obtained in eight patients with discrete surgical lesions of the trigeminal pathway confirmed the sites of origin of the early components and further proved that only the fastest group of fibers is responsible for scalp responses.

On the origin of synkinesis in hemifacial spasm: results of intracranial recordings

1984 ◽  
Vol 61 (3) ◽  
pp. 569-576 ◽  
Author(s):  
Aage R. Møller ◽  
Peter J. Jannetta
Keyword(s):  
Facial Nerve ◽  
Hemifacial Spasm ◽  
Orbicularis Oculi Muscle ◽  
Orbicularis Oculi ◽  
Content Type ◽  
Root Entry Zone ◽  
Marginal Mandibular Branch ◽  
Intracranial Recordings ◽  
Mandibular Branch ◽  
Stimulation Of

✓ Recordings were made from facial muscles and the facial nerve near its entrance into the brain stem in patients with hemifacial spasm (HFS). The purpose of this study was to determine if the synkinesis commonly seen in patients with HFS could be linked to ephaptic transmission at the presumed site of the lesion (at the root entry zone (REZ) of the facial nerve). When the mandibular branch of the facial nerve was electrically stimulated, a response could be recorded from the orbicularis oculi muscles during the operation. The latency of the earliest response was 11.03 ± 0.66 msec (mean response of seven patients ± standard deviation (SD)). With equivalent stimulation a response could also be recorded from the facial nerve near the REZ; the latency of this response was 3.87 ± 0.36 msec. Stimulation of the facial nerve at the same location yielded a response from the orbicularis oculi muscle, with a latency of 4.65 ± 0.25 msec. The latency of the earliest response from the orbicularis oculi muscle to stimulation of the marginal mandibular branch of the facial nerve (11.3 msec) is thus larger than the sum of the conduction times from the points of stimulation of the marginal mandibular branch to the REZ of the facial nerve and from the REZ of the facial nerve to the orbicularis oculi muscle (8.52 ± 0.38 msec). It is therefore regarded as unlikely that the earliest response of the orbicularis oculi muscle to stimulation of the mandibular branch of the facial nerve is a result of “crosstalk” in the facial nerve at a location near the REZ, and it seems more likely that HFS caused by injury of the facial nerve is a result of reverberant activity in the facial motonucleus, possibly caused by mechanisms that are similar to kindling.

Far-field responses to stimulation of the cochlear nucleus by microsurgically placed penetrating and surface electrodes in the cat

2001 ◽  
Vol 95 (5) ◽  
pp. 845-852 ◽  
Author(s):  
Steffen K. Rosahl ◽  
Gerhard Mark ◽  
Martin Herzog ◽  
Christos Pantazis ◽  
Farnaz Gharabaghi ◽  
...  
Keyword(s):  
Cochlear Nucleus ◽  
Auditory Brainstem ◽  
Mastoid Process ◽  
Electrode Arrays ◽  
Content Type ◽  
Surface Electrodes ◽  
Brainstem Response ◽  
The Mean ◽  
Fine Print ◽  
Stimulation Of

Object. A new generation of penetrating electrodes for auditory brainstem implants is on the verge of being introduced into clinical practice. This study was designed to compare electrically evoked auditory brainstem responses (EABRs) to stimulation of the cochlear nucleus (CN) by microsurgically implanted surface electrodes and insertion electrodes (INSELs) with stimulation areas of identical size. Methods. Via a lateral suboccipital approach, arrays of surface and penetrating microelectrodes with geometric stimulation areas measuring 4417 µm2 (diameter 75 µm) were placed over and inserted into the CN in 10 adult cats. After recording the auditory brainstem response (ABR) at the mastoid process, the CN, and the level of the inferior colliculus, EABRs to stimulation of the CN were recorded using biphasic, charge-balanced stimuli with phase durations of 80 µsec, 160 µsec, and 240 µsec at a repetition rate of 22.3 Hz. Waveform, threshold, maximum amplitude, and the dynamic range of the responses were compared for surface and penetrating electrodes. The EABR waveforms that appeared for both types of stimulation resembled each other closely. The mean impedance was slightly lower (30 ± 3.4 kΩ compared with 31.7 ± 4.5 kΩ, at 10 kHz), but the mean EABR threshold was significantly higher (51.8 µA compared with 40.5 µA, t = 3.5, p = 0.002) for surface electrode arrays as opposed to penetrating electrode arrays. Due to lower saturation levels of the INSEL array, dynamic ranges were almost identical between the two types of stimulation. Sectioning of the eighth cranial nerve did not abolish EABRs. Conclusions. Microsurgical insertion of electrodes into the CN complex may be guided and monitored using techniques similar to those applied for implantation of surface electrodes. Lower thresholds and almost equivalent dynamic ranges indicate that a more direct access to secondary auditory neurons is achieved using penetrating electrodes.

Sensory responses from stimulation of the inferior Rolandic and Sylvian regions in man

1983 ◽  
Vol 59 (1) ◽  
pp. 119-130 ◽  
Author(s):  
John M. Van Buren
Keyword(s):  
Electrical Stimulation ◽  
Ipsilateral Side ◽  
Content Type ◽  
Sensory Representation ◽  
Site Type ◽  
Sensorimotor Region ◽  
Trunk Limbs ◽  
Sensory Responses ◽  
Fine Print ◽  
Stimulation Of

✓ During the course of 134 craniotomies under local anesthesia, 274 sensory responses to electrical stimulation were recorded as to cortical site, type of sensation, and the site and lateralization of peripheral referral. The region of cortex exposed was largely the sensorimotor region near the Sylvian fissure and the temporal lobe. Differences in the type of sensation were seen on either side of the central fissure. Sensation of movement and specific sensations were reported more commonly from stimulation in the precentral region and crude sensation from the postcentral area. “Pain” was reported only once and taste not at all despite the large somatic sensory representation of the tongue. About 30% of the responses were referred to the ipsilateral side or bilaterally, with a somewhat higher percentage in the pre- than in the postcentral region. In general, the expected somatotopic sequence was followed, with tongue and mouth having the largest representation. An unexpected number of referrals to the head/face were found in the suprasylvian region, and it was uncertain whether this was part of Somatosensory area II. Eleven cases with sensory referrals to trunk/limbs in the suprasylvian area were found predominantly in the precentral region. No somatotopic pattern could be seen in these or on review of Penfield's material. Possible anatomical pathways for transmission of these responses were reviewed and questions raised as to the mechanisms involved.

Functional representation on the medial aspect of the frontal lobes in man

1976 ◽  
Vol 44 (3) ◽  
pp. 275-289 ◽  
Author(s):  
John M. Van Buren ◽  
Paul Fedio
Keyword(s):  
Frontal Lobe ◽  
Supplementary Motor Area ◽  
Motor Area ◽  
Speech Impairment ◽  
Content Type ◽  
Intractable Seizures ◽  
Functional Representation ◽  
Sensory Responses ◽  
Striatal Function ◽  
Stimulation Of

✓ Sensorimotor responses to stimulation of the medial frontal and cingulate area were studied in seven unrestrained, unsedated patients who suffered from intractable seizures. Complex postural synergies involving the trunk and proximal extremities appeared contralaterally or occasionally bilaterally. Contraversive turning of head and eyes was not observed. Sensory responses from the supplementary motor area were referred contralaterally and focally; those from the cingulate gyrus were widely referred. Speech impairment from stimulation of the supplementary motor area showed striking similarities with that obtained from stimulation in the frontostriatal region or lateral aspect of the frontal lobe. The observations support the hypothesis that interference with striatal function may be the basis of speech inhibition produced by stimulation of the frontal lobe.

scholarly journals Current Stimulation of the Midbrain Nucleus in Pigeons for Avian Flight Control

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 788
Author(s):  
Jung-Woo Jang ◽  
Changhoon Baek ◽  
Sunhyo Kim ◽  
Tae-Kyeong Lee ◽  
Gwang-Jin Choi ◽  
...  
Keyword(s):  
Flight Control ◽  
Motion Tracking ◽  
Electrode Array ◽  
Movement Control ◽  
Basic Research ◽  
Flight Behavior ◽  
Electrode Arrays ◽  
Channel Electrode ◽  
The Brain ◽  
Stimulation Of

A number of research attempts to understand and modulate sensory and motor skills that are beyond the capability of humans have been underway. They have mainly been expounded in rodent models, where numerous reports of controlling movement to reach target locations by brain stimulation have been achieved. However, in the case of birds, although basic research on movement control has been conducted, the brain nuclei that are triggering these movements have yet to be established. In order to fully control flight navigation in birds, the basic central nervous system involved in flight behavior should be understood comprehensively, and functional maps of the birds’ brains to study the possibility of flight control need to be clarified. Here, we established a stable stereotactic surgery to implant multi-wire electrode arrays and electrically stimulated several nuclei of the pigeon’s brain. A multi-channel electrode array and a wireless stimulation system were implanted in thirteen pigeons. The pigeons' flight trajectories on electrical stimulation of the cerebral nuclei were monitored and analyzed by a 3D motion tracking program to evaluate the behavioral change, and the exact stimulation site in the brain was confirmed by the postmortem histological examination. Among them, five pigeons were able to induce right and left body turns by stimulating the nuclei of the tractus occipito-mesencephalicus (OM), nucleus taeniae (TN), or nucleus rotundus (RT); the nuclei of tractus septo-mesencephalicus (TSM) or archistriatum ventrale (AV) were stimulated to induce flight aviation for flapping and take-off with five pigeons.

scholarly journals Characterization of Atrial Propagation Patterns and Fibrotic Substrate With a Modified Omnipolar Electrogram Strategy in Multi-Electrode Arrays

2021 ◽  
Vol 12 ◽  
Author(s):  
Jennifer Riccio ◽  
Alejandro Alcaine ◽  
Sara Rocher ◽  
Laura Martinez-Mateu ◽  
Sergio Laranjo ◽  
...  
Keyword(s):  
Electric Field ◽  
Electrode Array ◽  
Performance Comparison ◽  
Reference Voltage ◽  
Standard Approach ◽  
Diffuse Fibrosis ◽  
Electrode Arrays ◽  
Velocity Mapping ◽  
Unipolar Electrograms

Introduction: The omnipolar electrogram method was recently proposed to try to generate orientation-independent electrograms. It estimates the electric field from the bipolar electrograms of a clique, under the assumption of locally plane and homogeneous propagation. The local electric field evolution over time describes a loop trajectory from which omnipolar signals in the propagation direction, substrate and propagation features, are derived. In this work, we propose substrate and conduction velocity mapping modalities based on a modified version of the omnipolar electrogram method, which aims to reduce orientation-dependent residual components in the standard approach.Methods: A simulated electrical propagation in 2D, with a tissue including a circular patch of diffuse fibrosis, was used for validation. Unipolar electrograms were calculated in a multi-electrode array, also deriving bipolar electrograms along the two main directions of the grid. Simulated bipolar electrograms were also contaminated with real noise, to assess the robustness of the mapping strategies against noise. The performance of the maps in identifying fibrosis and in reproducing unipolar reference voltage maps was evaluated. Bipolar voltage maps were also considered for performance comparison.Results: Results show that the modified omnipolar mapping strategies are more accurate and robust against noise than bipolar and standard omnipolar maps in fibrosis detection (accuracies higher than 85 vs. 80% and 70%, respectively). They present better correlation with unipolar reference voltage maps than bipolar and original omnipolar maps (Pearson's correlations higher than 0.75 vs. 0.60 and 0.70, respectively).Conclusion: The modified omnipolar method improves fibrosis detection, characterization of substrate and propagation, also reducing the residual sensitivity to directionality over the standard approach and improving robustness against noise. Nevertheless, studies with real electrograms will elucidate its impact in catheter ablation interventions.

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.

Subcortical electrical stimulation for control of intractable pain in humans

1986 ◽  
Vol 64 (4) ◽  
pp. 543-553 ◽  
Author(s):  
Yoshio Hosobuchi
Keyword(s):  
Electrical Stimulation ◽  
Back Pain ◽  
Pain Control ◽  
Pain Syndrome ◽  
Leg Pain ◽  
Intractable Pain ◽  
Content Type ◽  
Implanted Electrodes ◽  
Severe Chronic Pain ◽  
Stimulation Of

✓ Chronic electrical stimulation of the subcortical area of the brain by implanted electrodes provides satisfactory control of a number of intractable pain syndromes that are refractory to medication. This series of 122 patients who underwent electrode implantation for the control of severe chronic pain was evaluated over a follow-up period of 2 to 14 years. Of the 65 patients with pain of peripheral origin, who were treated with stimulation of the periaqueductal gray region (PAG), 50 obtained successful pain control. Of 76 patients with a deafferentation pain syndrome, 44 obtained control of the dysesthesia with stimulation of the subcortical somatosensory region. Nineteen patients with both leg and back pain received electrodes in the PAG and the somatosensory regions; whereas back pain was relieved by PAG stimulation, dysesthetic leg pain was controlled more effectively by somatosensory region stimulation. The electrical stimulation technique appears to provide long-term pain control safely, with few side effects or complications.

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