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

✓ 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.

2004 ◽  
Vol 100 (6) ◽  
pp. 997-1001 ◽  
Author(s):  
Mitsuhiro Ogura ◽  
Naoyuki Nakao ◽  
Ekini Nakai ◽  
Yuji Uematsu ◽  
Toru Itakura

Object. Although chronic electrical stimulation of the globus pallidus (GP) has been shown to ameliorate motor disabilities in Parkinson disease (PD), the underlying mechanism remains to be clarified. In this study the authors explored the mechanism for the effects of deep brain stimulation of the GP by investigating the changes in neurotransmitter levels in the cerebrospinal fluid (CSF) during the stimulation. Methods. Thirty patients received chronic electrical stimulation of the GP internus (GPi). Clinical effects were assessed using the Unified PD Rating Scale (UPDRS) and the Hoehn and Yahr Staging Scale at 1 week before surgery and at 6 and 12 months after surgery. One day after surgery, CSF samples were collected through a ventricular tube before and 1 hour after GPi stimulation. The concentration of neurotransmitters such as γ-aminobutyric acid (GABA), noradrenaline, dopamine, and homovanillic acid (HVA) in the CSF was measured using high-performance liquid chromatography. The treatment was effective for tremors, rigidity, and drug-induced dyskinesia. The concentration of GABA in the CSF increased significantly during stimulation, although there were no significant changes in the level of noradrenaline, dopamine, and HVA. A comparison between an increased rate of GABA concentration and a lower UPDRS score 6 months postimplantation revealed that the increase in the GABA level correlated with the stimulation-induced clinical effects. Conclusions. Stimulation of the GPi substantially benefits patients with PD. The underlying mechanism of the treatment may involve activation of GABAergic afferents in the GP.


2000 ◽  
Vol 93 (5) ◽  
pp. 774-783 ◽  
Author(s):  
Maxwell Boakye ◽  
Sean C. Huckins ◽  
Nikolaus M. Szeverenyi ◽  
Bobby I. Taskey ◽  
Charles J. Hodge

Object. Functional magnetic resonance (fMR) imaging was used to determine patterns of cerebral blood flow changes in the somatosensory cortex that result from median nerve stimulation (MNS).Methods. Ten healthy volunteers underwent stimulation of the right median nerve at frequencies of 5.1 Hz (five volunteers) and 50 Hz (five volunteers). The left median nerve was stimulated at frequencies of 5.1 Hz (two volunteers) and 50 Hz (five volunteers). Tactile stimulation (with a soft brush) of the right index finger was also applied (three volunteers). Functional MR imaging data were transformed into Talairach space coordinates and averaged by group. Results showed significant activation (p < 0.001) in the following regions: primary sensorimotor cortex (SMI), secondary somatosensory cortex (SII), parietal operculum, insula, frontal cortex, supplementary motor area, and posterior parietal cortices (Brodmann's Areas 7 and 40). Further analysis revealed no statistically significant difference (p > 0.05) between volumes of cortical activation in the SMI or SII resulting from electrical stimuli at 5.1 Hz and 50 Hz. There existed no significant differences (p > 0.05) in cortical activity in either the SMI or SII resulting from either left- or right-sided MNS. With the exception of the frontal cortex, areas of cortical activity in response to tactile stimulation were anatomically identical to those regions activated by electrical stimulation. In the SMI and SII, activation resulting from tactile stimulation was not significantly different (p > 0.05) from that resulting from electrical stimulation.Conclusions. Electrical stimulation of the median nerve is a reproducible and effective means of activating multiple somatosensory cortical areas, and fMR imaging can be used to investigate the complex network that exists between these areas.


2004 ◽  
Vol 100 (3) ◽  
pp. 560-564 ◽  
Author(s):  
Dirk De Ridder ◽  
Gert De Mulder ◽  
Vincent Walsh ◽  
Neil Muggleton ◽  
Stefan Sunaert ◽  
...  

✓ Tinnitus is a distressing symptom that affects up to 15% of the population for whom no satisfactory treatment exists. The authors present a novel surgical approach for the treatment of intractable tinnitus, based on cortical stimulation of the auditory cortex. Tinnitus can be considered an auditory phantom phenomenon similar to deafferentation pain, which is observed in the somatosensory system. Tinnitus is accompanied by a change in the tonotopic map of the auditory cortex. Furthermore, there is a highly positive association between the subjective intensity of the tinnitus and the amount of shift in tinnitus frequency in the auditory cortex, that is, the amount of cortical reorganization. This cortical reorganization can be demonstrated by functional magnetic resonance (fMR) imaging. Transcranial magnetic stimulation (TMS) is a noninvasive method of activating or deactivating focal areas of the human brain. Linked to a navigation system that is guided by fMR images of the auditory system, TMS can suppress areas of cortical plasticity. If it is successful in suppressing a patient's tinnitus, this focal and temporary effect can be perpetualized by implanting a cortical electrode. A neuronavigation-based auditory fMR imaging-guided TMS session was performed in a patient who suffered from tinnitus due to a cochlear nerve lesion. Complete suppression of the tinnitus was obtained. At a later time an extradural electrode was implanted with the guidance of auditory fMR imaging navigation. Postoperatively, the patient's tinnitus disappeared and remains absent 10 months later. Focal extradural electrical stimulation of the primary auditory cortex at the area of cortical plasticity is capable of suppressing contralateral tinnitus completely. Transcranial magnetic stimulation may be an ideal method for noninvasive studies of surgical candidates in whom stimulating electrodes might be implanted for tinnitus suppression.


1997 ◽  
Vol 86 (2) ◽  
pp. 197-202 ◽  
Author(s):  
Ethan Taub ◽  
Michael Munz ◽  
Ronald R. Tasker

✓ The use of an implanted system for chronic electrical stimulation of the gasserian ganglion for relief of facial pain was described in 1980 by Meyerson and Håkansson. Between 1982 and 1995, the senior author (R.R.T.) performed gasserian ganglion stimulation in 34 patients for the relief of chronic medically intractable facial pain. The etiology of pain was peripheral damage to the trigeminal nerve in 22 patients (65%), central (stroke) damage in seven (21%), postherpetic neuralgia in four (12%), and unclassifiable cause in one (3%). All patients received a trial of transcutaneous stimulation (Stage I). Successful trials in 19 patients (56%) were followed by implantation of a permanent system (Stage II). Trial and postimplantation stimulation were deemed successful when there was a reduction of pain by at least 50% whenever the stimulator was on. Success rates varied from five (71%) of seven patients for central pain to five (23%) of 22 for peripheral pain and none (0%) of four for postherpetic neuralgia. The median follow-up duration in successful cases was 22.5 months. Infections occurred in seven patients, all of whom had undergone Stage II treatment. Infections were more frequent when the stimulating electrode from Stage I was left in place for Stage II (six [43%] of 14) than when completely new hardware was used and prophylactic antibiotic drugs were administered (one [20%] of five). Other complications included iatrogenic injury to the trigeminal nerve or ganglion in three cases (9%), transient diplopia in two (6%), increased pain in two (6%), and various technical problems in 10 (29%). It is concluded that pain of central origin (stroke) is the type most likely to be relieved by this procedure. This finding is new, as the few other clinical series reported to date contain no patients with this type of pain. The risk of infection seems to be lower when completely new hardware is used for Stage II and prophylactic antibiotic drugs are administered.


1985 ◽  
Vol 62 (3) ◽  
pp. 389-396 ◽  
Author(s):  
Ronald F. Young ◽  
Richard Kroening ◽  
Wayne Fulton ◽  
Robert A. Feldman ◽  
Israel Chambi

✓ Forty-eight patients underwent electrical stimulation of the brain for treatment of chronic pain between 1978 and 1983. Average pain duration prior to treatment was 4.5 years. Before selection for this procedure patients underwent pain treatment in a multidisciplinary pain center, intensive psychological and psychiatric evaluation, and assessment of pain responsiveness to intravenous administration of placebo, morphine, and naloxone. A total of 71 electrodes were placed in the 48 patients at a variety of stimulating targets, including the periaqueductal gray matter, periventricular gray matter, thalamus, and internal capsule. Seventy-two percent of patients experienced complete or partial pain relief. In addition, 59% of patients were able to discontinue narcotic usage. Twenty-five percent of patients returned to normal physical activities and another 33% showed marked improvement in functional capacity. Follow-up periods ranged from 2 to 60 months; with a mean follow-up period of 20 months. A variety of relatively minor complications occurred, but no mortality or permanent sequelae were experienced. No patient's pain was made worse as a result of electrical stimulation. Electrical stimulation of the brain offers a safe and relatively effective method for the treatment of chronic pain in appropriately selected patients, who are unresponsive to other forms of therapy.


2002 ◽  
Vol 97 (4) ◽  
pp. 941-944 ◽  
Author(s):  
Tatsuya Sasaki ◽  
Kyouichi Suzuki ◽  
Masato Matsumoto ◽  
Taku Sato ◽  
Namio Kodama ◽  
...  

Object. Evoked potentials elicited by electrical stimulation of the oculomotor nerve and recorded from surface electrodes placed on the skin around the eyeball reportedly originate in the eye and are represented on electrooculograms. Because evoked potentials recorded from surface electrodes are extremely similar to those of extraocular muscles, which are represented on electromyograms, the authors investigated the true origin of these potentials. Methods. Evoked potentials elicited by electrical stimulation of the canine oculomotor nerve were recorded from surface electrodes placed on the skin around the eyeball. A thread sutured to the center of the cornea was pulled and the potentials that were evoked during the resultant eye movement were recorded. These potentials were confirmed to originate in the eye and to be represented on electrooculograms because their waveforms were unaffected by the administration of muscle relaxant. To eliminate the influence of this source, the retina, a main origin of standing potentials of the eyeball, was removed. This resulted in the disappearance of electrooculography (EOG) waves elicited by eye movement. Surface potentials elicited by oculomotor nerve stimulation were the same before and after removal of the retina. Again the oculomotor nerve was electrically stimulated and electromyography (EMG) response of the extraocular muscles was recorded at the same time that potentials were recorded from the surface electrodes. In their peak latencies, amplitudes, and waveforms, the evoked potentials obtained from surface electrodes were almost identical to EMG responses of extraocular muscles. Conclusions. Evoked potentials elicited by electrical stimulation of the oculomotor nerves and obtained from surface electrodes originated from EMG responses of extraocular muscles. These evoked potentials do not derive from the eye.


2004 ◽  
Vol 101 (2) ◽  
pp. 189-194 ◽  
Author(s):  
Philippe Coubes ◽  
Laura Cif ◽  
Hassan El Fertit ◽  
Simone Hemm ◽  
Nathalie Vayssiere ◽  
...  

Object. Primary generalized dystonia (PGD) is a medically refractory disease of the brain causing twisting or spasmodic movements and abnormal postures. In more than 30% of cases it is associated with the autosomal DYT1 mutation. Continuous electrical stimulation of the globus pallidus internus (GPi) has been used successfully in the treatment of PGD. The aim of this study was to examine the long-term efficacy and safety of deep brain stimulation (DBS) in the treatment of PGD in children and adults with and without the DYT1 mutation. Methods. Thirty-one patients with PGD were selected for surgery. Electrodes were bilaterally implanted under stereotactic guidance and connected to neurostimulators that were inserted subcutaneously. Efficacy was evaluated by comparing scores on the clinical and functional Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) before and after implantation. The efficacy of stimulation improved with time. After 2 years, compared with preoperative values, the mean (± standard deviation) clinical and functional BFMDRS scores had improved by 79 ± 19% and 65 ± 33%, respectively. At the 2-year follow-up examination the improvement was comparable in patients with and without the DYT1 mutation in both the functional (p = 0.12) and clinical (p = 0.33) scores. Children displayed greater improvements in the clinical score than adult patients (p = 0.04) at 2 years of follow up. In contrast, there was no significant difference in functional scores between children and adults (p = 0.95). Conclusions. Electrical stimulation of the GPi is an effective, reversible, and adaptable treatment for PGD and should be considered for conditions refractory to pharmaceutical therapies.


1995 ◽  
Vol 83 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Ronald F. Young

✓ Between March 1990 and December 1992, 23 patients with chronic intractable facial pain due to various forms of injury to the trigeminal nerve or nerve root underwent implantation of an electrical stimulating system to treat their pain. All patients had failed previous extensive pain treatment efforts. A monopolar platinum-iridium electrode was implanted on the trigeminal nerve root via percutaneous puncture of the foramen ovale. All patients experienced at least 50% reduction in pain intensity during a period of trial stimulation and underwent internalization of the electrode and connection to a completely implanted pulse generator. Independent assessment of the effect of stimulation was obtained by a specially trained nurse practitioner. Over a mean follow-up period of 24 months, six patients reported nearly complete relief of pain and six others reported at least a 50% reduction in pain intensity using a visual analog scale. Thus, 12 (52%) of the 23 patients achieved 50% or greater reduction in pain intensity. Although changes in the patterns of analgesic medication usage were few, six patients (26%) now experience a normal life style. Only one complication was seen, namely a dislocated electrode, which was easily replaced. Chronic electrical stimulation of the trigeminal nerve root appears to be an easy and safe technique for providing relief of chronic facial pain related to injury to the trigeminal nerve in a significant number of patients.


1981 ◽  
Vol 55 (3) ◽  
pp. 420-430 ◽  
Author(s):  
Ronald F. Young ◽  
Terrence D. Oleson ◽  
Kent M. Perryman

✓ Trigeminal tractotomy near the level of the obex was carried out in 10 macaque monkeys. Behavioral responses were evaluated by a quantitative paradigm measuring lever-press responses to electrical stimulation of the dental pulp or facial skin, and by assessing facial response to cutaneous pin-scratch before and after the tractotomy. Two pharmacological agents, strychnine and L-dopa, were administered and their effect on behavioral responses to these stimuli was studied. Tractotomy did not produce dental analgesia. Thresholds for escape from cutaneous electrical stimulation of facial skin, however, were elevated, consistent with marked hypalgesia to pin-scratch. The adversive responses to pin-scratch were absent in peripheral portions of the face, but near the midline and inside the oral cavity they were usually decreased or normal. Pharmacological agents caused a reduction in escape thresholds to cutaneous electrical stimulation and a shrinkage or abolition of the zone of analgesia to pinscratch. The results imply that trigeminal nucleus caudalis, which undergoes deafferentation by tractotomy, may not be essential for processing of nociceptive information from the teeth, oral cavity, and midline facial zones. This finding is contrary to long-held hypotheses concerning facial pain mechanisms. The ability of strychnine and L-dopa to alter nociceptive escape thresholds is consistent with the idea, suggested by Denny-Brown, that facial nociception depends on central summation in the entire spinal trigeminal nucleus from overlapping afferent inputs contained in the trigeminal nerve, other cranial nerves, and the upper cervical nerve roots.


1995 ◽  
Vol 82 (6) ◽  
pp. 1030-1034 ◽  
Author(s):  
Yuzuru Takahashi ◽  
Kazuhisa Takahashi ◽  
Hideshige Moriya

✓ Previous dermatome drawings have been developed on the basis of investigations in humans and thus differ among investigators. The authors recently reported detailed dermatomes of the rat hindlimb that were mapped by electrical stimulation of spinal nerves and observation of plasma extravasation in the corresponding skin. In this paper a new human dermatome chart is proposed that has been reconstructed from rat dermatomes; the accuracy of previously reported dermatomes is also discussed. These newly defined dermatomes are arranged as serial semicircles, not as bands extending spirally from the low back down to the lower extremity as shown by Keegan. The posterior pattern differs markedly from that of any previously described charts in that the S-2 dermatome is “interposed” within the S-1 dermatome. This study clarifies the basic arrangement of lower-extremity dermatomes. Based on the present chart, it is concluded that Bonica's dermatomes are the most accurate among those previously reported.


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