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At least 469 records · Page 26Linked to original sources
PubMed1999

Right median nerve electrical stimulation to hasten awakening from coma.

Electrical stimulation of the right median nerve may hasten the awakening of closed head injured, comatose patients. A series of 25 comatose patients have been treated. These patients made better recoveries than similar individuals reported in the literature. In a double-blind pilot project patients in the treated group scored better on interval Glasgow Coma Scale scores, spent fewer days in the intensive care unit, and showed better Glasgow Outcome Scores at 1 month post-injury. Peripheral electrical stimulation of the right median nerve, through activation of the ascending reticular activating system, may be sufficient to arouse the moderate to severely comatose patient.

Adolescent↗
PubMed1991

Videoradiography at submental electrical stimulation during apnea in obstructive sleep apnea syndrome. A case report.

Percutaneous submental electrical stimulation during sleep may be a new therapeutic method for patients with obstructive sleep apnea syndrome (OSAS). Electrical stimulation to the submental region during obstructive apnea is reported to break the apnea without arousal and to diminish apneic index, time spent in apnea, and oxygen desaturation. The mode of breaking the apnea by electrical stimulation has not yet been shown. However, genioglossus is supposed to be the muscle responsible for breaking the apnea by forward movement of the tongue. To visualize the effect of submental electrical stimulation, one patient with severe OSAS has been examined with videoradiography. Submental electrical stimulation evoked an immediate complex muscle activity in the tongue, palate, and hyoid bone. This was followed by a forward movement of the tongue which consistently broke obstructive apnea without apparent arousal. Time spent in apnea was diminished but intervals between apnea were not affected.

Electric Stimulation Therapy↗
PubMed2006

Anal electrical stimulation with long pulses increases anal sphincter pressure in conscious dogs.

PURPOSE: This study was designed to investigate the effects and mechanisms of anal electric stimulation with long pulses on anal sphincter pressure in conscious dogs. METHODS: The study was performed after enema in nine healthy female hound dogs and composed of four randomized sessions ("dose"-response, anal electric stimulation only, or with atropine or phentolamine). The anal sphincter pressure was measured by using manometry and quantified by using the area under the contractile curve (mmHg/sec). Anal electric stimulation was performed via a pair of ring electrodes attached to a manometric catheter. The stimulation parameters in all but dose-response sessions included a frequency of 20 ppm, pulse width of 200 ms, and amplitude of 3 mA. RESULTS: The anal sphincter pressure was 55.7 +/- 6 at baseline and increased by 37 percent to 76.4 +/- 6.5 during electric stimulation (P = 0.009). The increase of anal pressure during stimulation was positively correlated with the stimulation energy (r = 0.395; P < 0.01). The excitatory effect of electric stimulation was sustained for at least 20 minutes. Atropine did not alter anal pressure and did not abolish the excitatory effect of anal electric stimulation on the sphincter. Phentolamine reduced anal pressure from the baseline value of 50.5 +/- 4.7 to 33.1 +/- 5.4 (P = 0.019). The electric stimulation induced increase in anal pressure was dropped from 19 +/- 2.6 to 9.9 +/- 2.8 (P = 0.029) at the presence of phentolamine. CONCLUSIONS: Anal electric stimulation with long pulses increases anal sphincter pressure in an energy-dependent manner. The alpha-adrenergic but not the cholinergic pathway at least partially mediates the excitatory effect of anal electric stimulation.

Adrenergic alpha-Antagonists↗
PubMed2007

The first successful case of hearing produced by electrical stimulation of the human midbrain.

HYPOTHESIS: Electrical stimulation of the inferior colliculus in the midbrain can provide a safe and efficacious alternative to auditory brainstem implants (ABIs). BACKGROUND: Patients with neurofibromatosis type 2 (NF2) receive limited speech recognition with ABIs. Some ABI patients without NF2 can achieve excellent speech understanding, suggesting that the limited NF2 performance is due to brainstem damage from the tumor and its removal. METHODS: An array of electrodes (Med-El ABI) was placed on the dorsal surface of the inferior colliculus in the midbrain of a human volunteer as an auditory prosthesis via an infratentorial supracerebellar median surgical approach. Electrophysiological responses, psychophysical responses, and speech recognition were measured. RESULTS: Electrical stimulation produced auditory sensations on all 12 electrodes with no nonauditory sensations. Auditory threshold levels indicated the stability of the electrode array over time. Electrophysiological measures showed activation in the contralateral auditory cortex but none in ipsilateral cortex. All electrodes demonstrated a full range of loudness sensation and electrode-specific pitch sensations. Speech recognition was significant, but limited in the first month after surgery. CONCLUSION: This approach may provide advantages for patients with brainstem damage.

Adult↗
PubMed2002

Efficacy of two forms of electrical stimulation in increasing quadriceps strength: a randomized controlled trial.

OBJECTIVE: To investigate whether electrical stimulation is effective in improving quadriceps strength in healthy subjects and to compare interferential and low-frequency current in terms of the effects on quadriceps strength and perceived discomfort. DESIGN: Randomized, controlled study. SETTING: Physical Medicine and Rehabilitation Department in a university hospital. SUBJECTS: Thirty medical faculty students, divided into three groups, participated in the study. INTERVENTIONS: Group A received electrical stimulation with bipolar interferential current while group B received electrical stimulation with low-frequency current (symmetrical biphasic). Group C served as the control group. Electrical stimulation was given for 15 minutes, five days a week for three weeks, at a maximally tolerated intensity with the knee fully extended in the sitting position. MAIN OUTCOME MEASURES: Before and after the study, quadriceps strength was measured with a Cybex dynamometer isokinetically at the angular velocities of 60 degrees/s and 120 degrees/s. The perceived discomfort experienced with each type of electrical stimulation was quantified by the use of a visual analogue scale (VAS). RESULTS: Statistically significant increase in isokinetic strength was observed after training in group A and group B. Increase in strength did not differ between the stimulation groups. No significant change in strength occurred in group C. Perceived discomfort by the stimulation groups was not significantly different. CONCLUSION: Both interferential and low-frequency currents can be used in strength training with the parameters used in this study.

Adult↗
PubMed1986

Neuromuscular electrical stimulation of the muscles surrounding the shoulder.

Neuromuscular electrical stimulation (NMES) can be used to augment range-of-motion, strengthening, and facilitation treatment programs of the muscles surrounding the shoulder. The purposes of this article are 1) to describe the uses of NMES around the shoulder joint as developed through our clinical use and 2) to detail the effects of an NMES program on chronic shoulder subluxation as determined by a clinical study. Because of the complexities of this multiarticular joint, NMES is most useful in the initial phase of the ROM, and stimulated contractions are compromised, relatively, as the humerus moves above the 90-degree horizontal plane. The use of NMES to provide scapular stabilization often entails unwanted alteration of the pressures on the spinal column, occasionally making the treatment program unusable. Electrical stimulation to prevent or correct shoulder subluxation, especially in the neurologically involved patient, provides the therapist with a powerful new treatment technique. In a group of stroke patients, shoulder subluxation was reduced significantly (p less than .05) at the completion of a six-week NMES program. Some of the problems, and possible solutions, unique to the development of electrical stimulation programs for the shoulder muscles are discussed.

Adult↗
PubMed2006

Implantable neural electrical stimulator for external control of gastrointestinal motility.

Functional electrical stimulation has been suggested as a possible avenue for treating a variety of gastrointestinal motility-related disorders such as gastroparesis, chronic constipation and morbid obesity. The aims of the present study were to design a radio-frequency controlled multi-channel implantable neural gastrointestinal electrical stimulator and test it in an acute canine model. The stimulation parameters can be reprogrammed after implantation, allowing the execution of parametric studies and the investigation of their efficacy in producing controlled gastrointestinal contractions. Bipolar pulse trains of 50Hz frequency, 8-16V(pp) amplitude, 10-100% duty cycle, 1-120s duration, and 2s to 1h pause between successive stimulation sessions were delivered to the stomachs of nine dogs. The resulting contractions were measured by force transducers and digitally recorded on a personal computer. The acute studies confirmed the effectiveness of electrical stimulation in producing invoked gastric contractile activity under the control of the implantable neurostimulator.

Animals↗
PubMed2001

The placement of the epidural catheter at the predicted site by electrical stimulation test.

UNLABELLED: More accurate segmental and sagittal positioning of the epidural catheter tip is required for the success of continuous epidural analgesia, spinal cord monitoring, and percutaneous epidural spinal cord stimulation. We examined the usefulness of an electrical stimulation test for verifying the proper placement of the epidural catheter tip at the predicted site in the posterior epidural space by using a locally developed epidural catheter with electrodes at its tip. The test included the observation of segmental bilateral muscle twitches and the patient's report of feeling in the region stimulated by moving the epidural catheter electrode back and forth and changing the direction of the bevel of the Tuohy needle. The success rate of midline placement at the required spinal segment was significantly more frequent (99%; P < 0.001) in the group (n = 289) receiving the electrical stimulation test compared with the group (n = 277) not receiving the test (success rate 57%). The results indicate the usefulness of this method. We concluded that the electrical stimulation test is effective for verifying the proper placement of the catheter electrode tip. IMPLICATIONS: Ideally the epidural catheter tip should be positioned in the posterior epidural space near the midline. We concluded that the electrical stimulation test is effective for verifying the proper placement of the catheter electrode tip.

Aged↗
PubMed2004

Locomotion induced by non-contingent intracranial electrical stimulation: Dopamine dependence and general characteristics.

Intracranial self-stimulation (ICSS) is induced by delivery of electrical stimulation contingent upon a response such as bar pressing. This procedure has been widely used to investigate the brain reward system. Recent investigations, however, have noted that non-contingent electrical stimulation, also called experimenter applied stimulation (EAS), produces a unique set of locomotion behaviors that appear to be related to ICSS, and that these behaviors resemble locomotion similar to those elicited by dopamine enhancing drugs. However, little is known about the general characteristics of EAS-induced locomotion. While ICSS appears to be robust, long lasting, and highly rewarding in that the rat will invest vast amounts of time or energy to obtain the electrical stimulation, these parameters have not been explored for EAS. Moreover, the dopamine dependence of EAS-evoked locomotion is also not firmly established. Thus, the present study investigated dopamine dependence and general characteristics of the EAS-induced locomotion to determine its similarity to ICSS. Results suggested that motor and limbic systems were strongly activated by non-contingent EAS, and that the resulting locomotion was dopamine dependent, robust, continued across long time horizons, and was greater than that evoked by contingent electrical stimulation.

Animals↗
PubMed1989

Cerebral responses evoked by electrical stimulation of the esophagus in normal subjects.

Cerebral responses to electrical stimulation of the esophagus were investigated in 11 healthy male volunteers, 20-40 yr old. The stimulus was applied via a probe equipped with bipolar ring electrodes. It was positioned in the middle and distal esophagus at 20 and 37 cm from the incisors, respectively, and sucked to the mucosa. Electrical stimuli (0.1-ms duration, different stimulus voltages) were applied at frequencies of 0.1-1.0 Hz or in randomized order. Cerebral responses to electrical stimulation were recorded after 20-40 stimulations and averaged on a time base of 1000 ms. Evoked potentials consisted of successive peaks and troughs in the averaged electroencephalogram with good reproducibility within and between subjects. Amplitudes of evoked potentials showed a significant reduction with electrical stimulation at 37 cm compared with 20 cm, and with stimulation frequencies of 0.5 and 1.0 Hz compared with 0.2 and 0.1 Hz. Evoked potentials from 37 cm showed longer latencies compared with those from 20 cm. Irregular stimulation and stimulation during mental distraction did not alter these responses. It is concluded that reproducible evoked potentials can be recorded from the scalp after electrical stimulation of the esophagus and that these are transferred centrally via vagal afferents. The technique may become a useful tool in the study of visceral nervous connections to the brain in health and disease.

Adult↗
PubMed1992

Acceleration of gastric emptying with electrical stimulation in a canine model of gastroparesis.

We investigated the effects of electrical stimulation of the stomach on gastric emptying and the electrical activity of the stomach in 10 dogs. A model of gastroparesis was developed in five dogs using truncal vagotomy combined with injections of glucagon. Glucagon also induced electrical dysrhythmias. Bipolar electrodes were implanted in the stomach and the duodenum for electrical stimulation and for recording electrogastrograms. Gastric emptying of an isotope-labeled solid meal was assessed for 2 h. External electrical stimulation was delivered to the corpus of the stomach at its own physiological frequency to investigate whether it could restore normal gastric emptying. Such stimulation had no significant effect on gastric emptying in intact animals (45 vs. 43%: retention of isotope after 2 h) or when only vagotomy was performed (78 vs. 66%), but it significantly accelerated gastric emptying in animals with vagotomy and glucagon (from 86 to 68%). From this model of delayed gastric emptying, we suggest that electrical stimulation of the stomach at its own intrinsic frequency may recoordinate uncoupled slow wave activity induced by glucagon after vagotomy thus improving the rate of gastric emptying.

Analysis of Variance↗
PubMed2002

Effects of electrical stimulation of the dorsal skin on systemic and mesenteric microvascular hemodynamics in anesthetized rats.

The effects of electrical stimulation of the dorsal skin area on the mesenteric arterioles were investigated in anesthetized rats by the use of an intravital microscope-television system. Changes in the diameter of the mesenteric precapillary arterioles (10-40 microm in diameter) were measured with an image processor. Blood flow velocity in the mesenteric precapillary arterioles was monitored by the dual sensor method developed by the authors. Electrical stimulation was performed through two platinum electrodes placed at the right dorsal Th5-12 level skin area by the use of an electrical stimulator (0.2 ms, 20 Hz). Continuous stimulation lasting for 30 s (1-10 mA) and intermittent stimulation lasting for 10 min (3 mA) were applied. The pressor response following the depressor response was induced by a stimulus current above 8 mA. The decrease in mesenteric blood flow velocity was induced by stimulus current above 10 mA. These responses were abolished by lidocaine injection into the subcutaneous area where the electrodes were attached. No significant change in arteriolar diameter or heart rate were induced by the stimulation for 30 s. Electrical stimulation of the skin for 10 min evoked a decrease in the diameter of arterioles (-3.4 +/- 2%, p < 0.01, n = 12). In the adrenalectomized group, electrical stimulation of the skin for 10 min elicited a slight increase in the diameter (1.1 +/- 0.5%, n = 6). It is therefore suggested that electrical stimulation of the skin for 30 s reflexly evoked decreases in MAP and in blood flow velocity, and that the constriction of the mesenteric precapillary arterioles induced by the stimulation for 10 min was mediated by humoral adrenaline and noradrenaline released by somato-adrenal medullary reflex.

Adrenalectomy↗
PubMedDate not supplied

Effects of electrical stimulation on the histological properties of wounds in diabetic mice.

The purpose of this study was to identify mechanisms underlying electrically stimulated wound closure in diabetic mice. Adult male mice (n = 58) with full-thickness excisional wounds were treated five times using negative polarity over the wound site for 15 minutes each over a 16-day period with sham (0 Volts) or 5.0, 10.0, 12.5 Volts. In addition, animals (diabetic (n = 33) and nondiabetic (n = 22)) received treatments of electrical stimulation (12.5 V), or sham treatment (0 V) at wound sites which were then harvested and prepared for histological analysis at 2, 8, and 16 days postwounding. Using computerized image analysis of sections stained with a picro sirus red-fast green staining technique, we found that increasing doses of electrical stimulation reduced collagen/noncollagenous protein ratios measured in the superficial scar of nondiabetic animals, with no effect in diabetic animals. In the deep scar, lower doses of electrical stimulation (5.0 V) produced significantly (p < 0.01) increased collagen deposition in wounds of nondiabetic animals compared with sham controls. Higher doses of electrical stimulation (12.5 V) were required to produce changes in diabetic animals than were observed in nondiabetic animals. These results suggest that electrical stimulation altered collagen deposition in excisional wounds of diabetic and nondiabetic animals. Electrical stimulation had a differential effect on wound healing in diabetic compared with nondiabetic animals. These data speak to the need to study the effects of electrical stimulation on healing in disease-specific models.

Animals↗
PubMed1999

Neuromuscular electrical stimulation after anterior cruciate ligament surgery.

This randomized, double blind, controlled trial was designed to determine the effectiveness of neuromuscular electrical stimulation of the knee extensor and flexor muscles in the prevention of muscular weakening after anterior cruciate ligament surgery. Neuromuscular electrical stimulation treatment was given in addition to an early exercise therapy regimen and compared with an early exercise therapy regimen alone. Forty-nine patients after anterior cruciate ligament surgery were assigned randomly either to a neuromuscular electrical stimulation and exercise group, a transcutaneous electrical nerve stimulation as analgesic and exercise group, or an exercise alone group as control. All groups received a standard regimen of rehabilitation after anterior cruciate ligament surgery. The neuromuscular electrical stimulation and transcutaneous electrical nerve stimulation group additionally received electrical stimulation during the first 6 weeks after surgery. Patients were measured for isometric and isokinetic torque in the knee extensor and flexor muscles after 6, 12, and 52 weeks. No statistical difference among groups was observed. It is concluded that neuromuscular electrical stimulation in combination with an early exercise therapy regimen is not significantly more effective in reducing weakening than an early exercise therapy regimen alone after anterior cruciate ligament surgery.

Adult↗
PubMed1996

Anaerobic metabolism during electrical stimulation of aged rat skeletal muscle.

BACKGROUND AND PURPOSE: During brief, high-intensity activities, skeletal muscle adenosine triphosphate (ATP) is rapidly resynthesized. Little is known, however, about the effect of age on ATP synthesis during such activities. In this study, aged muscle anaerobic metabolism during supramaximal, intermittent electrical stimulation was investigated. SUBJECTS: The flexor digitorum brevis (FDB) muscles from virgin 12-month-old (adult) and 32-month-old (aged) F1 hybrid Fisher 344 X Norway Brown male rats (12 rats per age group) were studied. There were three experimental groups (eight muscles per experimental group): control (no incubation or electrical stimulation), incubation (no electrical stimulation), and electrical stimulation (combined with incubation). METHODS: Incubation and electrical stimulation muscles were incubated in vitro in physiological medium for 15 minutes. Electrical stimulation muscles were stimulated intermittently, 10 seconds on:20 seconds off, using direct-current monophasic waveforms (intensity=80 V, pulse duration=200 milliseconds, and frequency=5.0 Hz). Muscle peak tension was measured, and intracellular ATP, creatine phosphate, glycogen, and lactate concentrations were determined. RESULTS: The ATP, creatine phosphate, and glycogen contents in adult and aged muscles were similar in control preparations. There were also no age-related differences in the muscles' utilization of intramuscular ATP and creatine phosphate during stimulation. A greater depletion of glycogen and accumulation of lactate occurred, however, in the aged muscles compared with the adult muscles during stimulation. CONCLUSION AND DISCUSSION: Aged rat FDB muscle appears to retain its capacity to rapidly resynthesize ATP through anaerobic metabolism during brief, high-intensity activity. Inadequate anaerobic resynthesis of ATP does not appear to contribute to the earlier and greater decline in peak train tension in the aged muscle.

Adenosine Triphosphate↗