Variations in visual evoked potentials under anesthesia.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
A Starr
Publications and source records attributed to A Starr.
Effect of halothane anesthesia on the human cortical visual evoked response.
The visual evoked response (VER) was monitored in eight women intraoperatively during anesthesia with halothane in oxygen administered via endotracheal tube. Control measurements were made prior to anesthetic induction in these unpremedicated patients. The latency of the positive peak designated P1 increased progressively from a mean of 113 +/- 10 (SD) msec in the awake state to the following values at indicated end-tidal halothane concentrations: 123 +/- 10 msec at 0.75 per cent; 130 +/- 9 msec at 0.90 per cent; 134 +/- 9 msec at 1.13 per cent. The differences among mean latency values at these anesthetic concentrations were insufficient to conclude that VER latency would be a useful monitor of anesthetic depth. However, significant effects were seen at clinical levels of halothane anesthesia, and the prolongation caused by anesthesia must be considered when using VERs to monitor central nervous system function during neurosurgery.
Adult↗
Post-traumatic bronchial stenosis and acute respiratory insufficiency.
A 31-year-old woman sustained multiple injuries, including severe contusion of the right lung with massive subcutaneous emphysema. Four weeks later she was transferred to our institution with post-traumatic adult respiratory distress syndrome and carbon dioxide retention, resulting from a postlaceration stenosis of the left main-stem bronchus. Bronchoplasty was contraindicated because of the serious condition of the patient. Repeated bronchial dilatations produced initial improvement in oxygenation and minute ventilation requirements. However, because of the nature of the stenosis and the lack of recovery of right lung function, the patient's encouraging clinical course reached a plateau and attempts at weaning from the respirator were unsuccessful. Bronchoplasty was performed on postadmission day 50 and resulted in gradual recovery of pulmonary function. Six months following discharge, the patient continues a steady improvement. Management of the patient's injuries represented a unique challenge previously unencountered.
Adult↗
Year of operation as a risk factor in the late results of valve replacement.
The actuarial thromboembolic rates of aortic and mitral silicone ball valves used during the second decade of cardiac valve replacement are significantly lower than the rates for the same prostheses implanted during the first decade, as shown in the following table: (Formula: see text). The embolus-free rates are significantly different (p < 0.01) in both the mitral and aortic series. Five-year embolus-free rates for the composite-strut caged-ball, Björk-Shiley tilting disc, and porcine xenograft valves all fall in the range of from 81% to 92% for the mitral position and from 91% to 97% for the aortic. Thus the standard silicone ball-valve prosthesis, used during the current era, has a thromboembolic risk as low as that reported with other concurrently utilized valve substitutes. This striking reduction in thrombogenicity demonstrates that the time frame of implantation must be considered when evaluating the results of cardiac valve replacement.
Adolescent↗
Short latency mechanically evoked somatosensory potentials in humans.
Somatosensory potentials evoked by mechanical stimulation were recorded by surface electrodes over (1) the digital nerves in the index finger, (2) the median nerve at the wrist, (3) the median nerve near the axilla, (4) the brachial plexus, (5) the cervical cord at CII, (6) the scalp overlying the somatosensory cortex. Nerve conduction velocities varied inversely with age and ranged from 43 to 68 m/sec. Mechanically evoked potentials recorded from the electrodes overlying the digital nerves were an artifact of the finger movement. All other electrode configurations recorded potentials comparable to those evoked by electrical stimulation of nerves. These mechanically evoked potentials could prove useful in the assessment of clinical disorders of somatosensory function from receptor to cortex in man.
Adolescent↗
Mechanically and electrically evoked somatosensory potentials in normal humans.
Somatosensory potentials evoked by mechanical stimulation of the fingernail and electrical stimulation of the nerve in the finger and at the wrist were recorded by surface electrodes over; (1) the digital nerve in the index finger, (2) the median nerve at the wrist, (3) the median nerve at the axilla, (4) the brachial plexus at Erb's point, (5) the cervical cord at C2, and (6) the scalp overlying the somatosensory cortex. Nerve conduction velocities were computed for two portions of the median nerve. Conduction times along the somatosensory pathway between spinal cord and cerebral cortex were also defined. The mechanically evoked potentials had less temporal dispersion, were of lower amplitude, and occasionally consisted of fewer components than the electrically evoked potentials. Electrical stimulation of the nerve trunk at the wrist evoked some additional components not detected by the other stimulation methods. Nerve conduction velocities and conduction times were comparable among the three methods of stimulation.
Arm↗
Long-term results after surgical correction of Ebstein's anomaly: report of two cases.
Two patients with Ebstein's anomaly had valve replacement with Starr-Edwards cloth-covered valves 11 and 8 years ago. They have been asymptomatic and very active despite the absence of anticoagulation. These cases provide some of the long-term results needed for proper evaluation of the different methods of operative treatment of Ebstein's anomaly.
Adolescent↗
Critical pulmonary valve stenosis with intact ventricular septum.
This study presents our experience in the surgical management of the newborn with critical pulmonary stenosis and intact ventricular septum. During the last decade we have seen 11 such patients, with a mean age of 2.3 days (maximum 6 days) and a mean weight of 3.6 kilograms (maximum 4.5 kilograms). The primary operation was a valvotomy in 7 patients (one of whom also had a systemic-pulmonary shunt), a commissurotomy with cardiopulmonary bypass in 3 patients, and a shunt alone in 1 patient. One infant died on the second postoperative day and another died following reoperation at 4 months. The other 9 patients were all alive and progressing satisfactorily when last seen. Five of these patients were beyond their third postoperative year and the longest survivor was at 7.9 years. Four of the long-term survivors had undergone reoperation. Our choice of operation remains transventricular valvotomy, although an open procedure utilizing cardiopulmonary bypass presents an attractive alternative. A systemic-pulmonary shunt as an addition to either of these operations is unnecessary. The perioperative use of prostaglandin E brings about substantial improvement in the early results.
Age Factors↗
Ureteral plication. A new concept in ureteral tailoring for megaureter.
Currently, the most favored surgical procedure used to restore normal peristalsis to massively dilated adynamic ureters is ureteral tailoring. This procedure, however, seriously jeopardizes the ureter's blood supply and frequently results in ischemia with ureteral stenosis and further renal deterioration. To preserve the distal ureter's vasculature a new technique of reducing ureteral caliber and restoring normal peristalsis with minimal disruption of the blood supply was developed and performed in 14 dogs with excellent results.
Animals↗
Current heart valve prostheses.
Current heart valve prostheses may be classified as either mechanical or tissue valves (bioprostheses). The principal advantage of mechanical devices is their established long-term durability; however, chronic anticoagulation is recommended to reduce the incidence of thromboembolic complications. Tissue valves are associated with a relatively low rate of thromboembolism but their durability level has not been determined. All contemporary prosthetic heart valves yield comparable survival rates.
Aortic Valve↗
Late results of mitral cleft closure for ostium primum atrial septal defect in adolescents and adults.
Explore the source record for details and available documents.
Adolescent↗
Primary tumors of the heart: a rewarding challenge.
During a 10-year period 21 patients were treated for tumors of the heart, including 19 myxomas, one fibroma, and one sarcoma. The latter two cases are presented separately, and the 19 myxomas are analyzed together. An unusual association of left-sided myxoma with mitral valve abnormalities was found. In the surgical group (18 patients) there were no deaths and one case of postoperative cerebrovascular accident (CVA) with residual sequelae during a mean follow-up of 55 months. The results show the good prognosis of patients operated upon for myxomas of the heart and that there is no need for routine full-thickness excision of the septum in its treatment.
Adolescent↗
Left ventricular fistula as a cause of intractable angina pectoris. Successful surgical repair.
Two patients had intractable angina pectoris due to left-coronary-artery to left-ventricle fistulas. Surgical repair resulted in complete relief of symptoms. Postoperative cardiac catheterization showed obliteration of the fistulas, with preservation of ventricular function. Operative therapy is indicated in this disorder.
Aged↗
Acute effects of alcohol on auditory brainstem potentials in humans.
Auditory brainstem potentials were recorded from human subjects before and after an intoxicating dose of alcohol. Following alcohol ingestion there were significant, progressive increases in the latencies of brainstem potential peaks III through VII. No changes in peak amplitudes were found. The results indicate that alcohol has a depressive effect on neural transmission within the primary auditory brainstem pathway.
Adult↗
Auditory brain stem potentials in chronic alcohol intoxication and alcohol withdrawal.
Auditory brain stem evoked responses were in unrestrained rats during periods of acute and chronic alcohol intoxication, alcohol withdrawal, and recovery. Acute alcohol administration altered the auditory brain stem potentials by a prolongation of both peak latency and central conduction time, beginning with early peaks. Similar but lesser effects affecting only the latter peaks were observed during chronic alcohol intoxication. By contrast, alcohol withdrawal resulted in a decrease in the peak latencies of auditory brain stem potentials and a facilitation of central conduction time. Recovery of the auditory brain stem potentials to the normal form required at least three to four weeks. The present study provides the first quantitative data, to our knowledge, on manifestations of alcohol tolerance and withdrawal.
Acoustic Stimulation↗
Age-related variations in evoked potentials to auditory stimuli in normal human subjects.
Auditory evoked potentials were recorded from 47 subjects ranging in age from 6 to 76 years in order to assess the effects of maturation and aging on the evoked (N1 and P2) and event-related (N2 and P3) components. Because of clear differences in the effects of age on the event-related components between children (less than 15 years of age) and adults the subjects were divided into two populations for analysis. For adults there was a systematic increase in the latency and decrease in amplitude of each component with age. Also the rate of the age-related increase in latency was proportional to the latency of the component. The scalp distributions of both the stimulus-evoked and event-related components were found to vary with age yielding a more nearly equipotential distribution for older subjects. For children the latencies of the event-related components decreased with age. The stimulus-evoked components had latencies which were not significantly different from those predicted from the adult data. In contrast to the adult data, age affected the scalp distributions of the stimulus-evoked components differently than the event-related components. These results suggest an aging process is relfected in the auditory evoked potential which is not the simple inverse of maturational processes.
Acoustic Stimulation↗
Auditory brain stem potentials with alcohol.
Auditory brain stem potentials were recorded from unrestrained rats and from cats paralyzed with Flaxedil, before and after ingestion of intoxicating dosages of alcohol. The acute effect of alcohol was a cumulative increase in the central conduction times of successive brain stem potential peaks. Statistically significant latency changes were found for peaks attributed to neural structures as far peripherally as the medulla. This depressive influence of alcohol on sensory transmission was independent of variations in stimulus intensity and body temperature.
Acoustic Stimulation↗
Auditory brain stem potentials in monkey (M. mulatta) and man.
Auditory brain stem potentials were mapped over the head of the rhesus monkey following monaural clicks. Latency and amplitude were dependent upon the recording site. No electrically indifferent point could be found on the head or neck. The results are interpreted as showing that waves I and V originate from single generators, whereas waves, II, III and IV originate from bilateral structures. Latency varied in a linear fashion with changes in intensity and click rate. In contrast there were variations in amplitude of the potentials independent of stimulus change. A comparison was made of auditory brain stem potentials in man, monkey, cat and rat to demonstrate the similarity of the responses across species.
Acoustic Stimulation↗