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At least 1,171 records · Page 65Linked to original sources
PubMed1976

The right to know: giving the patient his medical record.

Each patient admitted to the 16-bed Rehabilitation Medicine Service at Medical Center Hospital of Vermont since October 1972 has received a carbon copy of his full Admission and Discharge notes, containing the complete problem list, and for each problem the relevant data, the Assessment and the Plans. The objectives were to improve patient education; to improve the patient's chances to contribute to the planning of his care; and to increase the staff's accountability to the patient. Over a period of seven months, we evaluated the effect of this maneuver for 125 consecutive patients by means of (1) a report on the patient's reactions, completed by a nurse after she reviewed the record with the patient; (2) a report by the physician stating whether he had expurgated the record for patient use, and recording his observations of patient and family reaction; (3) a questionnaire mailed to patients after discharge. Results indicated that patients were generally comfortable about reading the record, found it educational and appreciated the trust implied. No substantial difficulties arose. Few records were expurgated. The staff has accepted this style as crucial to an appropriate sharing of responsibility between themselves and the patients. We conclude that giving the patient his record is a safe and inexpensive aid to the rehabilitation process, and is probably mandated by the changing relationships between professionals and their clients, and by the patient's need to negotiate his own health care in an increasingly complex and mobile society.

Adolescent↗
PubMed2004

Sedation records: TRACS electronic database.

The volume of data that should be recorded before, during and after a conscious sedation procedure makes accurate and complete manual recording impractical. Unless the data is in a structured electronic format, subsequent analysis is extremely difficult. The TRacking and Analysis of Conscious Sedation electronic database (TRACS) is designed to overcome these problems. The user is guided through the recording procedure, which follows the Guidelines for Conscious Sedation in the Provision of Dental Care. This, together with the 'Audit Trail' of events provided by TRACS could prove invaluable in the event of a legal or technical dispute. Since the information is in an electronic database, immediate analysis can be performed on both individual and groups of patient records. Provision has been made for records from many treatment centres to be consolidated thus enabling serious academic work to be performed on large numbers of records.

Anesthesia, Dental↗
PubMed1993

Comparison of scalp electroencephalogram with subdural electrocorticogram recordings and functional mapping in frontal lobe epilepsy.

We compared the findings of scalp electroencephalogram with subdural electrode array (SEA) recordings in 19 patients with refractory frontal lobe epilepsy. Prolonged scalp interictal recordings localized the epileptogenic zone in 12 patients; seven had no interictal sharp waves. The SEAs showed multifocal interictal sharp waves in all patients. Seven patients with localized seizure onset on scalp recording showed extensive ictal onset on the SEA recording. Five patients with lateralized seizure onset to one hemisphere on scalp recording were found to have ictal onset on SEA restricted to a smaller area. Because of the large epileptogenic zone found on SEA recordings, a complete resection was possible in only five (33%) of the 15 patients who had resections. Eight (53%) of the 15 patients benefited from surgery (mean follow-up, 4.6 years). The SEAs also allowed functional localization in most patients. From these data, we suggest that a localizing scalp electroencephalogram in patients with frontal lobe epilepsy may be misleading because SEA recordings show larger epileptogenic zones than anticipated. Furthermore, we postulate that the larger extensive epileptogenic zone may account for the poorer surgical outcome in patients with frontal lobe epilepsy compared with patients with temporal lobe epilepsy.

Adolescent↗
PubMed2003

Evaluation of a new device for home cardiorespiratory recording in children.

OBJECTIVE: To evaluate the feasibility of using a new home cardiorespiratory recording device (HCRD) in children. DESIGN: Cross-sectional study. PATIENTS: Consecutive children scheduled for adenotonsillectomy to treat habitual snoring and/or apneas at otorhinolaryngology clinics in 2 academic and 7 general hospitals. INTERVENTION: Single-night unattended home cardiorespiratory recording prior to adenotonsillectomy using the HCRD. MAIN OUTCOME MEASURES: Number of technically acceptable recordings and successful recordings with artifact-free signals (respiration, saturation, and nasal flow) present for sufficient duration to allow scoring of the polysomnogram and to make a diagnosis. RESULTS: Of 53 eligible children, 24 participated in the study. The main reason for nonparticipation was refusal of caregivers (n = 16). Mean (SD) age of participants was 4.2 (1.6) years; median Brouillette obstructive sleep apnea score was 2.54. Technically acceptable recordings were obtained in 18 children (75%). Only 7 recordings (29%) were classified as successful. The poorest signal quality was obtained from the nasal cannula. CONCLUSION: Based on strict scoring criteria in this study, the results of single-night unattended recordings at home with the HCRD fell short of expectations.

Adenoidectomy↗
PubMed2005

Criminal records of homicide offenders.

CONTEXT: Homicide prevention strategies can be either targeted toward high-risk groups or addressed to the population at large. One high-risk group of particular interest is adults with a criminal record. But the prevalence of a criminal record among homicide offenders has not been reliably quantified, nor has the prevalence of criminal record in the general population. OBJECTIVE: To determine what portion of the homicide problem would be addressed by interventions linked to arrest or conviction. DESIGN, SETTING, AND PARTICIPANTS: A case-control analysis was performed using a comprehensive data set of all arrests and felony convictions in Illinois for 1990-2001. Cases were defined as Illinois residents aged 18 to 64 years who were arrested for homicide in 2001. Controls were all other Illinois residents aged 18 to 64 years in 2001. Illinois criminal and juvenile record information for cases and controls was compiled for 1990-2000. Five definitions of previous record were considered (arrest, arrest for a violent crime, 5 or more arrests with at least 1 for a violent crime, felony conviction, and violent-felony conviction), each measured for 1990-2000 and for 1996-2000. MAIN OUTCOME MEASURE: The population-attributable risk: the portion of homicide offenses that would be eliminated by a hypothetical intervention that reduced the offending risk of individuals with a record to the offending risk of those who lack a record. RESULTS: For 1990-2000, 42.6% of 884 cases had at least 1 felony conviction compared with 3.9% of nearly 7.9 million controls, for a population-attributable risk of 40.3% (95% CI, 37.0%-43.8%); among cases, 71.6% had experienced any arrest from 1990-2000 compared with 18.2% of controls, for a population-attributable risk of 65.3% (95% CI, 61.6%-68.8%). For 1996-2000, the population-attributable risk among individuals with a felony conviction or any arrest was 31.0% (95% CI, 27.9%-34.2%) and 58.5% (95% CI, 54.9%-62.1%), respectively. CONCLUSIONS: Interventions after arrest or conviction, such as supervised release, imprisonment, correctional programs, or bans on firearm possession, are targeted toward a group that has relatively high incidence of lethal violence, but they leave a large portion of the problem untouched.

Adult↗
PubMed1999

Extracellular single-unit recordings of piriform cortex neurons in rats: influence of different types of anesthesia and characterization of neurons by pharmacological manipulation of serotonin receptors.

In epilepsy research, there is a growing interest in the role of the piriform cortex (PC) in the development and maintenance of limbic kindling and other types of limbic epileptogenesis leading to complex partial seizures. Neurophysiological studies on PC or amygdala-PC slice preparations from kindled rats showed that kindling of the amygdala induces long-lasting changes in synaptic efficacy in the ipsilateral PC, including spontaneous discharges and enhanced susceptibility of PC neurons to evoked burst responses. These long-lasting electrophysiological changes in the PC during kindling appear to be due, at least in part, to impaired function of gamma-aminobutyric acid (GABA)ergic interneurons. The aim of the present study was to develop an anesthetic protocol allowing electrophysiological single-unit recordings from inhibitory, presumably GABAergic PC interneurons in vivo. In addition to recording of spontaneously active PC neurons, microiontophoretic application of glutamate was used to activate silent neurons. Anesthesia of rats with ketamine/xylazine was not suited for single-unit recordings in the PC because of marked cardiovascular depression. Anesthesia with chloral hydrate allowed recording of spontaneous or glutamate-driven single-unit activity in approximately 40% of all animals. A similar percentage was obtained when recordings were done with the narcotic opioid fentanyl (plus gallamine), after all surgical preparations were performed under anesthesia with repeated administration of the barbiturate methohexital. To avoid brain accumulation of methohexital by repeated applications, we modified the anesthetic protocol in that methohexital was only injected once for initiation of surgical anesthesia, followed by the short-acting anesthetic propofol which does not accumulate upon repeated application. Again, after surgical preparation, electrophysiological recordings were done under fentanyl (plus gallamine). By this procedure, spontaneous or glutamate-driven single-unit activity could be measured in all rats in either layer II or III of the PC. Based on shape and frequency of action potentials, two types of neurons were recorded. The predominant type was similar in its firing characteristics to GABAergic neurons in other brain regions, was mainly located in layer III, and could be suppressed by the serotonin2A receptor antagonist MDL 100,907, suggesting that this type of PC neuron represents inhibitory, putative GABAergic interneurons. This new in vivo preparation may be useful for evaluation of PC neurons in kindled rats.

Action Potentials↗
PubMed1996

Monopolar needle electrode spatial recording characteristics.

The recording characteristics of the monopolar needle in three dimensions have not been well established. A simple spherical recording territory is commonly assumed with the very tip proposed to have a greater spatial recording sensitivity by some authors. We demonstrate by enlarged physical modeling in a homogeneous volume conductor that the recorded amplitude diminishes more gradually radially away from the conical surface than distally past the tip or proximal to the insulation edge. The sensitivity over the exposed metallic surface is found to be uniformly proportional to the area, which results in relatively less sensitivity at the tip than the middle and proximal portions of the conical recording surface. The overall spatial amplitude recording characteristics can be better described by an apple shape than a sphere, centered at the midportion of the exposed conical surface. A better appreciation of the actual spatial recording characteristics of the monopolar needle electrode can result in more accurate physiologic interpretations of quantitative motor unit analysis.

Electric Conductivity↗
PubMed2004

Suppression of photobleaching-induced artifacts in frequency-domain FLIM by permutation of the recording order.

BACKGROUND: Photobleaching can lead to significant errors in frequency-domain fluorescence lifetime imaging microscopy (FLIM). Existing correction methods for photobleaching require additional recordings and processing time and can result in additional noise. A method is introduced that suppresses the effects of photobleaching without the need for extra recordings or processing. METHODS: Existing bleach correction methods and the method introduced in this report whereby the recording order of the phases is permuted were compared using numerical simulations. RESULTS: Certain orders were found to make measurements virtually insensitive to photobleaching. At 12 recordings, errors in measured phase and modulation depth decreased by a factor 512 and 393, respectively, compared to recordings using sequential recording order. The optimal order is independent of modulation depth, phase, and extent of photobleaching. Thus, the same order can be used for practically all situations. Application of the method in FLIM measurements of EYFP-transfected HeLa cells was found effectively to suppress photobleaching induced artifacts. CONCLUSIONS: In view of the ease of implementation, its inherent robustness, and the possibility to still apply existing correction methods afterward, there is no good reason not to use the permuted recording order presented in this report instead of a sequential order.

Artifacts↗
PubMed2005

Visual evoked potentials may be recorded simultaneously with fMRI scanning: A validation study.

Integrating electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) data may help to optimize anatomical and temporal resolution in the investigation of cortical function. Successful removal of fMRI scanning artifacts from continuous EEG in simultaneous recordings has been reported. We assessed the feasibility of recording reliable visual evoked potentials (VEPs) during fMRI scanning using available artifact removing procedures. EEG during administration of visual stimuli was recorded using MRI-compatible 32-channel equipment in nine normal subjects (mean age, 23.9 +/- 2.5 years), with and without fMRI acquisition. fMRI scanning and cardioballistographic artifacts were removed after subtraction of averaged artifact waveforms. Consistency between VEPs waveforms and of P1 and N1 peak latencies and amplitudes in the two conditions was assessed. Good correlation was found between VEP waveforms (Pearson's correlation coefficient: r(P) between 0.76-0.94 across subjects; P < 0.0001) and between latency or amplitude of P1 and N1 peaks (latencies: r = 0.7, P < 0.035; amplitudes: r > 0.65, P < 0.05; Spearman rank correlation coefficient) in the two recording conditions. No significant differences were found between P1 and N1 parameters in the two conditions (Wilcoxon signed rank test). Consistent VEP waveforms, latencies, and amplitudes with and without fMRI scanning indicate that reliable VEPs may be obtained simultaneously with fMRI recording. This possibility might be helpful by shortening recording times and reducing variability from learning, habituation, and fatigue phenomena from separate recordings for the integration of event-related EEG and fMRI data.

Adult↗
PubMed2003

Longitudinally implanted intrafascicular electrodes for stimulating and recording fascicular physioelectrical signals in the sciatic nerve of rabbits.

The purpose of this experiment was to determine the stimulating and recording characters of fascicular physioelectrical signals in the activity of peripheral nerves by longitudinally implanted intrafascicular electrodes (LIFEs) in a rabbit sciatic nerve model, and discuss the future application of LIFEs in functional electrical stimulation (FES) and control of electric arm prosthesis. In methodology, LIFEs were inserted into the fasciculus of the sciatic nerves of rabbits and used as recording electrodes and stimulating electrodes, respectively. Motor-evoked potentials (MEPs), cortical somatosensory-evoked potentials (CSEPs), and electromyography (EMG) were recorded by using a transcranial stimulation system (TCS). LIFEs were found to have stable stimulating and recording characters. The interpeak amplitudes (IPAs) of MEPs ranged from 78-156 microV (mean +/- SD, 102 +/- 23.2 microV). The onset latency (OL) of MEPs ranged from 9.8-11.2 msec (mean +/- SD, 10.8 +/- 0.6 msec). The interpeak amplitudes (IPAs) of CSEPs ranged from 5.8-7.2 microV (mean +/- SD, 6.7 +/- 0.5 microV). The onset latency (OL) of CSEPs ranged from 11.4-14.6 msec (mean +/- SD, 12.8 +/- 1.3 msec). EMGs could be recorded in the gastrocnemius, but could not be recorded in the tibialis anterior muscle. In conclusion, longitudinally implanted intrafascicular electrodes can act as intrafascicular stimulating and recording electrodes with high selective characters. They can provide a new way to study fascicular physioelectrical signals and their function in the activity of peripheral nerves.

Animals↗
PubMed1996

Morphology of action potentials recorded from human nerves using microneurography.

This study investigated the morphology of action potentials and the frequency of occurrence of the various waveforms encountered when using microneurography to record single-unit muscle afferent activity in humans. With 75% of the afferents recorded in this study (55 of 73 afferents), action potentials had a double-peaked morphology. For action potentials with an initial, positive double-peaked morphology, the relevant afferent conducts impulses past the microelectrode, with the second peak representing current fluctuations at the node of Ranvier proximal to the electrode. Accordingly, in the majority of recordings, the afferent is capable of conducting impulses to the spinal cord. The mean interpeak interval for these double-peaked units was 168 microseconds (range 90-310 microseconds). This represents marked prolongation of conduction time across the impaled internode. When the interpeak interval was relatively short (90-120 microseconds), the double-peaked morphology could be recognized only if the low-pass filter was high (> or = 10 kHz). The probability of recording a double-peaked unit was the same whether the recording was acquired early or late in a 3-h experiment. Conduction block developed in 6 of 73 single units during the recordings. These findings indicate that the majority of isolated single afferents and, indeed, the majority of afferents within the relevant fascicle are capable of transmitting impulses across the recording site, even though conduction across the impaled internode is slow. Conduction block due to direct injury or pressure is relatively uncommon.

Action Potentials↗
PubMed1995

Motor evoked potentials: appropriate positioning of recording electrodes for diagnosis of spinal disorders.

The interpretation of normal and pathological findings of motor evoked potential obtained by the use of transcranial magnetic stimulation depends on adequate examination technique, including the appropriate positioning of the recording electrodes over the muscle. On the basis of knowing the location of the motor end plate zones in muscles, magnetic stimulation of the motor cortex of 30 healthy adults was performed in order to explore the influence of the position of the surface recording electrodes on potential parameters and to establish the standard location of the recording electrodes over the biceps brachii, medial vastus, anterior tibial and abductor hallucis muscles for diagnostic use in spine disorders. The cortical latencies and peak-to-peak amplitudes of the evoked potentials were analysed by varying the location of the recording electrodes and the stimulus intensities. The latencies were significantly shorter when the different electrode lay more proximally over the muscle belly. Reproducible potentials with sharp negative onset and maximum amplitude were recorded with a separation of 5-7.5 cm between the different electrode, located over the motor end plate area, and the different electrode, located over the distal myotendinous junction. This implies that the parameters of evoked potentials depend on the position and separation distance of the recording electrodes over the muscles and that it is possible to record the potentials using a lower stimulus intensity and, above all, on relaxed muscles, which may prove to be applicable for intraoperative monitoring of the spinal cord using magnetic stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1979

[Fiftieth anniversary of Hans Berger's publication of the electroencephalogram. His first records in 1924--1931 (author's transl)].

For the fiftieth anniversary of Berger's first EEG publication, some of his early recordings obtained between 1924 and 1931 are discussed and illustrated. Examples of his protocols from the Freiburg Berger Archives are reproduced. Three types of Berger's early investigations are described: (1) String-galvanometer recordings obtained between 1924 and 1926, mainly from trephined patients with cerebral diseases, which usually showed brain waves slowed to 6--8 per second; (2) Direct recordings from the cortex and white matter proving the cortical origin of the EEG in 1930; (3) Typical unpublished EEG recordings of epileptics and of petit-mal attacks obtained in 1930 and 1931. Berger's first six papers published between 1929 and 1933 described nearly all the main EEG findings of cerebral diseases and the EEG alterations of normals during attention, sleep, and narcosis, but they did not report on convulsive potentials in the EEGs of epileptics. Berger had, however, obtained excellent records of epileptic EEG features, here depicted in Figs. 4 through 7. These remained unpublished until 1933 and 1938, because Berger suspected that they contained artifacts caused by blinks and facial movements which he had recorded in his controls (Fig. 4). Only in 1933, after other authors had described large amplitudes of convulsive potentials in the cortex of animals, did Berger publish parts of the EEGs of a petit-mal attack and of focal attacks in progressive paresis. In 1938, Berger presented the EEG of the beginning of a petit-mal attack with large 3/s spikes and waves recorded in 1931 which were similar to those described by Gibbs and coworkers in 1935. In 1933 and 1938, Berger interpreted the abnormal brain potentials of epileptics as signs of a preconvulsive state of the forebrain and suggested that the periods of 3/s waves were cortical correlates of an epileptic absence.

Electroencephalography↗
PubMed1981

Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.

1. The extracellular patch clamp method, which first allowed the detection of single channel currents in biological membranes, has been further refined to enable higher current resolution, direct membrane patch potential control, and physical isolation of membrane patches. 2. A description of a convenient method for the fabrication of patch recording pipettes is given together with procedures followed to achieve giga-seals i.e. pipette-membrane seals with resistances of 10(9) - 10(11) omega. 3. The basic patch clamp recording circuit, and designs for improved frequency response are described along with the present limitations in recording the currents from single channels. 4. Procedures for preparation and recording from three representative cell types are given. Some properties of single acetylcholine-activated channels in muscle membrane are described to illustrate the improved current and time resolution achieved with giga-seals. 5. A description is given of the various ways that patches of membrane can be physically isolated from cells. This isolation enables the recording of single channel currents with well-defined solutions on both sides of the membrane. Two types of isolated cell-free patch configurations can be formed: an inside-out patch with its cytoplasmic membrane face exposed to the bath solution, and an outside-out patch with its extracellular membrane face exposed to the bath solution. 6. The application of the method for the recording of ionic currents and internal dialysis of small cells is considered. Single channel resolution can be achieved when recording from whole cells, if the cell diameter is small (less than 20 micrometer). 7. The wide range of cell types amenable to giga-seal formation is discussed.

Acetylcholine↗
PubMed1995

An intra-arterial electrode for intracranial electro-encephalogram recordings.

A new method for intracranial monitoring of brain electrical activity by means of an intra-arterial guide wire as electrode is described. We carried out intracranial electro-encephalography (EEG) using an insulated Seeker Lite-10 guide wire 18 times in 14 patients: ten times in 6 patients with cerebral arteriovenous malformation (AVM) before embolization, and another 8 times in 8 patients with epilepsy. In all cases, a 2-5 times stronger high voltage potential EEG compared with scalp EEG could be recorded. In 3 patients with complex partial epilepsy, intra-arterial (IA) EEG was recorded under subdural strip electrode monitoring, and IAEEG at the sphenoidal portion of the middle cerebral artery was compared with subdural electrode recordings. Frequent interictal spike discharges recorded with subdural electrodes in the lesional medial temporal lobe were simultaneously visible on IAEEG recording. This method is equivalent to that using a semi-invasive electrode, but ECoG recording can be performed at angiography. IAEEG is a method of electrode recording that has the possibility of clinical application.

Adolescent↗
PubMed1990

Errors in tracheal pressure recording in patients with a tracheostomy tube--a model study.

The recording of intratracheal pressure in patients breathing through a tracheostomy tube is marred by methodological problems. In model experiments it has been shown that the introduction of a recording catheter into the tracheostomy tube alters the recorded pressure by as much as 20-40%. To avoid such inaccuracy, a specially designed tracheostomy tube is proposed with an externally placed channel for introduction of the recording catheter. In in vivo measurements, recordings can be made at a distance of up to about 20 mm below the end of tube. Pressure recordings from this part of a model trachea are compared with results obtained from a reference pressure port 100 mm below the tube ending. The results show that it is possible to record expiratory pressure with good accuracy but that inspiratory pressure is still overestimated by 9-16%.

Airway Resistance↗
PubMed1991

Analysis and use of the perforated patch technique for recording ionic currents in pancreatic beta-cells.

We have used the nystatin perforated patch technique to study ionic currents in rat pancreatic beta-cells. The access resistance (Ra) between the pipette and the cell cytoplasm, measured by analyzing capacitive currents, decreased with a slow exponential time course (tau = 5.4 +/- 2.7 min) after seal formation. As Ra decreased, the magnitude of voltage-dependent K and Ca currents increased with a similar time course, and their activation kinetics became faster. After Ra stabilized, the macroscopic currents remained stable for up to an hour or more. When the final Ra was sufficiently low, Ca tail currents could be resolved which had properties similar to those recorded with the classical whole-cell technique. Two types of K channels could be characterized with perforated patch recordings of macroscopic K currents: (i) ATP-blockable K (KATP) channels which generate a time and voltage independent current that is blocked by glyburide and enhanced by pinacidil and (ii) voltage-dependent K (Kv) channels. Whole-cell recordings of KATP currents in the absence of ATP in the pipette showed that the maximum KATP conductance of the beta-cell was 83.8 +/- 40 nS. Perforated patch recordings show that the resting KATP conductance is 3.57 +/- 2.09 nS, which corresponds to about 4% of the channels being open in the intact beta-cell. In classical whole-cell recordings. Kv activation kinetics become faster during the first 10-15 min of recording, probably due to a dissipating Donnan potential. In perforated patch recordings where the Donnan potential is very small, Kv activation kinetics were nearly identical to the steady-state whole cell measurements.

Adenosine Triphosphate↗
PubMed1982

Heart block in children. Evaluation of subsidiary ventricular pacemaker recovery times and ECG tape recordings.

To evaluate subsidiary ventricular pacemaker function in 20 children with congenital or surgically induced complete heart block, we measured recovery times following overdrive ventricular pacing. Long-term ECG tape recordings were performed in eight of these children. Ages ranged from 1 month to 17 years. The resting R-R intervals ranged from 595 to 1,740 msec. The ventricles were paced at various cycle lengths of 400 to 1,000 msec with either transvenous electrode catheters or surgically implanted epicardial electrodes. His bundle recordings showed that the site of block did not allow separation of patients with symptoms from those without symptoms. Prolonged recovery times were present in patients with block above the His bundle recording site who had symptoms of syncope or dizziness, as well as in patients who had a wide QRS. However, some asymptomatic patient with heart block above the His bundle recording site also had long recovery times. None of the asymptomatic patients who had ECG tape recordings had paroxysmal tachycardia in more than 300 hours of recordings. However, one symptomatic patient with congenital heart block and a prolonged recovery time had brief episodes of paroxysmal ventricular tachycardia that produced no symptoms at the time of recording. The results suggest that the coexistence of prolonged recovery times and paroxysmal tachycardia may be predisposing factors to the development of symptoms in patients with complete heart block. We believe that further electrophysiologic investigation of this possibility is warranted in patients with heart block.

Adolescent↗