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At least 685 records · Page 38Linked to original sources
PubMed2006

Interviews or medical records, which type of data yields the best information on elderly people's health status?

BACKGROUND AND AIMS: Self-reported data and/or medical records are often used to assess the prevalence of illness and impairment in epidemiological studies. However, these two data sources do not always provide the same information. The aim was to compare data from interviews and medical records regarding illness, symptoms and impairment in the elderly, and to analyze the agreement between a consensus from both data sources and data from interviews and medical records, respectively. METHODS: We interviewed 130 persons (age range 67-99) regarding socio-demographic background data and physical and mental health. Medical records were reviewed. Illness burden was rated according to the Cumulative Illness Rating Scale for Geriatrics, and was rated in three ways based on: (1) interview data; (2) medical records; (3) information from both interviews and medical records considered to be consensus. Agreement was measured by the Kappa coefficient and the Svensson Paired Rank Measurement. A permutation test tested whether the ratings from interviews and medical records had the same agreement when compared with consensus. RESULTS: Statistically significant differences in agreement were found between interview versus consensus and medical records versus consensus for the vascular system (medical records best), eyes/ears/nose/throat/larynx and musculoskeletal/integument (interview best). Medical records gave better in formation concerning specific diseases and diagnoses, whereas interview data provided a better measure of illness, functional impairment and health in a broader sense. CONCLUSIONS: Both medical records and interviews yield good information of elderly people's health status, but they focus on different aspects of health.

Adult↗
PubMed1989

A comparison of protrusive interocclusal records to pantographic tracings.

The rationale for recording protrusive mandibular movement is to accurately adjust an articulator. Techniques to record condylar inclination include radiographic interpretation, extraoral tracings, and intraoral recording materials. This study compared the protrusive settings on an articular adjusted by a pantograph to protrusive settings recorded by two intraoral recording materials, one a polyvinyl siloxane material and one a laminated, metalized wax. Pantographs were completed for 20 patients by using a kinematic hinge axis and conventional pantographic techniques. The patients also had three protrusive interocclusal records made with two intraoral registration materials completed and averaged. The average condylar inclination recorded with a pantograph (29.5 degrees) was greater than the recording by either intraoral registration material. Standard deviations ranged from 4.1 degrees to 6.6 degrees. An analysis of variance showed that the condylar inclination recorded by wax was statistically less than recorded with a pantograph. A comparison between the pantograph and the polyvinyl siloxane displayed no statistically significant difference in recording condylar inclination.

Adult↗
PubMed1999

Cardiovascular diseases and risk factors in a population-based study in The Netherlands: agreement between questionnaire information and medical records.

BACKGROUND: Since 1987 the Monitoring Project on Cardiovascular Risk Factors has been carried out in The Netherlands. The purpose of the present study was to assess the agreement between the self-reported questionnaire information that was collected in this survey on cardiovascular diseases and risk factors and information from medical records. METHODS: From 1987 to 1991, over 36,000 men and women aged 20-59 years have participated in the Monitoring Project on Cardiovascular Disease Risk Factors, a cross-sectional population-based study. We compared self-reported information on cardiovascular diseases and risk factors with the general practitioners medical records from a sample of 899 hypertensive subjects. RESULTS: The highest proportion of positive self-reports could be confirmed by the medical records for diabetes conditional on self-report of medication use for this condition (100%), and a history of hypertension conditional on the presence of blood pressure recordings in the medical records (91%). The lowest percentage of positive self-reports confirmed by medical records was a family history of myocardial infarction (3-5%). More than 80% of the negative self-reports were confirmed by the medical records for most conditions, except for history of hypertension, conditional on the presence of blood pressure recordings in the medical records (40%). The overall agreement above chance was substantial for cerebrovascular disease (kappa = 0.78) and diabetes (kappa = 0.75), moderate for myocardial infarction (kappa = 0.55), poor for myocardial infarction of the respondents' father (kappa = 0.07) and mother (kappa = 0.05), and fair to moderate for all other self-reported conditions. CONCLUSION: Agreement between self-reported information and medical records was variable. For further studies, self-reports of cardiovascular diseases and risk factors should preferably be complemented with information from other sources such as medical records.

Adult↗
PubMed2001

Clinical record keeping by general dental practitioners piloting the Denplan 'Excel' accreditation programme.

BACKGROUND: Denplan is a private capitation-based system of providing primary dental care in the UK. An additional programme called Denplan Excel has been developed which requires General Dental Practitioners to instigate various quality processes within their practices in order to become accredited. Clinical record keeping is one area where standards are monitored. This study reports changes in record keeping at patient recall appointments following the implementation of the Denplan Excel programme. METHOD: Fifty dentists participating in the Denplan Excel pilot programme from different areas of the UK were sampled by means of cluster sampling. Twenty records for each dentist were sampled and items recorded for patients recalled both pre- and post-pilot were compared. RESULTS: The majority of dentists recorded presenting complaint, diagnosis and treatment plan both pre- and post-pilot. However, post-pilot there were a number of improvements in record keeping. Caries recorded on a grid increased from 7% of records to 46%, basic periodontal examination increased from 48% to 85% of records and the updating of medical history increased from 51% to 65% of records. These findings were all significant at the p<0.01 level. CONCLUSION: Changes can be achieved by voluntary participation in a system of structured record keeping.

Accreditation↗
PubMed1999

Use of initial risk assessment and recording as the main nursing intervention in identifying risk of falls.

The consequences of falls among hospital patients are a great problem, for the patient, the family and society, and cost billions of dollars. In Sweden, almost one-third of all hip fractures occur in the hospital population. Despite this, very few prevention strategies have been developed and tested. In this study, a risk assessment and recording programme in relation to the risk of falling among patients in a geriatric department at a Swedish hospital was implemented. The records of all patients admitted to a geriatric unit during one year, and a stratified random sample of patient records, constituting the control group from the year before, were reviewed. No recording of assessments regarding the patients' risk of falling, and no preventive nursing interventions, were found in the records of the control group. The study group, however, increased the recording of risk assessment to 96%. Only implemented nursing interventions were found in the patients' records, despite the fact that Swedish law makes it obligatory for the registered nurse to record both the planning and implementation of nursing care. In the study group there were explicit descriptions of problems of concern for nursing regarding the patients' risk of falling in less than one-third of the records, the nursing care plans were rare, and the evaluations were not satisfactory. Nursing interventions consisted mostly of information or education, promotion of patient participation, and structuring of the environment. There was no agreement on any standard-care plan. Recording of falls was found more often in the study group than in the control group (probably due to more careful recording), but the proportion of injuries in relation to falls was higher in the control group. The results of this study may be used as a baseline for developing a nursing strategy and documentation relating to falls.

Accidental Falls↗
PubMed1989

Differences between handwritten and automatic blood pressure records.

Comparison of 46 handwritten and electromechanically generated blood pressure records revealed substantial differences between the recordings. The highest automated record pressures exceeded the highest pressures found in corresponding handwritten records. Similarly, the lowest pressures from automated records were lower than those from handwritten records. Seventeen records (37%) had at least three automatic blood pressure determinations with values substantially in excess of the most extreme values recorded by hand. No handwritten record contained a diastolic pressure above 110 mmHg. Discrepancies between handwritten and automatic records may arise from one or more causes. Among these are readings captured automatically but not observed by the anesthesiologist, faulty reconstruction of handwritten records from memory, and bias in favor of less controversial values.

Adult↗
PubMed2001

The impact of record scattering on the measurement of immunization coverage.

BACKGROUND: Lack of a consolidated immunization record may lead to problems with determining individual immunization needs at office visits as well as measuring vaccination coverage levels of a clinician's practice or a community's population. OBJECTIVES: For children with multiple immunization providers, evaluate the difference in coverage levels using data from all responding immunization providers compared with: 1) the most recent immunization provider's records, 2) the first immunization provider's records, and 3) a randomly selected immunization provider's records. Identify characteristics of the most recent provider that may be associated with reporting incomplete immunization histories. METHODS: Data from the 1995 National Immunization Provider Record Check Study (NIPRCS) were used for analysis. The NIPRCS is a provider validation study of the household reported immunization histories of all children 19 to 35 months of age included in the National Health Interview Survey (NHIS). Providers identified by the child's parent during the NHIS interview are mailed a 2-page survey to report all immunizations (type and date) the child received, regardless of the provider who administered the shots, and child's first and most recent visit dates to the practice. RESULTS: Of the 1352 children with provider data, 304 (22%) had received immunizations from more than one provider. Compared with information from all providers and depending on the vaccine, the most recent provider records underestimated coverage by 9.6 to 13.4 percentage points; the initial provider records underestimated coverage by 15.6 to 34.6 percentage points; and the randomly selected provider records underestimated coverage by 10.0 to 20.7 percentage points. Public facilities and having an immunization summary sheet in the patient's chart were associated with having complete records. CONCLUSION: Scattered immunization records significantly compromise the ability of clinicians to determine the immunization status of their patients who received immunizations at other sites of health care. Routinely assessing immunization coverage levels at the practice level, implementing a recall system, and developing community-wide immunization registries are some strategies to reduce the problem of scattered immunization records.immunization, assessment, provider validation, record scattering.

Child, Preschool↗
PubMed2000

Adequacy of dental records in clinical practice: a survey of dentists.

PURPOSE: The purposes of the study were to determine Minnesota dentists' perception of the adequacy of their dental record documentation, assess the general format and contents of dental records they used, and compare the self-reported contents of dental records with guidelines established by the American Dental Association (ADA). METHOD: Using ADA's published recommendations for structure and guidelines of the dental record from 1987, a 20-item questionnaire was developed, pretested, and used to survey a random sample of 750 Minnesota dentists. Reminder postcards were sent two weeks after the initial survey mailing. A third mailing to nonrespondents, including cover letter and duplicate questionnaire, was conducted three weeks later. Of the surveys returned, 63% (N = 475) were analyzed. Data analyses, including frequencies and tests of chi-square, were conducted using Statview and SPSS. RESULTS: While 15% (N = 69) of respondents used a single-page record format, 44% (N = 209) used multiple forms filed in a specific location within the record. Of the dentists responding, 403 (85%) felt their record documentation was adequate without comparison to any specified criteria. However, statistically significant differences occurred between dentists' perception of record adequacy and the actual presence or absence of ADA criteria for all record components. Data analysis revealed that information was absent 9.4% to 87.1% of the time. CONCLUSION: A discrepancy exists between dentists' perception of dental record adequacy and the ADA recommendations for structure and guidelines. Inadequate dental record components should be targeted for improvement.

American Dental Association↗
PubMed1998

Comparison of video-recorded consultations with those in which patients' consent is withheld.

BACKGROUND: Video-recorded consultations are widely used for research in general practice. Recently, video recordings have begun to be used for the purposes of general practitioner (GP) registrar assessment. It is unknown, however, whether consultations in which patients withhold consent for recording differ from those that are recorded. AIM: To compare clinical problems and demographic characteristics of adult patients who consent to the video recording of consultations with those who withhold consent. METHOD: This was prospective study of 538 adult patients consulting 42 GPs, based in practices throughout Leicestershire. Each patient attended a surgery session with one of the 42 GPs between April 1995 and March 1996. Clinical presentations and demographic characteristics of patients consenting and withholding consent to the video recording of their consultations were compared. GPs' perceptions of whether patients in these two groups were distressed/upset or embarrassed were also compared. RESULTS: A total of 85.9% (462/538) of adults consented to video recording, and 14.1% (76/538) withheld consent. Multiple logistic regression revealed that patients who presented with a mental health problem were more likely to withhold consent to recording (odds ratio 2.5, 95% confidence interval 1.4-4.6). Younger patients were also more likely to withhold consent to video recording. Additionally, where patients' consent was withheld, GPs perceived patients to be more distressed or embarrassed. CONCLUSION: Younger patients and those suffering from mental health problems are more likely than others to withhold consent to being video recorded for research purposes in general practice. The implications of this study for the assessment of registrar GPs using video-recorded consultations are discussed.

Adolescent↗
PubMed2001

Recording previous adverse drug reactions--a gap in the system.

AIMS: To measure the accuracy of recording of previous adverse drug reaction (ADR) history in patients admitted to a teaching hospital before and after an education programme. METHODS: One month survey of patients on one medical and one surgical ward, repeated after a 1 month education programme. Patients answered a questionnaire about previous ADRs and this information was compared with that in all relevant sections of their medical records and medication charts. RESULTS: Of 117 patients at baseline, 50 had a total of 81 previous ADRs. Only 75% were recorded on medication charts and 57% and 64%, respectively, in medical and nursing notes. In the post education survey of 124 patients, 56 had 105 previous ADRs, 85% were recorded on medication charts and 64% and 70% in medical and nursing records. These differences were not significant. Serious ADRs were also poorly recorded at baseline but, due to intervention by ward pharmacists, their recording on medication charts improved significantly after education. Pharmacists also significantly improved the quality of description of previous ADRs in both parts of the study. CONCLUSIONS: Previous ADR history obtainable from hospital patients is poorly recorded in medical records and an intensive education programme only produced a significant change in recording by ward pharmacists. Better strategies are needed to improve this essential aspect of history taking.

Adverse Drug Reaction Reporting Systems↗
PubMed2002

Identification of randomized controlled trials in systematic reviews: accuracy and reliability of screening records.

A study was conducted to estimate the accuracy and reliability of reviewers when screening records for relevant trials for a systematic review. A sensitive search of ten electronic bibliographic databases yielded 22 571 records of potentially relevant trials. Records were allocated to four reviewers such that two reviewers examined each record and so that identification of trials by each reviewer could be compared with those identified by each of the other reviewers. Agreement between reviewers was assessed using Cohen's kappa statistic. Ascertainment intersection methods were used to estimate the likely number of trials missed by reviewers. Full copies of reports were obtained and assessed independently by two researchers for eligibility for the review. Eligible reports formed the 'gold standard' against which an assessment was made about the accuracy of screening by reviewers. After screening, 301 of 22 571 records were identified by at least one reviewer as potentially relevant. Agreement was 'almost perfect' (kappa>0.8) within two pairs, 'substantial' (kappa>0.6) within three pairs and 'moderate' (kappa>0.4) within one pair. Of the 301 records selected, 273 complete reports were available. When pairs of reviewers agreed on the potential relevance of records, 81 per cent were eligible (range 69 to 91 per cent). If reviewers disagreed, 22 per cent were eligible (range 12 to 45 per cent). Single reviewers missed on average 8 per cent of eligible reports (range 0 to 24 per cent), whereas pairs of reviewers did not miss any (range 0 to 1 per cent). The use of two reviewers to screen records increased the number of randomized trials identified by an average of 9 per cent (range 0 to 32 per cent). Reviewers can reliably identify potentially relevant records when screening thousands of records for eligibility. Two reviewers should screen records for eligibility, whenever possible, in order to maximize ascertainment of relevant trials.

Databases, Bibliographic↗
PubMed1987

Comparison of amplitude-modulated (direct) and frequency-modulated ambulatory techniques for recording ischemic electrocardiographic changes.

Continuous ambulatory electrocardiographic monitoring of ST-segment configuration has become a useful technique for evaluation of myocardial ischemia. Concern that direct or amplitude-modulated (AM) recording and playback systems have inherent limitations that cause inaccurate ST-segment recordings has led to preference for frequency-modulated (FM) devices. To determine the accuracy of AM and FM ambulatory electrocardiographic systems, the signal was compared from the same set of 2 bipolar leads simultaneously recorded by standard electrocardiography and AM and FM recorders in 14 patients during treadmill exercise. Also, simultaneous AM and FM recorders were compared in 9 ambulatory patients in 16 monitoring sessions. The AM recording system accurately reproduced ST segments recorded during treadmill exercise (range 4.0 mm of ST-segment depression to 2.0 mm of ST elevation) when measured at the J point (r = 0.91, p less than 0.0001), and 0.08 second after the J point (r = 0.95, p less than 0.0001). FM recording was equally accurate (r = 0.89 and 0.95, respectively, p less than 0.0001). Similarly, during ambulatory recording, the AM technique accurately recorded maximal ST depression in each episode as recorded by the FM device (28 episodes, range 0 to 3 mm of ST depression, r = 0.85, p less than 0.0001). Both AM and FM ambulatory electrocardiographic systems can accurately reproduce ST-segment deviation associated with ischemia and can be used to monitor transient ST-segment changes in patients with coronary artery disease.

Ambulatory Care↗
PubMed1985

Unit activity, evoked potentials and slow waves in the rat hippocampus and olfactory bulb recorded with a 24-channel microelectrode.

Activity from a number of neighboring neurons can be recorded simultaneously with multichannel microelectrodes. A new version of a 24-channel microelectrode system has been fabricated and used to record different types of neurophysiological data in the rat brain. The system called PRONG (Parallel Recording Of Neural Groups) includes a microelectrode, a lightweight reusable connector, a 24-channel FET-hybrid preamplifier, a 3-band 24-channel amplifier, a 24-channel spike monitor, high-speed digital and analog interfaces and a computer. The electrode-recording locations are arranged in 2 arrays of 12 sites. The arrays are spaced 100 micron apart along either edge of the recording section and the sites within each array are spaced 120 micron apart. The electrodes are fabricated using photolithography in patterned layers totaling 17 micron thick and 114 micron wide in the recording section. The recording sites are 20 micron2 and are plated with platinum black. Performance of the PRONG was compared with that of conventional single microelectrodes and with results in the literature on three kinds of extracellular activity in the rat hippocampal formation and olfactory bulb: action potentials, evoked field potentials and slow-wave activity. The selectivity and sensitivity of the PRONG compared favorably with characteristics of conventional electrodes. Background noise averaged 15 microV and no signal cross talk was observed between neighboring channels. Discriminable action potentials (signal-to-noise ratios of 2:1 to 15:1) were observed at 37-95% of the viable recording sites with a maximum of 19 units in one recording. Units were observed in waking animals for up to 4 days. The waveforms, firing repertoires and laminar distribution of units were the same as those recorded with conventional microelectrodes. This indicates that penetration by the PRONG spares tissue from functional damage. "Instant" laminar profiles were created for commissural and perforant path evoked potentials in the hippocampal formation. These profiles were nearly identical with those created by successive recordings made with conventional microelectrodes. Laminar profiles and behavioral activity appeared to be "normal" as collected with this electrode. These results set the foundation for use of the PRONG as a tool for the study of local neural interactions.

Animals↗
PubMed2005

Technical quality evaluation of EEG recording based on electroencephalographers' knowledge.

The aim of this study is to develop a technical quality evaluation system of electroencephalogram (EEG) recording in order to acquire technically satisfactory EEG records, which may contribute to the accuracy improvement of EEG interpretation. In our developed system, the evaluation of EEG recording comprises the detection of technical artifacts and physiological status, which indicates the recording status objectively. In addition, the caution signals to users are generated in the system according to the undesired status detected. The information displayed to users includes the updated EEG records and instant evaluation results. Two examples of evaluation results are introduced in this paper, illustrating unsatisfactory records and artifact free records, respectively. The experimental results are proposed to verify the effectiveness of the technical quality evaluation of EEG recording. The implementation of the technical quality evaluation of EEG recording is helpful to acquire technically satisfactory EEG records, which may improve the accuracy of results in both the visual and the automatic EEG interpretation, and ease the laborious work of EEG technicians in the recording progress.

Adult↗
PubMed2003

A prospective randomized comparison of loop recorders versus Holter monitors in patients with syncope or presyncope.

BACKGROUND: The initial management of syncope or presyncope typically involves short-term cardiac monitoring using a Holter monitor. A loop recorder is used to extend the period of monitoring to increase the probability of obtaining a symptom-rhythm correlation. Loop recorders and Holter monitors are both used commonly, but their utility has not been compared prospectively. METHODS: Patients with syncope or presyncope referred for a Holter monitor or a loop recorder were assigned randomly to receive either a 48-hour Holter monitor or a loop recorder for 1 month as an initial diagnostic strategy. If the initial strategy was unsuccessful, patients were offered crossover to the alternate strategy. RESULTS: One hundred patients (mean [+/- SD] age, 56 +/- 20 years; 44 women) with syncope (n = 21), presyncope (n = 29), or both (n = 50) were enrolled. Of the 49 patients assigned randomly to an external loop recorder first, 31 (63%) had an arrhythmia identified or excluded, versus 12 (24%) of 51 patients assigned to a Holter monitor initially (P <0.0001). Arrhythmia was identified as a cause of syncope in 1 patient with a loop recorder, compared with no patients with a Holter monitor (P = 0.31). Of the 29 patients with negative results with Holter monitoring who went on to receive a loop recorder, 13 (45%) had arrhythmia excluded, compared with none of the 4 patients who crossed over to receive a Holter monitor. The overall probability of obtaining a symptom-rhythm correlation was 56% (44/78) for loop recorders versus 22% (12/55) for Holter monitors (P <0.0001). Despite patient education and test transmissions, 13 (23%) of 57 patients who had recurrence of their symptoms failed to activate their loop recorder properly. CONCLUSION: Loop recorders have a much higher diagnostic yield for patients with syncope or presyncope as compared with Holter monitors. The utility of loop recorders is limited by some patients' inability to operate them correctly.

Electrocardiography, Ambulatory↗
PubMed1998

Reappraisal of the effect of electrode property on recording slow potentials.

Subdural electrodes made of stainless steel, which were believed to be unsuitable for recording slow potentials, can still record Bereitschaftspotential (BP) (Neshige, R., Lüders, H. and Shibasaki, H. Recording of movement-related potentials from scalp and cortex in man. Brain, 1988, 11: 719-736) and ictal DC shifts (Ikeda, A., Terada, K., Mikuni, N., Burgess, R.C., Comair, Y., Taki, W., Hamano, T., Kimura, J., Lüders, H.O. and Shibasaki, H. Subdural recording of ictal DC shifts in neocortical seizures in humans. Epilepsia, 1996b, 37: 662-674) sufficiently. In this study, therefore, the effects of different kinds of metals on slow potential recordings were reevaluated. First, slow electro-oculograms (EOGs) were recorded with 3 different levels of input impedance (200 M omega, 470 k omega and 10 k omega) of a DC amplifier by using surface electrodes made of silver (Ag), silver/silver chloride (Ag/AgCl) and stainless steel. Secondly, BP was recorded by using the above electrodes with a long time constant of 3 s and with a fixed input impedance of 100 M omega. As a result: (1) slow EOGs were equally recorded with the input impedance of 200 M omega and 470 k omega regardless of the kind of metals used, although stainless steel electrodes caused baseline fluctuation, (2) low input impedance of 10 k omega allowed only the Ag/AgCl electrode to record slow EOGs without any decay, and (3) electrodes made of stainless steel could record BP as efficiently as the other two types of electrode with high input impedance. In conclusion, electrodes with a large surface area contact such as cup electrodes and an amplifier with a large input impedance, electrodes made of Ag, and even of stainless steel, can record slow potentials reasonably well.

Contingent Negative Variation↗
PubMed2003

Intracranial volume conduction of cortical spikes and sleep potentials recorded with deep brain stimulating electrodes.

OBJECTIVE: To examine interictal epileptiform and sleep potentials recorded intracranially from deep brain stimulation (DBS) electrodes in patients treated with DBS for epilepsy. Specifically, this study sought to determine whether the DBS-recorded potentials represent: (a) volume conduction from surface neocortical discharges or (b) transsynaptic propagation along cortical-subcortical pathways with local generation of the subcortical potentials near the DBS targets. METHODS: Six patients with intractable epilepsy treated with thalamic DBS of the central median nucleus (CM; one patient) or anterior thalamus (5 patients) who had focal interictal spikes were studied. Sleep potentials were also studied in a 7th patient with Parkinson disease treated with DBS of the subthalamic nucleus (STN). RESULTS: Focal interictal cortical spikes recorded by scalp electroencephalography (EEG) were recorded synchronously, but with opposite polarity, from the DBS electrodes in CM as well as the more superficial anterior thalamic contacts situated in the anterior nucleus (AN) and dorsal medial nucleus (DM). In referential montages, the subcortical potentials were of highest amplitude ipsilateral to the focal cortical spikes, with a small but reproducible amplitude decrement present at each electrode contact more distant from the cortical source, irrespective of the specific DBS target. Subcortical sleep potentials (K-complexes and sleep spindles) were also recorded synchronously and with inverse polarity compared to the corresponding scalp potentials, and appeared in a similar fashion at all subcortical sites sampled by the DBS electrodes. Amplitude attenuation in the thalamus of intracranial volume conducted potentials with increasing distance from their cortical spike sources was measured at approximately 5-10 microV/mm. DISCUSSION: Recent reports on scalp-CM or scalp-STN EEG recordings in patients treated with DBS for epilepsy have interpreted the intracranial waveforms as evidence of transsynaptic cortical-subcortical transmission across neuroanatomical pathways presumed to be involved in the generation of sleep potentials (Clin. Neurophysiol. 113 (2002) 25) and epileptiform activity (Clin. Neurophysiol. 113 (2002) 1391). However, our results show that the intracranial spikes recorded from DBS electrodes in various regions of the thalamus (CM, AN and DM) represent subcortical volume conduction of the synchronous cortical spikes recorded with scalp EEG. The same is true for the intracranial reflections of scalp EEG sleep potentials recorded from DBS electrodes in CM, AN, DM and STN. These interictal DBS waveforms thus cannot be used to support hypotheses of specific cortical-subcortical pathways of neural propagation or subcortical generation of the DBS-recorded potentials associated with scalp EEG interictal spikes and sleep potentials. SIGNIFICANCE: Detailed analysis of the intracranial potentials recorded from DBS electrodes in association with scalp EEG spikes and sleep discharges shows that the intracranial waveforms represent volume conduction from discharges generated in the neocortex and not, as has been suggested, locally generated activity resulting from cortical-subcortical neural propagation.

Adult↗
PubMed2006

Chronic neural recordings using silicon microelectrode arrays electrochemically deposited with a poly(3,4-ethylenedioxythiophene) (PEDOT) film.

Conductive polymer coatings can be used to modify traditional electrode recording sites with the intent of improving the long-term performance of cortical microelectrodes. Conductive polymers can drastically decrease recording site impedance, which in turn is hypothesized to reduce thermal noise and signal loss through shunt pathways. Moreover, conductive polymers can be seeded with agents aimed at promoting neural growth toward the recording sites or minimizing the inherent immune response. The end goal of these efforts is to generate an ideal long-term interface between the recording electrode and surrounding tissue. The goal of this study was to refine a method to electrochemically deposit surfactant-templated ordered poly(3,4-ethylenedioxythiophene) (PEDOT) films on the recording sites of standard 'Michigan' probes and to evaluate the efficacy of these modified sites in recording chronic neural activity. PEDOT-coated site performance was compared to control sites over a six-week evaluation period in terms of impedance spectroscopy, signal-to-noise ratio, number of viable unit potentials recorded and local field potential recordings. PEDOT sites were found to outperform control sites with respect to signal-to-noise ratio and number of viable unit potentials. The benefit of reduced initial impedance, however, was mitigated by the impedance contribution of typical silicon electrode encapsulation. Coating sites with PEDOT also reduced the amount of low-frequency drift evident in local field potential recordings. These findings indicate that electrode sites electrochemically deposited with PEDOT films are suitable for recording neural activity in vivo for extended periods. This study also provided a unique opportunity to monitor how neural recording characteristics develop over the six weeks following implantation.

Action Potentials↗