Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 53
Filter
Add more filters

Publication year range
1.
Xenotransplantation ; 22(6): 476-86, 2015.
Article in English | MEDLINE | ID: mdl-26602493

ABSTRACT

INTRODUCTION: Research into the transplantation of solid organs from animals (xenotransplantation) is generating interest and curiosity given that this could be a way of resolving the shortage in transplant organs. However, the fact is that currently xenotransplantation is far from becoming a clinical practice. OBJECTIVE: To analyse the attitude of medical students from Spanish universities towards the donation of organs from animals and to determine the factors affecting their attitudes. TYPE OF STUDY: A sociological, interdisciplinary, observational and multicentre study in Spain. STUDY POPULATION: Students enrolled on the medical degree in Spain (n = 34 000). SAMPLE SIZE: A sample of 9598 students (a confidence level of 99% and precision of ± 1%) stratified by geographical area and academic year. Instrument of measurement: A validated questionnaire of attitude towards organ xenotransplantation (PCID-XenoTx RIOS) which was self-administered and completed anonymously. RESULTS: A completion rate of 95.7% (n = 9275) was obtained. If the results of xenotransplantation were as good as in human donation, 81% (n = 7491) would be in favour, 3% (n = 308) against and 16% (n = 1476) undecided. The following variables affected this attitude: sex (P < 0.001); academic year (P < 0.001); discussion of transplantation with one's family (P < 0.001) and friends (P < 0.001); the opinion of one's partner (P < 0.001); the respondent's attitude towards organ donation (P < 0.001); religion (P < 0.001); and participation in altruistic activities (P < 0.001). The following variables persisted in the multivariate analysis: (1) being a female (OR = 1.794; P < 0.001); (2) academic year (OR = 2.487; P < 0.001); (3) having spoken about the issue with one's family (OR = 1.200; P = 0.019); (4) the favourable opinion of one's partner (OR = 1.526; P = 0.028); (5) an attitude in favour of donation (OR = 2.087; P < 0.001); (6) being an atheist/agnostic, (OR = 2.5; P < 0.001); and (7) a belief that one's religion is in favour of transplantation (OR = 1.317; P = 0.005). CONCLUSIONS: Spanish medical students have a favourable attitude towards xenotransplantation. This willingness and interest could be a decisive platform for the development and strengthening of research, both for centres with a pre-clinical xenotransplantation programme and new healthcare centres.


Subject(s)
Attitude , Living Donors , Students, Medical/psychology , Surveys and Questionnaires , Tissue and Organ Procurement , Transplantation, Heterologous/statistics & numerical data , Humans , Schools, Medical/statistics & numerical data , Spain , Tissue and Organ Procurement/methods
2.
Clin Auton Res ; 25(4): 225-32, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26001693

ABSTRACT

BACKGROUND: Cardiac autonomic tone after long-term continuous positive airway pressure therapy in patients with obstructive sleep apnea remains unexplored. METHODS: Thirty patients with obstructive sleep apnea (14 with moderate and 16 with severe obstructive sleep apnea) were studied during a baseline polysomnographic study, after a full night of acute continuous positive airway pressure treatment, and after long-term (~2 years) chronic continuous positive airway pressure therapy. Twenty age- and gender-matched controls with baseline sleep study were selected for comparison purposes. Cross-spectral analysis and the low-frequency (LF) and high-frequency (HF) components of the heart rate variability were computed separately over 10-min ECG epochs during rapid eye movement sleep, non-rapid eye movement sleep, and wakefulness. RESULTS: During the baseline study, obstructive sleep apnea patients exhibited increased LF, decreased HF, and increased LF/HF ratio during sleep when compared to controls. In a multiple regression model, the mean oxygen saturation explained the increased LF during rapid and non-rapid eye movement sleep in obstructive sleep apnea patients. Acute continuous positive airway pressure therapy decreased the LF modulations and the LF/HF ratio and increased the HF modulations during sleep in patients with severe obstructive sleep apnea. Long-term continuous positive airway pressure therapy decreased LF modulations and LF/HF ratio with increased HF modulations during sleep in patients with moderate and severe obstructive sleep apnea. CONCLUSIONS: Long-term continuous positive airway pressure reduces the sympathovagal imbalance in patients with moderate and severe obstructive sleep apnea, both during rapid and non-rapid eye movement sleep. Continuous positive airway pressure seems to exert its changes in cardiac autonomic modulation by decreasing the burden of nocturnal hypoxia.


Subject(s)
Blood Pressure/physiology , Continuous Positive Airway Pressure/trends , Heart Rate/physiology , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/therapy , Sleep Stages/physiology , Adult , Aged , Autonomic Nervous System/physiology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Polysomnography/trends , Prospective Studies , Sleep Apnea, Obstructive/physiopathology , Time Factors , Treatment Outcome
3.
Clin Auton Res ; 25(1): 69-75, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25739474

ABSTRACT

OBJECTIVE: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia frequently affecting patients with synucleinopathies, but its exact prevalence in multiple system atrophy (MSA) is unclear. Whether questionnaires alone are sufficient to diagnose RBD is also unknown. METHODS: We performed a cross-sectional study of patients with probable MSA from six academic centers in the US and Europe. RBD was ascertained clinically and with polysomnography; we also performed a meta-analysis according to PRISMA guidelines for studies published before September 2014 that reported the prevalence of RBD in MSA. A random-effects model was constructed using weighted prevalence proportions. Only articles in English were included. Studies were classified into those that ascertained the presence of RBD in MSA clinically and with polysomnography. Case reports or case series (≤ 5 patients) were not included. RESULTS: Forty-two patients completed questionnaires and underwent polysomnography. Of those, 32 (76.1%) had clinically suspected RBD and 34 (81%) had polysomnography-confirmed RBD. Two patients reported no symptoms of RBD but had polysomnography-confirmed RBD. The primary search strategy yielded 374 articles of which 12 met the inclusion criteria. The summary prevalence of clinically suspected RBD was 73% (95 % CI, 62-84%) in a combined sample of 324 MSA patients. The summary prevalence of polysomnography-confirmed RBD was 88 % (95% CI, 79-94%) in a combined sample of 217 MSA patients. INTERPRETATION: Polysomnography-confirmed RBD is present in up to 88% of patients with MSA. RBD was present in some patients that reported no symptoms. More than half of MSA patients report symptoms of RBD before the onset of motor deficits.


Subject(s)
Multiple System Atrophy/complications , REM Sleep Behavior Disorder/diagnosis , REM Sleep Behavior Disorder/epidemiology , Aged , Cross-Sectional Studies , Europe , Female , Humans , Male , Middle Aged , Polysomnography , Prevalence , Prospective Studies , United States
4.
J Neural Transm (Vienna) ; 121(4): 385-90, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24241956

ABSTRACT

The relationship between the autonomic nervous system and periodic leg movements during sleep (PLMS) is not completely understood. We aimed to determine whether patients with PLMS exhibit any changes in their basal heart rate variability (HRV), excluding episodes of leg movements and arousals. To investigate this, we conducted a cross-sectional study including 13 patients with PLMS (PLMS ≥ 20) and 13 matched controls, free of cardiovascular diseases and medications. Time-and frequency-domain HRV measures [mean R-R interval, low frequency (LF), high frequency (HF), LF/HF] were calculated across all sleep stages as well during wakefulness just before and after sleep during one-night polysomnography. We only took ECG segments of sleep without arousals and excluded periods of 30 s before and after the leg movements. No statistical differences between PLMS and control subjects were found in any of the time- or frequency-domain HRV measures across sleep stages. Basal cardiac autonomic modulation in patients with PLMS is similar to that of control subjects. Our results argue against a role for a basal disturbance of the cardiac autonomic nervous system in the pathogenesis of PLMS.


Subject(s)
Autonomic Nervous System/physiology , Heart Rate/physiology , Nocturnal Myoclonus Syndrome/physiopathology , Adult , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , Polysomnography
5.
J Neurosci ; 30(19): 6667-77, 2010 May 12.
Article in English | MEDLINE | ID: mdl-20463229

ABSTRACT

In Parkinson's disease (PD), the oscillatory activity recorded from the basal ganglia shows dopamine-dependent changes. In the "off" parkinsonian motor state, there is prominent activity in the beta band (12-30 Hz) that is mostly attenuated after dopaminergic therapy ("on" medication state). The on state is also characterized by activity in the gamma (60-80 Hz) and high-frequency (300 Hz) bands that is modulated by movement. We recorded local field potentials from a group of 15 PD patients (three females) treated with bilateral deep brain stimulation of the subthalamic nucleus, using a high sampling rate (2 kHz) and filters suitable to study high-frequency activity (0.3-1000 Hz). We observed high-frequency oscillations (HFOs) in both the off and on motor states. In the off state, the amplitude of the HFOs was coupled to the phase of the abnormal beta activity. The beta-coupled HFOs showed little or even negative movement-related changes in amplitude. Moreover, the degree of movement-related modulation of the HFOs correlated negatively with the rigidity/bradykinesia scores. In the on motor state, the HFOs were liberated from this beta coupling, and they displayed marked movement-related amplitude modulation. Cross-frequency interactions between the phase of slow activities and the amplitude of fast frequencies have been attributed an important role in information processing in cortical structures. Our findings suggest that nonlinear coupling between frequencies may not only be a physiological mechanism (as shown previously) but also that it may participate in the pathophysiology of parkinsonism.


Subject(s)
Beta Rhythm , Parkinson Disease/physiopathology , Periodicity , Subthalamic Nucleus/physiopathology , Aged , Deep Brain Stimulation , Electrodes, Implanted , Female , Humans , Hypokinesia/physiopathology , Hypokinesia/therapy , Male , Middle Aged , Movement/physiology , Parkinson Disease/therapy , Regression Analysis , Rest , Severity of Illness Index
6.
Sleep Breath ; 15(2): 229-35, 2011 May.
Article in English | MEDLINE | ID: mdl-20886300

ABSTRACT

PURPOSE: Catathrenia (nocturnal groaning) is a rare and relatively little-understood parasomnia. The characteristics of the sound and the recordings are not similar in all the relevant research papers. Indeed, there is currently some discussion regarding whether or not this is a single entity. For some authors, catathrenia is a particular form of parasomnia; for others, it may be a variant of snoring or a respiratory problem. The goal is to establish whether or not catathrenia may be regarded as an expiratory vocal sound. An attempt was made to classify the origin of this sound according to its sound structure. METHODS: We present the sound analysis of two patients, a man and a woman, with clinically diagnosed catathrenia and we compared them with the analysis of snoring. We use the spectrogram and the oscillogram. We classified the sounds according to the Yanagihara criteria. RESULTS: The vocal nature of the sound was confirmed, and several significant differences to some snoring sounds were discovered. The analysis of the catathrenia samples demonstrated that these signals are type II according to Yanagihara classification; these signals had a very short jitter, and had formants and harmonics. However, snoring is a type III, very irregular and had formants but not harmonics. CONCLUSIONS: The oscillogram and the spectrogram in these patients show that the origins of the sounds are clearly different: catathrenia is laryngeal, while snoring is guttural. Catathrenia cannot be considered as expiratory snoring.


Subject(s)
Oscillometry , Parasomnias/physiopathology , Respiratory Sounds/physiopathology , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/physiopathology , Sound Spectrography , Aged , Female , Humans , Larynx/physiopathology , Male , Middle Aged , Parasomnias/diagnosis , Polysomnography , Sleep Stages
7.
Transplant Proc ; 52(5): 1428-1431, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32252996

ABSTRACT

The knowledge acquired during university education about organ donation and transplantation (ODT) decisively influences the information future health professionals transmit. This is important in ODT where the participation of the general public is essential to obtain organs. OBJECTIVE: To determine notions of Spanish medicine and nursing students on ODT and its relationship with attitude toward ODT. METHODS AND DESIGN: and design. We conducted a sociologic, multicenter, and observational study. The population for our study consisted of medical and nursing students in Spanish universities. Our database was the Collaborative International Donor Project, stratified by geographic area and academic course. A validated questionnaire (PCID-DTO-RIOS) was self-administered and completed anonymously. Our sample consisted of 9598 medical and 10,566 nursing students (99% confidence interval; precision of ±1%), stratified by geographic area and year of study. RESULTS: The completion rate for our study was 90%. Only 20% (n=3640) of students thought their notions on ODT were good; 41% (n=7531) thought their notions were normal; 36% (n=6550) thought their notions were scarce. Comparing groups, there were differences between those who believed that their notions on ODT were good (44% nursing vs 56% medical students; P < .000), and those who believed it scarce (54% nursing vs 46% medical students; P < .000). Notions on ODT were related with attitude toward the donation of one's own organs: those who considered their notions were good were more in favor then those who considered it scarce (88% vs 72%; P < .000). CONCLUSION: Only 20% of Spanish medical and nursing students thought their notions on ODT were good. Having good knowledge is related to a favorable attitude towards ODT. Receiving specific information on the subject could improve their knowledge about ODT during their training.


Subject(s)
Health Knowledge, Attitudes, Practice , Organ Transplantation/psychology , Students, Medical/psychology , Students, Nursing/psychology , Tissue and Organ Procurement , Adult , Female , Humans , Male , Spain
8.
Transplant Proc ; 52(2): 491-495, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32061423

ABSTRACT

A primary care physician (PCP) not only accompanies the patient in the process of an illness, but throughout his or her life. The confidence we have in these health professionals is fundamental, and their favorable attitude toward organ donation and transplantation (ODT) has a significant influence on the population. OBJECTIVE: To analyze trust in PCPs among Spanish medical and nursing students, the relationship with their attitude toward ODT, and the factors that condition it. METHODS AND DESIGN: A sociologic, multicenter, and observational study. POPULATION: medical and nursing students in Spanish universities. DATABASE: Collaborative International Donor Project, stratified by geographic area and academic course. A validated questionnaire (PCID-DTO-RIOS) was self-administered and completed anonymously. A sample of 9598 medical and 10,566 nursing students (99% confidence and precision of ±1%), stratified by geographic area and year of study. RESULTS: Completion rate: 90%. With respect to students' trust in their physician, 18% (n = 3267) of them totally trust (completely), 45% (n = 8101) trust enough, 30% (n = 5478) of them have not enough trust, and 7% not at all. Comparing groups, medical students totally trust more in PCPs than nursing students (55% vs 45%; P < .000), however, nursing students have less than enough trust in their PCP than medical students (53% vs 47%; P < .000). Students that totally trust in their PCP were more in favor toward ODT than students with not enough trust (83% vs 77%; P < .000). CONCLUSION: Only 18% of Spanish medical and nursing students totally trust in their PCP. Attitude toward ODT is related to a higher level of trust in PCPs among these students.


Subject(s)
Health Knowledge, Attitudes, Practice , Organ Transplantation/psychology , Physicians, Primary Care , Tissue and Organ Procurement , Trust , Adult , Female , Humans , Male , Social Behavior , Spain , Students, Medical/psychology , Students, Nursing/psychology , Surveys and Questionnaires
9.
Transplant Proc ; 52(2): 439-442, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32029316

ABSTRACT

INTRODUCTION: Information provided by health care professionals is crucial to create a climate of social opinion. This is important in organ donation and transplantation (ODT), where the participation of the general public is essential to obtain organs. OBJECTIVE: To determine the attitude toward the Law of Presumed Consent (LPC) among Spanish university students and to analyze their relation with attitude toward ODT. METHODS: and design. The type of study was a sociologic, multicenter, observational study. The population included medical and nursing students in Spanish universities. Database of Collaborative International Donor Project was used stratified by geographic area and academic course. A validated questionnaire (Collaborative International Donor Project, organ donation and transplantation questionnaire in Spanish [PCID-DTO-RIOS]) was self-administered and completed anonymously. A sample of 9598 medical and 10,566 nursing students was analyzed (99% confidence and precision of ±1%) and stratified by geographic area and year of study. RESULTS: Completion rate was 90%. Regarding attitude toward LPC, 66% of the students were against the law, whereas 34% accepted it. Of the students surveyed, 9% considered the law as a gesture of solidarity, 25% as an effective way of not wasting organs, 48% as an abuse of power, and 18% as offenses against the family. Those students who were in favor of LPC also had a more favorable attitude toward ODT (86% vs 76%; P < .001). Comparing groups, nursing students were less in favor of LPC than medical students (32% vs 36%; P < .000). CONCLUSION: Sixty-six percent of Spanish university medical and nursing students were against the LPC. The favorable attitude toward ODT is associated with considering the law as a gesture of solidarity or as an effective way of not wasting organs.


Subject(s)
Health Knowledge, Attitudes, Practice , Organ Transplantation/legislation & jurisprudence , Presumed Consent , Tissue and Organ Procurement/legislation & jurisprudence , Adult , Female , Humans , Male , Students, Medical , Students, Nursing , Surveys and Questionnaires , Universities
10.
Mov Disord ; 24(2): 254-60, 2009 Jan 30.
Article in English | MEDLINE | ID: mdl-18951542

ABSTRACT

The recordings of local field potentials in the subthalamic nucleus in patients with Parkinson's disease (PD), carried out through the stimulators implanted to treat the motor symptoms of the disease, show a prominent basal ("off") activity in the beta range, which is attenuated after dopaminergic therapy. A recent study described improvement of parkinsonian features during rapid eyes movements (REM) sleep. We describe, for the first time, the changes in activity of the subthlamic nucleus (STN) during different sleep stages in Parkinson's disease with special interest in the beta band. Ten patients with PD treated with deep brain stimulation of the STN were studied. Subthalamic local field potentials (LFPs) were recorded through the stimulation electrodes during wakefulness ("off" medication) and different sleep stages. In Stage 2 and slow-wave sleep, a significant decrease of beta activity was recorded. During REM sleep, beta power values were similar to wakefulness values or even higher. These findings indicate that STN activity is modulated and modified during different sleep stages. The increased beta activity during REM sleep is a new but unexpected finding, which requires further analysis.


Subject(s)
Beta Rhythm , Deep Brain Stimulation , Parkinson Disease/physiopathology , Sleep Stages/physiology , Subthalamic Nucleus/physiopathology , Aged , Female , Humans , Male , Middle Aged , Parkinson Disease/therapy , Sleep, REM/physiology , Wakefulness/physiology
11.
Epilepsia ; 50(4): 928-32, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19055490

ABSTRACT

Cardiac changes may occasionally occur during vagus nerve stimulation (VNS) used in epileptic patients. As they can be potentially life-threatening, it is important to detect them, and this is why an intraoperative test is performed during the implantation. Few cases of asystole during this test have been described. Only one patient with late-onset bradyarrythmia caused by VNS has been reported. This patient had been implanted 2 years and 4 months before the episode. We present another case of late asystole in a patient whose VNS had been implanted 9 years before the arrhythmia onset. In our patient, each run of stimulation produced bradyarrhythmias and very often severe asystolia due to atrium-ventricular block.


Subject(s)
Heart Arrest/etiology , Vagus Nerve Stimulation/adverse effects , Electrocardiography/methods , Electroencephalography , Epilepsy/therapy , Female , Humans , Middle Aged
12.
J Clin Neurophysiol ; 25(1): 42-7, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18303559

ABSTRACT

The amplitude of the auditory amplitude-modulation following responses (AMFR) is variable, depending on the modulation rate. Although 40-Hz responses have higher amplitudes in adults, the AMFR in the 80- to 120-Hz range are less influenced by sleep and more consistent in children. The effect of attention on 40-Hz responses has been addressed in some studies; however, no study to our knowledge has investigated the effect of attention on other stimulation rates. Our aim was to test the effect of attention on the AMFR to different frequencies of stimulation, using a chirp-modulated tone as stimulus. We recorded chirp-evoked responses in 12 subjects while attending to the sound (first condition) and reading a novel (second condition), in a randomly determined sequence. The energy of the response and the intertrial coherence (ITC) were measured by means of time-frequency transforms. The frequency range of response was similar in both conditions. No significant differences were found in the ITC values in the 40-Hz and the 80- to 120-Hz ranges, nor in the energy of the 40-Hz response. The only statistically significant difference found was the lower energy of the response in the 80- to 120-Hz range in the reading condition. Our results suggest that attention may affect auditory steady-state clinical testing using amplitude values. Phase measures may be preferable in this context.


Subject(s)
Attention/physiology , Auditory Perception/physiology , Brain Mapping , Evoked Potentials, Auditory/physiology , Acoustic Stimulation , Adult , Electroencephalography , Female , Humans , Male
13.
Wien Klin Wochenschr ; 119(17-18): 538-43, 2007.
Article in English | MEDLINE | ID: mdl-17943406

ABSTRACT

During the period 2000-2003, patients hospitalized for suspected tick-borne encephalitis in the Czech Republic were screened for possible A. phagocytophilum co-infection. Blood samples taken at admission were tested for the presence of A. phagocytophilum DNA by nested PCR using a modified target sequence as an internal control, and sera were tested for the presence of antibodies by indirect immunofluorescence and western blotting methods using cell-culture-derived antigens. To verify the assay specificity, a set of 45 sera of Patagonian residents served as a non-tick-exposed control group, and a set of 14 B. henselae-positive sera was used to check cross-reactivity. Of 809 patients hospitalized, 80 (9.9%) showed IgG antibodies reactive to A. phagocytophilum at > or =80 (reciprocal dilution factor) and 50 (6.2%) at > or =160; two (0.2%) patients showed elevated IgM titers of 40. No full blood obtained from 162 patients tested positive in PCR when false negativity was excluded. During hospitalization, the diagnosis of tick-borne encephalitis was confirmed in 536 patients, 57 (10.6%) of whom had anti-A. phagocytophilum IgG antibodies reactive at > or =80 and 41 (7.6%) at > or =160, which did not differ significantly from the whole set (P = 0.66/0.30), the maximum IgG titer registered was 5120, and no IgM titer reached the 40 cut-off. Available paired sera from 189 tick-borne encephalitis patients showed no significant shifts, but one case of slight seroconversion (IgG shift from < 80 to 320) was detected in one of the non-tick-borne encephalitis patients. The sex of the patient showed no significance for the prevalence of A. phagocytophilum antibodies; however, the seropositive patients were older on average than those who were seronegative (43.5 +/- 15.9 vs. 37.9 +/- 18.3 years, P = 0.05). Clinical manifestation of the disease did not differ noticeably between patients with and without A. phagocytophilumreactive antibodies, except for fever duration, which was significantly longer in patients with titers > or =1280. Overall, A. phagocytophilum co-infection did not seem to be a frequent and/or significant complication of tick-borne encephalitis acquired in the Czech Republic.


Subject(s)
Anaplasma phagocytophilum , Ehrlichiosis/epidemiology , Encephalitis, Tick-Borne/epidemiology , Adolescent , Adult , Age Factors , Aged , Anaplasma phagocytophilum/genetics , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Blotting, Western , Case-Control Studies , Child , Child, Preschool , Cross Reactions , Czech Republic/epidemiology , DNA, Bacterial/analysis , Ehrlichiosis/complications , Ehrlichiosis/diagnosis , Ehrlichiosis/immunology , Encephalitis, Tick-Borne/complications , Encephalitis, Tick-Borne/diagnosis , Encephalitis, Tick-Borne/immunology , Fluorescent Antibody Technique, Indirect , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Middle Aged , Polymerase Chain Reaction
14.
PLoS One ; 12(9): e0184044, 2017.
Article in English | MEDLINE | ID: mdl-28922360

ABSTRACT

Idiopathic epilepsy is characterized by generalized seizures with no apparent cause. One of its main problems is the lack of biomarkers to monitor the evolution of patients. The only tools they can use are limited to inspecting the amount of seizures during previous periods of time and assessing the existence of interictal discharges. As a result, there is a need for improving the tools to assist the diagnosis and follow up of these patients. The goal of the present study is to compare and find a way to differentiate between two groups of patients suffering from idiopathic epilepsy, one group that could be followed-up by means of specific electroencephalographic (EEG) signatures (intercritical activity present), and another one that could not due to the absence of these markers. To do that, we analyzed the background EEG activity of each in the absence of seizures and epileptic intercritical activity. We used the Shannon spectral entropy (SSE) as a metric to discriminate between the two groups and performed permutation-based statistical tests to detect the set of frequencies that show significant differences. By constraining the spectral entropy estimation to the [6.25-12.89) Hz range, we detect statistical differences (at below 0.05 alpha-level) between both types of epileptic patients at all available recording channels. Interestingly, entropy values follow a trend that is inversely related to the elapsed time from the last seizure. Indeed, this trend shows asymptotical convergence to the SSE values measured in a group of healthy subjects, which present SSE values lower than any of the two groups of patients. All these results suggest that the SSE, measured in a specific range of frequencies, could serve to follow up the evolution of patients suffering from idiopathic epilepsy. Future studies remain to be conducted in order to assess the predictive value of this approach for the anticipation of seizures.


Subject(s)
Electroencephalography/methods , Electronic Data Processing/methods , Epilepsy/physiopathology , Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged
15.
J Clin Neurophysiol ; 23(1): 72-8, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16514354

ABSTRACT

Independent component analysis (ICA) is a novel system that finds independent sources in recorded signals. Its usefulness in separating epileptiform activity of different origin has not been determined. The goal of this study was to demonstrate that ICA is useful for separating different spikes using samples of EEG of patients with focal epilepsy. Digital EEG samples from four patients with focal epilepsy were included. The patients had temporal (n = 2), centrotemporal (n = 1) or frontal spikes (n = 1). Twenty-six samples with two (or more) spikes from two different patients were created. The selection of the two spikes for each mixed EEG was performed randomly, trying to have all the different combinations and rejecting the mixture of two spikes from the same patient. Two different examiners studied the EEGs using ICA with JADE paradigm in Matlab platform, trying to separate and to identify the spikes. They agreed in the correct separation of the spikes in 24 of the 26 samples, classifying the spikes as frontal, temporal or centrotemporal, left or right sided. The demonstration of the possibility of detecting different artificially mixed spikes confirms that ICA may be useful in separating spikes or other elements in real EEGs.


Subject(s)
Brain Mapping , Cerebral Cortex/physiopathology , Electroencephalography , Epilepsy/physiopathology , Principal Component Analysis , Adult , Artifacts , Epilepsy/classification , Humans
16.
J Clin Neurophysiol ; 23(3): 265-72, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16751728

ABSTRACT

SUMMARY: A small series of high-frequency wavelets overlapping the earliest part of the N20 wave (high-frequency oscillations, HFOs) can be observed in the somatosensory evoked potentials (SSEPs) of normal subjects after filtering then with a high-pass filter (>500 Hz). These HFOs have been related to interneuronal activity in the primary somatosensory cortex. In patients with cortical myoclonus there is a sensorimotor cortical hyperexcitability, expressed neurophysiologically as high-amplitude waves in the SSEPs (giant SSEPs). There have been contradicting reports in the literature on the changes in the HFOs in these patients. The authors studied HFOs in a group of 20 patients with cortical myoclonus of different origins and in a control group by means of time-frequency transforms, comparing the results obtained with the amplitude and latency of the classical SSEP waves. All controls had normal HFOs, with two components. Nine patients had no HFOs, nine patients had low-amplitude and/or delayed HFOs, and the remaining two patients, the only without ataxia, had high-amplitude HFOs with a long latency. These results suggest heterogeneity in the pathophysiology of cortical myoclonus, which might be related to the different systems affected.


Subject(s)
Evoked Potentials, Somatosensory/physiology , High-Frequency Ventilation , Myoclonus/physiopathology , Somatosensory Cortex/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Brain Mapping , Electric Stimulation/methods , Electroencephalography/methods , Female , Humans , Male , Reaction Time/physiology , Somatosensory Cortex/physiopathology , Time Factors
17.
J Clin Neurophysiol ; 23(6): 551-8, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17143142

ABSTRACT

Independent component analysis (ICA) is a novel technique that can separate statistically independent elements from complex signals. It has demonstrated its utility in separating artifacts and analyzing interictal discharges in EEG. ICA has been used recently in ictal recordings, showing the possibility of isolating the ictal activity. The goal of our study was to analyze focal seizures with ICA, decomposing the elements of the seizures to understand their genesis and propagation, and to differentiate between various types of focal seizures. We studied 26 focal seizures of temporal, frontal, or parietal origin. Only seizures with suspected focal onset were included in the study. The EEG recordings were acquired by using standard video-EEG equipment, with scalp electrodes. All the off-line analysis was carried out on a PC by means of specific software developed in the Matlab environment. ICA components were calculated with the use of the JADE (Joint Approximate Diagonalization of Eigen-matrices) algorithm. The decomposition of the seizures varied according to the EEG seizure pattern. In the seizures with focal rhythmic theta slow or sharp waves, the rhythmic activity was separated into one to five components, having an initial component with a clear concordance with the focus, whereas the others had an onset a few milliseconds later and corresponded to neighboring areas. In the 6 frontal seizures with regional rhythmic low voltage fast activity, 4 to 10 components were found, practically with a simultaneous timing, having a frontal distribution. In the three frontal seizures with a diffuse attenuation of the EEG signal, it was not possible to differentiate components of cerebral origin from the components of muscle artifact. ICA is an interesting tool to study the nature of focal seizures. The results depend on the EEG pattern. In the seizures with a clear EEG focal pattern, ICA may be useful to separate components of the ictal onset from the propagated activity.


Subject(s)
Brain Mapping , Electroencephalography , Principal Component Analysis , Seizures/physiopathology , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Epilepsy, Frontal Lobe/pathology , Epilepsy, Frontal Lobe/physiopathology , Epilepsy, Temporal Lobe/pathology , Epilepsy, Temporal Lobe/physiopathology , Functional Laterality , Humans , Magnetic Resonance Imaging/methods , Monitoring, Physiologic/methods , Seizures/pathology , Signal Processing, Computer-Assisted , Video Recording/methods
18.
Epileptic Disord ; 8(1): 70-2, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16567330

ABSTRACT

We present a case of laryngospasm in a 12-year-old male who experienced sudden, nocturnal episodes of breathing difficulties and agitation. Apart from laryngospasm, the main differential diagnoses included frontal seizures, sleep-related choking syndrome, sleep asthma, sleep apnoea and REM sleep behaviour disorder. The video and the EEG recordings supported the diagnosis of laryngospasm. The pH-metry confirmed the existence of reflux. Its treatment successfully controlled the episodes. This case illustrates, with a typical video recording, this infrequent type of paroxysmal event with an important differential diagnosis.[Published with video sequences].


Subject(s)
Laryngismus/diagnosis , Polysomnography/methods , Sleep Wake Disorders/diagnosis , Child , Diagnosis, Differential , Electroencephalography , Humans , Male , Video Recording
19.
Nat Sci Sleep ; 8: 21-33, 2016.
Article in English | MEDLINE | ID: mdl-26834500

ABSTRACT

Sleep and circadian disorders in Alzheimer's disease (AD) are more frequent than in the general population and appear early in the course of the disease. Quality of sleep and quality of life are parallel in these patients, and such disorders also represent a heavy burden for caregivers. Although alterations in melatonin and hypocretins (orexins) seem to play a key role in the origin of these disturbances, the etiology of these disorders is multifactorial, including many factors such as environment, behavior, treatments, and comorbidities, among others. A comprehensive evaluation of sleep in each patient is essential in the design of the treatment that includes nonpharmacological and pharmacological approaches. One particularly interesting point is the possibility of a role of sleep disorders in the pathogenesis of AD, raising the possibility that treating the sleep disorder may alter the course of the disease. In this review, we present an update on the role of sleep disorders in AD, the bidirectional influence of sleep problems and AD, and treatment options. Behavioral measures, bright light therapy (BLT), melatonin, and other drugs are likely well known and correctly managed by the physicians in charge of these patients. In spite of the multiple treatments used, evidence of efficacy is scarce and more randomized double-blind placebo-controlled studies are needed. Future directions for treatment are the establishment of BLT protocols and the development of drugs with new mechanisms of action, especially hypocretin receptor antagonists, melatonin receptor agonists, and molecules that modulate the circadian clock.

20.
World J Gastroenterol ; 22(25): 5800-13, 2016 Jul 07.
Article in English | MEDLINE | ID: mdl-27433093

ABSTRACT

AIM: To analyze the attitude of Spanish medical students toward living liver donation (LLD) and to establish which factors have an influence on this attitude. STUDY TYPE: A sociological, interdisciplinary, multicenter and observational study. STUDY POPULATION: Medical students enrolled in Spain (n = 34000) in the university academic year 2010-2011. SAMPLE SIZE: A sample of 9598 students stratified by geographical area and academic year. Instrument used to measure attitude: A validated questionnaire (PCID-DVH RIOS) was self-administered and completed anonymously. Data collection procedure: Randomly selected medical schools. The questionnaire was applied to each academic year at compulsory sessions. STATISTICAL ANALYSIS: Student´s t test, χ(2) test and logistic regression analysis. RESULTS: The completion rate was 95.7% (n = 9275). 89% (n = 8258) were in favor of related LLD, and 32% (n = 2937) supported unrelated LLD. The following variables were associated with having a more favorable attitude: (1) age (P = 0.008); (2) sex (P < 0.001); (3) academic year (P < 0.001); (4) geographical area (P = 0.013); (5) believing in the possibility of needing a transplant oneself in the future (P < 0.001); (6) attitude toward deceased donation (P < 0.001); (7) attitude toward living kidney donation (P < 0.001); (8) acceptance of a donated liver segment from a family member if one were needed (P < 0.001); (9) having discussed the subject with one's family (P < 0.001) and friends (P < 0.001); (10) a partner's opinion about the subject (P < 0.001); (11) carrying out activities of an altruistic nature; and (12) fear of the possible mutilation of the body after donation (P < 0.001). CONCLUSION: Spanish medical students have a favorable attitude toward LLD.


Subject(s)
Attitude of Health Personnel , Liver Transplantation , Living Donors , Students, Medical , Adolescent , Adult , Age Factors , Altruism , Female , Humans , Kidney Transplantation , Logistic Models , Male , Sex Factors , Spain , Surveys and Questionnaires , Tissue and Organ Procurement , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL