Nuestros investigadores

Elena Urrestarazu Bolumburu

Líneas de investigación
Trastornos del sueño, Epilepsia, Neurofisiología Clínica, Análisis de señales
Índice H
15, (WoS, 03/03/2018)
19, (Google Scholar, 07/03/2018)

Publicaciones científicas más recientes (desde 2010)

Autores: Baptista, Peter Michael, (Autor de correspondencia); Álvarez, Laura; et al.
Revista: ACTA OTORRINOLARINGOLOGICA ESPAÑOLA
ISSN 0001-6519  Vol. 69  Nº 1  2018  págs. 42 - 47
The objective of this communication is to describe our preliminary results in upper airway stimulation surgery via hypoglossal nerve stimulation implantation for obstructive sleep apnoea. We describe 4 cases and the outcomes of the surgery were analysed using the Epworth scale, apnoea-hypopnoea index, minimal 02 Sat, average 02 Sat and snoring intensity. In all cases a significant reduction in Epworth scale values and apnoea-hypopnoea index were obtained (P<.05). The minimum and average oxygen saturation had better values after the surgery, however, there was no statistically significant difference. The snoring severity measured subjectively changed from "intense" to "absent", in all cases. The preliminary results obtained with the upper airway stimulation surgery via hypoglossal nerve stimulation showed objective and subjective improvement after the implant activation. (C) 2017 Elsevier Espana, S.L.U. and Sociedad Espanola de Otorrinolaringologia y Cirugia de Cabeza y Cuello. All rights reserved.
Autores: Urrestarazu, Elena; Iriarte, Jorge;
Revista: NATURE AND SCIENCE OF SLEEP
ISSN 1179-1608  Vol. 8  2016  págs. 21-33
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 mec
Autores: Iriarte, Jorge; Campo, Arantza; Alegre, Manuel; et al.
Revista: SLEEP MEDICINE
ISSN 1389-9457  Vol. 16  Nº 7  2015  págs. 827 - 830
Background The International Classification of Sleep Disorders ¿ Third Edition (ICSD-3) classifies catathrenia among the respiratory disorders and not as a parasomnia as in ICSD-2. Few patients have been reported during these years, and the clinical description of the sound is different from group to group. In fact, there is no full agreement about its nature, origin, meaning, and treatment. Methods and results In this paper we review the literature on catathrenia focusing on the characteristics of the sound, demographics of the patients, aetiology, response to treatment, etc., in order to support its classification as a respiratory disorder or a parasomnia. We also discuss the possibility of Catathrenia being not one disorder but two variants or two different disorders.
Autores: Iriarte, Jorge; Fernández, Secundino; et al.
Revista: CLINICAL AUTONOMIC RESEARCH
ISSN 0959-9851  Vol. 25  Nº 4  2015  págs. 225 - 232
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.
Autores: Iriarte, Jorge, (Autor de correspondencia); Fernández, Secundino; et al.
Revista: CLINICAL NEUROPHYSIOLOGY
ISSN 1388-2457  Vol. 125  Nº 9  2014  págs. 1783 - 1791
OBJECTIVE: The pathophysiological basis of obstructive sleep apnea (OSA) is not completely understood and likely varies among patients. In this regard, some patients with OSA do not exhibit hypoxemia. We aimed to analyze the clinical, sleep, and autonomic features of a group of patients with severe OSA without hypoxia (OSA-h) and compare to OSA patients with hypoxia (OSA+h) and controls. METHODS: Fifty-six patients with OSA-h, 64 patients with OSA+h, and 44 control subjects were studied. Clinical and sleep features were analyzed. Besides, time- and frequency-domain heart rate variability (HRV) measures comprising the mean R-R interval, the standard deviation of the RR intervals (SDNN), the low frequency (LF) oscillations, the high frequency (HF) oscillations, and the LF/HF ratio, were calculated across sleep stages during a one-night polysomnography. RESULTS: OSA-h patients had a lower body mass index, a lower waist circumference, lower apnea duration, and a higher frequency of previous naso-pharyngeal surgery when compared to OSA+h patients. In terms of heart rate variability, OSA+h had increased LF oscillations (i.e., baroreflex function) during N1-N2 and rapid eye movement (REM) sleep when compared to OSA-h and controls. Both OSA+h and OSA-h groups had decreased HF oscillations (i.e., vagal inputs) during N1-N2, N3 and REM sleep when compared to controls. The LF/HF ratio was increased during N1-N2 and REM sleep, only in patients with OSA+h. CONCLUSIONS: Patients with OSA-h exhibit distinctive clinical, sleep, and autonomic features when compared to OSA with hypoxia. SIGNIFICANCE: OSA is a heterogeneous entity. These differences must be taken into account in future studies when analyzing therapeutic approaches for sleep apnea patients.
Autores: Alegre, Manuel; Valencia, Miguel; et al.
Revista: JOURNAL OF NEURAL TRANSMISSION
Vol. 121  Nº 4  2014  págs. 385 - 390
Autores: Iriarte, Jorge; Alegre, Manuel; et al.
Revista: CLINICAL NEUROPHYSIOLOGY
ISSN 1388-2457  Vol. 125  Nº 1  2014  págs. 208 - 210
Autores: Iriarte, Jorge; Alegre, Manuel; et al.
Revista: CLINICAL NEUROPHYSIOLOGY
ISSN 1388-2457  Vol. 125  Nº 1  2014  págs. 208-210
Autores: Iriarte, Jorge; Alegre, Manuel; et al.
Revista: CLINICAL NEUROPHYSIOLOGY: OFFICIAL JOURNAL OF THE INTERNATIONAL FEDERATION OF CLINICAL NEUROPHYSIOLOGY
ISSN 1872-8952  Vol. 125  Nº 1  2014  págs. 208 - 210
Autores: Pascual, Eider; Pérez-Pevida, Belén; et al.
Revista: ENDOCRINOLOGIA Y NUTRICION
ISSN 1575-0922  Vol. 61  2014  págs. 112
Autores: Urrestarazu, Elena; Iriarte, Jorge;
Revista: SLEEP MEDICINE
ISSN 1389-9457  Vol. 14  Nº 3  2013  págs. 229-236
Sleep loss refers to sleep of shorter duration than the average baseline need of seven to eight hours per night. Sleep loss and sleep deprivation have severe effects on human health. In this article, we review the main aspects of sleep loss, taking into account its effects on the central nervous system. The neurocognitive and behavioral effects of sleep loss are well known. However, there is an increasing amount of research pointing to sleep deprivation as a risk factor for neurologic diseases, namely stroke, multiple sclerosis, Alzheimer's disease, headache, epilepsy, pain, and somnambulism. Conversely, sleep loss has been reported to be a potential protective factor against Parkinson's disease. The pathophysiology involved in this relationship is multiple, comprising immune, neuroendocrine, autonomic, and vascular mechanisms. It is extremely important to identify the individuals at risk, since recognition and adequate treatment of their sleep problems may reduce the risk of certain neurologic disorders.
Autores: Sánchez-Carpintero, Rocío; Patiño-Garcia, Ana; Urrestarazu, Elena;
Revista: DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY
ISSN 0012-1622  Vol. 55  Nº 7  2013  págs. 668-670
Dravet syndrome is an epileptic encephalopathy characterized by multiple types of seizures. We report the first case of musicogenic reflex seizures in a 7-year-old male with a mutation in the SCN1A gene causing Dravet syndrome. Reflex seizures have been reported in patients with Dravet syndrome provoked by body temperature elevation, looking at visual patterns, or under intermittent photic stimulation. The case we report widens the spectrum of reflex seizures recorded in patients with Dravet syndrome. Cortical hyperexcitability of genetic origin could explain the tendency of these patients to experience reflex seizures.
Autores:  et al.
Título: Obstructive
Revista: JOURNAL OF CLINICAL SLEEP MEDICINE
ISSN 1550-9389  Vol. 9  Nº 11  2013  págs. 1165-71
Morbid obesity is frequently associated with abnormal LVM, particularly in patients with OSA; this association is independent of HT, BMI, body composition, and other clinical factors, supporting a direct role of OSA on LVM in morbid obesity. This suggests that OSA and LVM might be taken as predictors of the cardiovascular risk in these patients.
Autores: Urrestarazu, Elena; López, Jon; et al.
Revista: SLEEP
ISSN 0161-8105  Vol. 36  Nº 6  2013  págs. 933 - 940
OBJECTIVE: To assess autonomic function by heart rate variability (HRV) during sleep in patients with sleep related alveolar hypoventilation (SRAH) and to compare it with that of patients with obstructive sleep apnea (OSA) and control patients. DESIGN: Cross-sectional study. SETTING: Sleep Unit, University Hospital of University of Navarra. PATIENTS: Fifteen idiopathic and obesity related-SRAH patients were studied. For each patient with SRAH, a patient with OSA, matched in age, sex, body mass index (BMI), minimal oxygen saturation (SatO2), and mean SatO2 was selected. Control patients were also matched in age, sex, and BMI with patients with OSA and those with SRAH, and in apnea/hypopnea index (AHI) with patients with SRAH. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Time- and frequency-domain HRV measures (R-R, standard deviation of normal-to-normal RR interval [SDNN], very low frequency [VLF], low frequency [LF], high frequency [HF], LF/HF ratio) were calculated across all sleep stages as well as during wakefulness just before and after sleep during a 1-night polysomnography. In patients with SRAH and OSA, LF was increased during rapid eye movement (REM) when compared with control patients, whereas HF was decreased during REM and N1-N2 sleep stages. The LF/HF ratio was equally increased in patients with SRAH and OSA during REM and N1-N2. Correlation analysis showed that LF and HF values during REM sleep were correlated with minimal SatO2 and mean SatO2. CONCLUSIONS: Patients with SRAH exhibited an abnormal cardiac tone during sleep. This fact appears to be related to the severity of nocturnal oxygen desaturation. Moreover, there were no differences between OSA and SRAH, supporting the hypothesis that autonomic changes in OSA are primarily related to a reduced nocturnal oxygen saturation, rather than a consequence of other factors such as nocturnal respiratory events.
Autores: Urrestarazu, Elena; Alegre, Manuel; et al.
Revista: CLINICAL NEUROPHYSIOLOGY
ISSN 1388-2457  Vol. 124  Nº 6  2013  págs. 1163 - 1168
OBJECTIVE: Cardiac physiology during sleep in Parkinson's disease (PD) remains poorly explored. We studied heart rate variability (HRV) across sleep stages in PD patients and correlated the results with clinical features. METHODS: Cross-sectional study comprising 33 patients with PD and 29 controls matched for age, gender, and number of apneas/hypopneas per hour. HRV measures, (mean R-R interval, SDNN, ULF, VLF, LF, HF and LF/HF) were calculated separately for all sleep stages as well as wakefulness just before and after sleep during one-night polysomnography. Correlation analysis was performed between HRV values and PD patients' characteristics. RESULTS: The mean R-R interval was lower in all sleep stages in PD patients when compared with controls. VLF and LF were lower during REM sleep in PD patients. HF during N1-N2 stage was higher in PD. We found inverse correlations between VLF and LF during REM sleep and UPDRS-ON and UPDRS-OFF. CONCLUSION: VLF and LF during REM sleep might constitute surrogate markers of disease severity. SIGNIFICANCE: These findings provide additional clinical evidence of the autonomic impairment commonly observed in PD, and prove that cardiac autonomic dysfunction during REM sleep is correlated with disease severity.
Autores: Urrestarazu, Elena; Iriarte, Jorge;
Revista: SLEEP MEDICINE
ISSN 1389-9457  Vol. 14  Nº 3  2013  págs. 229-36
Sleep loss refers to sleep of shorter duration than the average baseline need of seven to eight hours per night. Sleep loss and sleep deprivation have severe effects on human health. In this article, we review the main aspects of sleep loss, taking into account its effects on the central nervous system. The neurocognitive and behavioral effects of sleep loss are well known. However, there is an increasing amount of research pointing to sleep deprivation as a risk factor for neurologic diseases, namely stroke, multiple sclerosis, Alzheimer's disease, headache, epilepsy, pain, and somnambulism. Conversely, sleep loss has been reported to be a potential protective factor against Parkinson's disease. The pathophysiology involved in this relationship is multiple, comprising immune, neuroendocrine, autonomic, and vascular mechanisms. It is extremely important to identify the individuals at risk, since recognition and adequate treatment of their sleep problems may reduce the risk of certain neurologic disorders
Autores: Iriarte, Jorge; Fernández, Secundino; et al.
Revista: SLEEP MEDICINE
ISSN 1389-9457  Vol. 14  Nº 2  2013  págs. 217 - 219
Objectives This is a video case report of a 58-year-old male patient with severe obstructive sleep apnea (OSA) who underwent a pharyngo-laryngoscopy during non-drug-induced sleep. Methods The pharyngo-laryngoscopy was performed transnasally during a 30-minute nap, in the afternoon, with a flexible endoscope in supine position. During the procedure, the patient was monitored with polysomnography. Results The patient slept for 20 minutes in supine position, reaching N2 sleep stage. During the sleep, 15 respiratory events (apneas or hypopneas) were recorded. The video-recording showed that, during apneas, the obstruction at the pharyngeal level was never complete, although the nasal sensor showed a total stop in the nasal airflow. Conclusions This case highlights that OSA could not be as obstructive as generally thought, at least during N2 sleep; moreover, it suggests that apneic episodes are not a totally passive and monomorphic phenomenon, but a rather complex event.
Autores: Urrestarazu, Elena; et al.
Revista: SEIZURE-EUROPEAN JOURNAL OF EPILEPSY
ISSN 1059-1311  Vol. 22  Nº 1  2013  págs. 20-23
Purpose: To evaluate evolution and elucidate clinical phenotypes related to prognosis of patients with mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) treated exclusively with antiepileptic drugs (AED). Methods: Forty-seven out of 68 MTLE-HS patients treated between January 2005 and June 2010 were retrospectively studied for demographic, clinical and outcome data. The population was divided into drug-responder and drug-resistant patients; the latter was divided, according to the duration of the seizure-free periods along their evolution, into patients with at least one seizure-free period longer than one year and those with shorter periods. Variables were compared between drug-responders vs drug-resistants and drug-resistants with long seizure-free periods vs drug-resistants without it. Results: There were 7 (15%) drug-responders, 39 (83%) drug-resistants and 1 patient (2%) with an undetermined response. Eighteen (46%) drug-resistant individuals had seizure-free periods longer than one year, with mean duration of 46 months (3.8 years). Since no factor was statistically associated with long seizure-free period within drug-resistants, we can clinically distinguish two phenotypes: women with left HS and late onset of seizures, with poor prognosis, and men with right HS and earlier appearance of seizures, attaining a better outcome. Twenty out of 47 (42.5%) patients followed an intermittent pattern of epilepsy. Conclusions: Non-surgical MTLE-HS drug-resistant patients can achieve long seizure-free periods with AED, but relapses are common. Female gender, left or bilateral lesion and later onset of seizures seem to be bad prognosis factors within MTLE-HS drug-resistant patients. (C) 2012 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.
Autores: Jesús; Iriarte, Jorge; et al.
Revista: SCIENTOMETRICS
ISSN 0138-9130  Vol. 95  Nº 3  2013  págs. 941-952
During the period 2000¿2009 there was a significant increase in Clinical Neurology publications. Most of the publications and citations comprised 14 countries, with the USA in the first position. Interestingly, most of the publications and citations originated from only 14 countries, with European countries with relatively low population, such as Switzerland, Austria, Sweden, Belgium, and the Netherlands, in this top group.
Autores: Pascual, Eider; et al.
Revista: ENDOCRINOLOGIA Y NUTRICION
ISSN 1575-0922  Vol. 60  2013  págs. 91
Autores: Kufoy, E.; López, Jon; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 7  Nº 3  2012  págs. e33769
Introduction: Obstructive Sleep Apnea (OSA) is a major risk factor for cardiovascular disease. The goal of this study was to demonstrate whether the use of CPAP produces significant changes in the heart rate or in the heart rate variability of patients with OSA in the first night of treatment and whether gender and obesity play a role in these differences. Methods: Single-center transversal study including patients with severe OSA corrected with CPAP. Only patients with total correction after CPAP were included. Patients underwent two sleep studies on consecutive nights: the first night a basal study, and the second with CPAP. We also analyzed the heart rate changes and their relationship with CPAP treatment, sleep stages, sex and body mass index. Twenty-minute segments of the ECG were selected from the sleep periods of REM, no-REM and awake. Heart rate (HR) and heart rate variability (HRV) were studied by comparing the R-R interval in the different conditions. We also compared samples from the basal study and CPAP nights. Results: 39 patients (15 females, 24 males) were studied. The mean age was 50.67 years old, the mean AHI was 48.54, and mean body mass index was 33.41 kg/m(2) (31.83 males, 35.95 females). Our results showed that HRV (SDNN) decreased after the use of CPAP during the first night of treatment, especially in non-REM sleep. Gender and obesity did not have any influence on our results. Conclusions: These findings support that cardiac variability improves as an acute effect, independently of gender or weight, in the first night of CPAP use in severe OSA patients, supporting the idea of continuous use and emphasizing that noncompliance of CPAP treatment should be avoided even if it is just once.
Autores: Iriarte, Jorge; Fernández, Secundino; Fernández-Arrechea, Natalia; et al.
Revista: SLEEP AND BREATHING
ISSN 1520-9512  Vol. 15  Nº 2  2011  págs. 229 - 235
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.
Autores: Alegre, Manuel; Urrestarazu, Elena;
Revista: J CLIN NEUROPHYSIOL
ISSN 0736-0258  Vol. 122  Nº 8  2011  págs.  1480 - 1481
Autores: Sánchez-Carpintero, Rocío; Urrestarazu, Elena; Perea, D.A.; et al.
Revista: EPILEPSIA
ISSN 0013-9580  Vol. 52  Nº Supl.6  2011  págs. 4
Autores:  et al.
Revista: NEUROLOGIST
ISSN 1074-7931  Vol. 17  Nº 5  2010  págs. 273 -275