Polysomnographic parameters associated with cognitive function in patients with major depression and insomnia.

OBJECTIVE: To examine whether objective sleep parameters are associated with cognitive function (CF) in patients with major depressive disorder (MDD) with chronic insomnia (CI) and whether the severity of these disorders is related to CF. METHOD: Thirty patients with MDD with CI attending a tertiary care institution underwent two consecutive nights of polysomnographic (PSG) recording and a battery of neuropsychological tests, which included episodic memory, sustained attention, working memory, and executive function. The severity of MDD and CI was assessed by clinical scales. We examined the relationship between PSG parameters and CF, as well as whether the severity of the disorders is related to CF. RESULTS: Linear regression analysis revealed that total sleep time (TST) was positively associated with higher learning and recall of episodic memory, as well as better attention. Slow-wave sleep (SWS) showed a positive association with better working memory. Furthermore, wake after sleep onset (WASO) was negatively associated with episodic memory and lower attention. No significant relationships were found between the severity of MDD or CI with CF. CONCLUSION: Both sleep duration and depth are positively associated with several aspects of CF in patients with MDD with CI. Conversely, a lack of sleep maintenance is negatively related to CF in these patients. These findings could help identify modifiable therapeutic targets to reduce CF impairment.

Sleep Quality After Intradialytic Oral Nutrition: A New Benefit of This Anabolic Strategy? A Pilot Study.

Background: Since disturbances of appetite and sleep are closely related and both affect metabolic disorders, it would be expected that a renal specific oral nutritional supplement (RS-ONS) that covers the energy the patient does not consume on the HD day, could contribute to improve the nutritional status and body composition, as well as sleep quality. There is still scarce information related to this topic. Aim: To evaluate the effect of the use of intra-dialytic RS-ONS vs. RS-ONS at home on sleep quality, nutritional status, and body composition in patients on HD. Methods: Adult patients < 65 years, with ≥3 months on HD were invited to participate in an open randomized pilot study (ISRCTN 33897). Patients were randomized to a dialysis-specific high-protein supplement provided during the HD session (Intradialytic oral nutrition [ION]) or at home (control), during non-HD days (thrice weekly, for both) 12 weeks. The primary outcome was sleep quality defined by the Pittsburgh Sleep Quality Index (PSQI) score. Nutritional assessment included Malnutrition Inflammation Score (MIS), bioelectrical impedance analysis, anthropometry, 3-day food records, and routine blood chemistries. Results: A total of 23 patients completed the study. Age was median 35 (range 24-48 years), 42% were women. At baseline, the PSQI score was median 4 (range 2-7), and MIS showed a median of 6 (range 5-8); there were no baseline differences between groups. After intervention, both groups improved their MIS scores and similarly when we analyzed the whole cohort (pre- vs. post-intervention P < 0.01). Patients in the ION group improved the overall PSQI score to median 3 (2-5), and assessment of sleep duration and sleep disturbances (pre- vs. post-intervention P < 0.05), with a trend toward an effect difference compared to patients consuming the supplement at home (P for treatment-effect across arms 0.07 for PSQI score and 0.05 for sleep latency). Conclusion: Oral supplementation improved nutritional status in the whole cohort, but only ION improved the PSQI score. More studies are needed to explore the nutritional strategies that influence the relationship between sleep and nutritional status in HD patients.

Sleep habits and sleep problems associated with depressive symptoms in school-age children.

PROBLEM: Sleep disturbance is a characteristic symptom of depression, but it is also a problem in itself related to the severity of this illness. Hence, the objective of this study was to examine sleep habits and sleep problems associated with increased depressive symptoms in children. METHODS: The sample included 524 children equally distributed by gender (51.1% female), with an average age of 10.29 (SD = 1.34) years. The administered instruments were the Children's Depression Inventory (CDI; Cronbach α = 0.82) and a Sleep Habits and Sleep Problems Questionnaire (α = 0.91). FINDINGS: The mean score for the CDI was 12.51 (SD = 6.74) and 20% presented symptoms of depression. The linear regression model showed that sleep habits associated with the increase in symptoms of depression were: little sleep, hours of sleep during the week, and wake-up time on weekdays. In the same model, the associated sleep problems were: nocturnal awakenings, nightmares, and difficulty waking up. The presence of these sleep habits and sleep problems increased the score from 2.07 to 13.50 points on the CDI scale. CONCLUSIONS: Depressive symptoms increase with the presence of sleep habits related to sleep deprivation and sleep problems related to parasomnias in school-age children.

Partial sleep deprivation on dietary energy intake in healthy population: a systematic review and meta-analysis / Efectos de la privación parcial de sueño sobre la ingesta energética en una población sana: revisión sistemática y metaanálisis

INTRODUCTION: the restriction of nocturnal sleep has immediate effects, including the presence of excessive daytime sleepiness, general fatigue, or impaired concentration. In the long term, it increases the risk of death from cardiac, respiratory, and metabolic disorders, and the prevalence of obesity in healthy populations. However, despite the existence of a large number of studies on this topic, results have been controversial. OBJECTIVE: to discuss and analyze the evidence on the effects of nocturnal sleep restriction versus habitual sleep on dietary energy intake, including specific meals, as well as the relationship between ghrelin and leptin levels in a healthy population. METHODS: a systematic search of the literature was conducted in October 2016 and February 2019 using the PubMed, Scopus, Lilacs, and Embase databases. Terms used were "sleep," "feeding behavior," "dietary energy intake," "energy intake," "meal," "ghrelin," and "leptin." RESULTS: the bibliographic search identified 384 potential articles. Of a total of eight articles accepted in the review, six contain information available for the analysis of total energy intake. The overall result shows a significant difference in energy intake between study groups (149.86 (95 % CI: 10.09-289.63); p = 0.04), and a higher intake of all macronutrients. CONCLUSIONS: the present systematic review and meta-analysis demonstrated that partial sleep deprivation increases total energy intake, as well as all macronutrients, when compared to habitual sleep

INTRODUCCIÓN: la restricción del sueño nocturno tiene efectos inmediatos, como la presencia de somnolencia diurna excesiva, fatiga general o alteraciones en la concentración; a largo plazo, aumenta el riesgo de muerte por trastornos cardíacos, respiratorios y metabólicos, y aumenta la prevalencia de la obesidad en las poblaciones sanas. Sin embargo, a pesar de la existencia de una gran cantidad de estudios, los resultados siguen siendo controvertidos. OBJETIVO: discutir y analizar la evidencia sobre la restricción parcial del sueño frente al sueño habitual y su efecto en la ingesta dietética de energía, incluyendo comidas específicas, así como en las concentraciones de ghrelina y leptina en una población sana. MÉTODOS: se realizó una búsqueda electrónica de la literatura entre octubre de 2016 y febrero de 2019 en PubMed, Scopus, Lilacs y Embase. Los términos utilizados fueron "sleep", "feeding behavior", "dietary energy intake", "energy intake", "meal", "ghrelin" y "leptin". RESULTADOS: la búsqueda bibliográfica identificó 384 artículos potenciales. De un total de 8 artículos aceptados en la revisión, 6 tenían información disponible para el análisis de la ingesta total de energía. El resultado general mostró una diferencia significativa en la ingesta de energía (149,86 (IC 95 %: 10,09-289,63); p = 0,04) y una mayor ingesta de todos los macronutrientes. CONCLUSIONES: la presente revisión sistemática y meta-análisis indicó que la restricción del sueño aumenta la ingesta total de energía, así como la de todos los macronutrientes, en comparación con el sueño habitual

Partial sleep deprivation on dietary energy intake in healthy population: a systematic review and meta-analysis.

INTRODUCTION: Background: the restriction of nocturnal sleep has immediate effects, including the presence of excessive daytime sleepiness, general fatigue, or impaired concentration. In the long term, it increases the risk of death from cardiac, respiratory, and metabolic disorders, and the prevalence of obesity in healthy populations. However, despite the existence of a large number of studies on this topic, results have been controversial. Objective: to discuss and analyze the evidence on the effects of nocturnal sleep restriction versus habitual sleep on dietary energy intake, including specific meals, as well as the relationship between ghrelin and leptin levels in a healthy population. Methods: a systematic search of the literature was conducted in October 2016 and February 2019 using the PubMed, Scopus, Lilacs, and Embase databases. Terms used were "sleep," "feeding behavior," "dietary energy intake," "energy intake," "meal," "ghrelin," and "leptin." Results: the bibliographic search identified 384 potential articles. Of a total of eight articles accepted in the review, six contain information available for the analysis of total energy intake. The overall result shows a significant difference in energy intake between study groups (149.86 (95 % CI: 10.09-289.63); p = 0.04), and a higher intake of all macronutrients. Conclusions: the present systematic review and meta-analysis demonstrated that partial sleep deprivation increases total energy intake, as well as all macronutrients, when compared to habitual sleep.

INTRODUCCIÓN: Antecedentes: la restricción del sueño nocturno tiene efectos inmediatos, como la presencia de somnolencia diurna excesiva, fatiga general o alteraciones en la concentración; a largo plazo, aumenta el riesgo de muerte por trastornos cardíacos, respiratorios y metabólicos, y aumenta la prevalencia de la obesidad en las poblaciones sanas. Sin embargo, a pesar de la existencia de una gran cantidad de estudios, los resultados siguen siendo controvertidos. Objetivo: discutir y analizar la evidencia sobre la restricción parcial del sueño frente al sueño habitual y su efecto en la ingesta dietética de energía, incluyendo comidas específicas, así como en las concentraciones de ghrelina y leptina en una población sana. Métodos: se realizó una búsqueda electrónica de la literatura entre octubre de 2016 y febrero de 2019 en PubMed, Scopus, Lilacs y Embase. Los términos utilizados fueron "sleep", "feeding behavior", "dietary energy intake", "energy intake", "meal", "ghrelin" y "leptin". Resultados: la búsqueda bibliográfica identificó 384 artículos potenciales. De un total de 8 artículos aceptados en la revisión, 6 tenían información disponible para el análisis de la ingesta total de energía. El resultado general mostró una diferencia significativa en la ingesta de energía (149,86 (IC 95 %: 10,09-289,63); p = 0,04) y una mayor ingesta de todos los macronutrientes. Conclusiones: la presente revisión sistemática y meta-análisis indicó que la restricción del sueño aumenta la ingesta total de energía, así como la de todos los macronutrientes, en comparación con el sueño habitual.

Accessibility and adherence to positive airway pressure treatment in patients with obstructive sleep apnea: a multicenter study in Latin America.

PURPOSE: Information on access and adherence to positive airway pressure (PAP) treatment is lacking at the regional level in Latin America. This study characterized access and adherence to PAP in patients with moderate-severe obstructive sleep apnea (OSA) in Latin America. METHODS: Cross-sectional study, conducted at 9 sleep centers across Argentina, Brazil, Chile, Colombia, Mexico, and Peru. Adults diagnosed with moderate-severe OSA (apnea-hypopnea index [AHI] ≥ 15/h) in the previous 12-18 months were eligible. Anthropometrics, health coverage, and OSA severity data were collected. Data on access to therapy, barriers to access, adherence, and factors related to non-compliance were obtained via standardized telephone survey. RESULTS: Eight hundred eighty patients (70% male, 54 ± 13 years, AHI 49 ± 28/h, body mass index 32 ± 7 kg/m2) were included. Four hundred ninety patients (56%) initiated PAP, 70 (14%) discontinued therapy during the first year (mainly due to intolerance), and 420 (48%) were still using PAP when surveyed. Health insurance was private in 36.9% of patients, via the social security system in 31.1%, and via the state in 13.3%, and 18.7% did not have any coverage; 49.5% of patients had to pay all equipment costs. Reasons for not starting PAP were unclear or absent indication (42%), coverage problems (36%), and lack of awareness of OSA burden (14%). Patients with better adherence were older (55.3 ± 13 vs 52 ± 13; p = 0.002) and had more severe OSA (AHI 51.8 ± 27 vs 45.6 ± 27; p = 0.001). CONCLUSIONS: Less than half moderate-severe OSA patients started and continue to use PAP. Unclear or absent medical indication and financial limitations were the most relevant factors limiting access to therapy.

Intermittent hypoxemia and sleep fragmentation: associations with daytime alertness in obese sleep apnea patients living at moderate altitude.

BACKGROUND: Although obstructive sleep apnea (OSA) has long been associated with daytime sleepiness, far less is known about its association with the ability to remain awake. The aim of this study was to examine the relative importance of inter-correlated measures of OSA severity (eg, various indices of oxygen saturation and sleep fragmentation) in the ability to stay alert as measured objectively by the Maintenance of Wakefulness Test (MWT), defined by a mean sleep latency of ≥12 min. METHODS: Seventy-eight obese women and men of similar age and body mass index living at altitude (Mexico City) underwent standard polysomnography, MWT, and completed validated sleep-related questionnaires. RESULTS: Men had more severe sleep apnea than women (p = 0.002) and were also less alert on MWT (p = 0.022). Logistic regression models indicated that measures of desaturation consistently predicted MWT-defined alertness, whereas varied measures of sleep fragmentation did not. Nearly a third of the variance (r(2) = 0.304) in MWT-defined alertness was accounted for by the number of desaturations per hour of sleep (p = 0.003), which is considerably higher than other studies have reported in different populations. CONCLUSION: The ability to remain awake in obese patients is best accounted for by hypoxemia rather than sleep fragmentation. Whether the size of this effect reflects differences in the population under study (eg, extent of obesity, racial background, residence at moderate altitude) and/or is a function of the measurement of alertness with the MWT remains uncertain.

Alteraciones neuropsicológicas asociadas en pacientes con infarto lacunar / Neuropsychological disorders associated with patients with lacunar infarct / Alterações neuropsicológicas associadas em pacientes com enfarte lacunar

Existe poca evidencia del deterioro cognoscitivo que defina el perfil del paciente con Infarto Lacunar (IL). El propósito de este estudio fue identificar las alteraciones neuropsicológicas en este tipo de pacientes. La muestra estuvo compuesta por 16 pacientes con IL y 16 participantes sanos con una edad promedio de 63 ± 9.41 y 64.75 ± 9.06 años y una escolaridad de 7.55 ± 4.34 y 7.94 ± 3.51, respectivamente. Se valoró la función cognoscitiva mediante un instrumento de tamizaje y una batería neuropsicológica. El análisis estadístico se llevó a cabo a través de la prueba Kruskal-Wallis y la U de Man-Whitney. Los pacientes con IL se caracterizan por la alteración de dominios como planeación, fluidez verbal, cambio atencional, habilidad visoconstructiva y velocidad de procesamiento de la información (p < 0.050). El IL se relaciona con el deterioro del funcionamiento ejecutivo y de velocidad de procesamiento, debido a la interrupción de circuitos frontocortico-subcorticales asociados con su correcto desempeño.

There is little evidence of cognitive impairment to define the profile of patients with Lacunar Infarction (IL). The purpose of this study was to identify the neuropsychological disorders in these patients. The sample consisted of 16 patients with IL and 16 healthy control participants with an average age of 63 ± 9.41 and 64.75 ± 9.06 years, and average schooling of 7.55 ± 4.34 and 7.94 ± 3.51, respectively. Cognitive function was assessed using a screening tool and a neuropsychological battery. Statistical analysis was carried out by the Kruskal-Wallis and Mann-Whitney U tests. Patients with IL are characterized by the alteration of domains such as planning, verbal fluency, attention switching, visoconstructive skill and information processing speed (p <0.050). The IL is related to the impairment of executive functioning and processing speed, due to the interruption of frontocortico-subcortical circuits associated with their proper performance.

Existe pouca evidência da deterioração cognoscitiva que defina o perfil do paciente com Enfarte Lacunar (IL). O propósito deste estudo foi identificar as alterações neuropsicológicas neste tipo de pacientes. A mostra foi composta por 16 pacientes com IL e 16 participantes sãos com uma idade média de 63 ± 9.41 e 64.75 ± 9.06 anos e uma escolaridade de 7.55 ± 4.34 e 7.94 ± 3.51, respectivamente. Avaliou-se a função cognoscitiva mediante um instrumento de tamizagem e uma bateria neuropsicológica. A análise estadística foi feita através do teste Kruskal-Wallis e a U de Man-Whitney. Os pacientes com IL se caracterizan pela alteração de dominios como planejamento, fluêcia verbal, mudança atencional, habilidade visoconstructiva e velocidade de processamento da informação (p < 0.050). O IL se relaciona com a deterioração do funcionamento executivo e da velocidade de processamento, devido à interrupção de circuitos frontocortico-subcorticais associados com seu correto desempenho.

Adaptación y validación psicométrica del Cuestionario de Consecuencias Funcionales del Dormir (Functional Outcomes Sleep Questionnaire [FOSQ]) en habitantes de la Ciudad de México / Adaptation and psychometric validation of the functional outcomes sleep questionnaire (FOSQ) in México City habitants

Excessive daytime sleepiness (EDS) is a highly disabling sleep disorder related to alterations in behavioral performance, work injuries and vehicle accidents. A high prevalence of EDS (from 16% to 32%) in the general population has been reported. The Functional Outcomes Sleep Questionnaire (FOSQ) is an instrument that measures the impact of EDS in a patient's functional state in different sleep disorders. This questionnaire has been validated in different countries (Norway, Turkey, Spain). Therefore, the objective of this study was to obtain the cultural validation, the internal consistency, construct validity and factor congruence of the adapted questionnaire for the inhabitants of Mexico City (FOSQ-México). In the first part of the study we translated the questionnaire using the standard methodological process. The FOSQ cultural adaptation was made by the Natural Modified Semantic Networks technique in a sample of 78 participants. In the second part, the adapted FOSQ was applied to 152 participants to test items discrimination, internal consistency, factor analysis by principal-components and factorial congruence with the original version. The principal-components analysis of the FOSQ yielded six meaningful factors that explained 67.2% of the total variance, an average a coefficient between 0.85 to 0.94 for the six factors. The factorial congruence coefficients ranged from 0.360 to 0.969 between the original and the FOSQ-México version. This study demonstrated that the FOSQ version for inhabitants of Mexico City is reliable, valid and conceptually equivalent to the American version.

La Somnolencia Diurna Excesiva (SDE) es uno de los problemas de sueño más incapacitantes ya que se relaciona con déficits en la ejecución conductual, accidentes laborales y vehiculares. Se estima una prevalencia en la población general de entre 16% y 32%. El Functional Outcomes Sleep Questionnaire (FOSQ) es el cuestionario más utilizado para medir el impacto de la SDE en el estado funcional de pacientes con diferentes trastornos del dormir, el cual se ha validado en distintos países. Por lo tanto, el objetivo de este estudio fue adaptar culturalmente el FOSQ y obtener la confiabilidad, la validez de constructo y los coeficientes de congruencia factorial para la versión FOSQ-México. En una primera fase se tradujo el cuestionario utilizando el procedimiento metodológico estándar. También se hizo la adaptación cultural de los reactivos mediante la técnica de Redes Semánticas Naturales Modificadas en una muestra de 78 participantes. En una segunda fase, el cuestionario adaptado se aplicó a 152 participantes para determinar la discriminación entre reactivos, la consistencia interna, el análisis factorial con rotación ortogonal con un método de componentes principales y comprobar la congruencia factorial. Los resultados indicaron que los 30 reactivos del FOSQ se agruparon en seis factores que explican el 67.2% de la varianza total, con un coeficiente a total de 0.94 y de 0.85 promedio para los factores. Se obtuvieron coeficientes de congruencia factorial de 0.360 a 0.969 entre la versión original y el FOSQ-México. Se demostró que la versión adaptada del FOSQ para habitantes de la Ciudad de México es confiable, válida y equivalente conceptualmente con la versión norteamericana.

Estructura del sueño y funciones ejecutivas en niños con depresión / Sleep architecture and executive functions in children with depression

Sleep disturbance is a common complaint in depression. However, objective data in relation to the architecture of sleep associated with depression in childhood have been inconsistent. The objective measurement of sleepiness and executive functions is little known in depressive children. The objective of this study was to determine the differences in the sleep architecture, daytime sleepiness and executive functions in children with and without depression. Method The participants were 20 children with an average of 10.5 (SD=1.5) years old; nine were girls. Ten met the diagnostic criteria for major depression and ten were control. There were no differences by sex and age between groups with and without depression (p>.05). The instruments were: Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version (K-SADS-PL), the Children Depression Inventory, and the Battery of Executive Frontal Functions. Also, there were two consecutive nights of polysomnographic recording and Multiple Sleep Latency Test (MSLT). Results No differences were found in the architecture of sleep, sleep efficiency was greater than 90% in both groups and the indexes of initiation and sleep maintenance did not show statistically significant differences. There were no differences in daytime sleepiness, sleep onset latency in the MSLT was 22.8 (SD=6.4) minutes for the group with depression and 23.7 (SD=4.1) for the control. The executive functions showed differences in tasks involving: visual-motor and impulse control, working memory and identification of the risk-benefit ratio. Conclusions The results suggest that prefrontal structures are more vulnerable to depression than the structures that regulate the circadian and homeostatic sleep.

La alteración del sueño es una queja común en la depresión. Sin embargo, los datos objetivos sobre las alteraciones en la estructura del sueño asociadas a la depresión infantil han sido inconsistentes. Por otro lado, el estudio objetivo de la somnolencia y las funciones ejecutivas en niños con depresión es poco conocida. El objetivo fue conocer si existen diferencias en la estructura del sueño, la somnolencia diurna y las funciones ejecutivas en niños con y sin depresión. Método Participaron 20 niños con promedio de 10.5 (DE=1.5) años de edad, de los cuales 45% fueron niñas. Diez cumplieron los criterios diagnósticos de depresión mayor y 10 fueron controles. No hubo diferencias por sexo y edad entre los grupos (p>.05). Los instrumentos fueron: La entrevista Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version (K-SADS-PL), el Inventario de Depresión Infantil, y la Batería de Funciones Frontales y Ejecutivas. Asimismo, se realizaron dos noches consecutivas de registro polisomnográfico y la Prueba de Latencias Múltiples a Sueño (PLMS). Resultados No se encontraron diferencias en la estructura del sueño, la eficiencia del sueño fue mayor al 90% en ambos grupos y no hubo diferencias en los índices de inicio y continuidad del sueño, así como en las diferentes etapas de sueño. Tampoco se obtuvieron diferencias en la somnolencia diurna, la latencia al inicio de sueño en la PLMS fue de 22.8 (DE=6.4) minutos para el grupo con depresión y 23.7 (DE=4.1) para el control. Las funciones ejecutivas mostraron diferencias en tareas que implican: control visomotor y de impulsos, memoria de trabajo e identificación de la relación riesgo-beneficio. Conclusiones Los resultados sugieren que las estructuras prefrontales son más vulnerables a la depresión que las estructuras que regulan el ritmo circadiano y homeostático del sueño.

[Sleep medicine: development, contributions and perspectives. Report of the work group on sleep medicine]. / Medicina del dormir: desarrollo, contribuciones y perspectivas. Reporte del grupo de trabajo en medicina del dormir.

Sleep is a basic biological process that has an impact on all the functions of the body, and interacts bidirectionally with virtually all of the body systems, so that the sleep disorders are associated with disturbances in other systems, either respiratory, neurological, cardiovascular, endocrine, immune, etc., and vice versa. The complexity of the regulatory mechanisms of sleep and the variety of their disorders, together with the clinical evidence accumulated in recent decades, have led to the birth of a new branch in medicine: the Sleep Medicine, with well defined intrinsic disorders. The consequences of sleep deprivation or fragmentation induced by changes in social and work dynamics, as well as sleep disorders have harmful effects on individuals in the short and long-term, the most important are an elevated risk for vehicular and occupational accidents, cardiovascular damage, cognitive impairment, obesity, diabetes mellitus, among others, impacting individuals of all ages. The sleep clinics and laboratories in Mexico, have made significant contributions, at both the basic and clinical levels, for the diagnosis and treatment of sleep disorders; however, without a specific health policy, we will continue to commit resources only on the attention of its effects and not on prevention, making the impact on the economy and quality of life of patients with sleep disorders, much higher than in developed countries. It is necessary to build a program of medical care to incorporate the Sleep Medicine in the priorities of medical care in the National Institutions of Health at all levels. Solutions and guides to optimize the achievement of the proposed results, and increase efficiency and effectiveness of the resources applied in this new field of Medicine are offered.

Caffeine challenge in insomniac patients after total sleep deprivation.

BACKGROUND AND PURPOSE: This study compared the effects of caffeine in patients with primary insomnia and normal volunteers. The main goal was to determine the differences in sensitivity to caffeine between the groups. We investigated the effects on daytime sleep of placebo or caffeine after a night of total sleep deprivation (SD). We hypothesized that insomniacs would be more affected by caffeine, which would suggest a change in adenosine receptor (number or sensitivity) in primary insomniacs. PATIENTS AND METHODS: Six primary insomnia patients (Diagnostic and Statistical Manual of Mental Disorders (DSM-IV)) and six normal volunteers with no sleep complaints participated in a double-blind study with caffeine or placebo administered under a cross-over design with each subject serving as his or her own control. The participants did not have a history of drinking coffee or caffeinated beverages. Data from all-night polysomnography and multiple sleep latency test (MSLT) were collected in the sleep research laboratory of National Institute of Medical Sciences and Nutrition Salvador Zubirán. RESULTS: During the baseline night, patients with insomnia had significantly less delta sleep and less total sleep time than the normal volunteers. Mean sleep latency under basal MSLT did not differ between the groups. However, insomnia patients had significantly less total sleep during each nap compared to normal volunteers. After one night of total SD and under caffeine administration, the insomniacs had significantly longer sleep latency and less total sleep time in MSLT compared to normal volunteers. After SD, healthy volunteers reduced sleep latencies in MSLT with or without caffeine. CONCLUSIONS: Patients with insomnia had a higher sensitivity to the diurnal awakening effect of caffeine even after one night of SD. This suggests that changes in the adenosine receptors could, in part, be responsible for the hyperarousal state that has been reported in primary insomnia.

Effect of bariatric surgery on obstructive sleep apnea and hypopnea syndrome, electrocardiogram, and pulmonary arterial pressure.

BACKGROUND: We evaluated the impact of surgically-induced weight loss on Obstructive Sleep Apnea/Hypopnea Syndrome (OSAHS), electrocardiographic changes, pulmonary arterial pressure and daytime sleepiness in morbidly obese patients. METHODS: 16 women and 13 men (n=29) underwent bariatric surgery in a 3-year period. The following tests were performed before and 1 year after surgery: nocturnal polysomnography, daytime Multiple Sleep Latency Test (MSLT), and echocardiogram. RESULTS: Mean age was 37.9+/-11 years (range 20-56). Preoperative body mass index was 56.5+/-12.3 kg/m(2) and it was 39.2+/-8.5 kg/m(2) at 13.7+/-6.6 months follow-up. Performed surgical procedures included: vertical banded gastroplasty in 6, Roux-en-Y gastric bypass in 12, and Distal Roux-en-Y gastric bypass in 11. Weight loss induced by surgery eliminated OSAHS in 46% of obese patients with an important improvement in oxygen saturation. Neck, thorax, waist and hip circumferences decreased significantly after surgical intervention but only neck circumference correlated significantly with the apnea/hypopnea index (Spearman rho=0.63, P <0.0001). Electrocardiographic abnormalities were present in 9 patients (31%) before surgery (sinus arrhythmia, ventricular arrhythmias, and sinus arrest). The number of electrocardiographic abnormalities decreased after surgery but new abnormalities appeared in some patients. Systolic pulmonary arterial pressure significantly decreased in the group of patients in whom OSAHS disappeared after surgery. Daytime sleepiness persisted after surgery in most patients. CONCLUSION: Bariatric surgery effectively reduces respiratory disturbances during sleep and improves pulmonary hypertension. Electro cardiographic abnormalities change after surgery. Daytime sleepiness appeared not to be related to respiratory disturbances during sleep.

Abnormal SPECT myocardial perfusion imaging during periods of obstructive sleep apnea in morbid obese patients without known heart disease.

OBJECTIVE: Determine the myocardial perfusion characteristics in obstructive sleep apnea and its possible role in cardiovascular damage. METHODS AND PROCEDURES: Fourteen patients from the Obesity Clinic weighing less than 130 kg underwent myocardial perfusion studies using single photon emission computed tomography with technetium 99m-labeled sestamibi during nighttime polysomnographic recordings. Coronary angiograms were performed on patients with suspect of severe coronary obstruction according nighttime myocardial perfusion studies or pharmacological stress carried out during waking hours. RESULTS: All 14 patients manifested myocardial perfusion defects during sleep, affecting an average of 5.5 segments/patient, although only 8 presented ischemic ST segment changes and none demonstrated rhythm or conduction disturbances. Angiographic examination of the 10 patients with the most severe perfusion defects did not reveal significant coronary obstruction, and fewer perfusion defects were documented during daytime scintigraphy. DISCUSSION: In obese patients with obstructive sleep apnea, myocardial perfusion defects appear to occur with highest frequency and severity during nighttime sleep, justifying further investigation in a larger number of patients with obstructive sleep apnea and more significant obesity.

Aspectos neurológicos y neurofisiológicos de la risa / Neurological and neurophysiological aspects of laughter

El ser humano es el único animal que ríe. La risa es un programa motor altamente especializado que puede ser desencadenado por un estímulo interno o externo y que manifiesta la emoción conocida como alegría. Este estímulo tiene su procesamiento a nivel del sistema nervioso central en áreas primarias, secundarias y de asociación multimodal. En el sistema límbico se lleva a cabo el procesamiento de las emociones y es probablemente el origen de los potencíales motores que caracterizan a la risa, incluidos la expresión facial y los movimientos de los músculos que controlan la ventilación y fonación. Una vez procesado el estímulo, además de los actos motores automáticos mencionados, se lleva a cabo una activación autonómica generalizada la cual tiene salida por diversas vías, incluyen el eje hipotálamo-hipófisis y sistema nervioso autónomo. Todos estos componentes conforman la emoción, proceso que involucra, cuando se trata de alegría, el acto motor llamado risa.