La actigrafía como herramienta diagnóstica / ROLE OF ACTIGRAPHY IN THE STUDY OF SLEEP AND CIRCADIAN RHYTHMS : ACCURACY, SENSITIVITY AND SPECIFICITY OF ACTIGRAPHY FOR THE ASSESSMENT OF SLEEP DISORDERS

El diagnóstico y tratamiento de los trastornos de sueño, especialmente los asociados al Ritmo Circadiano, utilizan métodos costosos, invasivos e incómodos tanto para los pacientes como para los médicos, quienes deben realizar un seguimiento de los hábitos de sueño. La actigrafía ha sido aceptada como una herramienta válida para el estudio y diagnóstico de trastornos circadianos. Más de 300 dispositivos se comercializan actualmente para el uso personal, pero pocos de estos han sido probados para un uso diagnóstico. En este estudio comparativo compuesto por 21 sujetos, se informa acerca de los patrones de sueño y actividad registrados por algunos dispositivos, como Micro-Mini Motionlogger Watch, Condor Act Trust, MisFit Flash y Fitbit Flex. No se observan diferencias significativas en el análisis del patrón de actividad de descanso entre dispositivos. Tampoco se observan para el sueño Onset (inicio), el Tiempo Total de Sueño y la Eficiencia del Sueño. Según el tipo de estudio y análisis deseado, éstos dispositivos pueden resultar alternativos para los registros de actividad y sueño.

This is a comparative analysis of actigraphy performance in comparison with different sleep Parameters. Actigraphy is a non-invasive and valid method of monitoring human rest activity cycles. The report describes the role of actigraphy to assess the study of sleep-wake patterns and circadian rhythms, evaluating its development as a diagnostic tool, with a comparative analysis of actigraphy performance in comparison with different sleep parameters. The diagnosis and treatment of sleep disorders, especially those associated with the cicardian rhythm, employ very expensive costs, invasives or unconfortable for the patients the same as for physicians, who must perform a demand of the sleeping habits. The International Classification of Sleep Disorders has identified more than 80 sleep disorders, all of them have associated treatments. Actinography has been accepted as a valid tool for the study and diagnosis of circadian disorders. All these aspects are discussed in the article

Dolor perdurable II. Tratamiento / [Enduring pain II. Treatment].

Pain disorders present highly challenging therapeutic problems, owing in part to complex co-morbidities associated with pain disorders, notably including psychiatric disorders characterized by depressed mood or anxiety. Many treatments are employed to treat pain-disorder patients, and most are unsatisfactory. Virtually all analgesic medicines in long-term use provide only partial efficacy and present substantial risks of adverse effects, loss of benefit over time, or dependency and risk of abuse. Commonly employed drugs with analgesic properties include non-opioids (mainly nonsteroidal anti-inflammatory agents [NSAIDs] or acetaminophen), many natural or synthetic opioids (including opiates and phenylpiperidines), some antidepressants (especially those with noradrenergic activity), a few anticonvulsants, skeletal muscle relaxants or topical remedies, and a growing variety of experimental treatments. The major overlap between pain and psychiatric disorders, as well as the currently unsatisfactory state of treatments available for chronic pain syndromes, encourage a comprehensive approach to assessment and clinical management of patients with chronic pain. Many current treatment programs for pain disorder patients offer narrowly specialized and incomplete treatment options. Ideally however, such care should be provided by multi-disciplinary teams with expertise in neurology, general medicine, pain management, physical medicine and rehabilitation, as well as psychiatry. Psychiatrists as well as pain specialists can serve an essential role in leading comprehensive assessment and general management of such complex and challenging patients who are typically only partially responsive to available treatments.

Dolor perdurable I. Nosología y epidemiología / [Enduring pain I. Nosology and epidemiology].

Pain disorders are extraordinarily prevalent throughout clinical medicine, and are highly co-morbid with various psychiatric disorders, particularly those including depression or anxiety. Assessment of such patients tends to be based on diagnostic criteria that may not reflect the complexity of the clinical problem and can result in prioritizing somatic aspects of painful syndromes at the expense of psychiatric aspects or, conversely, over-emphasize psychiatric aspects. In the first part of this overview we consider current nosological perspectives and their potential clinical consequences, epidemiological data that underscore the association of comorbid painful and affective or anxious syndromes, and consider the importance of psychiatric assessment and treatment of such patients. The major overlap between pain disorders and psychiatric disorders, as well as the unsatisfactory state of treatments available for chronic pain syndromes, encourage a comprehensive approach to assessing and clinically managing patients with chronic pain. Many programs for pain disorder patients offer narrowly specialized treatment options. To be preferred are multi-disciplinary teams with expertise in internal medicine, neurology, pain management, and rehabilitation, as well as psychology and psychiatry. In the second part of this overview, we propose that psychiatrists can serve a key role in leading comprehensive assessment and management of complex and challenging pain-psychiatric patients who are typically only partially responsive to available treatments.

Introducción al estudio de los sesgos en investigación clínica / Introduction to the study of clinical investigation bias

La medicina actual recurre a la investigación científica para hallar respuestas a algunas preguntas entre lasque se encuentra las causas de las enfermedades como también los efectos beneficiosos y adversos de los medicamentos o procedimientos terapéuticos. El método científico consiste en una serie de pasos, a modo de “receta de cocina”, que si son completados confieren un alto nivel de validez a los conocimientos adquiridos.Los estudios de investigación clínica que utilizan este método producen, por tanto, el conocimiento de mayor validez posible acerca de las relaciones causales en medicina. Si bien existe un debate epistemológico muy amplio en torno a la definición de una relación causal, a efectos puramente prácticos podemos afirmar en medicina que un factor es causa de un evento cuando la frecuencia del evento en el grupo expuesto es superior al grupo no expuesto, y no hay explicaciones alternativas para lo observado. Estas explicaciones alternativas, son en realidad particularidades en el diseño de los estudios clínicos, que hacen menos creíble o generalizable el resultadoobtenido. Estos sesgos pueden ocurrir durante la selección o conducción del estudio o se pueden presentarcomo distorsiones a la relación entre un factor y un evento, relacionadas con la presencia de un tercer factor. Los sesgos de selección surgen cuando las características del grupo expuesto son diferentes a las del grupo no expuesto, por eso si hubiera alguna asociacióncon el evento en estudio, no se podrá asegurar que no se deba a las diferencias observadas en dichas características. Por otro lado, los sesgos de información ocurren siempre que los grupos de sujetos, expuestos yno expuestos, no son evaluados de la misma manera, lo cual provoca que cualquier diferencia observada no sedebiera al factor de interés en estudio sino a la diferencia en los métodos de evaluación utilizados.

Science is a powerful ally in the search for the answers to some of the most important medical questions, suchas the cause of diseases or the effects of drugs or therapeutical procedures. The scientific method, which consists in an ordered set of predefined steps, confers a high level of validity to the knowledge acquired by its use. In this way, clinical scientific studies that employ it can produce valid knowledge about the causes of diseases or the effect of treatment procedures. Althoughthe nature of causal relationship is a matter of intense debate, in medicine it is usually sufficient to consider that a causal relationship exists when there is no better explanation for an observed association (i.e. when the rate of the studied event is higher in the group ofsubjects exposed to the risk factor studied as compared to subjects that were not exposed). The term “a betterexplanation” usually refers to bias, which generically refers to a set of factors whose occurrence greatly reduces the credibility or the generalizability of the clinicalstudy results. These factors can occur during the selection of the subjects to be studied or during the conductionof the study. Selection bias occurs when the characteristics of the exposed and unexposed subjects differ, making it impossible to rule out the possibilitythat any difference in the event rate observed is due to these differences and not the risk factor. On the otherhand, Information bias occurs when exposed and unexposed subjects are not evaluated similarly during the study, which can raise doubt in the case that a difference in the occurrence of the event is observed.