Melatonin in sleep disorders.

Melatonin is the main hormone involved in the control of the sleep-wake cycle. It is easily synthesisable and can be administered orally, which has led to interest in its use as a treatment for insomnia. Moreover, as production of the hormone decreases with age, in inverse correlation with the frequency of poor sleep quality, it has been suggested that melatonin deficit is at least partly responsible for sleep disorders. Treating this age-related deficit would therefore appear to be a natural way of restoring sleep quality, which is lost as patients age. However, despite the undeniable theoretical appeal of this approach to insomnia, little scientific evidence is available that supports any benefit of this substitutive therapy. Furthermore, the most suitable dose ranges and pharmaceutical preparations for melatonin administration are yet to be clearly defined. This review addresses the physiology of melatonin, the different pharmaceutical preparations, and data on its clinical usefulness.

Melatonina en los trastornos de sueño / Melatonin in sleep disorders

La melatonina es la principal hormona implicada en la regulación de la oscilación entre sueño y vigilia. Es fácilmente sintetizable y administrable por vía oral, lo que ha propiciado el interés para usarla en el tratamiento de una de las patologías humanas más prevalentes, el insomnio. Además, el hecho de que su producción se reduzca con la edad, en una relación inversamente proporcional a la frecuencia de mala calidad de sueño, ha reforzado la idea de que su déficit es, al menos en parte, responsable de estos trastornos. En esta línea de pensamiento, remontar el déficit que se va instaurando a medida que transcurre la vida sería un modo natural de restaurar la integridad del sueño, que se va perdiendo con la edad. Sin embargo, a pesar del innegable atractivo teórico de esta aproximación al problema del insomnio, la evidencia científica que sustenta el posible beneficio de esta terapia sustitutiva es escasa. Ni siquiera están bien definidos los rangos de dosis a los que administrarla o la formulación farmacológica más adecuada. En la presente revisión se repasa la fisiología de la melatonina, se revisan las características farmacológicas de su administración exógena y se analizan los datos existentes sobre su utilidad clínica. (AU)

Melatonin is the main hormone involved in the control of the sleep-wake cycle. It is easily synthesisable and can be administered orally, which has led to interest in its use as a treatment for insomnia. Moreover, as production of the hormone decreases with age, in inverse correlation with the frequency of poor sleep quality, it has been suggested that melatonin deficit is at least partly responsible for sleep disorders. Treating this age-related deficit would therefore appear to be a natural way of restoring sleep quality, which is lost as patients age. However, despite the undeniable theoretical appeal of this approach to insomnia, little scientific evidence is available that supports any benefit of this substitutive therapy. Furthermore, the most suitable dose ranges and pharmaceutical preparations for melatonin administration are yet to be clearly defined. This review addresses the physiology of melatonin, the different pharmaceutical preparations, and data on its clinical usefulness. (AU)

Melatonin in sleep disorders. / Melatonina en los trastornos de sueño.

Melatonin is the main hormone involved in the control of the sleep-wake cycle. It is easily synthesisable and can be administered orally, which has led to interest in its use as a treatment for insomnia. Moreover, as production of the hormone decreases with age, in inverse correlation with the frequency of poor sleep quality, it has been suggested that melatonin deficit is at least partly responsible for sleep disorders. Treating this age-related deficit would therefore appear to be a natural way of restoring sleep quality, which is lost as patients age. However, despite the undeniable theoretical appeal of this approach to insomnia, little scientific evidence is available that supports any benefit of this substitutive therapy. Furthermore, the most suitable dose ranges and pharmaceutical preparations for melatonin administration are yet to be clearly defined. This review addresses the physiology of melatonin, the different pharmaceutical preparations, and data on its clinical usefulness.

Sleep disorder in alien hand syndrome.

A 63-year-old right-handed woman developed an alien hand syndrome (AHS) after an acute infarction in the territory of the left anterior cerebral artery. The uncontrolled hand movements were present during the daytime and eventually disturbed sleep. Polysomnography revealed that these motor actions only appeared when the patient was awake. These awakenings emerged mostly from NREM sleep stage 2 during the first half of the night. There was no evidence of any epileptiform activity, dyssomnia or parasomnia. These movements were controlled making her wear an oven mitt during sleep. The temporal distribution of this motor activity seems to follow the progressive hyperpolarization of anterior horn neurons that occurs when sleep deepens. The accommodation of the grasp reflex in AHS probably helps control this unwanted motor activity.

[Neurophysiology in Creutzfeldt-Jakob disease]. / Neurofisiología en la enfermedad de Creutzfeldt-Jakob.

INTRODUCTION: Neurophysiological studies conducted in subjects who it is suspected are suffering from Creutzfeldt-Jakob disease (CJD) are usually aimed at searching for what is called a typical EEG. However, the EEG is a dynamic test and therefore subject to variations in time. Furthermore, there are other kinds of neurophysiological tests that may also be of interest, and the lack of typical traces in the new variant of the disease forces us to explore other diagnostic approaches. METHOD: We performed a clinical EEG correlation in the course of the evolution of the disease, in which we observed a significant variability throughout the different stages. We then review the neurophysiological studies that have been conducted on CJD, in which shortcomings and important discrepancies can be seen. CONCLUSION: EEG has proved to be a fundamental element in CJD probability diagnosis. It is also found that sleep and waking records, obtaining series of EEGs, the detection of poligraphic changes related with variations in the degree of consciousness and, lastly, studies conducted by means of other neurophysiological techniques associated with clinical data will all undoubtedly enable us to achieve higher efficiency in diagnosis

[Electroencephalography in Creutzfeld-Jakob disease]. / Electroencefalograma en la enfermedad de Creutzfeldt-Jakob.

INTRODUCTION: The electroencephalogram is very useful in the diagnosis of probable Creutzfeldt-Jakob disease. DEVELOPMENT: It is considered that a typical pattern is formed of periodic sharp wave complexes, widely distributed (synchronously and symmetrically) over both cerebral hemispheres. The frequency of presentation is approximately 1/second. However during the course of the disease other patterns are seen, such as frontal intermittent rhythmical delta activity, a cyclical alternating pattern and a low output electroencephalogram. CONCLUSION: Recognition of these patterns, their electroclinical correlation and serial polygraphic studies are very important to the reliability of the test.