Spotlight on Encephalitis lethargica

In this article, Dr. Garg of King George’s Medical University in Lucknow, India discusses encephalitis lethargica, a mysterious epidemic disease of the 1920s and 1930s that was better known as the “sleepy” or “sleeping” sickness. It is associated with the subsequent development of postencephalitic parkinsonism, a condition that was popularized in Oliver Sacks 1973 book, Awakenings, and the 1990 movie of the same name.

Encephalitis lethargica evolved to have many manifestations other than a “lethargic type,” including types that were primarily characterized by insomnia and/or movement disorders. In the acute stage, encephalitis lethargica was characterized by intractable somnolence, which was then attributed to abnormalities of the diencephalon. Since then, anatomical localization of sleep is focused in the subcortical brain.

Differentiating points from idiopathic Parkinson disease include young age of onset, oculogyric crises, altered sleep-wake cycle, respiratory disturbances, and pyramidal signs. Pathologically, there is diffuse involvement of gray matter of the brain dominantly, the diencephalon, and the mesencephalon. There has been extensive debate about a possible role of the “Spanish” H1N1 influenza A pandemic virus in the development of encephalitis lethargica, but this relation has not yet been established. MR signal abnormalities in the substantia nigra, thalamus, hippocampus, and subcortical white matter of the frontal lobes have been described. No definite treatment is available. Prognosis is variable. Many of the survivors had permanent neurologic sequelae and were completely akinetic.

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Spotlight on Psychophysiological insomnia

The essence of psychophysiological insomnia is the focused attention on inability to sleep. Psychophysiological insomnia usually begins as a somaticized response to a stressful event and then, depending on genetic and other environmental variables, becomes a more chronic condition because of negative conditioning. This form of insomnia occurs in 1% to 2% of the general population and 12% to 15% of patients presenting to a sleep disorders center.

Three types of factors play a role in the development of psychophysiological insomnia: (1) predisposing or constitutional factors, eg, the tendency to worry excessively and the tendency to be hyperaroused; (2) precipitating factors, eg, a transient stressor; and (3) perpetuating factors, eg, the individual’s expectation of a poor night’s sleep that becomes a self-fulfilling prophecy.

In this article, Dr. Deirdre Conroy of the University of Michigan discusses diagnosis, complications, and treatment of psychophysiological insomnia. Updates include new information regarding the pathophysiology and unique electroencephalogram characteristic of psychophysiological insomnia. Dr. Conroy also discusses additional data to support cognitive behavioral therapy for insomnia as first-line treatment for psychophysiological insomnia.

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Spotlight on Hypersomnolence

Hypersomnolence is deleteriously prevalent, especially in modern society. The common medical complaint has various underpinnings. Sleep medicine, as a growing field or subspecialty, can evaluate the nature of the problem and improve life and longevity with a myriad of scientifically effective interventions. The cost to society, if sleepiness is left unaddressed, is profound given the negative effects on health and on education and on work-related issues. Fitness to drive is a challenging dilemma given an aging and senior population.

Hypersomnolence, or excessive daytime sleepiness, is a frequent complaint of patients and a symptom associated with many medical conditions, including intrinsic sleep disorders, such as narcolepsy and obstructive sleep apnea or insufficient nighttime sleep. Though a nearly universal experience, sleepiness is often ignored or minimized by patients, often increasing their risk for industrial or motor vehicle accidents. In this article, Dr. Richard Knudsen of University of California Davis Medical Center discusses the differential diagnosis, evaluation, and treatment of this often overlooked symptom complex. Information from the International Classification of Sleep Disorders (3rd edition) is highlighted. Newer therapeutic agents, deemed somnolytics, are reviewed.

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Spotlight on Sleep and alcohol use and abuse

In this article, Dr. Deirdre Conroy of the University of Michigan explains the basics of alcohol-related sleep disorders. She discusses the acute and chronic effects of alcohol on sleep as well as the management of sleep disorders during alcohol withdrawal and in recovering alcoholics. Insomnia in abstinent alcoholics is a common clinical problem that can increase the risk of relapse. Unfortunately, this is an area of only limited clinical research, though there are some data for the utility of cognitive-behavioral therapy for the treatment of insomnia in recovering alcoholics. The potential usefulness of ramelteon, gabapentin, and acamprosate for this condition is also discussed. New research has focused on the effects of ethanol on circadian rhythms. Child and adolescent sleep disturbances may predict alcohol abuse.

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Spotlight on Paradoxical insomnia

In this clinical summary, Dr. Deirdre A Conroy of the University of Michigan describes paradoxical insomnia (previously called sleep state misperception). Paradoxical insomnia is characterized by complaints of little or no sleep over long periods of time without the level of impairment expected with such a level of sleep deprivation. Patients often describe heightened awareness of their surroundings when lying down to sleep. Sleep study reveals normal sleep architecture with normal sleep onset latency and sleep efficiency but with subjective patient reports indicating prolonged sleep onset latency and poor sleep efficiency. Treatment usually involves patient reassurance. Behavioral therapy and sedative-hypnotics have also been tried.

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MedLink Neurology authors are always at work to bring you broad and up-to-date coverage of neurology topics. We are pleased to highlight clinical summaries that have been recently added or updated and to introduce the authors who write these authoritative articles. We hope you enjoy these overviews and appreciate the contributions of our more than 450 authors who keep MedLink Neurology the premier information resource for neurologists.

Spotlight on Psychophysiological insomnia

Psychophysiological insomnia usually begins as a somaticized response to a stressful event and then, depending on genetic and other environmental variables, becomes a more chronic condition because of negative conditioning. In this clinical summary, Dr. Deirdre Conroy of the University of Michigan discusses diagnosis, complications, and treatment of psychophysiological insomnia. New updates include drugs coming down the research pipeline, new neurophysiologic information regarding the hyperarousal theory of insomnia, and the relationship of insomnia and short sleep duration to the development of chronic disease such as hypertension.

To view the complete clinical summary, click here.

MedLink Neurology authors are always at work to bring you broad and up-to-date coverage of neurology topics. We are pleased to highlight clinical summaries that have been recently added or updated and to introduce the authors who write these authoritative articles. We hope you enjoy these overviews and appreciate the contributions of our more than 450 authors who keep MedLink Neurology the premier information resource for neurologists.