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Biomedical subjects

M W Mahowald

Publications and source records attributed to M W Mahowald.

At least 19 recordsLinked to original sources

Evolving concepts of human state dissociation.

The concept of state dissociation in humans was made possible only by applying information obtained from basic science animal research studies to the human condition--without which these often dramatic, and treatable conditions would have remained in the mystical, supra-natural, or psychiatric arenas, without appropriate or effective treatment options. Sleep or wakefulness occurring asynchronously in bits and pieces of the brain is a most useful concept. From our standpoint, the basic science work in the function and mechanism of sleep is pertinent, not only adding to our knowledge in these important areas for the sake of knowledge, but also in providing clinicians with important information that is of immense clinical importance. The payoff of such research has been great, and demands that it should be ongoing. The field of sleep research and sleep medicine is in a unique position to foster close interactions between basic scientists and clinicians, the result being basic science answers to clinical questions, and unanswered clinical questions guiding the direction of and reinforcing the basic science research. The clinical conditions discussed above underscore the value of close cooperation among those working at all levels: molecular, cellular, multi-cellular, and clinical. Continued study of state dissociation by both basic scientists and clinicians will undoubtedly identify and explain even more of these fascinating conditions, with important therapeutic implications. The reciprocal benefits of close collaboration between basic scientists and clinicians will continue to be realized.

Animals↗

Sleep in a community sample of elderly war veterans with and without posttraumatic stress disorder.

BACKGROUND: Although sleep disturbances are commonly reported by individuals with posttraumatic stress disorder (PTSD), objective findings have been inconsistent, due in part to small sample sizes, comorbid psychiatric disorders, variations in the recentness of trauma exposure, and the use of PTSD subjects involved in psychiatric treatment. METHODS: A community sample of elderly males (n = 59) exposed to war trauma 28-50 years ago and free from sleep-affecting medications and disorders other than PTSD completed 3 nights of polysomnography. Of these participants, 30 met criteria for current PTSD; three were receiving supportive outpatient psychotherapy. RESULTS: Two statistically significant differences were observed: Those with PTSD had a higher percentage of rapid eye movement (REM) sleep and fewer arousals from non-REM sleep. The perceptions of sleep quality among the participants with PTSD were lower than the perceptions of non-PTSD participants. Although participants with untreated obstructive sleep apnea and sleep movement disorders were not included in the sample, many cases were detected on initial screening. Treatment resulted in improved sleep and increased feelings of well being. CONCLUSIONS: Alterations in REM and arousals characterized PTSD in this sample. When comorbid sleep disorders were ruled out, sleep was clinically similar across the groups. Trauma-related sleep disturbances that subjects reported as arising early in the course of the disorder appear to have declined over time.

Aged↗

Diagnosis and management of parasomnias.

Parasomnias are unpleasant or undesirable behavioral or experiential phenomena that occur predominately or exclusively during sleep. These phenomena were initially thought to represent a unitary event, often attributed to psychiatric disease. Recent clinical and polygraphic analysis has revealed that they are, in fact, the result of a large number of very different conditions, most of which are diagnosable and treatable. In fact, most are not the manifestation of psychiatric disorders, and they are far more prevalent than previously suspected. Although there are many parasomnias (1,2), from a practical standpoint only the few that comprise the overwhelming majority will be discussed in this review. These include disorders of arousal, rapid-eye-movement sleep behavior disorder, nocturnal seizures, and restless legs syndrome. Most parasomnias are readily diagnosable and, more importantly, are treatable.

Diagnosis, Differential↗

Does snoring predict sleepiness independently of apnea and hypopnea frequency?

Obstructive apneas and hypopneas during sleep are a well recognized cause of excessive daytime sleepiness. Snoring is also associated with excess sleepiness, although it is not known whether this reflects an independent effect of snoring or whether snoring is simply a marker for obstructive sleep apnea. To further explore the relation of snoring to sleepiness, we conducted a cross-sectional cohort study of community-dwelling adults participating in the Sleep Heart Health Study. The study sample comprises 2,737 men and 3,040 women with a mean age of 64 (SD 11) yr. Sleepiness was quantified using the Epworth Sleepiness Scale (ESS). Snoring history was obtained via a self-completion questionnaire. The respiratory disturbance index (RDI), defined as the number of apneas plus hypopneas per hour of sleep, was measured during in-home polysomnography. The ESS score increased progressively with increasing RDI, from a mean of 7.1 (4.2) in subjects with RDI < 1.5 to 8.8 (4.8) in subjects with RDI >/= 15 (p < 0.001). A progressive increase in ESS score was also seen across five categories of snoring frequency, from 6.4 (4.2) in current nonsnorers to 9.3 (4.8) in subjects who snored six to seven nights per week (p < 0.001). The prevalence of excessive daytime sleepiness, defined as an ESS score >/= 11, increased from 15% in never-snorers to 39% in those who snored six to seven nights per week. The relation of snoring to sleepiness was seen at all levels of RDI, with no significant change in the relation of snoring to ESS score after adjustment for RDI in multivariate models. The effects of snoring and RDI on sleepiness were little affected by adjustment for age, sex, race, body mass index, or questionnaire evidence of insufficient sleep time or nocturnal leg jerks or cramps. We conclude that both snoring and RDI are independently associated with excess sleepiness in community-dwelling, middle-aged and older adults.

Adult↗

What is causing excessive daytime sleepiness? Evaluation to distinguish sleep deprivation from sleep disorders.

Many people have a temporary spell, often in early afternoon, when they feel drowsy. This passing desire for a quick nap is completely different from excessive daytime sleepiness, which is a much more significant problem. Considering the potentially dire personal and economic consequences of falling asleep unintentionally or at inappropriate times, excessive daytime sleepiness must be taken very seriously. A thorough evaluation, as described by Dr. Mahowald, virtually always leads to a specific underlying cause, allowing effective treatment recommendations.

Diagnosis, Differential↗

Parasomnias. Managing bizarre sleep-related behavior disorders.

Sleep can be a troubling experience for persons plagued by nocturnal disorders known as parasomnias. While they are "asleep," such persons may be walking, screaming in terror, rearranging furniture, eating odd food concoctions, or wielding weapons. Or they may be unable to fall asleep because of the unpleasant sensations of restless legs syndrome. Although these disorders are indeed bizarre, effective treatments are available. In this article, Drs Schenck and Mahowald discuss the evaluation and treatment of parasomnias and provide illustrative patient vignettes from their extensive experience at a sleep disorders center.

Aged↗

Eyes wide shut. The dangers of sleepy driving.

Most Americans are chronically sleep-deprived. However, few people are aware of the extent to which sleep deprivation impairs cognitive functioning. In the United States, at least 56,000 motor vehicle crashes (MVCs) each year, resulting in 1,550 deaths and thousands more nonfatal injuries, are attributed to sleepiness behind the wheel. As lawsuits from fall-asleep MVCs mount, individuals, the transportation industry, public policymakers, and the legal profession are starting to take notice.

Accidents, Traffic↗

Medical-legal aspects of sleep medicine.

Sleepiness and sleep disorders are increasingly raising interesting and important medical-legal issues in three areas: violent or injurious behavior arising from the sleep period, accidents or errors in judgment caused by sleepiness behind the wheel or in the workplace, and disability determinations caused by sleepiness-induced work impairment. Sleep-related violence may be caused by many conditions, most of which are diagnosable and treatable. Legal issues raised by these behaviors are usually enigmatic. The nature of such behaviors may be extremely complex, and documenting that a given violent act was caused by such a behavior, after the fact, may be difficult. Guidelines for the medical-legal evaluation of such behaviors have been developed and are evolving. Culpability determination in sleepiness-related industrial or motor vehicle accidents is in the developmental stage, and varies by jurisdiction. Disability determination for workplace sleepiness caused by sleep disorders is in its infancy, and poses a challenge, given the erroneous but pervasive societal attitude that sleepiness is a manifestation of laziness, depression, sloth, work-avoidance behavior, or a defect of character.

Accidents↗

Polysomnographic sleep is not clinically impaired in Vietnam combat veterans with chronic posttraumatic stress disorder.

BACKGROUND: Because sleep is typically disturbed in posttraumatic stress disorder (PTSD), this study was undertaken to evaluate a group of Vietnam combat veterans with the disorder using clinical polysomnographic techniques. METHODS: Eighteen Vietnam combat veterans with PTSD and 10 healthy non-combat-exposed Vietnam era veterans participated in 2 nights of polysomnographic study and a multiple sleep latency test. RESULTS: No significant differences between subjects and controls were noted except for greater sleep onset latency to stage 2 (p < .03), and lower arousals/hour from stages 3 & 4 (p < .04) on night 2, and lower subjectively estimated total sleep time on night 1 (p < .005) in the case of PTSD subjects. Otherwise, results from the second night served to replicate those from the first, and no significant differences appeared on 2 successive nights for any polysomnographic variable. No daytime hypersomnolence was detected. CONCLUSIONS: Polysomnographically recorded sleep was notably better than expected in the presence of clinically significant PTSD with typical histories of disrupted sleep. In these subjects, there is no clinically significant sleep disorder or typical pattern of sleep disturbance detectable by standard polysomnography.

Adult↗

Parasomnias including the restless legs syndrome.

The three states of mammalian being, W, REM sleep, and NREM sleep, are not mutually exclusive, and may occur simultaneously, oscillate rapidly, or appear in dissociated or incomplete form to produce primary sleep parasomnias. In addition, dysfunctions of a wide variety of organ systems may take adwide variety of organ systems may take advantage of the sleeping state to declare themselves, resulting in secondary sleep parasomnias. Contrary to popular opinion, the majority of the often bizarre and frightening experiences are not the manifestation of underlying psychological or psychiatric conditions. There is an interesting interaction between sleep-disordered breathing and parasominas. Formal study in an experienced sleep disorders center will usually reveal a diagnosable and treatable condition that explains the spells. Continued study of unusual sleep-related events undoubtedly will reveal more fascinating conditions, expanding our knowledge of sleep physiology, and strengthening the bonds between clinicians and basic-science sleep researchers.

Adult↗

Blood pressure effects of long-term stimulant use in disorders of hypersomnolence.

Untoward cardiovascular effects have been implicated as a deterrent to long-term central nervous system (CNS) stimulant use in disorders of hypersomnolence. In this study, we reviewed the relationship between blood pressure and long-term stimulant use. Medical records of 54 patients with narcolepsy and idiopathic CNS hypersomnolence (ICH) were reviewed. The overall mean number of months of follow-up for the entire group was 45.6 (95% CI: 42-49). Both simple linear regression and multiple regression utilizing generalized estimating equations were used to show relationships between blood pressure (BP), time and other covariates. In the simple linear regression model, the average slope of the line of systolic BP (SBP) on time for the entire group was 0.06 (95% CI: -0.09, 0.13) and the line of diastolic BP (DBP) on time was 0.01 (95% CI: -0.05, 0.07). Two multiple regression equations were fitted for the continuous response variables SBP and DBP. Covariates in the model included: time, hypertension, weight at baseline, weight, SBP baseline (SBPBL), DBP baseline (DBPBL), high vs. low dose stimulant therapy and age at starting treatment. For SBP, the covariates weight at baseline, weight and SBPBL were significant (P < 0.05) predictors. For DBP, covariates reaching statistical significance (P < 0.05) included weight and DBPBL. There was no significant change in SBP or DBP over time in either model. Two different statistical models support the conclusion that there was no significant change in SBP or DBP over time in this population.

Adult↗

Analysis of polysomnographic events surrounding 252 slow-wave sleep arousals in thirty-eight adults with injurious sleepwalking and sleep terrors.

A systematic study of electrophysiologic events [eight-channel EEG, electrocardiogram, electromyogram (EMGs)] surrounding 252 arousals from slow-wave sleep (SWS) in adults with sleepwalking (SW) and sleep terrors (ST) is reported. Hospital-based, overnight polysomnographic monitoring was conducted in 38 adults presenting to a sleep disorders center with injurious SW, ST (21 males, 17 females; mean age 29 years, range 17-69 years). Before nonbehavioral or behavioral arousals from SWS, neither EEG "delta wave buildup," nor heart rate (HR) acceleration, nor tonic/phasic EMG activation was identified. The postarousal EEG demonstrated three patterns: (a) diffuse, rhythmic, delta activity with a typical frequency of 2.2 Hz, a typical amplitude of 85 microV, and a typical duration of 20 s; (b) diffuse delta and theta activity intermixed with alpha and beta activity; and (c) prominent alpha and beta activity. Multichannel, high-voltage, delta activity was observed in <2% of all prearousal periods. HR acceleration emerged abruptly with SWS arousals, with significant changes in mean pre- versus postarousal HR (p < .001). Macrostructural sleep parameters ("sleep architecture") were intact. Therefore, our findings in adults with SW, ST strongly support the classification of SW/ST as disorders of (abrupt) arousal.

Adult↗

An analysis of a recent criminal trial involving sexual misconduct with a child, alcohol abuse and a successful sleepwalking defence: arguments supporting two proposed new forensic categories.

The final judgment from a recent criminal trial in the British Columbia (Canada) Supreme Court is summarized and discussed. The trial involved sexual misconduct with a child, excessive alcohol use, and a successful 'sleepwalking (SW) defence' (non-insane automatism). Our comments on this trial provide an opportunity to present our arguments buttressing two newly proposed forensic categories: (i) parasomnia with continuing danger as a non-insane automatism, which originally was proposed for cases involving recurrent, sleep-related violence, but which can also be applied to SW cases involving sleep-related sexual misconduct and alcohol abuse (and other high-risk self-abusive behaviours); (ii) (intermittent) state-dependent continuing danger, an intermediate category within the 'continuing danger' concept, with the core feature being that a person acquitted of a criminal charge on the basis of the 'SW defence' (or some other parasomnia defence), in which the SW episode was provoked by a high-risk behaviour (e.g. alcohol intoxication) should bear full legal culpability for any future episode that was provoked by a recurrence of the high-risk behaviour--provided that the individual had wilfully engaged in that behaviour.

Adult↗