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Biomedical subjects

W B Webb

Publications and source records attributed to W B Webb.

At least 19 recordsLinked to original sources
PubMed1995

The cost of sleep-related accidents: a reanalysis.

This journal published a special report titled "The Cost of Sleep-Related Accidents: A Report for the National Commission on Sleep Disorders Research". The report estimated that sleep-related accidents were annually associated with 23,318 fatalities, between 1,907,072 and 2,474,430 disabling injuries and costs between $43.15 billion and $56.02 billion. This paper reanalyzes the data base and assumptions underlying these estimates and concludes that they greatly overestimated the probable relationship between sleepiness and accidents. A more moderate estimate of this important relationship is proposed.

Accidents↗
PubMed1994

Sleep as a biological rhythm: a historical review.

In the early 1960s sleep was generally viewed as a homeostatic system and its circadian rhythm characteristics were unexplored. During this period the maturing field of chronobiology had paid scant attention to sleep as a biological system. In the late 1960s and early 1970s, the concepts and procedures of chronobiology were rapidly incorporated into sleep research. By the 1980s, the conception of sleep as a circadian rhythm had been accomplished. This major and rapid paradigm shift can be attributed largely to the accessibility of the developed area of chronobiology.

Biological Clocks↗
PubMed1994

A case of extremely long sleep and waking episodes.

This report analyzes the sleep/wake patterns of a 32-year-old severely mentally retarded person with extreme periods of sleep and waking. The sleep and waking patterns were obtained from behavioral observations for 1 year. The validity of these observations was assessed by parallel actigraph recordings and behavioral observations for 1 month. The mean sleep episode was 30.5 hours in length and the mean waking episode was 30.9 hours in length. The longest sleep episode was 131 hours and the longest wake episode was 154 hours. There was little evidence of systematic homeostatic or circadian patterning.

Adult↗
PubMed1993

Sleep disorders.

Explore the source record for details and available documents.

Female↗
PubMed1989

Consistency of respiratory measurements from night to night during the sleep of elderly men.

Fourteen healthy elderly men had polysomnography performed on two consecutive nights to assess the consistency of sleep and breathing from night to night. The reported first-night effect was seen on electroencephalographic sleep, leading to lighter or fitful sleep on the first night. Mean values for apneas, hypopneas, and oxygen desaturations did not change from night 1 to night 2. Five of 14 subjects would have changed classification from night to night if a cutoff of five apneas and hypopneas per hour were used to define normality. Because this numerical cutoff may not be valid in the elderly, the clinical significance of such a changing classification is not clear.

Aged↗
PubMed1989

Age-related changes in sleep.

Within a wide range of individual differences, there are age-associated changes in the characteristics of sleep. There are shifts toward the extremities in sleep amounts, increased difficulties in initiating or maintaining sleep at night, and an emergence of naps. There are also changes in sleep structure. It is within these age-related changes that sleep disorders must be considered.

Adult↗
PubMed1988

An objective behavioral model of sleep.

Theories and models are useful in organizing research data. This paper reviews earlier models and a recent model that combines restorative and adaptive models into a two-factor theory. A model emphasizing a three-factor model with modulators is presented as an organizing schema.

Adaptation, Psychological↗
PubMed1987

Temperature rhythms in native Alaskan and Caucasian children.

The oral temperatures of native Eskimo and Caucasian school children between 10 and 13 years of age were measured at four times of day and once at night on four consecutive days during the Spring and Fall. There were significant differences across the daily measures indicating circadian entrainment. There were no differences between the native and Caucasian groups indicating that earlier reports of less well defined circadian rhythms in adult native Eskimos were not due to inherent rhythm limitations in native Eskimos.

Adolescent↗
PubMed1986

Enhanced slow sleep in extended sleep.

The slow wave sleep (0.5-2.5 Hz) of 42 subjects who slept in a laboratory for more than 8 h was examined. Although the amount of slow wave sleep diminished exponentially across the first 11 h of sleep, there is evidence of an increase in amount of slow wave sleep in more extended sleep. This finding complicates the concepts of slow wave sleep as an index of sleep need due to prior wakefulness or an index of a restoration process.

Adult↗
PubMed1986

Sleep deprivation of rats by punitive and non punitive procedures.

A series of experiments compared sleep deprivation of rats by sleep contingent shock and by non punitive procedures. Sleep overrode shock in approximately 24 hours. Animals were kept awake by non punitive procedures for 12 and 15 days. Recovery measures were higher for the non punitive procedures.

Animals↗
PubMed1986

Sleep deprivation and reading comprehension.

Ten older subjects (50-60 years of age) took a college level reading comprehension test after two nights without sleep. Their performance was compared with performance on an alternate form given prior to sleep deprivation. The six subjects who completed the test showed little evidence of reduced reading rate or comprehension. However, only three subjects were able to sustain their levels of non-deprived performance.

Arousal↗
PubMed1986

Effects of a limited nap on night sleep in older subjects.

The night sleep of sixteen 50-60-year-old women, which had been preceded by either afternoon naps or no-nap control periods, was assessed by polygraphic and subjective measures. There were 2 nap and 2 non-nap nights. The naps were limited to a 1-hr opportunity. The measures of all subjects, good nappers (more than 20-min sleep on both nap occasions), and subjects with 50-min or more nap time, were separately analyzed. The null hypothesis of a nap effect could not be rejected. Within limits, naps may be recommended to offset the common night-time awakenings in older persons.

Circadian Rhythm↗
PubMed1986

Nocturnal hypoxia and neuropsychological variables.

Hypoxia is a well known cause of brain dysfunction. Neuropsychological impairments have been observed in normal subjects experiencing hypoxia iatrogenically as well as in patients with chronic lung disease. Recent investigations have demonstrated significant nocturnal hypoxia in subjects with sleep-disordered breathing. In the present study, heavy-snoring males, a group known to experience frequent episodes of sleep-disordered breathing received neuropsychological testing and a night of continuous monitoring of respiratory parameters. Partial correlations, controlling for age, weight, and education, indicated reliable relationships between nocturnal hypoxia and measures of general intelligence, verbal and nonverbal memory, and expressive verbal fluency. It is proposed that heavy-snoring males may potentially serve as a population in which to model the neurobehavioral effects of hypoxia. Further research in subjects with sleep-disordered breathing may help clarify the extent of the possible cognitive deficits as well as point out possible ameliorative treatments.

Brain Damage, Chronic↗
PubMed1986

Sleep-disordered breathing and its concomitants in a subclinical population.

In order to evaluate possible deficits accompanying sleep-disordered breathing (SDB) in a subclinical population, the nocturnal respiration, health status, and sleep/wake cycle of 46 healthy, heavy-snoring men were measured. Sixty-two percent of these subjects had at least one episode of apnea/hypopnea, while 13% had high levels of apnea/hypopnea [apnea/hypopnea index (AHI) greater than or equal to 5]. Most events occurred in stages 1 or 2 or in REM sleep. Strong relationships between weight and SDB were observed, as were more modest relationships between age and SDB. Correlational procedures indicated relationships between SDB and higher blood pressure, subjective sleepiness, and napping. Because similar, but stronger, relationships involving these variables are observed in patients with a sleep apnea syndrome (SAS), it appears that a continuum exists between heavy-snoring men and patients with SAS. When these subjects were grouped by level of SDB, subjects with high levels of SDB (AHI greater than or equal to 5) had significantly lower nocturnal oxygenation parameters than the remaining subjects. However, there were no between-group differences in health or sleep/wake variables. It is concluded that while apnea/hypopnea events in subclinical populations may not be completely benign events, the level at which they may be considered frankly pathological is presently unclear.

Adult↗