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Biomedical subjects

D T Berry

Publications and source records attributed to D T Berry.

30 records · Page 2Linked to original sources
PubMed1990

Nocturnal bruxing events in healthy geriatric subjects.

Thirty healthy geriatric subjects were studied during a single night of sleep in a sleep laboratory. Unilateral masseter muscle activity was recorded in addition to the standard polysomnographic study. The geriatric subjects in this study exhibited fewer bruxing events than other subjects reported in the literature. Certain conditions that have not been previously investigated, such as sleep position, type of bruxing event, and relationship to the state of the dentition, are reported.

Aged↗
PubMed1990

Treatment of obstructive sleep apnea. A preliminary report comparing nasal CPAP to nasal oxygen in patients with mild OSA.

Nasal CPAP is presently accepted as first-line therapy for obstructive sleep apnea, but a significant minority of patients do not tolerate nasal CPAP. The purpose of this study was to compare the benefits of nasal CPAP, nasal oxygen (O2), and placebo (air) using patients as their own controls. We studied eight men, aged 33 to 72 (mean 57 years), who had mild obstructive sleep apnea. To be eligible for study, patients had to have an apnea plus hypopnea index greater than or equal to 5, plus one or more of the following: blood pressure greater than 150/95 mm Hg, multiple sleep latency test mean score less than or equal to 10 minutes, or significant nocturnal cardiac ectopy. After a baseline study, patients received a month each of nocturnal O2 at 4 LPM and air at 4 LPM, presented in random order. The third month of treatment consisted of nasal CPAP (range 2.5 to 12.5 cm H2O). Patients underwent evaluation at baseline and after each month of treatment. It was concluded that oxygen was more effective in improving oxygenation and hypopneas than is nasal CPAP. However, oxygen did not reduce apneas or improve daytime hypersomnolence as well as nasal CPAP in patients with mild OSA. Oxygen might be considered as an alternate form of treatment for patients who are not hypersomnolent, or as an adjunct to nasal CPAP.

Adult↗
PubMed1989

Isocapnic hypoxemia and neuropsychological functioning.

We evaluated the cognitive effects of hypoxemia independent of hypocapnia in 20 right-handed male subjects using a battery of brief neuropsychological tests. Results of a profile analysis indicated that performance during hypoxia was reliably different for Digit Symbol and Finger Tapping tests. Trend analysis demonstrated a significant linear pattern for Finger Tapping results, such that lower levels of oxygen were associated with slower rates of tapping. No significant trends were observed for Digit Symbol results. The observation of hypoxic effects on Digit Symbol and Finger Tapping tests is consistent with previous findings of neuropsychological changes secondary to hypoxia. The negative results observed for the remaining tests are inconsistent with past literature. It is likely that methodological differences contributed to these discrepancies, including previous reliance on inspired air to index hypoxemia rather than monitoring arterial oxygen saturation directly and failure to control for differences in CO2 levels during induced hypoxia. These variables should be controlled in future research.

Adult↗
PubMed1989

Sleep-disordered breathing in healthy aged persons: one-year follow-up of daytime sequelae.

We studied the waking medical, sleep, and psychological status of 28 healthy older persons who had undergone nocturnal polysomnography and daytime assessment approximately 1-year earlier. In a previous report based on this sample, we found that sleep-disordered breathing (SDB) indices were not related to concurrent measurements of daytime functioning. However, in the present study, we observed relationships between the original SDB indices and several measures of cardiopulmonary functioning obtained 1 year later. At follow-up, subjects with originally high levels of SDB had significantly higher systolic blood pressure and poorer pulmonary function test results, were more likely to report irregular heartbeats in the previous year, and had experienced more disruptive snoring than the remaining subjects. When combined with other recent data, these results raise the possibility that SDB exerts an insidious pathological influence on the health and daytime functioning of otherwise healthy older persons.

Aged↗
PubMed1987

Sleep-disordered breathing in healthy aged persons: possible daytime sequelae.

We assessed the overnight sleep and breathing as well as daytime medical, sleep, and psychological status of a group of 34 healthy older persons. Analyses indicated that sleep-disordered breathing (SDB) was not related to any aspects of daytime functioning as measured in this study and that persons with an apnea + hypopnea index (AHI) greater than or equal to 5 (M AHI = 14.6) were not significantly impaired relative to those with lower levels of SDB (M AHI = 1.0) on any aspect of daytime performance. We conclude that SDB occurring in healthy aged persons is probably not of immediate concern and that the use of a cutting score of AHI greater than or equal to 5 for diagnosis of sleep apnea syndrome is not indicative in healthy aged persons. However, these results may not be applicable to older persons who are not in the excellent state of health that was required for participants in our study.

Aged↗
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↗
PubMed1985

Mood and sleep in aging women.

The possible covariations of mood and sleep was examined in a group of 25 normal, aging women. Mood assessments made in the evenings of 3 consecutive days were independently related to both before and after sleep night. Only two sleep variables: sleep efficiency and latency to first rapid eye movement (REM) period--were reliably related to daytime moods. The relative paucity of relation between mood and sleep variables was interpreted as reflecting a general insulation of sleep from day-to-day mood variations.

Affect↗
PubMed1985

Sleep and cognitive functions in normal older adults.

Data on cognitive and sleep variables were collected from a large, normal aging sample. The sleep and cognitive variables selected for the study had all been demonstrated previously to be sensitive to aging processes. Only two sleep variables, number of awakenings and time in Stage 1 sleep, correlated with cognitive scores. The limited number of relationships between sleep and cognitive variables was interpreted as consistent with the discontinuity hypothesis. This formulation suggests that relationships between biological and psychological measures are only present after a threshold of deterioration in the biological substrates is passed. Thus the paucity of relationships between the two variable classes is predicted in this normal aging sample.

Aged↗
PubMed1984

Sleep apnea syndrome. A critical review of the apnea index as a diagnostic criterion.

The utility of the apnea index (number of apneic events per hour of sleep) in diagnosing sleep apnea syndrome is reviewed. Data from currently extant reports indicate that many otherwise normal, aging subjects may be classified as having sleep apnea syndrome based on the current diagnostic threshold of five apneic episodes per hour: A chi 2 analysis suggests a relationship between age and level of sleep apnea. Several other reports indicate that use of a threshold of five apneic episodes per hour does not reliably predict increased health risk or somnolence in aging subjects. Adjustment of the apnea index, based on studies of aging normal subjects and of aging patients with sleep apnea syndrome is necessary to ensure reliable results in clinical and research applications.

Adult↗