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W C Dement

Publications and source records attributed to W C Dement.

At least 19 recordsLinked to original sources
PubMed1992

Melatonin influences Fos expression in the rat suprachiasmatic.

Administration of the pineal hormone melatonin to rats induces expression of Fos, the protein product of the c-fos proto-oncogene, in the suprachiasmatic nucleus (SCN), the putative biological clock of mammals. Expression of the Fos protein is dependent on circadian phase: injections in the late subjective night (circadian time (CT) 22) induce Fos expression in cells within the ventral SCN whereas injections during the subjective day are ineffective. Since melatonin injections in the late subjective day have previously been shown to phase advance circadian rhythms, these results indicate that phase-advances of the circadian system can occur without increased expression of Fos protein in the SCN, at least at levels detectable by immunohistochemistry. In support of in situ hybridization histochemical evidence obtained previously, immunocytochemical data from vehicle-injected control rats suggest that the Fos protein undergoes an endogenous fluctuation with peak levels in the SCN occurring during the subjective night. These observations indicate that melatonin can affect immediate early gene expression within the SCN.

Animals↗
PubMed1979

REM sleep episodes during the Multple Sleep Latency Test in narcoleptic patients.

Forty narcoleptic patients were given the Multiple Sleep Latency Test, consisting of 20 min opportunities to sleep offered at 10.00, 12.00, 14.00, 16.00 and 18.00 o'clock. Eleven patients had 2 episodes of REM sleep, 5 had 3, 11 had 4, and 13 had 5 before they were awakened. Fourteen control subjects given similar opportunities to sleep (reported in a companion article (Richardson et al. 1978)) had no REM sleep episodes. For the 10.00-18.00 o'clock opportunities respectively, there were 32, 29, 30, 28 and 27 REM sleep episodes. We conclude that this procedure can provide physicians with data useful in the diagnosis of narcolepsy.

Adult↗
PubMed1979

Sleep state effects on breathing after spinal cord transection and vagotomy in the cat.

The role of chest wall and vagal afferents on breathing during wakefulness (W), nonrapid eye movement sleep (NREM), and REM sleep was assessed in 16 adult cats implanted with electrodes and skull bolts for sleep recordings with head restraint. Breathing was monitored with a pneumotachograph. Following control recordings establishing characteristic respiratory patterns during each state, cats sustained spinal cord transections at T-1, vagotomies, or both. The transections decreased variability of breathing rate, while vagotomies decreased rate but increased variability and tidal volume. These deafferentations alone or in combination failed to eliminate the major effects of state upon breathing pattern. Different states of consciousness were associated with significant changes on every measured breathing parameter, but the interactions of these effects with the deafferentations were small or nonsignificant. The vagus, however, appears to play its largest role during NREM. We hypothesize that while vagal afference functions during all states to terminate inspiration, during W and REM separate but functionally equivalent mechanisms of central origin supplement the vagus in facilitating the termination of inspiration. The absence of these mechanisms during NREM accounts for the increased vagal influence during this state.

Animals↗
PubMed1979

Genetic factors in canine narcolepsy.

The mating of narcopleptic Doberman pinschers yielded 30 puppies in five litters, all of which developed the disease between 1 and 4 months of age. Pedigrees of the Doberman probands are indicative of an autosomal recessive mode of transmission. An analysis of the pedigree of five affected Labrador retriever littermates suggests a similar mode of transmission. Crosses of affected dogs in two other breeds (miniature poodles and beagles) have resulted in all-unaffected F1 generations, thus allowing rejection of the simplest genetic hypothesis of a fully penetrant autosomal or sex-linked dominant or recessive gene.

Age Factors↗
PubMed1979

Hypnotic efficacy of temazepam: a long-term sleep laboratory evaluation.

1 Temazepam was evaluated in a strictly defined insomniac patient population under sleep laboratory conditions. Two protocols were used: a short-term (26-night) and a long-term (54-night) protocol evaluated the efficacy of the drug administered at night at 15 mg (short-term study) and 30 mg (long-term study), respectively. 2 Temazepam seemed to be both safe and effective at doses of 15 and 30 mg with up to 5 weeks of ingestion. 3 Suppression of slow wave sleep was observed at the high dose, but no suppression of REM sleep, found in studies with other benzodiazepines, was noted. 4 No evidence was found for development of tolerance or rebound effects.

Adult↗
PubMed1979

Effects of total sleep loss on sleep tendency.

Effects of two nights of sleep loss were assessed in six young adult (18--21 yr.) volunteers (2 women, 4 men). Performance on the Wilkinson Addition Test fell significantly below baseline values during the sleep-loss procedure and recovered after one or two full nights of sleep. Performance on a Serial Alternation Task also declined during sleep loss. Mood and sleepiness, assessed by subjective self-rating scales, showed a significantly less positive mood and a greater degree of sleepiness during sleep loss, with a recovery to baseline levels after one full night of sleep. Sleep tendency, measured at 2-hr. intervals during all waking periods, was assessed using an objective measure of latency to sleep onset, the Sleep Latency Test. The scores fell to about 1 min. at 0600 on the first night of sleep loss and remained at similarly low values throughout the sleep loss period. After one night of recovery sleep the scores remained significantly below baseline levels, which were not achieved until after the second recovery night. The multiple sleep latency test appears to be a valuable operationally defined tool for measuring daytime sleepiness.

Achievement↗
PubMed1978

Sleep habits of children and the identification of pathologically sleepy children.

Sleep disorders and daytime sleepiness have been investigated only minimally in children. The sleep habits of 218 children, ages 10-13 years, were surveyed by a sleep habits questionnaire (SHQ). Our results demonstrate that total night time sleep on school nights begins to fall in early adolescence, whereas it remains relatively stable on non-school nights. Daytime sleepiness is not a common problem in this age group, in contrast to a college age population. We conclude that in adolescence chronic sleep deficits begin to occur which cumulatively affect later functioning. The potential use of the SHQ for depicting pathological sleepiness is also discussed.

Adolescent↗
PubMed1978

Excessive daytime sleepiness in man: multiple sleep latency measurement in narcoleptic and control subjects.

Excessive daytime sleepiness is a complaint characterizing many disorders of the wakefulness--sleep cycle. This paper addresses the complaint of sleepiness objectively by an attempt to differentiate a group of control subjects from a group of patients with unambiguous narcolepsy. Fourteen control and 27 narcoleptic subjects were evaluated by one of three protocols involving nocturnal recordings, detailed interviews, and 5 or more 20-min opportunities to sleep offered at 2-h intervals beginning at 10.00 o'clock, +/- 30 min. Each 20-min opportunity to sleep was given to subjects lying in a darkened quiet room and asked to try to fall asleep. Polysomnographic variables were monitored and sleep was scored in 30-sec epochs by standard criteria. The interval from the start of each test to the first epoch of NREM (including stage 1 sleep) or REM sleep was called sleep latency. In two of the protocols, the subjects were awakened immediately after sleep onset. In the third protocol, the subjects were awakened after 10 min of sleep. Narcoleptics consistently fell asleep much more readily than did control subjects. We conclude that the Multiple Sleep latency test, in addition to providing opportunities to clinically document sleep onset REM sleep periods, can demonstrate pathological sleepiness. Based on these data, we suggest that an average sleep latency less than 5 min be set as the minimum cutoff point for pathological sleepiness.

Adult↗
PubMed1978

Baclofen trial in six myotonic dystrophy patients.

Six young adult patients with grade I myotonic dystrophy and a complaint of daytime somnolence underwent 36-hour polygraphic monitoring, dynamometric and electromyographic studies before and under baclofen (60 mg/daily). Patients with the most severe daytime sleepiness had pathologic Sleep Apnea Indexes. After 6 weeks' ingestion of baclofen, no subjective or objective effect on patient symptomatology was found.

Adolescent↗
PubMed1978

Tracheostomy and hemodynamic changes in sleep-inducing apnea.

Because pulmonary hypertension and systemic hypertension occur during sleep-induced obstructive apnea, six patients underwent overnight hemodynamic monitoring before and after tracheostomy. Variables studied included heart rate, pulmonary artery pressure, femoral artery pressure, and arterial oxygen tension (Po2). After tracheostomy, significant reductions were noted during sleep in mean pulmonary artery pressure from 45 +/- 6 mm Hg (mean +/- SEM) to 22 +/- 2 mm Hg (P less than 0.05) and in mean femoral artery pressure from 137 +/- 6 mm Hg to 97 +/- 3 mm Hg (P less than 0.005). There was also a significant increase for the group in arterial Po2 recorded during the apneic episodes from 38 +/- 3 mm Hg before tracheostomy to 71 +/- 2 mm Hg (P less than 0.001) after tracheostomy. We conclude that tracheostomy improves the hemodynamic abnormalities and hypoxemia that occur during sleep in patients with sleep-induced obstructive apnea.

Adult↗