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Biomedical subjects

P Lavie

Publications and source records attributed to P Lavie.

At least 19 recordsLinked to original sources
PubMed1992

Increased motor activity and recurrent manic episodes: predictors of rapid relapse in remitted bipolar disorder patients after lithium discontinuation.

Ten patients with remitted bipolar illness on lithium maintenance therapy underwent placebo-controlled lithium discontinuation. Clinical ratings and recording of sleep-wake activity using wrist-worn actigraphs were carried out before and after lithium discontinuation. Seven patients experienced relapse into mania or hypomania within the first 3 months after lithium discontinuation. Actigraphic recordings revealed that patients who relapsed had higher baseline levels of daytime motor activity than patients without relapse. This may suggest that motor activity can be a sensitive marker of subclinical manic tendencies and early relapse following lithium discontinuation.

Adult↗
PubMed1992

Bariatric surgery in morbidly obese sleep-apnea patients: short- and long-term follow-up.

Forty-seven obese sleep-apnea patients were investigated in the sleep laboratory before and after a massive weight reduction achieved by bariatric surgery. The first postoperative sleep investigations were performed approximately 1 y after surgery and revealed a highly significant decrease in the number of apneic episodes per hour of sleep and a significant improvement in all sleep-quality-related measures. A second postoperative sleep study was performed approximately 7 y postoperatively and revealed that regaining of weight was associated with the reappearance of sleep apnea syndrome, although the great majority of the patients still felt, subjectively, that they were well and did not suffer from recurrence of the sleep apnea syndrome.

Adult↗
PubMed1992

Prolonged sleep-deprivation induced disturbed liver functions serum lipid levels, and hyperphosphatemia.

Sixty-four healthy young male volunteers were kept awake from 76 to 80 h. Blood tests conducted at the start and conclusion of the continuous sleep deprivation revealed an increase of 170% in mean SGOT, 58.5% in mean SGPT and 37.5% in mean plasma phosphorus levels. Triglyceride levels decreased by 16%, while HDL levels increased by 18% and the apoB/apoA ratio decreased by 12%. Morning plasma cortisol showed a significant increase during the experiment while evening cortisol showed a significant decrease. Morning T3 levels increased from the first to second day and decreased on the third day. There were no significant changes in other plasma electrolyte levels.

Adult↗
PubMed1992

Toddlers' sleep and temperament: reporting bias or a valid link? A research note.

Objective sleep measures derived from a computerized movement detector attached to the child's leg, were obtained for a group of 31 toddlers (mean age: 18.5 months). The monitored sleep parameters were compared with maternal assessment of the child's sleep and her perception of his temperament. The validity of maternal diaries as a measure of the child's sleep was not supported. Nevertheless, a link between both subjective and objective sleep measures with temperament dimensions was indicated. The modest association between sleep and temperament may suggest either a continuity between some aspects of day- and night-time functioning or, alternatively, the influence of the child's sleep behavior in shaping the mother's perceptions of her toddler's temperament.

Child, Preschool↗
PubMed1992

The 24-hour sleep propensity function: experimental bases for somnotypology.

The present study investigated the temporal structure of sleep propensity during 48 hours using an ultrashort 7-min sleep/13-min wake cycle. Eight subjects were tested under two experimental conditions of either attempting sleep, or resisting sleep after a monitored night in the laboratory. Electrophysiological recordings were carried out during the 7-min trials. The temporal structure and the overall level of sleepiness of the 48-hour sleep propensity functions calculated from the amount of total sleep in each trial revealed a high within-subjects stability. This was found both across the two days of the study within conditions, and across conditions. Also, diurnal levels of sleepiness were systematically related to nocturnal sleep parameters. Subjects having short nocturnal sleep latencies and higher sleep efficiencies slept more during the day. It is proposed that the structure and level of the sleep propensity function can be used to characterize individuals along two dimensions of somnotypology: "morningness-eveningness" and "sleepy-alert."

Adult↗
PubMed1992

The importance of timing in melatonin administration in a blind man.

An 18-year-old blind man suffered from chronic sleep disturbances associated with daytime fatigue and excessive daytime somnolence. After two unsuccessful treatment regimens with 5 mg and 10 mg melatonin administered at bedtime (2200-2230), a third regimen of 5 mg melatonin administered at 2000 for 3 weeks resulted in a successful resolution of his sleep disturbances. We suggest that the efficacy of melatonin in ameliorating sleep disturbances because of alterations in circadian rhythmicity may be dependent on the time of administration.

Adolescent↗
PubMed1992

Two 19th-century chronobiologists: Thomas Laycock and Edward Smith.

This article describes the works of two 19th-century chronobiologists. Thomas Laycock (1812-1876), who held the Chair of Medicine in Edinburgh from 1855-1876, published a series of seven articles in Lancet, all dedicated to periodicities in "vital phenomena." Laycock considered the understanding of periodicities essential for the advancement of the treatment of diseases. Edward Smith (1818-1874) was a pioneer in experimental chronobiology. In his 1861 book entitled: Health and disease as influenced by daily, seasonal and other cyclical changes in the human, Smith summarized a large number of experiments in which he investigated the occurrence of periodicities in pulse rate, urine flow, urea excretion, and respiration. From his experimental results and those of others, Smith drew practical conclusions regarding patients' care, the timing of drug administration, and the design of night work.

Animals↗
PubMed1992

Actigraphic measurements of sleep in rheumatoid arthritis: comparison of patients with low back pain and healthy controls.

Actigraphic recordings during sleep were carried out in patients with rheumatoid arthritis (RA), in patients with chronic low back pain, and in healthy controls for 4 consecutive nights. All derived measures of sleep quality showed that the sleep of patients with RA was significantly poorer than controls, while patients with chronic low back pain had sleep quality not significantly different from either group. Polysomnographically defined periodic movements in sleep were significantly related to sleep efficiency in patients with RA. Clinical status in these patients was significantly related to several actigraphic sleep measures.

Arthritis, Rheumatoid↗
PubMed1991

Elevated awakening thresholds in sleep stage 3-4 in war-related post-traumatic stress disorder.

Awakening thresholds from sleep stage 3/4 were investigated in 19 DSM-III-defined, war-related post-traumatic stress disorder (PTSD) patients compared with 6 normal controls. Patients had significantly higher awakening thresholds and significantly longer latencies to an arousal response than controls. These results are interpreted to suggest modifications in the depth of sleep as one of the long-term sequelae of traumatic events.

Acoustic Stimulation↗
PubMed1991

Nonsteroidal antiinflammatory drug therapy in rheumatoid arthritis patients. Lack of association between clinical improvement and effects on sleep.

Thirteen patients with rheumatoid arthritis (mean +/- SD age 55.8 +/- 10.5 years) received 20 mg of tenoxicam daily for 90 days following a 3-7 day "washout" period and 4 days of placebo treatment. Clinical evaluations were conducted at the end of the washout period and at monthly intervals thereafter. All-night polysomnography was performed in a sleep laboratory during the last 2 days of placebo treatment and on days 13, 14, 89, and 90 of tenoxicam treatment. Although there was improvement in the patients' clinical condition, there were no treatment-related changes in any of the sleep parameters. Eight of the 13 patients, however, were found to have primary sleep disorders. Four had periodic leg movements during sleep, 3 had sleep apneas, and 1 had a combination of both disorders. The implications of these findings in the treatment of sleep disorders in patients with rheumatoid arthritis are discussed.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

The value of sleep recording in evaluating somnambulism in young adults.

Somnambulism (SOM) is a benign childhood sleep disorder which may persist until young adulthood. The diagnosis relies heavily on the history, and no polysomnographic (PSG) criteria have yet been defined. The present study attempts to evaluate the role of whole-night polysomnographic recording in the investigation of SOM. The PSG records of 24 sleepwalkers, 18-25 years old, and 12 age-matched controls, were analysed. Sleepwalkers had remarkably more epochs containing hypersynchronous delta waves (HSD) (59.6 +/- 60.1 vs. 1.7 +/- 3.2; P less than 0.0001), a higher proportion of HSD/total time spent in stage 3-4 (24.9 +/- 21.1% vs. 1.1 +/- 2.0%, P less than 0.0002), and more stage 3-4 sleep interruptions (8.4 +/- 5.7 vs. 3.7 +/- 1.7, P less than 0.004). They also tended to have a larger proportion of their sleep time in stage 3-4 (30.6 +/- 11.7% vs. 22.6 +/- 6.8%; P less than 0.07). Although their sensitivity and specificity have yet to be more fully investigated, these seem to be quantitative, easy-to-use variables which may characterize adult SOM and may aid in its proper diagnosis.

Adolescent↗
PubMed1991

REM periodicity under ultrashort sleep/wake cycle in narcoleptic patients.

Six narcoleptic patients were tested three times on the 13-min waking/7-min resisting sleep paradigm each time after a night of sleep in the laboratory. The three experiments were conducted after 10 days without any antinarcoleptic treatment or after 2 weeks of daily treatment with either methyl-phenidate or aniracetam. The results showed that patients had pronounced levels of diurnal sleepiness in all three experimental conditions with a midafternoon peak at around 1300-1500 hr and a nadir at around 1800 hr. Methyl-phenidate significantly reduced REM sleep and marginally reduced total sleep in comparison with the no-treatment and aniracetam conditions. REM sleep in the 7/13 paradigm appeared cyclically with a dominant periodicity of 80 min/cycle. The cycles tended to be synchronized across patients and were unrelated to the temporal structure of total sleep. The present results support the continuation of the REM oscillator during brief periods of waking, but suggest that the REM periodicity is unrelated to Kleitman's BRAC model of arousal.

Adult↗
PubMed1991

Discontinuation of lithium treatment in remitted bipolar patients: relationship between clinical outcome and changes in sleep-wake cycles.

In this preliminary report, we describe four patients in whom long-term lithium therapy was discontinued, combined with actigraphic monitoring to assess changes in motor activity and the sleep-wake cycle. Two patients experienced rapid relapse of manic symptomatology, while two remained stable throughout a 1-year follow-up. Actigraphic monitoring revealed disintegration of the sleep-wake cycle and increased motor activity in the relapsed patients only. It is suggested that actigraphic recordings can be used to monitor lithium discontinuation.

Ambulatory Care↗
PubMed1991

Sleep and dreaming in Holocaust survivors. Dramatic decrease in dream recall in well-adjusted survivors.

Sleep data were obtained on 12 well-adjusted and 11 less-adjusted Holocaust survivors and on 10 control subjects. Each was also awakened from rapid eye movement sleep for dream recall. The less-adjusted survivors had more prolonged sleep latency than the well-adjusted and the control groups and lower sleep efficiency than the control subjects. The well-adjusted group had a significantly lower dream recall rate (33.7%) than the less-adjusted (50.5%) and control groups (80%). There were also significant between-groups differences in dream structure and dream content, in the direction of less complex and less salient dreams in the well-adjusted survivors. It is suggested that the decrease in dream recall is one of the forms of long-term adjustment to severe traumatic events.

Adaptation, Psychological↗
PubMed1991

Sleep-wake cycles in multi-infarct dementia and dementia of the Alzheimer type.

We monitored by actigraphs minute-by-minute activity of 10 patients with multi-infarct dementia (MID), 15 patients with dementia of the Alzheimer type (DAT), and 11 control volunteers for eight consecutive 24-hour periods to assess sleep-wake cycles and sleep quality. MID patients had disrupted sleep-wake cycles associated with decreased sleep quality. In contrast, ambulatory DAT patients maintained a relatively normal sleep-wake cycle that did not differ significantly from controls. There was no correlation between the severity of intellectual deterioration and the degree of sleep-wake cycle disintegration in either group of dementia patients.

Aged↗
PubMed1991

Circadian rhythms in 6-sulphatoxymelatonin and nocturnal sleep in blind children.

This article describes the relationship between melatonin secretion and sleep quality and subjective complaints about sleep in totally blind children. Eleven boarding-school children (mean age 15.2 years) participated. The major urinary melatonin metabolite 6-sulphatoxymelatonin (aMT6s) was measured five times a day for 48 h. Sleep-wake cycles were recorded by continuous actigraphic recordings during the same time period. Results showed that delayed secretory peaks in aMT6s were significantly associated with disturbed nocturnal sleep and with complaints about morning fatigue.

Adolescent↗
PubMed1991

Actigraphic home-monitoring sleep-disturbed and control infants and young children: a new method for pediatric assessment of sleep-wake patterns.

Two studies were conducted to evaluate actigraphic home-monitoring for the assessment of infants' and children's sleep patterns. In the first study, 11 children (aged 12 to 48 months) were monitored in the laboratory by traditional polysomnography and by actigraphy for one night. Actigraphic automatic sleep-wake scorings were compared with those of the polysomnograph; total agreement rate was 85.3%. In the second study, sleep patterns of 63 sleep-disturbed and 34 control healthy children (aged 9 to 27 months) were compared. These children were home-monitored by actigraph for a mean of 4.45 nights (total 482 nights). Actigraphic data were analyzed by an automated scoring procedure. Sleep quality of the sleep-disturbed children, measured by actigraphically derived sleep percent and number of longer-than-5-minute wakings, was significantly lower than that of the control subjects (P less than .0001). Sleep measures showed significant night-to-night stability in both groups. The stability of specific measures and their age trends were different between the groups. Actigraphic sleep measures alone could discriminate between sleep-disturbed and control children with a highly correct assignment rate of 79.4% and 91.2%, respectively.

Age Factors↗