1/5. Decreased human circadian pacemaker influence after 100 days in space: a case study.OBJECTIVE: The objectives of this study were (1) to assess the circadian rhythms and sleep of a healthy, 42-year-old male astronaut experiencing microgravity (weightlessness) for nearly 5 months while living aboard Space Station Mir as it orbited Earth and (2) to determine the effects of prolonged space flight on the endogenous circadian pacemaker, as indicated by oral temperature and subjective alertness rhythms, and their ramifications for sleep, alertness, and performance. methods: For three 12- to 14-day blocks of time (spread throughout the mission), oral temperatures were taken and subjective alertness was self-rated five times per day. sleep diaries and performance tests were also completed daily during each block. RESULTS: Examination of the subject's circadian alertness and oral temperature rhythms suggested that the endogenous circadian pacemaker seemed to function quite well up to 90 days in space. Thereafter (on days 110-122), the influence of the endogenous circadian pacemaker on oral temperature and subjective alertness circadian rhythms was considerably weakened, with consequent disruptions in sleep. CONCLUSIONS: Space missions lasting more than 3 months might result in diminished circadian pacemaker influence in astronauts, leading to eventual sleep problems.- - - - - - - - - - ranking = 1keywords = circadian rhythm, rhythm (Clic here for more details about this article) |
2/5. Psychiatric features and disturbance of circadian rhythm of temperature, pulse, and blood pressure in Wilson's disease.Wilson's disease (hepatolenticular degeneration), a disease of genetic origin, is due to abnormal copper metabolism affecting many organs and systems, especially the liver and the nervous system. The initial symptoms can be exclusively or predominantly psychiatric, including psychotic features. Three cases are reported in which the clinical picture at the beginning was compatible with a psychiatric diagnosis. During hospitalization, before treatment, there were abnormal and spontaneous changes in the circadian rhythm of temperature, pulse, and blood pressure, recorded every 6 hours, with febrile peaks in the absence of infectious focus. Because the hypothalamus is important in the regulation of these autonomic functions, the hypothesis of a possible hypothalamic dysfunction was made, justifying a wide clinical and laboratory investigation that allowed the diagnosis of Wilson's disease. Alertness to circadian rhythm abnormalities in such cases may help the psychiatrist avoid an erroneous diagnosis.- - - - - - - - - - ranking = 2.9565243197114keywords = circadian rhythm, rhythm, hour (Clic here for more details about this article) |
3/5. Selective circadian rhythm disturbance in cerebral lymphoma.We present a patient with cerebral lymphoma who developed a selective circadian rhythm disturbance. Treatment with modafinil led to a considerable improvement in quality of life.- - - - - - - - - - ranking = 2.4637699858502keywords = circadian rhythm, rhythm (Clic here for more details about this article) |
4/5. association between delayed sleep phase and hypernyctohemeral syndromes: a case study.STUDY OBJECTIVE: We investigated whether the hypernyctohemeral syndrome (non-24-hour sleep-wake syndrome) may show a clinical association with the delayed sleep phase syndrome (DSPS) in a 39-year-old woman who developed sleep disturbances following a traumatic brain injury. MEASUREMENTS AND RESULTS: sleep-wake log documentation and wrist-activity recordings for more than 6 consecutive months confirmed the patient's tendency to live on longer-than-24-hour "days." Episodes of relative coordination to the 24-hour day were also noted, suggesting that the patient was transiently in and out of phase with environmental synchronizers too weak to fully entrain her to the geophysical environment. Interestingly, we noted a tendency to initiate sleep between 3:00 am and 5:00 am and wake up from sleep between noon and 1:00 pm. CONCLUSIONS: These results support an association between the hypernyctohemeral syndrome and the DSPS. This association may carry implications for the treatment of circadian rhythms disorders.- - - - - - - - - - ranking = 0.49275500724345keywords = circadian rhythm, rhythm, hour (Clic here for more details about this article) |
5/5. Transient short free running circadian rhythm in a case of aneurysm near the suprachiasmatic nuclei.A free running circadian rest-activity cycle is rare in sighted individuals living in a normal environment. Even more rare is a periodicity shorter than 24 hours, as observed in actigraphic recordings in a female patient during convalescence after a whiplash injury in a car accident. The documented free running period was 22.5 hours for 19 days. During the subsequent weeks re-entrainment occurred following re-establishment by a social zeitgeber, with a slightly early circadian phase of nocturnal melatonin onset relative to a late sleep period. magnetic resonance imaging and cerebral angiography showed an aneurysm at the bifurcation of the right internal carotid artery, close to the circadian pacemaker structure (the suprachiasmatic nuclei), which was later occluded.- - - - - - - - - - ranking = 1.9710166620624keywords = circadian rhythm, rhythm, hour (Clic here for more details about this article) |