The cephalometric analysis of two groups: 30 sleep apnoea patients, and 30 age- and sex-matched control patients, established predictors for the orthopaedic mandibular advancement by means of the Esmarch device (ED) in treating obstructive sleep apnoea (OSA). Polysomnographic sleep and ventilation data gathered for each patient with and without mandibular advancement by means of the ED were compared. Cephalometric data and treatment efficacy for each patient were submitted to a regression analysis. Maximal efficacy is predicted by: 1. The combination of an orthognathic to prognathic maxilla (SNA larger than or equal to 83 degrees) with an orthognatic to retrognathic mandible (SNB less than or equal to 77 degrees) 2. An anterior superior displacement of the mandible, with the supramentale situated at a distance from the anterior part of second cervical vertebra (B-HWK 2 longer than or equal to 95.5 mm) and a narrow angle between the skull and the mandibular ramus (SN/B-Go equal to or less than 1.5 degrees) 3. Short oral height (TB-PNS equal to or less than 35.5 mm), with the uvula not extending beyond the tongue base (UT-PNS, equal to or less than 30 mm). 4. A narrow oropharynx (PAS equal to or less than 3.4 mm). The narrower the SNB-angle, the wider the SNA-angle, and the shorter the uvula, the more effective the device.

Five subjects--four men, ages 17-28, and one woman, age 30--with Kleine-Levin syndrome were investigated during symptomatic (SP) and asymptomatic (ASP) periods. Investigations comprised medical history, MRI, polysomnography, 24-hour hormone profile of human growth hormone, melatonin, TSH, cortisol and FSH (in the woman only) assessed every 2 hours, actimetry, and sleep logs. Medical history confirmed presence of the three symptoms diagnostic of of typical Kleine-Levin syndrome: hypersomnia, excessive food intake, and psychic alteration. MRIs of the brain were normal in all patients. Symptomatic periods were triggered by unspecific events, such as infection, sleep deprivation, and alcohol. Polysomnography revealed low sleep efficiency during SPs, decreased amount of slow-wave sleep, and high frequency of stage shifts, indicating sleep fragmentation. Mean 24-hour growth hormone levels were reduced during the SPs in only two patients. Their hGH peaks were dissociated from slow-wave sleep during attacks and intervals, often occurring during wake time. Twenty-four-hour melatonin levels were increased during the SPs in all patients, but were lower in two patients during the nocturnal sleep period. Cortisol, TSH and FSH did not reveal important differences between attacks and intervals. Except for hGH, all hormones had normal circadian excretion during symptomatic and asymptomatic periods. Amplitude of nocturnal activity as assessed by actimetry was significantly increased in two patients, whereas amplitude of daytime activity was significantly reduced in three patients. Actimetry and sleep logs demonstrated prolonged sleep phases during SPs. Our investigation could confirm changes of sleep structure described in the literature. The neuroendocrinological findings could not confirm decreased hGH and cortisol and increased TSH levels during SPs, as previously reported in single cases by many authors. Endocrinological findings did not support an underlying circadian disorder in KLS.

This preliminary study investigates effects of methyl- and cyanocobalamin on circadian rhythms, well-being, alertness, and concentration in healthy subjects. Six women (mean age 35 years) and 14 men (mean age 37 years) were randomly assigned to treatment for 14 days with 3 mg cyano-(CB12) or methylcobalamin (MB12) after 9 days of pre-treatment observation. Levels in the CB12 group increased rapidly in the first, then slowly in the second treatment week, whereas increase in the MB12 group was linear. Urinary aMT6s excretion was reduced by both forms of vitamin B12 over 24 hours with a significant decrease between 0700-1100 hours, whereas urinary excretion of potassium was significantly increased between 0700-1100 hours. Activity from 2300-0700 hours increased significantly under both forms of vitamin B12. Sleep time was significantly reduced under MB12 intake. In this group the change in the visual analogue scales items "sleep quality," "concentration," and "feeling refreshed" between pretreatment and the first week of treatment showed significant correlations with vitamin B12 plasma levels. Cortisol excretion and temperature were not affected by either medication. We conclude that vitamin B12 exerts a direct influence on melatonin. Only MB12 has a positive psychotropic alerting effect with a distribution of the sleep-wake cycle toward sleep reduction.

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