Abstract: Sleep-wake rhythms in the elderly are deeply modified compared to young subjects, irrespective of physical or mental illnesses. However, still controversial are the results about age-related circadian variations of sleepiness levels. The objective of this study is to investigate the profile of diurnal sleepiness in healthy elderly subjects through subjective scales and by measuring spontaneous eye-blink rate (BR). In fact, we have previously found that BR, a reliable and non-invasive peripheral measure of central dopamine activity, increases in the young at times when subjective sleepiness is increased. Twelve healthy elderly volunteers (F=9, M=3, age range 64-79) participated in the experiment. At four times during the day (10a.m., 1.30p.m., 5p.m., 8.30p.m.), Karolinska sleepiness scale and a visual analogue scale for mood were administered to the subjects and BR was measured through vertical EOG. Alpha EEG power was used as objective measure of sleepiness. Sleepiness significantly changes across the day; according to post hoc contrasts, this is due to more sleepiness at 5p.m. Future research should be aimed at clarifying whether this peak is related to phase-advanced core body temperature in elderly people. Differently from the young, no significant differences were found in BR across the day, suggesting that an age-related modification of dopaminergic arousal mechanisms counteracting the rising sleep drive should be further explored.
Abstract: Twenty-four hour sleep patterns were measured in six healthy male volunteers during a 90-minute short sleep-wake (SW 30:60) cycle protocol for 48 hours. Sleep pressure estimates (amount of Slow Wave Sleep [SWS], SWA, and Rate of Synchronization [RoS: the rate of SWA build-up at the beginning of the NREM period]) were compared with the 24-hour patterns of body temperature (Tb24) and sleep propensity. A moderate sleep debt was incurred over the 48 hour study as indicated by decreased levels of 24 hour sleep. On day 1, ultradian patterns of REM and SWS sleep were prominent; on day 2, more prominent were circadian patterns of REM sleep, SWS, Sleep Latency, TST and Tb24. Also on Day 2, biphasic patterns of SWA and RoS were expressed, with peaks occurring during the falling and rising limbs of Tb24. The biphasic peaks in SWA and RoS may be associated with phase-specific interactions of the circadian pacemaker with the sleep homeostat during conditions of moderate sleep pressure. Further research is needed to replicate the finding and to identify biological factors that may underlie the twelve hour pattern in SWA.
Abstract: A sample of 33 eminent Italian writers was studied. They were nominees of three of the most important literary Italian awards (Strega, Campiello, and Viareggio). The Seasonal Pattern Assessment Questionnaire was mailed to 105 writers during the period October 2003 and January 2004, of whom 39 replied. 33 (M age=54.5 yr., SD= 12.5; 8 women and 25 men) completed the questionnaire. Among respondents, spring and summer months showed highest ratings of "feel best." During the summer a decline in creativity was not significant; respondents also reported sleeping least. Scores on the Global Seasonality Score suggested writers appeared to show higher seasonal sensitivity than the general population. Seasonal changes were considered as a problem by a majority of them. Although writers showed high seasonal sensitivity, no significant relationship was found between the seasonal pattern of mood and self-reported creativity.
Abstract: BACKGROUND: Most of the earlier studies on mood seasonality were conducted in adults and there are few available data on children and adolescents. In two cross sectional surveys, we examined the role of age and gender on seasonal sensitivity in subjects aged 10 to 25 years. METHODS: In survey one, the Seasonal Pattern Assessment Questionnaire for Children and Adolescents (SPAQ-CA) was administered to 1709 subjects (845 females and 864 males) from 10 to 17 years. In survey two, the Seasonal Pattern Assessment Questionnaire (SPAQ) was administered to 1867 subjects (1061 females and 806 males) from 18 to 25 years. RESULTS: Only in survey one was a significant positive correlation found between age and Global Seasonality Score (GSS) (r=.29; p<.00001). Significant gender differences were found at age 14 years and above in survey one, and at all ages in survey two. CONCLUSIONS: The results support the hypothesis that seasonal sensitivity is higher in female subjects.
Abstract: Eye blink rate, a peripheral measure of central dopaminergic activity, has been investigated in 20 female anorexic "restricting-type" patients and 16 healthy female subjects. A significantly increased blink rate was found in the anorexic patients. A significant positive correlation between blink rate and duration of illness was also found.
Abstract: OBJECTIVES: There is no agreement in the literature as to whether sleep interruption causes rapid eye movement (REM) pressure to increase, and if so, whether this increase is expressed as shortened REM latency, increased REM density, or increased duration of REM sleep. The purpose of the present study was to examine the effect of different durations of spontaneous sleep interruptions on the regulation of REM sleep that occurs after return to sleep. METHODS: The occurrence of spontaneous periods of wakefulness and their effects on subsequent REM sleep periods were analysed in a total sample of 1189 sleep interruptions which occurred across 364 extended nights in 13 normal subjects. RESULTS: Compared with sleep interruptions that last less than 10 min, sleep interruptions that last longer than 10 min occur preferentially out of REM sleep. In both the short and long types of sleep interruptions, the duration of REM periods that ended in wakefulness were shorter than the duration of those that were not interrupted by wakefulness. REM densities of the REM periods that terminated in periods of wakefulness were higher than those of uninterrupted REM periods. The proportion of episodes of wakefulness following REM sleep that were long-lasting progressively increased over the course of the extended night period. The sleep episodes that followed the periods of wakefulness were characterised by a short REM latency. REM duration was increased in episodes that followed long sleep interruptions compared to those that followed short sleep interruptions. REM density did not appear to change significantly in the episodes that followed sleep interruption. CONCLUSIONS: REM sleep mechanisms appear to be the main force controlling sleep after a spontaneous sleep interruption, presumably because during the second half of the night, where more sleep interruptions occur, the pressure for non-rapid eye movement sleep is reduced and the circadian rhythm in REM sleep propensity reaches its peak. Processes promoting REM sleep at the end of the night are consistent with the Pittendrigh and Daan dual oscillator model of the circadian pacemaker.
Abstract: Dynamics of electroencephalographic (EEG) slow wave activity (0.5-4.5 Hz) and body temperature, as estimates, respectively, of the process S and process C, regulating sleep and waking alternate occurrence, were measured during monophasic and biphasic sleep patterns that occurred spontaneously in a 35-year-old woman who lived for 105 days in a winter-type photoperiod (10-14 h light-dark). In monophasic nights, rate of EEG synchronization showed a decreasing trend across the first three non-rapid eye movement (NREM) periods. In biphasic nights, rate of EEG synchronization increased during the third NREM period which precedes the nocturnal awakening. Temperature cycle was not different between biphasic and monophasic nights. Those results confirm that EEG dynamics reflects homeostatic sleep regulatory mechanism, and suggest that the period of prolonged wakefulness in the middle of biphasic night is pre-programmed.
Abstract: The daily pattern of spontaneous eye-blink rate (BR), a non-invasive peripheral measure of central dopamine activity, was investigated in 24 healthy subjects. The spontaneous eye-blink rate showed a stable pattern in morning, midday and afternoon hours. A significant increase was found at the evening time point (20.30 h). The finding is suggestive of a late evening increase of central dopamine activity. An increased level of subjective sleepiness was also found at the same evening point, at a time corresponding to the 'evening wake maintenance zone' or the 'forbidden zone for sleep'. A possible hypothesis is that the 'forbidden zone for sleep' may reflect a dopamine-mediated activation that counteracts a rising sleep drive. The role of diurnal variation of dopamine function should be considered both in the choice of the drug treatment regimen, and in the evaluation of biological and neuropsychological parameters.
Abstract: Prevalence and risk factors for extrapyramidal syndromes (EPS) were investigated in a sample of 1,559 patients. The overall prevalence of EPS was 29.4% (N = 458). Among the EPS-diagnosed patients, parkinsonism as assessed by the presence of core parkinsonian symptoms (rigidity, tremor, bradykinesia) was present in 65.9% of patients (N = 302), akathisia in 31.8% (N = 145), and acute dystonia in 2.1% (N = 10). Old age and long-term neuroleptic drug (NL) treatment were significantly associated with EPS in both the univariate and the multivariate analyses, whereas no relationship was observed with average NL daily doses and current NL treatment. EPS was diagnosed in 50.2% of 285 patients with persistent tardive dyskinesia (TD). Distribution of EPS in patients with TD showed that tremor and akathisia were more frequent in peripheral TD cases than in orofacial TD cases. Furthermore, there was a stronger association of NL-induced parkinsonism with peripheral TD than with orofacial TD. This study suggests that the association between EPS and TD may be limited to specific subtypes of TD. Peripheral TD showed a higher association with parkinsonism and with akathisia, suggesting that these symptoms may share a common pathophysiology.
Abstract: Benington and Heller (1994) recently proposed a sleep-dependent model for the homeostatic control of REM sleep in which the amount of REM sleep propensity discharged in each bout of REM sleep affects the timing of the subsequent REM episode. Consistent with their hypothesis, they reported that in rats the duration of a REM episode was positively correlated with the duration of the succeeding NREM episode and not with the duration of the preceding NREM episode. To assess this hypothesis in humans, we used 308 sleep records from 11 subjects who remained at bedrest in the dark and slept ad libitum during 14-hour periods each night for 4 weeks. The timing of the onset of the first REM episode of the long night was linked to the timing of sleep onset. NREM-REM cycle duration decreased progressively throughout the night as a result of a progressive decrease in duration of the NREM component. Durations of REM sleep episodes correlated significantly with durations of subsequent NREM episodes in three out of the eight rank cycles analyzed (p < .0031, Bonferroni corrected); positive correlation coefficients were found for all the remaining cycles, but were not statistically significant when the conservative Bonferroni correction of the alpha level was applied. With the exception of the first sleep cycle, durations of REM sleep episodes did not correlate with durations of preceding NREM sleep episodes. According to the present results, the amount of REM sleep in one episode controls the time of occurrence of the next REM episode when the impact of other possible regulating factors are at a low level. We hypothesize that the extended dark/rest period, by increasing the time window allowed for sleep, provided a condition under which the systems governing REM sleep expression were free of the masking imposed by the conventional 16 hours light/8 hours dark schedule that consolidates and compresses sleep.
Abstract: A mail survey of degree of seasonal suffering was conducted in Italy using the SPAQ (Seasonal Pattern Assessment Questionnaire). Experiencing seasonal changes as a problem was reported by more than half of the 543 responders. Both mean GSS (Global Seasonality Score) and circannual profile of 'feeling worst' yielded results similar to those reported in the USA at comparable latitudes. Global prevalences of SAD, Reverse-SAD and Sub-SAD were 4.4, 2.1 and 4.8%, respectively. Female sex and young age were associated with a higher degree of seasonal sensitivity. No clear evidence was found of higher sensitivity at higher latitudes or of a significant influence of sociocultural factors.
Abstract: The sleep patterns of 8 normal subjects living in a winter-type photoperiod (10 h light and 14 h darkness; LD 10:14) for 4 weeks were characterized by the presence of periods of spontaneous wakefulness alternating with periods of spontaneous sleep. Transitions from sleep to wakefulness occurred much more frequently out of REM sleep than out of NREM sleep (P < 0.002). REM periods that terminated in wakefulness showed shorter REM durations (P < 0.0005) and higher REM densities (P < 0.0005) than REM periods that did not terminate in wakefulness. The authors discuss these results in terms of a possible relationship between REM density and arousal level. The higher REM density preceding wakefulness and the increased number of REM periods terminating in spontaneous awakenings could reflect an enhanced level of a brain arousing process, resulting from reduced sleep pressure in the extended nights.
Abstract: We investigated spontaneous eye-blink rates in 19 drug-free patients with winter seasonal affective disorder (SAD) and 18 normal control subjects. At baseline, there were no significant differences between the two groups (mean +/- SD blink rate: 15/minute +/- 8 vs. 15/minute +/- 7). Light therapy (10,000 lux: 1 hour each morning for 1 week) produced no significant change in mean (+/- SD) blink rates either in 10 SAD patients (13/minute +/- 8 vs. 10/minute +/- 7) or in 12 normal control subjects (15/minute +/- 6 vs. 14/minute +/- 6). A post hoc exploratory analysis of the effect of light therapy on premenopausal female subjects (5 patients and 9 control subjects) showed a significant decrease in mean (+/- SD) blink rate in the patients after treatment (17 +/- 6 vs. 12 +/- 8 compared with 15 +/- 7 vs. 16 +/- 5). These results do not support the idea that an elevated blink rate may be a general biological marker in SAD, but they suggest a possible link between light treatment and mechanisms that regulate blink rate in premenopausal SAD patients.
Abstract: The demographic, clinical and pharmacological risk factors for persistent tardive dyskinesia (TD) were investigated in a sample of 1745 patients. When simultaneously adjusting for the effects of demographic and pharmacological factors using multivariate logistic regression, female sex and advanced age were positively and significantly associated with increased risk of TD. Interaction between these two variables, investigated by cross-stratification, was significant. Furthermore, high neuroleptic dose and concomitant use of neuroleptic and antiparkinsonian drugs were both significantly associated with increased risk of TD. The results support the view that both vulnerability factors and high neuroleptic doses contribute to the occurrence of TD and further stress the relevance of a conservative use of antipsychotic medication, particularly in older women.
Abstract: In animals, circadian pacemakers respond to seasonal changes in day length by making corresponding adjustments in the durations of diurnal and nocturnal periods of circadian rhythms; these adjustments mediate effects of photoperiod on breeding and other seasonally recurring phenomena. Little is known about photoperiod responses of human circadian pacemakers. To investigate this question, we recorded and compared circadian rhythm profiles of 15 individuals after chronic exposures to short (8 h) and long (14 h) nights. As occurs in animals, durations of nocturnal periods of active melatonin secretion (11.9 +/- 1.6 vs. 10.3 +/- 1.3 h, df = 14, t = 4.583, P < 0.0005, paired t test), high prolactin secretion (12.9 +/- 2.1 vs. 9.9 +/- 2.2 h, df = 11, t = 2.917, P < 0.01), and sleep (10.6 +/- 0.8 vs. 7.6 +/- 0.4 h, df = 14, t = 17.122, P < 0.0005) were longer after exposure to long nights than after short ones. Durations of nocturnal periods of low rectal temperature (11.6 +/- 2.3 vs. 9.5 +/- 1.6 h, df = 12, t = 3.912, P < 0.001) and rising cortisol secretion (10.8 +/- 1.6 vs. 9.3 +/- 1.9 h, df = 14, t = 3.130, P < 0.005) were also longer. Some of these differences persisted during 24-h periods of enforced wakefulness in constant dim light, indicating that prior exposure to the two regimes induced abiding changes in the timing of internal processes, such as circadian pacemaker oscillations, that control the durations of nocturnal and diurnal periods of the rhythms.
Abstract: Plasma homovanillic acid (pHVA) levels were measured in 16 chronically ill patients with schizophrenia who also suffered from tardive dyskinesia, and in a group of 14 chronically ill patients with schizophrenia who did not have tardive dyskinesia. All patients were studied following an extensive drug-free period (mean = 32.9 months). Patients with orofacial dyskinesia had significantly lower levels of pHVA than did controls. In patients without tardive dyskinesia, pHVA levels were significantly correlated with both positive and negative symptomatology. In contrast, pHVA levels from patients with tardive dyskinesia bore neither a significant nor a nearly significant relationship to symptomatology. The implications of these findings for dopaminergic models of tardive dyskinesia are discussed.
