Showing papers on "Actigraphy published in 1997"
TL;DR: It is suggested that cumulative nocturnal sleep debt had a dynamic and escalating analog in cumulative daytime sleepiness and that asymptotic or steady-state sleepiness was not achieved in response to sleep restriction.
Abstract: To determine whether a cumulative sleep debt (in a range commonly experienced) would result in cumulative changes in measures of waking neurobehavioral alertness, 16 healthy young adults had their sleep restricted 33% below habitual sleep duration, to an average 4.98 hours per night [standard deviation (SD) = 0.57] for seven consecutive nights. Subjects slept in the laboratory, and sleep and waking were monitored by staff and actigraphy. Three times each day (1000, 1600, and 2200 hours) subjects were assessed for subjective sleepiness (SSS) and mood (POMS) and were evaluated on a brief performance battery that included psychomotor vigilance (PVT), probed memory (PRM), and serial-addition testing, Once each day they completed a series of visual analog scales (VAS) and reported sleepiness and somatic and cognitive/emotional problems. Sleep restriction resulted in statistically robust cumulative effects on waking functions. SSS ratings, subscale scores for fatigue, confusion, tension, and total mood disturbance from the POMS and VAS ratings of mental exhaustion and stress were evaluated across days of restricted sleep (p = 0.009 to p = 0.0001). PVT performance parameters, including the frequency and duration of lapses, were also significantly increased by restriction (p = 0.018 to p = 0.0001). Significant time-of-day effects were evident in SSS and PVT data, but time-of-day did not interact with the effects of sleep restriction across days. The temporal profiles of cumulative changes in neurobehavioral measures of alertness as a function of sleep restriction were generally consistent. Subjective changes tended to precede performance changes by 1 day, but overall changes in both classes of measure were greatest during the first 2 days (P1, P2) and last 2 days (P6, P7) of sleep restriction. Data from subsets of subjects also showed: 1) that significant decreases in the MSLT occurred during sleep restriction, 2) that the elevated sleepiness and performance deficits continued beyond day 7 of restriction, and 3) that recovery from these deficits appeared to require two full nights of sleep. The cumulative increase in performance lapses across days of sleep restriction correlated closely with MSLT results (r = -0.95) from an earlier comparable experiment by Carskadon and Dement (1). These findings suggest that cumulative nocturnal sleep debt had a dynamic and escalating analog in cumulative daytime sleepiness and that asymptotic or steady-state sleepiness was not achieved in response to sleep restriction.
2,247 citations
TL;DR: During increased illumination, the stability of the rest-activity rhythm increased in patients with intact vision, but not in visually impaired patients, and the hypothesis than an enduring increase in the daytime environmental illumination level improves rest- activity rhythm disturbances in demented patients is tested.
449 citations
TL;DR: Preliminary data indicate a relationship between adolescent development and circadian phase and the long nights protocol is a feasible way in which to assess circadian parameters in young humans as well as to examine intrinsic sleep processes.
Abstract: The "long nights" protocol was designed to evaluate sleep processes and circadian rhythm parameters in young humans. A total of 19 children (10 boys, ages 11.2 to 14.1 years [mean = 12.7 +/- 1.0], and 9 girls, ages 12.2 to 14.4 years [mean = 13.1 +/- 0.7]) took part in the study. Sleep/wake initially was assessed at home using actigraphy and diary for 1 week on each child's self-selected schedule followed by an 8-night fixed light-dark (LD) condition, while sleeping from 22:00 to 08:00 h and wearing an eye mask to exclude as much light as possible. Phase measurements included 4-night mean actigraphically estimated sleep onset and offset as well as 1-night dim light salivary melatonin onset (DLSMO) phase at the end of each condition. Subjects then lived in the laboratory for 6 consecutive cycles: Day 1 LD = 14:10 h, lights out 22:00 to 08:00 h; Days 2-4 LD = 6:18 h, lights out 18:00 to 12:00 h; Days 5-6 = constant routine in continuous dim light (about 20 lux); Night 6 = 14 h recovery sleep. Phase markers (sleep onset, sleep offset, DLSMO) were significantly less dispersed after the fixed LD as compared to the self-selected condition, indicating efficacy of the LD protocol. Phase markers were correlated at the self-selected assessment (sleep onset vs. sleep offset r = .72; DLSMO vs. sleep onset r = .82; DLSMO vs. sleep offset r = .76) but not on the fixed schedule, probably due to restricted range. The constant routine provided additional phase markers, melatonin offset and midphase. Offset phase of melatonin secretion was significantly correlated with age (r = .62) and Tanner stage (r = .62). In conclusion, these preliminary data indicate a relationship between adolescent development and circadian phase. Thus, the long nights protocol is a feasible way in which to assess circadian parameters in young humans as well as to examine intrinsic sleep processes.
297 citations
TL;DR: It is concluded that BRM has some important advantages as a simple, minimally invasive method for monitoring sleep and was more accurate in determining SOL and subsequent wakefulness than polysomnography.
Abstract: Two alternative methods for detecting sleep, wrist actigraphy (ACT) and behavioral response monitoring (BRM), were compared to polysomnography (PSG). In the BRM paradigm, a threshold intensity visual or auditory stimulus generated by a palm-top computer was presented about once per minute, and subjects pressed a microswitch if the stimulus was detected. A response within 5 seconds of the stimulus was scored as "wake" and a failure to respond as "sleep." Four males and four females underwent two nights of simultaneous in-home PSG, BRM, and ACT. Each night, subjects underwent a protocol designed to generate five sleep latency trials. Subjects were awakened by alarm clocks at approximately 1-hour intervals and remained awake for 10 minutes before returning to bed for another sleep onset latency (SOL) trial. Minute-by-minute comparisons were made for PSG versus ACT and BRM. All measures were fairly sensitive in detecting sleep, but BRM was more accurate in determining SOL and subsequent wakefulness. Behavioral response monitoring using a tone resulted in more responses and arousals prior to and during light stages of sleep than BRM using a light. It is concluded that BRM has some important advantages as a simple, minimally invasive method for monitoring sleep.
187 citations
TL;DR: Results suggest that the mood changes experienced by the perimenopausal group may be mediated by sleep disruption, which is significantly related to age and sociodemographic variables.
179 citations
TL;DR: The results suggest that fitness training may be helpful in elderly people suffering from sleep problems related to circadian rhythm disturbances, and several possible mechanisms involved in the effect of fitness training on circadian rhythms are discussed.
Abstract: In old age, the circadian timing system loses optimal functioning. This process is even accelerated in Alzheimer's disease. Because pharmacological treatment of day-night rhythm disturbances usually is not very effective and may have considerable side effects, nonpharmacological treatments deserve attention. Bright light therapy has been shown to be effective. It is known from animal studies that increased activity, or an associated process, also strongly affects the circadian timing system, and the present study addresses the question of whether an increased level of physical activity may improve circadian rhythms in elderly. In the study, 10 healthy elderly males were admitted to a fitness training program for 3 months. The circadian rest-activity rhythm was assessed by means of actigraphy before and after the training period and again 1 year after discontinuation. As a control for possible seasonal effects, repeated actigraphic recordings were performed during the same times of the year as were the pre and post measurements in a control group of 8 healthy elderly males. Fitness training induced a significant reduction in the fragmentation of the rest-activity rhythm. Moreover, the fragmentation of the rhythm was negatively correlated with the level of fitness achieved after the training. No seasonal effect was found. Previous findings in human and animal studies are reviewed, and several possible mechanisms involved in the effect of fitness training on circadian rhythms are discussed. The results suggest that fitness training may be helpful in elderly people suffering from sleep problems related to circadian rhythm disturbances.
150 citations
TL;DR: Melatonin replacement therapy can improve sleep quality in the elderly and that the beneficial effects are augmented in the presence of benzodiazepines, as compared to placebo.
75 citations
TL;DR: The 24-hour rest-activity pattern and the amount of motor activity was studied in a patient with fatal familial insomnia by means of wrist actigraphy and showed severe disruption with increased motor activity up to 80%.
Abstract: The 24-hour rest-activity pattern and the amount of motor activity was studied in a patient with fatal familial insomnia (FFI) by means of wrist actigraphy. During the study, the patient underwent indirect calorimetry. The 52-day recording showed severe disruption of the 24-hour rest-activity pattern with increased motor activity up to 80%. The 24-hour energy expenditure, assayed in a respiration chamber, was strikingly elevated by 60%. Chronic motor overactivity and loss of circadian rest-activity rhythm may play a role in the progressive metabolic exhaustion leading to death in FFI patients.
40 citations
TL;DR: Results suggest dual-mode actigraphy may be useful for the study of performance variation and structure in healthy and chronically ill individuals.
Abstract: The purpose of this study was to test the sensitivity and reproducibility of dual-mode actigraphy as an objective measure of functional performance in healthy adults under controlled levels of activity intensity. Twenty subjects wore the instrument on the nondominant wrist while performing standardized tasks selected to represent day-to-day activities at three levels of intensity (five tasks in each level): light (1-2 metabolic equivalents), moderate (3-4 metabolic equivalents), and heavy (4-6 metabolic equivalents). Upon completion of each intensity level, subjects were asked to rate their level of exertion using Borg's 15-point rating of perceived exertion (RPE) scale. Eighteen subjects repeated the protocol within 7 days. Zero-crossing and time-above-threshold modes successfully differentiated between light and moderate and between light and heavy activity. Reproducibility correlation coefficients (rs) across activity levels were .80 and .66 for the two modes, respectively. Results suggest dual-mode actigraphy may be useful for the study of performance variation and structure in healthy and chronically ill individuals.
36 citations
TL;DR: Treatment teams on psychiatric units should in general consider nursing reports of sleep more accurate than patient self-report, since nursing staff and patients observe different aspects of sleep, both sources of data are important to inpatient treatment teams on clinical units.
Abstract: This study was designed to evaluate the conventional techniques of assessing sleep, nursing and patient report, of inpatients on a clinical psychiatric unit. Nurses assessed sleep/wake status at hourly checks and patients completed a sleep diary. For three nights patients wore a wrist actigraph, a portable instrument which provides objective data about sleep/wake activity. The nursing and patient data obtained were compared with actigraphy data. Nursing staff evaluated sleep with satisfactory agreement (76.5% night 1 and 81.6% night 3) that improved over the first three nights of hospitalization (p < 0.03). When the nurses' report did not agree with the actigraph, they tended to overestimate sleep. Patients tended to underestimate their total sleep time and total time awake after sleep onset. Time in bed and initial sleep latency were overestimated. There was great intersubject variability, making determination of agreement impossible. This data suggest that treatment teams on psychiatric units should in general consider nursing reports of sleep more accurate than patient self-report. However, since nursing staff and patients observe different aspects of sleep, both sources of data are important to inpatient treatment teams on clinical units.
31 citations
TL;DR: Measured activity was related to predictors of fatigue but not to fatigue, and self-rating scales developed to assess Chronic Fatigue Syndrome and actigraphy were not validated.
Abstract: Chronic Fatigue Syndrome is a baffling disease potentially affecting millions of Americans. Self-rating scales were developed to assess this condition but have yet to be validated with objective measures of activity. The present study of a 45-yr.-old man evaluated the relationships between scores on self-rating scales used to measure Chronic Fatigue Syndrome and actigraphy. Measured activity was related to predictors of fatigue but not to fatigue. The implications of these findings are discussed.
TL;DR: The effects of fluvoxamine and dothiepin on behavioural activity and psychomotor abilities, in 12 healthy male volunteers, was investigated in a placebo-controlled, double-blind, crossover study as discussed by the authors.
Abstract: Actigraphy is the continuous measurement of the motor component of behaviour. A change in behaviour will result in a change in activity. Drugs that are behaviourally toxic will cause changes in activity which can be measured using an actigraph. It is hypothesized that a reduction in daytime activity is a measure of sedation. A study was conducted comparing actigraphy with valid, reliable psychometric tests which are sensitive to the behaviourally toxic effects of psychoactive drugs. The study was designed to investigate whether actigraphy could accurately measure the daytime sedation associated with tricyclic antidepressants. The effects of fluvoxamine and dothiepin on behavioural activity and psychomotor abilities, in 12 healthy male volunteers, was investigated in a placebo‐controlled, double‐blind, crossover study. Subjects completed a battery of psychometric tests prior to dosing then at 1, 2, 3, 4 and 6 h post dose. Actigraphy showed that dothiepin caused daytime sedation, defined as a reduction in activity and this result was confirmed by the results from the psychometrics which showed that dothiepin impaired cognitive and psychomotor performance in the majority of the tests. These results show that actigraphy is capable of accurately measuring daytime sedation. © 1997 John Wiley & Sons, Ltd.
Journal Article•
TL;DR: It is concluded that actigraphy could quantitatively assess the degree of akinesia in Parkinsonian patients and may be applied to the clinical assessment of drugs.
Abstract: Actigraphy measures physiological activity by using an acceleration sensor and RAM equipped with a data logger. Since actigraphy can continuously and easily record data over a long period of time without disturbing the normal activities of subjects, it is possible to analyze a large number of subjects. Actigraphy was performed in patients with Parkinson's disease who did not exhibit trembling. Results showed that the daily motor activity of patients was lower than that of the healthy individual. Daily motor activity was also found to be correlated with Hoehn-Yahr's classification. Furthermore, side-effects due to L-dopa, such as abnormal involuntary movement and on-off phenomenon, could be objective assessed. The results of long-term actigraphic examination, conducted after anti-Parkinsonian treatment, showed that akinesia improved with time. From these findings, it is concluded that actigraphy could quantitatively assess the degree of akinesia in Parkinsonian patients. Furthermore, actigraphy may be applied to the clinical assessment of drugs.
Journal Article•
TL;DR: It is demonstrated that actigraphy is a simple and quantitative method of assessing motor activity in Parkinson patients with tremor and was associated with the severity of hand tremor.
Abstract: In Parkinson's disease, resting tremor is often the initial symptom. This report focuses on the mechanism underlying tremor in Parkinson's disease and quantitative assessment of tremor. Central factors including Vim (nucleus ventralis intermedius) in the thalamus, and peripheral factors, such as acceleration of input pathways from muscle spindles via muscle tonus, are important aspects of the tremor mechanism in Parkinson's disease. It has also been suggested that tremor in Parkinson's disease is associated with parasympathetic and sympathetic dysfunctions. Objective assessments of tremor, such as the application of surface electromyography, are useful in the diagnosis and treatment of Parkinson's disease. Actigraph, as introduced herein, is a three dimensional motor sensing apparatus. Therefore, motor counts over 0.01 G can be detected by actigraphy. To date, this device has been used for evaluating akinesia in Parkinson's disease and insomnia. In this study, actigraphy was used in Parkinson patients with tremor, and it reflected motor activity in the wrist and was associated with the severity of hand tremor. Activities of daily living (ADL) are disturbed by hyperkinesia of the hand for Parkinson patients with hand tremor. We demonstrated that actigraphy is a simple and quantitative method of assessing motor activity in Parkinson patients with tremor.
TL;DR: The question is therefore, if actigraphs are really more useful in the record of sleep in patients with insomnia and fragmented sleep than sleep calenders, and the correlation with data from polysomnography is reasonable.
Abstract: Actigraphy is more and more used in the longterm record of sleep of patients with insomnia. The correlation with data from polysomnography is reasonable for parameters like total sleep period (TSP) with r = 0,95-0,97 in healthy controls and r = 0,77-0,91 in patients. However for parameters, which inform about sleep fragmentation like wake after sleep onset (WASO) the correlation is not satisfieing with r = 0,87 in healthy controls and r = 0,49-0,63 in patients with fragmented sleep. The question is therefore, if actigraphs are really more useful in the record of sleep in patients with insomnia and fragmented sleep than sleep calenders.
TL;DR: In this article, two validation studies were conducted: one for individuals without sleep disorders and the other for patients diagnosed with insomnia, and the results of these two studies using the Actigraph Data Analysis Software as the scoring method have shown that the described system is fairly precise.
Abstract: Decades of empirical observations have established the validity of actigraphy primarily in individuals without sleep disorders. Methodological problems encountered thus far coupled with the widespread use of actigraphy signal the need for concentrated efforts to establish a consensus regarding scoring procedures. Currently available scoring methods show less reliability in clinical populations. To address these issues two validation studies were conducted: one for individuals without sleep disorders and the other for patients diagnosed with insomnia. The results of these two studies using the Actigraph Data Analysis Software as the scoring method have shown that the described system is fairly precise. It can be used for actigraphs with different features and mode of operation and is applicable to individuals with insomnia. These findings corroborate previous research showing that actigraphy is a valid instrument for assessment of sleep and wakefulness.
Journal Article•
TL;DR: Although there is some correlation between motor activity and sleep stages, the predictive value of actimetry data analysis in the assessment of sleep structure appeared to be limited mainly by individual movement density, especially during REM and NREM 2.
Abstract: UNLABELLED Purpose of the investigation was to evaluate the differences of movement density during the sleep stages and waking. 22 diurnally active, healthy, male volunteers of mean age 30.7 (+/-Standard deviation +/- 3.3) years and a Body-Mass-Index 23.6 +/- 3.3 kg/m2 participated in the study. All subjects were recorded in the sleep lab via cardiorespiratory polysomnography and wrist actigraphy (Ambulatory Monitoring, Ardsley, USA) worn on the non-dominant hand, for two consecutive nights. The activity data, consisting of the number of zero crossings (NZC) were recorded in 1-minute periods. Sleep stages were scored visually according to standard criteria. EEG- and actigraphy data were converted to the same data format (European Feature Files). Attaching the actimetry data to the sleep stages was calculated mean NZC for every sleep stage and Wake. In spite of high differences in total individual NZC we observed that most NZC occurred during Wake. NREM 1 movement density was significantly higher in 19 recordings (86%) than in any other sleep stage. In 18 cases (82%) lowest movement density was found in NREM 3/4 with significant difference to all other sleep stages. Within 50% of the recordings were found decreasing activity in the following sequence of stages: Wake > NREM 1 > REM > NREM 2 > NREM 3/4 However, in all other cases there was a varying pattern of activity. CONCLUSION Although there is some correlation between motor activity and sleep stages, the predictive value of actimetry data analysis in the assessment of sleep structure appeared to be limited mainly by individual movement density, especially during REM and NREM 2.
TL;DR: It was found that the sleep quality of the two groups differed over the course of the night, which suggests a difference in sleep architecture.
Abstract: The aim of the present study was to compare the sleep of 12 children with attention deficit hyperactivity disorder (ADHD) with that of 12 normal controls. The children were examined in their natural environment, using continuous actigraphic monitoring over several consecutive nights, as well as undergoing subjective parental reports. It was hypothesized that children diagnosed with ADHD would suffer from reduced sleep quality than children without ADHD. This hypothesis was supported by the actigraphic measures, but not supported by the subjective parental reports. It was also found that the sleep quality of the two groups differed over the course of the night, which suggests a difference in sleep architecture. Various possible explanations for these findings, their implications regarding the relationship between sleep and ADHD, and the resulting treatment ramifications are discussed, and suggestions for further research are provided.
TL;DR: It is concluded that theactigraphy is the most feasible technique for studying sleep and wake activity in demented nursing-home patients by testing the reliability of a wrist-activity monitor, the Actillume, against traditional sleep measurements and against observations of nursing- home patients.
Abstract: Actigraphy is applicable for studying sleep in populations who are unable to tolerate traditional sleep-recording techniques, such as nursing-home patients who are infirm and demented This study examined whether actigraphy can accurately reflect sleep/wake activity in this population by testing the reliability of a wrist-activity monitor, the Actillume, against traditional sleep measurements and against observations of nursing-home patients Data from the Actillume are presented as two variables, the sum (total of all activity movements within the prescribed epoch) and the maximum activity (the largest or maximum movement recorded during the prescribed epoch), and by electroencephalogram (EEG) One difficulty in making comparisons was that the EEG records showed diffuse slowing, making it extremely difficult to score sleep/wake activity and making it difficult to use the EEG as a "gold standard" Nevertheless, the correlation for total sleep time from EEG and Actillume was r = 091 (p < 0001) for sum activity and r = 081 for maximum activity (p < 0005) Correlations for percent sleep were r = 078 (p < 001) for maximum activity and r = 061 for sum activity The comparison of sleep/wake determined by the Actillume vs observations resulted in a sensitivity of 87% and specificity of 90% We conclude that the Actillume is the most feasible technique for studying sleep and wake activity in demented nursing-home patients