Actigraphic and melatonin alignment in older adults with varying dementia risk.

Circadian rhythms alter with ageing and may be aetiologically linked to neurodegeneration. This study explored the association between clinical markers and 1) dim light melatonin onset (DLMO) time and 2) phase angle derived from sleep midpoint, in older adults with varying dementia risks. Participants completed 14 days of actigraphy followed by in-lab measurement of salivary melatonin, from which DLMO time and phase angle were computed. Eighty participants (age = 65.5, SD = 9.6), 44 males (55%), MMSE (28.6, SD = 1.5) were included in the analysis. Sex (t = 2.15, p = .04), sleep onset (r = 0.49, p < .001) and midpoint (r = 0.44, p < .001) also correlated with DLMO time. Multiple linear regression showed chronotype, average actigraphy-derived light exposure during the DLMO window (window 2 h prior to DLMO to 2 h post), early biological day (6-10 h post DLMO time) and late biological day (10-14 h post DLMO time) were predictive of DLMO time (adjusted R2 = 0.75). Sleep offset, depression severity, average light exposure during the early biological night and early and late biological day were shown to be predictive variables in the estimation of phase angle (adjusted R2 = 0.78). The current study highlights the potential use of clinical variables, such as actigraphy-derived light, as circadian markers in ageing which could be easily implemented into existing clinical practice and could yield potential targets focusing on chronotherapeutic interventions.

Sharing the load: How a personally coloured calculator for grapheme-colour synaesthetes can reduce processing costs.

Synaesthesia refers to a diverse group of perceptions. These unusual perceptions are defined by the experience of concurrents; these are conscious experiences that are catalysed by attention to some normally unrelated stimulus, the inducer. In grapheme-colour synaesthesia numbers, letters, and words can all cause colour concurrents, and these are independent of the actual colour with which the graphemes are displayed. For example, when seeing the numeral '3' a person with synaesthesia might experience green as the concurrent irrespective of whether the numeral is printed in blue, black, or red. As a trait, synaesthesia has the potential to cause both positive and negative effects. However, regardless of the end effect, synaesthesia incurs an initial cost when compared with its equivalent example from normal perception; this is the additional processing cost needed to generate the information on the concurrent. We contend that this cost can be reduced by mirroring the concurrent in the environment. We designed the Digital-Colour Calculator (DCC) app, allowing each user to personalise and select the colours with which it displays its digits; it is the first reported example of a device/approach that leverages the concurrent. In this article we report on the reactions to the DCC for a sample of fifty-three synaesthetes and thirty-five non-synaesthetes. The synaesthetes showed a strong preference for the DCC over its normal counterpart. The non-synaesthetes showed no obvious preference. When using the DCC a subsample of the synaesthete group showed consistent improvement in task speed (around 8%) whereas no synaesthete showed a decrement in their speed.

Circadian rhythm and sleep alterations in older people with lifetime depression: a case-control study.

BACKGROUND: Depression is common in older people and is associated with underlying brain change increasing the risk of dementia. Sleep disturbance is frequently reported by those with lifetime depression, however whether circadian misalignment also exists is unclear. We aimed to examine circadian rhythms and sleep associations in older patients with and without lifetime depression. METHODS: Thirty-four older people meeting DSM-IV criteria for lifetime major depression (mean age = 63.9 years), and 30 healthy controls (mean age = 65.7 years) were recruited. Participants underwent 2-weeks of actigraphy followed by a 3-night protocol including dim light melatonin onset (DLMO) assessment and overnight polysomnography (PSG) for sleep architecture. DLMO and phase angle of entrainment were computed. RESULTS: Compared to controls, participants with depression had a significantly longer phase angle of entrainment (6.82 h ± 1.45 vs. 5.87 h ± 1.60, p = 0.02, Cohens-d = 0.62). A small to moderate yet non-significant difference in DLMO times, with earlier DLMO (34 ± 27 min) observed in depression (20:36 ± 1:48 vs. 21:10 ± 1:48, p = 0.22, Cohens-d = 0.32). Individuals with depression had longer sleep latency and latency to rapid eye movement sleep than controls (all p < 0.05). CONCLUSION: Circadian advancement and alterations to the timing of sleep and REM onset are evident in older people with lifetime major depression, despite having only mild residual symptoms. Further research examining the prognostic significance of these changes is warranted as well as chronotherapeutic treatment studies.

Nocturnal Hypoxemia Is Associated with Altered Parahippocampal Functional Brain Connectivity in Older Adults at Risk for Dementia.

BACKGROUND: Obstructive sleep apnea is associated with an increased risk of developing mild cognitive impairment and dementia. Intermittent nocturnal hypoxemia in obstructive sleep apnea is associated with brain changes in key regions that underpin memory. OBJECTIVE: To determine whether older adults with severe nocturnal hypoxemia would exhibit reduced functional connectivity within these regions, with associated deficits in memory. METHODS: Seventy-two participants 51 years and over underwent polysomnography with continuous blood oxygen saturation recorded via oximetry. The oxygen desaturation index (ODI, 3% dips in oxygen levels per hour) was the primary outcome measure. ODI was split into tertiles, with analyses comparing the lowest and highest tertiles (N = 48). Thirty-five of the 48 participants from these two tertiles had mild cognitive impairment. Participants also underwent resting-state fMRI and comprehensive neuropsychological, medical, and psychiatric assessment. RESULTS: The highest ODI tertile group demonstrated significantly reduced connectivity between the left and right parahippocampal cortex, relative to the lowest ODI tertile group (t(42) = -3.26, p = 0.041, beta = -1.99).The highest ODI tertile group also had poorer working memory performance. In the highest ODI tertile group only, higher left-right parahippocampal functional connectivity was associated with poorer visual memory recall (between-groups z = -2.93, p = 0.0034). CONCLUSIONS: Older adults with severe nocturnal hypoxemia demonstrate impaired functional connectivity in medial temporal structures, key regions involved in sleep memory processing and implicated in dementia pathophysiology. Oxygen desaturation and functional connectivity in these individuals each relate to cognitive performance. Research is now required to further elucidate these findings.

Substantiating synesthesia: a novel aid in a case of grapheme-colour synesthesia and concomitant dyscalculia.

Here we present the case of SP, a 21-year-old female with life-long dyscalculia. SP was subsequently diagnosed with grapheme-color synesthesia, a diagnosis that serendipitously catalyzed our development of a novel aid:The digit-color calculator (DCC). The DCC substantiates SP's color concurrents, dramatically ameliorating her difficulties with basic calculations. We envisage the DCC and its analogues may assist others in educational settings, particularly if they experience difficulties with the acquisition of literacy and numeracy. Further devices that leverage synesthesia may also have the potential to improve the quality of life for others with trait synesthesia regardless of concomitant disorder.

"Sleep Well, Think Well" Group Program for Mild Cognitive Impairment: A Randomized Controlled Pilot Study.

Objective/Background: Sleep-wake disturbance is associated with poor cognitive functioning and several other adverse outcomes that increase dementia risk in older adults. Targeting sleep-wake disturbance in individuals at risk for dementia may be an important treatment. This study evaluated the efficacy of a four-session multicomponent group intervention for participants with mild cognitive impairment (MCI). Participants: Thirty-five older adults with MCI (mean age = 69.7 years, SD = 9.1), were recruited. MCI was determined via consensus from neuropsychological, medical, and neurological review. Methods: Participants were randomized to the "Sleep Well, Think Well" (SWTW) group condition or a passive control group. The SWTW group received four fortnightly face-to-face sessions conducted by an experienced sleep psychologist and neuropsychologist. The control group received written material detailing strategies to improve sleep quality. Both groups received fortnightly coaching phone calls. The primary outcome was subjective sleep quality, measured by the Pittsburgh Sleep Quality Index (PSQI). Secondary outcomes included actigraphy sleep measures, daytime sleepiness, cognitive functioning, and depression severity. Results: The SWTW intervention was associated with a large and statistically significant improvement in subjective sleep quality (Cohen's d = 0.83, p < 0.02). A moderate nonsignificant effect was evident in reducing daytime sleepiness (Cohen's d = 0.70, p = .08). No significant effects were found on actigraphy markers, depressive symptoms, or tests of cognitive functioning. Conclusions: The eight-week SWTW group intervention for MCI significantly improved subjective sleep quality when compared with a passive control condition. The program also had a moderate (nonsignificant) effect on reducing daytime sleepiness.

Current sleep disturbance in older people with a lifetime history of depression is associated with increased connectivity in the Default Mode Network.

BACKGROUND: The present study investigated Default Mode Network (DMN) functional connectivity in subjects with a lifetime history of major depression, comparing those with and without current sleep disturbance. Controls were included to assess DMN abnormalities specific to depression. METHODS: A total of 93 adults aged 50 years and over were recruited from the Healthy Brain Ageing Clinic at the Brain and Mind Centre, Sydney, Australia. The sample comprised two groups, including 22 controls and 71 participants with a lifetime history of DSM-IV major depression (with depressive episode current or remitted). 52 of those with a lifetime history of depression also met criteria for Mild Cognitive Impairment (MCI). Participants underwent resting-state fMRI along with comprehensive psychiatric, neuropsychological, and medical assessment. Subjective sleep quality was assessed via the Pittsburgh Sleep Quality Index (PSQI). Sleep disturbance was defined as a PSQI score > 5. A total of 68% (n = 48) of cases with a lifetime history of depression met criteria for sleep-disturbance. DMN functional connectivity was assessed via ROI-to-ROI analyses. RESULTS: Relative to controls, those with lifetime major depression demonstrated significantly increased functional connectivity between the ventromedial prefrontal cortex and the temporal pole. Within the depression group (n = 48), those with current sleep disturbance had significantly increased connectivity between the anterior medial prefrontal cortex and both the parahippocampal cortex and the hippocampal formation, relative to those without sleep disturbance (n = 23). These results were present after controlling for MCI diagnosis. CONCLUSIONS: Current sleep disturbance together with depression is associated with distinct abnormalities in DMN functioning incorporating regions responsible for self-reflection and declarative memory processes. Impaired sleep is associated with increased connectivity between these regions. Future studies may augment these findings with complementary imaging techniques including cortical thickness and diffusion tensor imaging, as well as high density electroencephalogram recording.

Association between Sleep Disordered Breathing and Nighttime Driving Performance in Mild Cognitive Impairment.

OBJECTIVES: The effect of sleep disordered breathing (SDB) on driving performance in older adults has not been extensively investigated, especially in those with mild cognitive impairment (MCI). The aim of this study was to examine the relationship between severity measures of SDB and a simulated driving task in older adults with and without MCI. METHODS: Nineteen older adults (age ≥50) meeting criteria for MCI and 23 age-matched cognitively intact controls underwent neuropsychological assessment and a driving simulator task in the evening before a diagnostic sleep study. RESULTS: There were no differences in driving simulator performance or SDB severity between the two groups. In patients with MCI, a higher oxygen desaturation index (ODI) was associated with an increased number of crashes on the simulator task, as well as other driving parameters such as steering and speed deviation. Poorer driving performance was also associated with poorer executive functioning (set-shifting) but the relationship between ODI and crashes was independent of executive ability. CONCLUSIONS: While driving ability did not differ between older adults with and without MCI, oxygen saturation dips in MCI were related to worse driving performance. These results suggest that decreased brain integrity may render those with SDB particularly vulnerable to driving accidents. In older adults, both cognition and SDB need to be considered concurrently in relation to driving ability. (JINS, 2017, 23, 502-510).

Functional Connectivity in the Default Mode Network is Reduced in Association with Nocturnal Awakening in Mild Cognitive Impairment.

BACKGROUND: Sleep disturbance is prevalent in MCI, and is a risk factor for cognitive deterioration. OBJECTIVE: To identify functional connectivity deficits in the default mode network (DMN) in patients with mild cognitive impairment (MCI) and sleep disturbance, relative to MCIs with intact sleep. METHODS: Participants comprised 47 adults aged 55 years and over, recruited from the Healthy Brain Ageing Clinic at the Brain and Mind Centre, Sydney, Australia. This sample contained 15 controls and 32 participants meeting criteria for MCI. Participants underwent resting-state fMRI and actigraphy, along with comprehensive neuropsychological, medical and psychiatric assessment. MCIs were split into two groups according to average wake after sleep onset (WASO) per night. WASO equal to or greater than 1 standard deviation (SD) above the control mean was deemed to reflect disturbed sleep. There were 11 patients in the MCI sleep-disturbed group, and 21 in the MCI sleep-intact group. RESULTS: Relative to controls, MCIs demonstrated significant connectivity reductions between parietal and temporoparietal regions, and between temporal regions. Relative to MCIs with intact sleep, MCIs with sleep disturbance demonstrated reductions in functional connectivity between temporal and parietal regions, and between temporal and temporoparietal regions. CONCLUSIONS: MCIs with nocturnal awakenings demonstrate reductions in DMN connectivity. These reductions comprise brain regions that are crucially involved in sleep and memory processes. These results strengthen our previous findings, which found reduced connectivity in MCIs with self-reported sleep disturbances. Future studies may build on these findings through incorporating complementary neuroimaging techniques and experimental manipulations of sleep.

Quantifying the effect of body mass index, age, and depression severity on 24-h activity patterns in persons with a lifetime history of affective disorders.

BACKGROUND: Patients with affective disorders of different ages have been found to present weight changes and different circadian activity patterns. This study assessed the effects of age, Body Mass Index (BMI) and depression severity on the activity-rest cycle in persons with affective disorders using a novel multifactorial 24-h analysis method. METHODS: Two hundred and thirty-six participants aged between 14 and 85 years underwent 5 to 22 days of actigraphy monitoring (mean duration = 14 days). BMI was also recorded and symptom severity was assessed with the Hamilton Depression Rating Scale (HDRS). Participants were divided into two groups: healthy controls (n = 68) and participants with a lifetime diagnosis of affective disorders (n = 168). First, the multiple regression method was employed to formulate the circadian activity pattern in term of the factors age, BMI and HDRS. For each group, the functional linear analysis method was applied to assess the relative effects of the factors. Finally, Wald-tests were used to assess the contribution of each factor on the circadian activity pattern. RESULTS: In the affective disorders group, higher BMI was associated with higher activity levels from 3 am until 5.30 am and with lower activity levels from 10 am until 10.30 pm. Older age was associated with less activity across the day, evening, and night - from 11 am until 5.30 am. Higher HDRS scores were associated with higher activity around 1:30 am. In healthy controls, the effects of BMI and age on activity patterns were less pronounced and affected a narrower portion of the 24-h period. CONCLUSION: These findings suggest that older age and higher BMI are linked to lower daytime activity levels. Higher BMI and worse symptom severity were also associated with nocturnal activity patterns suggestive of sleep disturbances. The influence of age and BMI on 24-h activity profiles appear to be especially pronounced in people with affective disorders.

Sleep disturbance in mild cognitive impairment is associated with alterations in the brain's default mode network.

This study aimed to identify default mode network (DMN) functional connectivity deficits in patients with mild cognitive impairment (MCI) and sleep disturbance, relative to those with MCI and no sleep disturbance. A control group was included to aid in identifying DMN changes specific to MCI. A cross-sectional, single-center study was performed at the Brain and Mind Research Centre in Sydney, Australia. Participants (95 adults over the age of 65: 38 controls and 57 meeting criteria for MCI) underwent resting-state functional MRI along with comprehensive neuropsychological, medical, and psychiatric assessment. Self-report data were collected including sleep quality assessment via the Pittsburgh Sleep Quality Index. A total score of greater than 5 on the Pittsburgh Sleep Quality Index was used to signify the presence of significant sleep disturbance, as per commonly used methodology. Using this criterion, 53% (n = 30) of our MCI group were classified as sleep-disturbed. Whereas the total group of MCI subjects and controls demonstrated no significant differences, sleep-disturbed MCIs demonstrated increased connectivity between temporal and parietal regions, and decreased connectivity between the prefrontal cortex and the temporoparietal junction relative to sleep-disturbed controls. Relative to those MCIs without sleep disturbance, sleep-disturbed MCI participants demonstrated significantly diminished DMN connectivity between temporal and parietal regions, a finding that was particularly pronounced in amnestic MCI. Sleep disturbance in MCI is associated with distinct alterations in DMN functional connectivity in brain regions underpinning salient memory and sleep systems. Future studies may build on these results via experimental manipulation and objective measurement of sleep. (PsycINFO Database Record

Association of Anterior Cingulate Glutathione with Sleep Apnea in Older Adults At-Risk for Dementia.

STUDY OBJECTIVES: Sleep disordered breathing (SDB) is common in older adults and is strongly associated with cognitive decline, with increasing evidence suggesting that it may represent a risk factor for dementia. Given that SDB is characterized by intermittent episodes of hypoxemia during sleep, it is possible that cognitive impairment may relate to cerebral oxidative stress. This study aimed to examine the relationship between nocturnal markers of hypoxemia and proton magnetic resonance spectroscopy ((1)H-MRS) markers of oxidative stress within the anterior cingulate cortex (ACC) of the brain. METHODS: Twenty-four older adults (mean age = 67.9 y) at-risk for dementia were recruited from our Healthy Brain Ageing Research Clinic. At-risk was defined as participants seeking help for assessment and/or intervention for cognitive decline, including those with subjective and/or objective cognitive complaints. This could occur in the context of prior depression or risk factors (e.g., vascular) for dementia. All participants underwent psychiatric, medical and neuropsychological assessment followed by overnight polysomnography. In addition, participants underwent (1)H-MRS to derive levels of ACC metabolite glutathione (GSH) reported as a ratio to creatine (GSH/Cr). RESULTS: Increased levels of GSH/Cr were associated with lower oxygen desaturation (r = -0.54, P = 0.007) and more severe apnea-hypopnea index scores during rapid eye movement sleep (r = 0.42, P = 0.050). In addition, ACC GSH/Cr correlated with poorer executive functioning (i.e., response inhibition: r = -0.49, P = 0.015; set shifting: r = -0.43, P = 0.037). CONCLUSIONS: Markers of nocturnal hypoxemia and SDB are associated with cerebral oxidative stress in older people at-risk for dementia, suggesting a potential mechanism by which SDB may contribute to brain degeneration, cognitive decline, and dementia. Further work focused on utilizing this biomarker for the early identification and treatment of this possible modifiable risk factor in older persons is now warranted.

Napping in older people 'at risk' of dementia: relationships with depression, cognition, medical burden and sleep quality.

Sleep disturbance is prevalent in older adults, particularly so in those at a greater risk of dementia. However, so far the clinical, medical and neuropsychological correlates of daytime sleep have not been examined. The aims of this study were to investigate the characteristics and effects of napping using actigraphy in older people, particularly in those 'at risk' of dementia. The study used actigraphy and sleep diaries to measure napping habits in 133 older adults 'at risk' of dementia (mean age = 65.5 years, SD = 8.4 years), who also underwent comprehensive medical, psychiatric and neuropsychological assessment. When defined by actigraphy, napping was present in 83.5% (111/133) of participants; however, duration and timing varied significantly among subjects. Nappers had significantly greater medical burden and body mass index, and higher rates of mild cognitive impairment. Longer and more frequent naps were associated with poorer cognitive functioning, as well as higher levels of depressive symptoms, while the timing of naps was associated with poorer nocturnal sleep quality (i.e. sleep latency and wake after sleep onset). This study highlights that in older adults 'at risk' of dementia, napping is associated with underlying neurobiological changes such as depression and cognition. Napping characteristics should be more routinely monitored in older individuals to elucidate their relationship with psychological and cognitive outcomes.

Mild Cognitive Impairment Subtypes in Older People With Depressive Symptoms: Relationship With Clinical Variables and Hippocampal Change.

AIMS: To examine the rates and clinical characteristics of mild cognitive impairment (MCI) in older people with depressive symptoms and to determine the relative contribution of hippocampal volume and MCI to memory change. METHOD: One hundred and fifty-two participants with lifetime Major Depression and remitted or mild symptoms and 28 healthy controls underwent psychiatric and neuropsychological assessments. Magnetic resonance imaging was also conducted in a subset of the patients (n = 81) and healthy controls (n = 18). RESULTS: MCI was diagnosed in 75.7% of the patients and was associated with increasing age, medical burden, vascular risk factors, later age of depression onset and smaller hippocampi. Multiple regression showed that both hippocampal volume and MCI diagnosis mediate memory performance in depression. CONCLUSIONS: MCI occurs in older adults with a history of depression and is not simply due to symptom severity. Memory change is linked to underlying hippocampal atrophy in this patient group.

Association between Sleep-Disordered Breathing and Neuropsychological Performance in Older Adults with Mild Cognitive Impairment.

Sleep-disordered breathing in middle-age and older adults has been shown to be linked to a range of neuropsychological deficits, but the extent to which these relationships are evident in older people 'at risk' of developing dementia in unknown. In this study, we aimed to determine whether changes in sleep-disordered breathing and sleep fragmentation during nocturnal sleep were related to neuropsychological dysfunction in patients with mild cognitive impairment. Forty-six patients with MCI (mean age = 66.1 y, sd = 8.4) and 40 age-matched healthy controls (mean age = 63.5 y, sd = 8.9) underwent psychiatric, medical, and neuropsychological assessment, in addition to overnight polysomnography and self-report questionnaires. Measures of hypoxemia, sleep fragmentation, and sleep quality were derived including the apnoea-hypopnea index, oxygen desaturation index, percentage of total sleep time spent below 90% oxygen saturation, arousal index, sleep efficiency, and wake after sleep onset. Patients with MCI did not differ from healthy aging on any measure of sleep-disordered breathing or sleep fragmentation. In MCI, processing speed was negatively correlated with greater sleep time spent below 90% oxygen saturation and a higher apnoea-hypopnea index. In contrast, in the healthy aging, processing speed was negatively correlated with an increased oxygen desaturation index and the arousal index. Sleep-disordered breathing is evident in both healthy aging and MCI with associated decrements in processing speed. Future research is needed to determine the unique and synergistic effects of these differential associations, their potential to inform disease trajectory, and possible therapeutic interventions.

Validation of the Psychosis and Hallucinations Questionnaire in Non-demented Patients with Parkinson's Disease.

People diagnosed with Parkinson's disease (PD) frequently experience visual and non-visual hallucinations often with comorbid psychosis, however, there is currently no gold standard tool for accurately assessing these symptoms. To address this problem, we designed a novel questionnaire to evaluate the presence of hallucinatory and psychotic symptoms in PD, as well as related symptoms, such as attentional dysfunction and sleep disturbance. We administered the 20-item Psychosis and Hallucinations Questionnaire (PsycH-Q) and three common questionnaire measures in a large cohort of 197 patients with idiopathic PD via a postal survey. We established concurrent validity, convergent validity, and internal consistency of the questionnaire and then assessed test-retest reliability in a subcohort of 44 patients. PsycH-Q was found to be a valid instrument when analogous items were compared across three other existing tools (Spearman's rho range: 0.34-0.64; P < 0.01). PsycH-Q demonstrated a strong relationship between self-reported hallucinations and psychosis and symptoms of the broader hallucinatory phenotype (Kendall's tau = 0.41; P < 0.01; positive predictive value = 0.97). PsycH-Q also displayed a high level of internal consistency (Cronbach's alpha = 0.900; range, 0.696-0.923) and reproducibility (intraclass correlation coefficient = 0.928). PsycH-Q is a simple, valid, self-completed instrument that reliably identifies hallucinations and psychosis in PD and has the ability to characterize related patterns of attentional and sleep impairments. As such, PsycH-Q is a highly valuable tool for use in both clinical and research settings.

Investigating the night-to-night variability of REM without atonia in Parkinson's disease.

OBJECTIVES: Rapid eye movement (REM) sleep behaviour disorder is frequently observed in Parkinson's disease and is characterized electrophysiologically by the absence of atonia during REM sleep. However, the night-to-night variability of REM sleep without atonia is yet to be determined in Parkinson's disease. METHODS: Using polysomnography, this study measured the variability of REM sleep without atonia across two consecutive nights, using the REM atonia index in 38 patients with Parkinson's disease. RESULTS: The intraclass correlation coefficient between the REM sleep atonia index across two nights was 0.816 (F = 9.795, p < 0.001) and the difference between the two nights was 4.7% (standard deviation (SD) 8.2). CONCLUSION: The REM atonia index demonstrated low variability across two consecutive nights of PSG. Furthermore, the diagnosis of REM sleep behaviour disorder based on this electrophysiological marker and other clinical variables was in agreement across the two nights.

Prevalence and predictors of poor sleep quality in mild cognitive impairment.

AIMS: To investigate the prevalence of and contributors to poor sleep quality in patients with mild cognitive impairment (MCI). METHODS: Data were collected for 158 patients meeting the criteria for MCI. Measures included the Pittsburgh Sleep Quality Index, Geriatric Depression Scale, and Mini-Mental State Examination. Demographic, lifestyle, medication, and substance use data were also collected. RESULTS: A total of 63% of patients with MCI demonstrated sleep disturbance, a significantly higher rate than that of the controls (44%; chi-square = 8.77; P = .003). Depressive symptoms, cognition, antidepressant usage, alcohol consumption, age, and education were identified as significant predictors of self-reported sleep quality in patients with MCI (R(2) = .327, F 6,145 = 11.729, P < .0001). CONCLUSIONS: Sleep disturbance occurs in around two-thirds of patients with MCI. Interventions addressing depression, cognition, and substance and medication use may improve sleep quality in MCI.

Investigating rapid eye movement sleep without atonia in Parkinson's disease using the rapid eye movement sleep behavior disorder screening questionnaire.

Rapid eye movement (REM) sleep behavior disorder (RBD) is frequently observed in patients with Parkinson's disease (PD). Accurate diagnosis is essential for managing this condition. Furthermore, the emergence of idiopathic RBD in later life can represent a premotor feature, heralding the development of PD. Reliable, accurate methods for identifying RBD may offer a window for early intervention. This study sought to identify whether the RBD screening questionnaire (RBDSQ) and three questionnaires focused on dream enactment were able to correctly identify patients with REM without atonia (RWA), the neurophysiological hallmark of RBD. Forty-six patients with PD underwent neurological and sleep assessment in addition to completing the RBDSQ, the RBD single question (RBD1Q), and the Mayo Sleep Questionnaire (MSQ). The REM atonia index was derived for all participants as an objective measure of RWA. Patients identified to be RBD positive on the RBDSQ did not show increased RWA on polysomnography (80% sensitivity and 55% specificity). However, patients positive for RBD on questionnaires specific to dream enactment correctly identified higher degrees of RWA and improved the diagnostic accuracy of these questionnaires. This study suggests that the RBDSQ does not accurately identify RWA, essential for diagnosing RBD in PD. Furthermore, the results suggest that self-report measures of RBD need to focus questions on dream enactment behavior to better identify RWA and RBD. Further studies are needed to develop accurate determination and quantification of RWA in RBD to improve management of patients with PD in the future.