Mild cognitive impairment in moderate to severe COPD: a preliminary study.

BACKGROUND: Cognitive impairment is a frequent feature of COPD. However, the proportion of patients with COPD with mild cognitive impairment (MCI) is still unknown, and no screening test has been validated to date for detecting MCI in this population. The goal of this study was to determine the frequency and subtypes of MCI in patients with COPD and to assess the validity of two cognitive screening tests, the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA), in detecting MCI in patients with COPD. METHODS: Forty-five patients with moderate to severe COPD and 50 healthy control subjects underwent a comprehensive neuropsychologic assessment using standard MCI criteria. Receiver operating characteristic curves were obtained to assess the validity of the MMSE and the MoCA to detect MCI in patients with COPD. RESULTS: MCI was found in 36% of patients with COPD compared with 12% of healthy subjects. Patients with COPD with MCI had mainly the nonamnestic MCI single domain subtype with predominant attention and executive dysfunctions. The optimal MoCA screening cutoff was 26 (≤ 25 indicates impairment, with 81% sensitivity, 72% specificity, and 76% correctly diagnosed). No MMSE cutoff had acceptable validity. CONCLUSIONS: In this preliminary study, a substantial proportion of patients with COPD were found to have MCI, a known risk factor for dementia. Longitudinal follow-up on these patients is needed to determine the risk of developing more severe cognitive and functional impairments. Moreover, the MoCA is superior to the MMSE in detecting MCI in patients with COPD.

Validity of the Mattis Dementia Rating Scale to detect mild cognitive impairment in Parkinson's disease and REM sleep behavior disorder.

BACKGROUND/AIMS: Mild cognitive impairment (MCI) is frequent in Parkinson's disease (PD) and idiopathic REM sleep behavior disorder (iRBD). However, only a few studies have evaluated the validity of brief cognitive measures to detect MCI in PD or iRBD using standard diagnostic criteria for MCI. Our aim was to evaluate the validity of the Mini-Mental State Examination (MMSE) and the Mattis Dementia Rating Scale (DRS-2) to detect MCI in PD and iRBD. METHODS: Forty PD patients and 34 iRBD patients were studied. Receiver operating characteristic curves were created for both tests to assess their effectiveness in identifying MCI in PD and iRBD. RESULTS: In PD, a normality cutoff of 138 on the DRS-2 yielded the best balance between sensitivity (72%) and specificity (86%) with a correct classification of 80%. In iRBD, the optimal normality cutoff was 141 on the DRS-2, with a sensitivity of 90%, a specificity of 71% and a correct classification of 82%. No cutoff for the MMSE was found to have acceptable sensitivity or specificity. CONCLUSION: The DRS-2 has satisfactory validity to detect MCI in PD or iRBD. The MMSE proved to be invalid as a screening test for MCI in both populations.

The effect of three months of aerobic training on response preparation in older adults.

This study assessed the effects of an aerobic training program on reaction time tasks that manipulated preparatory intervals (PI) to produce temporal preparation effects using short (1, 3, 5 s) and long (5, 7, 9 s) PI. Older adults were assigned to either a 3-month aerobic training group or to a control group. Individuals in the training group participated in an aerobic training program of three 60-min sessions per week. The control group did not receive any training. Results indicated that 12 weeks of aerobic training induced a significant improvement in cardiorespiratory capacity (VO(2)max estimate). All participants who completed the aerobic program showed improvement after training in the choice RT task, along with enhanced preparation, such that they maintained preparation over time more efficiently after the training program. Moreover, enhanced ability to use the short PI was observed but only in lower fit individuals. Results of the present study suggest that improving aerobic fitness may enhance attentional control mechanisms in older adults.

The Montreal Cognitive Assessment: a screening tool for mild cognitive impairment in REM sleep behavior disorder.

Mild cognitive impairment (MCI) is a frequent feature in idiopathic REM sleep behavior disorder (RBD), a sleep disturbance that can be a preclinical stage of Parkinson's disease or Lewy body dementia. We evaluated the sensitivity and specificity of two brief screening tools, the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE), in detecting MCI in idiopathic RBD. Thirty-eight idiopathic RBD patients underwent a comprehensive neuropsychological assessment, including the MoCA and the MMSE. Receiver operating characteristic curves were created for the MoCA and the MMSE to assess their ability to identify MCI in idiopathic RBD patients, with neuropsychological assessment as the gold standard. For the MoCA, a normality cutoff of 26 yielded the best balance between sensitivity (76%) and specificity (85%) with a correct classification of 79%. For the MMSE, the optimal normality cutoff was 30, with a sensitivity of 84% and a specificity of 54% and a correct classification of 74%. The MoCA is superior to the MMSE in detecting MCI in idiopathic RBD patients, showing good sensitivity and very good specificity.

Hypersynchronous delta waves and somnambulism: brain topography and effect of sleep deprivation.

STUDY OBJECTIVES: Hypersynchronous delta activity (HSD) is usually described as several continuous high-voltage delta waves (> or = 150 microV) in the sleep electroencephalogram of somnambulistic patients. However, studies have yielded varied and contradictory results. The goal of the present study was to evaluate HSD over different electroencephalographic derivations during the non-rapid eye movement (NREM) sleep of somnambulistic patients and controls during normal sleep and following 38 hours of sleep deprivation, as well as prior to sleepwalking episodes. DESIGN: N/A. SETTING: Sleep disorders clinic. PATIENTS: Ten adult sleepwalkers and 10 sex- and age-matched control subjects were investigated polysomnographically during a baseline night and following 38 hours of sleep deprivation. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: During normal sleep, sleepwalkers had a significantly higher ratio of HSD over the time spent in stage 2, 3 and 4 on frontal and central derivations when compared with controls. Sleep deprivation resulted in a significant increase in the ratio of the time in HSD over the time in stage 4 on the frontal lead in both groups and on the central lead in controls. There was no evidence for a temporal accumulation of HSD prior to the episodes. CONCLUSIONS: HSD shows a clear frontocentral gradient across all subjects during both baseline and recovery sleep and has relatively low specificity for the diagnosis of NREM parasomnias. Increases in HSD after sleep deprivation may reflect an enhancement of the homeostatic process underlying sleep regulation.

Analysis of postarousal EEG activity during somnambulistic episodes.

Early studies found that electroencephalographic (EEG) recordings during somnambulistic episodes were characterized by a combination of alpha, theta, and delta frequencies, without evidence of clear wakefulness. Three postarousal EEG patterns associated with slow-wave sleep (SWS) arousals were recently identified in adults with sleepwalking and sleep terrors. The goal of the present study was to evaluate the distribution of these postarousal EEG patterns in 10 somnambulistic patients (three males, seven females, mean age: 25.1, SD: 4.1) evaluated at baseline and following 38 h of sleep deprivation. A total of 44 behavioral arousals were recorded in the laboratory; seven episodes at baseline (five from SWS, two from stage 2 sleep) and 37 episodes during recovery sleep (30 from SWS, seven from stage 2 sleep). There was no significant difference in the distribution of postarousal EEG patterns identified during baseline and recovery sleep. One pattern, comprised of diffuse rhythmic and synchronous delta activity, was preferentially associated with relatively simple behavioral episodes but did not occur during episodes from stage 2 sleep. Overall, delta activity was detected in 48% of the behavioral episodes from SWS and in 22% of those from stage 2. There was no evidence of complete awakening during any of the episodes. The results support the view of somnambulism as a disorder of arousal and suggest that sleepwalkers' atypical arousal reactions can manifest themselves in stage 2 sleep in addition to SWS.

The value of sleep deprivation as a diagnostic tool in adult sleepwalkers.

OBJECTIVE: Adult somnambulism can result in injury to the sleeper and to others. Attempts to induce sleepwalking episodes in the sleep laboratory have yielded mixed results. Having shown that sleepwalkers have lower slow-wave activity power than control subjects, the authors hypothesized that an enhanced pressure of the homeostatic process underlying sleep regulation could affect the disorder's characteristics even further. Therefore, the effects of 38 hours of sleep deprivation in adult sleepwalkers and control subjects were investigated. METHODS: Ten adult somnambulistic patients and 10 sex- and age-matched control subjects were studied in the sleep laboratory. After a screening night, participants were monitored during 1) one night of baseline recording, and 2) one recovery night in which subjects slept ad libitum immediately after the sleep deprivation protocol. Behavioral manifestations were assessed for frequency and complexity using a 3-point scale of increasing complexity. RESULTS: None of the control subjects had any behavioral manifestations on either of the two nights. Conversely, sleepwalkers showed a significant increase in the frequency and complexity of the somnambulistic episodes during the recovery night compared with baseline. Somnambulistic patients had a greater number of awakenings from slow-wave sleep than control subjects on both nights, but there was no significant increase during the recovery night. CONCLUSION: Sleep deprivation can be an effective tool for inducing somnambulistic episodes in the laboratory, thereby facilitating the diagnosis of sleepwalking.