More daytime sleeping predicts less functional recovery among older people undergoing inpatient post-acute rehabilitation

STUDY OBJECTIVES: To study the association between sleep/wake patterns among older adults during inpatient post-acute rehabilitation and their immediate and long-term functional recovery DESIGN: Prospective, observational cohort study. SETTING: Two inpatient post-acute rehabilitation sites (one community and one Veterans Administration). PARTICIPANTS: Older patients (aged > or = 65 years, N = 245) admitted for inpatient post-acute rehabilitation. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Based on 7-day wrist actigraphy during the rehabilitation stay, mean nighttime percent sleep was only 52.2% and mean daytime percent sleep was 15.8% (16.3% based on structured behavioral observations). Using the Pittsburgh Sleep Quality Index (PSQI), participants reported their sleep was worse during rehabilitation compared to their premorbid sleep. Functional recovery between admission and discharge from rehabilitation (measured by the motor component of the Functional Independence Measure) was not significantly associated with reported sleep quality (PSQI scores) or actigraphically measured nighttime sleep. However, more daytime percent sleep (estimated by actigraphy and observations) during the rehabilitation stay was associated with less functional recovery from admission to discharge, even after adjusting for other significant predictors of functional recovery (mental status, hours of rehabilitation therapy received, rehospitalization, and reason for admission; adjusted R2= 0.267, P < 0.0001). More daytime sleeping during rehabilitation remained a significant predictor of less functional recovery in adjusted analyses at 3-month follow-up. CONCLUSIONS: Sleep disturbance is common among older people undergoing inpatient post-acute rehabilitation. These data suggest that more daytime sleeping during the rehabilitation stay is associated with less functional recovery for up to three months after admission for rehabilitation.     

Effect of zolpidem on the efficacy of continuous positive airway pressure as treatment for obstructive sleep apnea

STUDY OBJECTIVE: Assess the effect of the hypnotic zolpidem on the efficacy of nasal continuous positive airway pressure for treatment of Obstructive Sleep Apnea. DESIGN: Randomized double blind placebo controlled, cross-over study. SETTING: Veterans Administration Medical Center. PATIENTS: 16 patients with severe obstructive sleep apnea (apnea+ hypopnea index > 30/hr), on CPAP therapy for at least 6 months. INTERVENTION: Three sleep studies were performed over three consecutive weeks. On night one the pressure level required to prevent apnea, hypopnea, and snoring was determined. On the second and third study nights, either placebo (P) or 10 mg of zolpidem (Z) was given (random order) and subjects slept on the CPAP level determined on the first night. MEASUREMENTS: Sleep architecture, apnea + hypopnea index, arterial oxygen saturation. RESULTS: The sleep architecture was similar on the placebo and zolpidem nights except for a decrease in the sleep latency ( P: 23.5 +/- 4.7; Z: 13.1 +/- 3.3 minutes, P < 0.02) and a small decrease in the arousal index (P < 0.03) on zolpidem nights. The was no significant difference between placebo and zolpidem nights in the apnea + hypopnea index (P: 4.8 +/- 1.4 versus Z : 2.7 +/- 0.47 events/hour), oxygen desaturation index (1.46 +/- 0.53 versus 0.81 +/- 0.29 desaturations/hour), or the lowest SaO2 (91.4 +/- 0.6 versus 91.0 +/- 0.7%). CONCLUSIONS: Acute administration of zolpidem 10 mg does not impair the efficacy of an effective level of CPAP in patients with severe obstructive sleep apnea.     

Complex sleep apnea syndrome: is it a unique clinical syndrome?

STUDY OBJECTIVES: Some patients with apparent obstructive sleep apnea hypopnea syndrome (OSAHS) have elimination of obstructive events but emergence of problematic central apneas or Cheyne-Stokes breathing pattern. Patients with this sleep-disordered breathing problem, which for the sake of study we call the "complex sleep apnea syndrome," are not well characterized. We sought to determine the prevalence of complex sleep apnea syndrome and hypothesized that the clinical characteristics of patients with complex sleep apnea syndrome would more nearly resemble those of patients with central sleep apnea syndrome (CSA) than with those of patients with OSAHS. DESIGN: Retrospective review SETTING: Sleep disorders center. PATIENTS OR PARTICIPANTS: Two hundred twenty-three adults consecutively referred over 1 month plus 20 consecutive patients diagnosed with CSA. INTERVENTIONS: NA. MEASUREMENTS AND RESULTS: Prevalence of complex sleep apnea syndrome, OSAHS, and CSA in the 1-month sample was 15%, 84%, and 0.4%, respectively. Patients with complex sleep apnea syndrome differed in gender from patients with OSAHS (81% vs 60% men, p < .05) but were otherwise similar in sleep and cardiovascular history. Patients with complex sleep apnea syndrome had fewer maintenance-insomnia complaints (32% vs 79%; p < .05) than patients with CSA but were otherwise not significantly different clinically. Diagnostic apnea-hypopnea index for patients with complex sleep apnea syndrome, OSAHS, and CSA was 32.3 +/- 26.8, 20.6 +/- 23.7, and 38.3 +/- 36.2, respectively (p = .005). Continuous positive airway pressure suppressed obstructive breathing, but residual apnea-hypopnea index, mostly from central apneas, remained high in patients with complex sleep apnea syndrome and CSA (21.7 +/- 18.6 in complex sleep apnea syndrome, 32.9 +/- 30.8 in CSA vs 2.14 +/- 3.14 in OSAHS; p < .001). CONCLUSIONS: Patients with complex sleep apnea syndrome are mostly similar to those with OSAHS until one applies continuous positive airway pressure. They are left with very disrupted breathing and sleep on continuous positive airway pressure. Clinical risk factors don't predict the emergence of complex sleep apnea syndrome, and best treatment is not known.     

Comparison of CPAP titration at home or the sleep laboratory in the sleep apnea hypopnea syndrome

STUDY OBJECTIVES: Continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea hypopnea syndrome (OSAHS) is conventionally started after in-laboratory overnight titration. This use of sleep laboratory space is both costly and limits access for diagnostic studies. This study aimed to evaluate whether automated CPAP titration in the home produced patient outcomes equal to those following laboratory-based automated CPAP titration. The main outcomes were Epworth Sleepiness Scale score, objective daytime sleepiness (Oxford SLEep Resistance test or OSLER test), and CPAP use; we also performed quality-of-life questionnaires: Functional Outcomes of Sleep Questionnaire and SF-36. DESIGN: Prospective, randomized, single-blind, parallel-group, controlled trial SETTING: Regional sleep center and patients' homes. PATIENTS: Two hundred CPAP-na?ve patients with OSAHS requiring CPAP treatment. INTERVENTIONS: One hundred patients were randomly assigned to a standard 1-night in-hospital CPAP titration and 100 to 3 nights' home CPAP titration and then issued with fixed pressure CPAP. Data were analyzed on an intention-to-treat basis. MEASUREMENTS AND RESULTS: The patient groups did not differ at baseline. The CPAP pressures defined at titration (mean+/- SEM: 10.6+/-0.2, 10.4+/-0.2 cm H20, p = .19), number of mask leaks, and initial acceptance rates were similar in the sleep-laboratory and home-titrated groups. At 3-month follow-up, there was no significant difference in CPAP use (mean+/-SEM: 4.39+/-0.25, 4.38+/-0.25 h/night; p > .9), Epworth Sleepiness Scale score (9.5+/-0.5, 8.5+/-0.5, p = .14), OSLER, Functional Outcomes of Sleep Questionnaire, or SF-36 between the sleep-laboratory and home-titrated groups. CONCLUSIONS: Home-based automated CPAP titration is as effective as automatic in-laboratory titrations in initiating treatment for OSAHS.     

Acute effects of paroxetine on genioglossus activity in obstructive sleep apnea

STUDY OBJECTIVE: To determine the acute effects of paroxetine on genioglossus activity during NREM sleep. DESIGN: A single dose of Paroxetine (40 mg) or placebo was administered four hours before bedtime on nights separated by one week in a double blind randomized crossover manner. The moving time average of genioglossus muscle activity (EMGgg) expressed as a percentage of maximum was measured using a mouthpiece electrode customized for each subject. The peak inspiratory and tonic values of EMGgg and the corresponding esophageal pressure deflections (DP) during the last three occluded breaths of obstructive apneas during NREM sleep were analyzed. SETTING: NA. PARTICIPANTS: 8 adult men with severe obstructive sleep apnea (OSA). INTERVENTIONS: NA. MEASUREMENTS AND RESULTS: Paroxetine increased the peak inspiratory EMGgg (29.8+/-2.4 (SE) versus 24.4+/-2.7 % max, p<0.05) and peak EMGgg/DP ratio (0.78+/-0.12 versus 0.65+/-0.11 % max/cm H2O, p<0.01) but not the tonic EMGgg (11.6+/-0.9 versus 9.8+/-0.7 % max) nor the DP (39.4+/-2.2 versus 38.2+/-2.8 cm H2O). Linear regression analysis of the peak inspiratory EMGgg versus DP relationship showed that paroxetine increased the slope (0.62+/-0.11 versus 0.49+/-0.09 % max/cm H2O, p<0.01). However, the apnea + hypopnea index (paroxetine: 75.2+/-5.5 versus placebo: 73.7+/-6.9 events/hour) did not differ. CONCLUSIONS: Paroxetine augmented peak inspiratory genioglossus activity during NREM sleep but this effect was not sufficient to decrease the frequency of obstructive apnea in this group with severe OSA.     

Night-to-night alterations in sleep apnea type in patients with heart failure

In patients with heart failure, apnea type can shift overnight from mainly obstructive to mainly central in association with reductions in PCO(2) and increases in periodic breathing cycle length, indicative of a fall in cardiac output. We hypothesized that the predominant apnea type could also vary from one night to another in association with alterations in PCO(2) and cycle length. We studied 12 men with heart failure in whom the predominant apnea type changed from one night to the next over periods of at least 1 month, and two groups with either predominantly obstructive or central sleep apnea (OSA or CSA) in whom apnea type remained stable over time. In patients with unstable apnea type (n = 12, duration between sleep studies 9.0 +/- 4.4 months), PCO(2) was significantly lower (37.6 +/- 1.6 mmHg versus 41.7 +/- 1.9 mmHg, P < 0.01), and cycle length significantly longer (61.9 +/- 3.4 s versus 51.0 +/- 1.9 s, P < 0.001) during nights with predominantly central than nights with predominantly obstructive apnea. In contrast, in both the stable central (n = 8, duration between sleep studies 11.9 +/- 5.3 months) and the stable obstructive (n = 8, duration between studies 6.9 +/- 5.2 months) sleep apnea groups, neither PCO(2) nor cycle length changed significantly between the baseline and follow-up sleep studies. We conclude that in some patients with heart failure, OSA and CSA are part of a spectrum of periodic breathing that can shift over time in association with alterations in PCO(2), cycle length and probably cardiac function.     

Sleep apnea in acute cerebrovascular diseases: final report on 128 patients

Although obstructive sleep apnea (OSA) appears to be a cardiovascular risk factor, its frequency in patients with transient ischemic attack (TIA) and stroke remains poorly known. We prospectively studied 128 patients (mean +/- SD age = 59 +/- 15 years) with stroke (n = 75) or TIA (n = 53). Assessment included body mass index (BMI); history of snoring and daytime sleepiness; cardiovascular risk factors and diseases; and severity of stroke (Scandinavian Stroke Scale = SSS). Polysomnography (PSG) was obtained in 80 subjects (group 1), a mean of 9 days (range, 1-71 days) after TIA or stroke. In 48 subjects (group 2), PSG was not available, refused, or inadequate. Groups 1 and 2 were similar with the exception of gender distribution. Clinical and PSG data were compared to those of 25 healthy controls matched for age, gender, and BMI. An apnea-hypopnea index (AHI) > 10 was found in 62.5% of subjects and 12.5% of controls. Between patients and controls there was a significant difference in AHI (mean [range]: 28 (0-140) vs 5 (0-24), p < 0.001), maximal apnea duration (mean + SD: 37 +/- 23 vs 23 +/- 13 seconds, p = 0.009), and minimal oxygen saturation (mean + SD: 82 +/- 10% vs 90 +/- 5%, p < 0.001). Conversely, frequency and severity of OSA were similar in stroke and TIA subjects. Multiple regression analysis identified age, BMI, diabetes, and SSS as independent predictors of AHI. Sleep apnea has a high frequency in patients with TIA and stroke, particularly in older patients with high BMI, diabetes, and severe stroke. These results may have implications for prevention, acute treatment, and rehabilitation of patients with acute cerebrovascular diseases.     

Driving simulation with EEG monitoring in normal and obstructive sleep apnea patients

STUDY OBJECTIVES: To measure simulated driving performance in obstructive sleep apnea patients and its relationship with EEG defined attention lapses. DESIGN: Prospective, mixed design comparing apnea patients and control subjects over a 60-minute driving simulation task while continuously recording both driving performance and EEG measures. SETTING: Sleep disorders center. PARTICIPANTS: 15 polysomnographically diagnosed obstructive sleep apnea patients (mean age 42 +/- 6 yrs.) and 15 healthy volunteers (mean age 38 +/- 6 yrs.). INTERVENTIONS: NA. MEASUREMENTS AND RESULTS: A computer based driving simulator recorded lane position variability, speed variability, steering rate variability, and crash frequency. The frequency and duration of EEG-defined attention lapses were also measured. The results demonstrated that the apnea group had significantly greater variability in lane position, steering rate, and speed than the control group. The apnea group also had more crashes. In addition, the apnea group had more EEG-defined attention lapses of longer duration. Except for speed and steering rate variability, these differences increased over the 60-minute task. Measures of lane position variability and crash frequency had a significant positive correlation with attention lapse frequency and duration. CONCLUSIONS: The driving simulation task unmasked and quantified marked performance impairments in the sleep apnea group that increased over time. The poor performance appeared related to the EEG-defined attention lapses. Lane position variability appeared to be the most sensitive measure for assessing and quantifying impairment. This study suggests that poorer driving performance and crashes are not entirely due to overt sleep, but inattention due to sleepiness.     

Comparison of pleural pressure and transcutaneous diaphragmatic electromyogram in obstructive sleep apnea syndrome

STUDY OBJECTIVES: Based on studies of the impact of esophageal pressure on cardiovascular variables during sleep, this signal can be used to refine the severity level in the clinical diagnosis of obstructive sleep apnea syndrome. We hypothesized that relative changes in diaphragmatic electromyogram (EMG) can reflect short-term changes in esophageal pressure durng obstructive apneas and hypopneas. DESIGN: Diaphragmatic EMG was sampled at 0.25 kHz; diaphragmatic EMG waveform was band-pass filtered and digitally converted; the electrocardiogram artifact was eliminated; using a gating procedure, the waveform was fast-Fourier transformed and digitally rectified; and a moving average of 200 milliseconds was calculated. For each inspiratory effort during apnea or hypopnea, we calculated maximum diaphragmatic EMG and esophageal pressure. Data were normalized calculating the percentage difference between the first obstructed and each subsequent inspiratory effort during the respiratory event. SETTING: Sleep disorders laboratory. PATIENTS: 9 patients with moderate obstructive sleep apnea syndrome presenting with apneas and hypopneas during sleep. INTERVENTION: None. MEASUREMENTS AND RESULTS: 861 respiratory events were scored, and the evolution between esophageal pressure and diaphragmatic EMG were compared. Normalized data showed a good correlation between the 2 measures during apneas and hypopneas. There was a significant difference between the percentage increase in esophageal pressure and diaphragmatic EMG for apneas and hypopneas (esophageal pressure, apnea: 118.1% +/- 118.5%, hypopnea: 76.1% +/- 74.3%, P = .000; diaphragmatic EMG, 123.5% +/- 131.7%, hypopnea: 73.3% +/- 74.2%, P = .000). No significant differences for apnea or hypopnea were noted between the 2 measures under investigation. CONCLUSION: Diaphragmatic EMG may be clinically useful to describe relative changes in respiratory effort under conditions of apnea and hypopnea during sleep and to reliably dissociate central from obstructive events where esophageal pressure monitoring is not readily available.     

Physical examination: Mallampati score as an independent predictor of obstructive sleep apnea

STUDY OBJECTIVE: To assess the clinical usefulness of the Mallampati score in patients with obstructive sleep apnea. Mallampati scoring of the orophyarynx is a simple noninvasive method used to assess the difficulty of endotracheal intubation, but its clinical usefulness has not been validated in patients with sleep-disordered breathing. DESIGN: Prospective multivariate assessment of a predictor variable. SETTING: The UCSF Sleep Disorders Center. PATIENTS OR PARTICIPANTS: One hundred thirty-seven adult patients who were evaluated for possible obstructive sleep apnea. INTERVENTIONS: Prospective determination of the Mallampati score, assessment of other variables for multivariate analysis, and subsequent overnight polysomnography. MEASUREMENTS AND RESULTS: The Mallampati score was an independent predictor of both the presence and severity of obstructive sleep apnea. On average, for every 1-point increase in the Mallampati score, the odds of having obstructive sleep apnea (apnea-hypopnea index> or = 5) increased more than 2-fold (odds ratio [per 1-point increase] = 2.5; 95% confidence interval: 1.2-5.0; p = .01), and the apnea-hypopnea index increased by more than 5 events per hour (coefficient = 5.2; 95% confidence interval: 0.2-10; p = .04). These results were independent of more than 30 variables that reflected airway anatomy, body habitus, symptoms, and medical history. CONCLUSION: Our results indicate that Mallampati scoring is a useful part of the physical examination of patients prior to polysomnography. The independent association between Mallampati score and presence and severity of obstructive sleep apnea suggests that this scoring system will have practical value in clinical settings and prospective studies of sleep-disordered breathing.     

Portable monitoring and autotitration versus polysomnography for the diagnosis and treatment of sleep apnea

STUDY OBJECTIVES: To compare a clinical pathway using portable monitoring (PM) for diagnosis and unattended autotitrating positive airway pressure (APAP) for selecting an effective continuous positive airway pressure (CPAP) with another pathway using polysomnography (PSG) for diagnosis and treatment of obstructive sleep apnea (OSA). DESIGN: Randomized parallel group SETTING: Veterans Administration Medical Center PATIENTS: 106 patients with daytime sleepiness and a high likelihood of having OSA MEASUREMENTS AND RESULTS: The AHI in the PM-APAP group was 29.2 +/- 2.3/h and in the PSG group was 36.8 +/- 4.8/h (P= NS). Patients with an AHI > or = 5 were offered CPAP treatment. Those accepting treatment (PM-APAP 45, PSG 43) were begun on CPAP using identical devices at similar mean pressures (11.2 +/- 0.4 versus 10.9 +/- 0.5 cm H2O). At a clinic visit 6 weeks after starting CPAP, 40 patients in the PM-APAP group (78.4% of those with OSA and 88.8% started on CPAP) and 39 in the PSG arm (81.2% of those with OSA and 90.6% of those started on CPAP) were using CPAP treatment (P = NS). The mean nightly adherence (PM-APAP: 5.20 +/- 0.28 versus PSG: 5.25 +/- 0.38 h/night), decrease in Epworth Sleepiness Scale score (-6.50 +/- 0.71 versus -6.97 +/- 0.73), improvement in the global Functional Outcome of Sleep Questionnaire score (3.10 +/- 0.05 versus 3.31 +/- 0.52), and CPAP satisfaction did not differ between the groups. CONCLUSIONS: A clinical pathway utilizing PM and APAP titration resulted in CPAP adherence and clinical outcomes similar to one using PSG.     

Hypersynchronous delta sleep EEG activity and sudden arousals from slow-wave sleep in adults without a history of parasomnias: clinical and forensic implications

STUDY OBJECTIVES: To determine the frequency of classical markers of non-rapid eye movement (NREM) parasomnias--hypersynchronous delta sleep (HSD) electroencephalogram waves and sudden arousals from slow-wave sleep (SWS)--in patients without histories of somnambulism or other NREM parasomnias. DESIGN: Retrospective review. SETTING: Sleep disorders center laboratory. PATIENTS: 82 consecutive patients without a history of parasomnias who underwent diagnostic polysomnograms; 57 men and 25 women, mean age 48+/-13.3 years, were included without regard to diagnosis or findings. All patients had at least 30 seconds of stage 3 or 4 sleep during the polysomnogram. MEASUREMENTS AND RESULTS: The primary diagnosis of all but 4 patients was obstructive sleep apnea (mean respiratory disturbance index, 30 +/- 23.6 [range, 2.7-117] per hour of sleep). Polysomnograms were then reviewed for the presence of HSD and SWS arousals. A total of 235 arousals (mean, 2.9 +/- 2.7; range, 0-14) from stage 3 or 4 sleep were noted. Eight-five percent of all patients had at least 1 SWS arousal and 45% had 3 or more SWS arousals; 85.1% of all arousals from SWS were secondary to sleep-disordered breathing, and 5.9% were secondary to leg movements. At least 1 episode of HSD (mean, 1.4 +/- 1.6; range, 0-9) was noted in 65.8% of patients. CONCLUSIONS: HSD and SWS arousals were a common finding in patients without clinical histories of sleepwalking or other parasomnias but who were found to have frequent respiratory-related arousals during sleep. HSD and SWS arousals thus have a low specificity for NREM parasomnias and, without further research, are not useful for the objective confirmation of parasomnias in clinical evaluations and in the forensic evaluation of sleepwalking as a legal defense.     

Modafinil for treatment of residual excessive sleepiness in nasal continuous positive airway pressure-treated obstructive sleep apnea/hypopnea syndrome

STUDY OBJECTIVES: Nasal continuous positive airway pressure (nCPAP) usually reduces sleepiness in patients with obstructive sleep apnea/hypopnea syndrome. However, even with regular use of nCPAP, some patients experience residual excessive sleepiness. We evaluated the efficacy and safety of the wake-promoting agent modafinil for treating residual excessive sleepiness in nCPAP-treated patients. DESIGN: 12-week, multicenter, randomized, double-blind, parallel-group, placebo-controlled trial. PATIENTS: Patients aged 18 to 70 years diagnosed with obstructive sleep apnea/hypopnea syndrome and having residual excessive sleepiness during nCPAP therapy were eligible. INTERVENTIONS: Once-daily modafinil, 200 mg or 400 mg, or placebo. MEASUREMENTS AND RESULTS: Assessments included the Maintenance of Wakefulness Test, Epworth Sleepiness Scale, Clinical Global Impression of Change, and Functional Outcomes of Sleep Questionnaire. Both doses of modafinil significantly improved mean (SD) sleep latency on the Maintenance of Wakefulness Test at weeks 4, 8, and 12 compared with placebo (week 12: modafinil 400 mg, 15.0 [5.3] minutes; 200 mg, 14.8 [5.3] minutes; placebo, 12.6 [5.8] minutes; P < .0001). The Epworth Sleepiness Scale score decreased more in patients taking modafinil compared with those in the placebo group (week 12: modafinil 400 mg, -4.5 [4.3]; 200 mg, -4.5 [4.7]; placebo, -1.8 [3.5]; P < .0001). At week 12, overall clinical condition improved for 61% and 68% of patients treated with modafinil 200 mg and 400 mg, respectively, versus 37% of placebo-treated patients (P < .001). Modafinil was generally well tolerated and did not adversely affect nighttime sleep or nCPAP use. CONCLUSIONS: These results confirm previous shorter-term controlled trials, indicating modafinil is a useful adjunct therapy for improving wakefulness in patients with residual excessive sleepiness associated with obstructive sleep apnea/hypopnea syndrome who were treated with nCPAP.     

Relationship between cytokine concentration and activities of daily living in rehabilitation patients with stroke

Stroke rehabilitation is effective in some patients, however not so effective in others. Our ultimate aim is to use the clinical laboratory assessment as a tool for effectiveness discrimination in rehabilitation. Subjects were 15 stroke patients (68.1 +/- 12.7 years old) who were admitted to our convalescent rehabilitation wards. Fasting blood samples were analyzed for serum concentrations of hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and insulin-like growth factor-I (IGF-I) which are considered to be involved in hypermyotrophy using ELISA methods on admission and at discharge. Sixteen healthy control subjects (63.0 +/- 7.6 years old) were also employed. As accuracy control of these analyses, decrease of serum HGF after keeping at -20 degrees C for 499 days were measured. The concentration was 0.66ng/mL from 0.71 ng/mL and residual ratio was 94.0%. Reaction specificity to MW 60 kDa HGF antibody using the Western blot method was confirmed. Average HGF and VEGF were higher in stroke patients than those in control subjects. Average IGF-I was lower in stroke patients. The correlations between HGF, VEGF, and IGF-I and the score of activities of daily living expressed by the Functional Independence Measure (FIM) were calculated. Highest correlation coefficient of 0.67 (p < 0.01) was obtained between HGF at discharge and the FIM efficiency (the gain of the FIM during hospitalization divided by length of stay). The correlation coefficients related to VEGF or IGF showed lower value. High FIM efficiency denotes rapid recovery with vigorous exercise. HGF at discharge would reflect the result of high activity.     

Adaptive servoventilation versus noninvasive positive pressure ventilation for central, mixed, and complex sleep apnea syndromes

RATIONALE: Although continuous positive airway pressure (CPAP) is most often effective in patients with obstructive sleep apnea, optimal treatment of patients with predominantly mixed apneas, central sleep apnea syndrome/Cheyne-Stokes respiration (CSA/CSR), or complex sleep apnea (CompSAS) is less straightforward, and may require alternative ventilatory assist modalities. OBJECTIVES: To compare the efficacy of noninvasive positive pressure ventilation (NPPV) with adaptive servoventilation (ASV) in treating patients with centrally mediated breathing abnormalities. We hypothesized that NPPV and ASV would be equivalently efficacious in improving the apnea/hypopnea index (AHI) and respiratory arousal index (RAI). METHODS: Prospective randomized crossover clinical trial comparing NPPV with ASV in patients with CSA/CSR, predominantly mixed apneas, and CompSAS in an acute setting. MEASUREMENTS AND MAIN RESULTS: 21 patients (6 with CSA/CSR, 6 with predominantly mixed apneas, and 9 with CompSAS) with initial diagnostic AHI +/- standard deviation 51.9 +/- 22.8/hr and RAI 45.5 < or = 26.5/hr completed the study. Following optimal titration with CPAP (N = 15), disturbed breathing and disturbed sleep remained high with mean AHI = 34.3 +/- 25.7 and RAI = 32.1 +/- 29.7. AHI and RAI were markedly reduced with both NPPV (6.2 +/- 7.6 and 6.4 +/- 8.2) and ASV (0.8 +/- 2.4 and 2.4 +/- 4.5). Treatment AHI and RAI were both significantly lower using ASV (P < 0.01). CONCLUSION: These data confirm that in patients with CSA/CSR, mixed apneas, and CompSAS, both NPPV and ASV are effective in normalizing breathing and sleep parameters, and that ASV does so more effectively than NPPV in these types of patients.     

A novel adaptive wrist actigraphy algorithm for sleep-wake assessment in sleep apnea patients

STUDY OBJECTIVES: Current actigraphic algorithms are relatively less accurate in detecting sleep and wake in sleep apnea patients than in people without sleep apnea. In the current study, we attempted to validate a novel automatic algorithm, which was developed for actigraphic studies in normal subjects and patients with obstructive sleep apnea by comparing it on an epoch-by-epoch basis to standard polysomnography. DESIGN: Prospective cohort study. SETTING: Multicenter, university hospital, sleep laboratories. PARTICIPANTS: A total of 228 subjects from 3 different sleep centers (Skara, Boston, Haifa) participated. INTERVENTION AND MEASUREMENTS: Simultaneous recording of polysomnography and Watch_PAT100, an ambulatory device that contains a built-in actigraph. The automatic sleep/wake algorithm is based on both the quantification of motion (magnitude and duration) and the various periodic movement patterns, such as those occurring in patients with moderate to severe obstructive sleep apnea. RESULTS: The overall sensitivity and specificity to identify sleep was 89% and 69%, respectively. The agreement ranged from 86% in the normal subjects to 86%, 84%, and 80% in the patients with mild, moderate, and severe obstructive sleep apnea, respectively. There was a tight agreement between actigraphy and polysomnography in determining sleep efficiency (78.4 +/- 9.9 vs 78.8 +/- 13.4%), total sleep time (690 +/- 152 vs 690 +/- 154 epochs), and sleep latency (56.8 +/- 31.4 vs 43.3 +/- 45.4 epochs). While for most individuals the difference between the polysomnography and actigraphy was relatively small, for some there was a substantial disagreement. CONCLUSIONS: We conclude that this actigraphy algorithm provides a reasonably accurate estimation of sleep and wakefulness in normal subjects and patients with obstructive sleep apnea on an epoch-by-epoch basis. This simple method for assessment of total sleep time may provide a useful tool for the accurate quantification of obstructive sleep apnea in the home environment.     

Haptoglobin polymorphism is a risk factor for cardiovascular disease in patients with obstructive sleep apnea syndrome

STUDY OBJECTIVES: Obstructive sleep apnea syndrome is associated with a marked increase in the risk for cardiovascular disease. Increased oxidative stress and leukocyte adhesiveness have been implicated as fundamental pathophysiologic mechanisms underlying the increased susceptibility in these patients. Haptoglobin is an antioxidant and immunomodulatory protein encoded by 2 alleles with profoundly different biophysical and biochemical properties. We therefore sought to determine if the haptoglobin phenotype was a determinant of cardiovascular disease in patients with obstructive sleep apnea syndrome. DESIGN: Haptoglobin phenotype was determined by gel electrophoresis in 465 patients with and 757 individuals without obstructive sleep apnea syndrome. SETTING: Eight-bed Technion Sleep Medicine Center in Haifa, serving the northern part of Israel. PARTICIPANTS: Patients referred for sleep recordings because of suspected breathing disorders in sleep and healthy industry workers. MEASUREMENTS AND RESULTS: Patients with obstructive sleep apnea syndrome and cardiovascular disease had a significantly different distribution of the 3 haptoglobin phenotypes as compared to patients with obstructive sleep apnea syndrome but without cardiovascular disease. No difference in the haptoglobin phenotype frequency was found between controls with and without cardiovascular disease. Log linear analysis revealed a significant interaction effect of haptoglobin phenotype and the presence of sleep apnea on the presence of cardiovascular disease. Logistic regression analysis revealed that the risk of cardiovascular disease in sleep apnea patients younger than 55 years with haptoglobin 2-2 was 2.32-fold higher than in their counterparts with haptoglobin 2-1. CONCLUSIONS: These results suggest that haptoglobin phenotype is an important risk factor in determining susceptibility to cardiovascular disease in obstructive sleep apnea syndrome, which may be mediated by the decreased antioxidant and antiinflammatory actions of the haptoglobin 2 allelic protein product.     

Early rehabilitation outcome in patients with middle cerebral artery stroke

Although important data on the prognosis and rehabilitation outcome in stroke patients have been reported, data on functional recovery according to stroke subtypes are limited. This retrospective study aimed to evaluate functional outcome in patients with middle cerebral artery (MCA) stroke-the most common subtype of ischemic stroke. The records of stroke patients that underwent the rehabilitation program at our brain injury rehabilitation service between January 2007 and December 2008 were reviewed, and those with MCA stroke were included in the study. Patient demographic and clinical data, and Barthel Index (BI) and Functional Independence Measure (FIM) scores at admission and discharge were collected. The study included 80 MCA stroke patients with a mean age of 63.54 years. FIM and BI scores improved significantly post rehabilitation (P < 0.05). Age was negatively correlated with both BI and FIM scores at admission and discharge. Length of stay was not correlated with improvement in BI or FIM scores during hospitalization. The patients that had ≤1 month of inpatient rehabilitation had similar outcomes as those that had >1 month of inpatient rehabilitation (P > 0.05). Length of time after stroke onset was not correlated with BI or FIM scores at admission. Regardless of initial functional status, prediction of discharge functional status was misleading. Physiatrists should keep in mind that functional improvement does not always increase with duration of inpatient therapy.     

Sleepiness in obstructive sleep apnea: a harbinger of impaired cardiac function?

STUDY OBJECTIVES: Daytime sleepiness is a common clinical presentation in both obstructive sleep apnea (OSA) and cardiovascular diseases. The purpose of this study was to assess the relationship between degree of subjective daytime sleepiness and cardiac performance in patients with obstructive sleep apnea. DESIGN: Observational study. SETTING: General Clinical Research Center. PATIENTS: The study sample was comprised of 86 patients (68 men and 18 women) with an average age of 47 years. All were suspected of having obstructive sleep apnea and underwent confirmatory diagnostic polysomnography (respiratory disturbance index > or = 15). MEASUREMENTS AND RESULTS: Stroke volume and cardiac output were measured using impedance cardiography and corrected for body surface area to yield stroke index and cardiac index. Daytime sleepiness was quantified using the Epworth Sleepiness Scale. A higher Epworth Sleepiness Scale score, suggesting more daytime sleepiness, was significantly related to lower stroke index and cardiac index. In multiple regression analyses, the relationships of Epworth Sleepiness Scale score with both stroke index and cardiac index were significant (p < .05), even after controlling for age, sex, ethnicity, respiratory disturbance index, and mean sleep oxygen saturation. CONCLUSIONS: These results suggest that daytime sleepiness is independently associated with decreases in cardiac function as assessed by impedance cardiography in patients with obstructive sleep apnea.     

Sleep apnea in heart failure increases heart rate variability and sympathetic dominance

AIMS: Sleep disordered breathing (SDB) is common in heart failure and ventilation is known to influence heart rate. Our aims were to assess the influence of SDB on heart rate variability (HRV) and to determine whether central sleep apnea (CSA) and obstructive sleep apnea (OSA) produced different patterns of HRV. METHODS AND RESULTS: Overnight polysomnography was performed in 21 patients with heart failure and SDB. Two 10-minute segments each of SDB and stable breathing from each patient were visually identified and ECG signal exported for HRV analysis. SDB increased total power (TP) with very low frequency (VLF) power accounting for the greatest increase (1.89+/-0.54 vs 2.96+/-0.46 ms2, P <0.001); LF/HF ratio increased during SDB (1.2+/-1.0 vs 2.7+/-2.1, P <0.001). Compared to OSA, CSA was associated with lower absolute LF (2.10+/-0.47 vs 2.52+/-0.55 ms2, P = 0.049) and HF power (1.69+/-0.41 vs 2.34+/-0.58 ms2, P = 0.004), increased VLF% (78.9%+/-13.4% vs 60.9%+/-19.2%, P = 0.008), decreased HF% (6.9%+/-7.8% vs 16.0%+/-11.7%, P = 0.046) with a trend to higher LF/HF ratio. CONCLUSIONS: SDB increases HRV in the setting of increased sympathetic dominance. HRV in CSA and OSA have unique HRV patterns which are likely to reflect the different pathophysiological mechanisms involved.