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Continuous positive airway pressure (CPAP) is the treatment of choice for the sleep apnoea/hypopnoea syndrome (SAHS); it is usually given with the aim of improving daytime cognitive function, mood, and sleepiness. However, its efficacy has not been validated by controlled trials. We have carried out a randomised, placebo-controlled, crossover study of objective daytime sleepiness, symptoms, cognitive function, and mood in a consecutive series of 32 SAHS patients with a median apnoea plus hypopnoea frequency of 28 (range 7-129) per hour slept. Patients were treated with 4 weeks each of CPAP and an oral placebo, which they were told might improve upper airway muscle function during sleep. Assessments on the last day of each treatment included a multiple sleep latency test and tests of symptom scores, mood profiles, and cognitive performance. The patients had significantly less daytime sleepiness on CPAP than during the placebo period (mean sleep latency 7.2 [SE 0.7] vs 6.1 [0.7] min, p = 0.03). There were also improvements with CPAP in symptom ratings (2.1 [0.2] vs 4.3 [0.3], p < 0.001), mood (p < 0.05 for several measures), and cognitive performance, which showed improved vigilance (obstacles hit in Steer Clear "driving" test 76 [5] vs 81 [6], p < 0.01), mental flexibility (trail-making B time 66 [5] vs 75 [5] s, p < 0.05), and attention (p < 0.05). Objectively monitored CPAP use averaged only 3.4 (0.4) hours per night, but this study provides evidence of improved cognitive performance even at this low level of CPAP compliance. [ABSTRACT FROM AUTHOR]

Introduction: Professional drivers are at high risk of sleepiness due to a combination of factors including shift work and obstructive sleep apnea/hypopnea syndrome (OSAHS), and sleepiness in professional drivers is highly dangerous. This study aimed to determine the prevalence of excessive daytime sleepiness and accident rates in bus drivers., Materials and Methods: Drivers employed at bus depots within 30 miles of Edinburgh were given a sleep questionnaire. One thousand eight hundred fifty-four drivers were approached, and 677 (37%; 25 female) completed questionnaires with a 97% response rate among the 456 given directly to drivers by the researcher., Results: Of the responding drivers, 133 (20% of total, 19% of researcher-delivered questionnaires) reported an Epworth sleepiness score >10. Eight percent of drivers reported falling asleep at the wheel at least once/month, and 7% having an accident, and 18% a near-miss accident due to sleepiness while working., Discussion: This study shows a concerningly high rate of sleepiness and sleep-related accidents among bus drivers. Screening for OSAHS among commercial drivers needs to be seriously evaluated with some urgency.

Background: Sleep-disordered breathing (SDB) is common after stroke, but it is unclear whether it should be treated., Objective: To conduct a randomised controlled trial of continuous positive airway pressure (CPAP) after stroke., Methods: Patients with stroke with > or = 30 apnoeas and hypopnoeas per hour ((A+H)/h) with predominant obstructive sleep apnoea or hypopnoea were randomised to either CPAP treatment or conservative treatment for 8 weeks. Outcomes were measured blind to treatment allocation at 8 weeks and 6 months after the stroke. The primary outcome was physical function on the Nottingham Extended Activities of Daily Living Scale., Results: Of 658 patients with stroke screened, only 71 (10.7%) were eligible and consented to a sleep study 14-19 days after stroke. 66 patients completed the sleep study (21 women; mean age 72 years), 33 (50%) had > or = 30 (A+H)/h that were predominantly obstructive. 15 were randomised to CPAP treatment and 15 to conventional treatment. Despite intensive efforts, objective use of CPAP was poor, averaging 1.4 h a night. CPAP treatment resulted in no significant improvements (p>0.1) in the primary outcome or in neurological function or sleepiness, and in poorer health status on some measures., Conclusions: This trial showed no benefit from CPAP treatment, the relevance of the observed detrimental effects is questionable. Even in our highly selected patients with stroke, use of CPAP was poor. At present, CPAP treatment should be advocated for patients with stroke only if they have symptoms of SDB.

Snoring and obstructive sleep apnoea/hypopnoea syndrome (OSAHS) are often treated with mandibular repositioning splints (MRS), but the efficacy and satisfaction of them has not been comprehensively addressed. A survey on the use of and satisfaction with MRS was posted to 177 patients referred by a hospital orthodontic department for custom-fitting of a MRS. Data were analysed using non-parametric techniques. The response rate was 81% (n=144). Responders (30F, 114M) had mean (SD) age of 51 (11) years, apnoea+hypopnoea index (AHI) of 24 (21) per hr and Epworth Score of 10 (5) at diagnosis, and had been supplied with their MRS a median 7 (IQR 5-11) months previously. Fifty of the 144 patients (35%) had been offered continuous positive airway pressure (CPAP) treatment but had declined or abandoned this. Self-reported MRS use was 5 (2) h/night, with 74 of the 144 patients (51%) continuing to use MRS at least occasionally at a median 7 months after fitting. Survival analysis showed 12% still using MRS at 12 months. Epworth score fell slightly with MRS therapy [-2.4 (3.5); P=0.005] and 7 daytime and 2 nocturnal symptoms improved in MRS users (all P<0.05). Marital satisfaction did not change with MRS. Problems preventing MRS use in 70 non-users included: non-retention (n=12), sore mouth (n=13) or jaw (n=7), difficulties falling asleep (n=10) or breathing (n=7), excessive salivation (n=4), dental damage (n=4) and other problems (n=3). Continued use of MRS therapy was associated with a higher number of teeth, low marital satisfaction perceived by partners and greater improvement in symptoms reported by patients and partners. Continuance with MRS may be low and linked to tolerance problems.

The present study objective was to establish whether pretreatment social cognitive variables may contribute to the explanation of variance in adherence to continuous positive airway pressure (CPAP) treatment for patients with obstructive sleep apnoea/hypopnoea syndrome (OSAHS). A total of 119 of 180 consecutive OSAHS patients were recruited to the study prior to initial CPAP titration. Patients completed psychological measures of health value, health locus of control (incorporating internality, chance, powerful others) and self-efficacy prior to CPAP titration. Objective adherence data were measured by CPAP unit time clocks and collected at 3-month follow-up. Average nightly use was calculated over this period. Logistic regression of prospective predictors of adherence produced a model comprising psychological (health value, internality, powerful others), as well as clinical variables (Epworth score, body mass index, apnoea/hypopnoea index, CPAP pressure). This model explained 24% of the variance in CPAP use, and correctly identified 75% of adherers and 53% of nonadherers. Although the psychological variables explained only a small amount of the overall variance in adherence behaviour, this result provides further support for the hypothesis that psychological variables contribute, in part, to continuous positive airway pressure adherence. Future research should focus on highlighting discrete variables, which may helpfully inform psychologically based interventions aimed at improving the use of continuous positive airway pressure by patients with obstructive sleep apnoea/hypopnoea syndrome at risk of discontinuance.

Sleepiness, cognitive performance, and quality of life are overlapping aspects of daytime function that may be affected in patients with obstructive sleep apnoea/hypopnoea syndrome. The evidence is compatible with hypotheses that these deficits are reversible with treatment, particularly for patients with severe disease.

Though continuous positive airway pressure (CPAP) is the treatment of choice for the sleep apnoea/hypopnoea syndrome (SAHS), suboptimal adherence to CPAP is common. Internationally, some 5-50% of SAHS patients recommended for CPAP either reject this treatment option or discontinue within the first week, and 12-25% of remaining patients can be expected to have discontinued CPAP by 3 years. Biomedical investigations of patients' CPAP use reveal frequent adverse effects, weak prospective relationships between symptomatic or physiological disease severity and CPAP use, and moderate correlations between use and benefit. Relatively expensive high-technological interventions to improve CPAP use (e.g. "intelligent" CPAP, humidification) are the subject of several well-conducted studies favouring their effectiveness. More basic educational and behavioural supports, and low-technological interventions (e.g. chinstraps, mask re-fitting) appear valued, but are currently less rigorously evaluated. In other diseases with demanding treatment regimens, cognitive constructs including health attitudes and beliefs (health value, locus of control, chance, powerful others, self-efficacy) and mental and physical health status are significant predictors of adherence. The enhancement of multidisciplinary models with psychosocial interpretations may provide increased explanatory and interventional potential in models of CPAP use. While acknowledging the scarcity of evidence, a structured, multidisciplinary, cost-efficient model is suggested, containing educational, behavioural and technological components as basic support, and with high-expertise cognitive-behavioural intervention in more difficult cases of low CPAP use.

Mandibular repositioning splints (MRSs) and continuous positive airway pressure (CPAP) are used to treat the sleep apnea/hypopnea syndrome (SAHS). There are some data suggesting that patients with milder symptoms prefer MRS, but there are few comparative data on outcomes. Therefore, we performed a randomized crossover trial of 8 weeks of CPAP and 8 weeks of MRS treatment in consecutive new outpatients diagnosed with SAHS (apnea/hypopnea index [AHI] >or= 5/hour, and >or= 2 symptoms including sleepiness). Assessments at the end of both limbs comprised home sleep study, subjective ratings of treatment value, sleepiness, symptoms, and well-being, and objective tests of sleepiness and cognition. Forty-eight of 51 recruited patients completed the trial (12 women; age [mean +/- SD], 46 +/- 9 years; Epworth 14 +/- 4; median AHI, 22/hour; interquartile ratio [IQR], 11-43/hour). Significant (p

The aim of the study was to investigate psychosocial function before and after continuous positive airway pressure (CPAP) therapy, and establish the determinants and consequences of objective CPAP use. In a prospective, parallel-group study, changes in psychosocial scores were compared with conservative management or CPAP therapy for the sleep apnoea/hypopnoea syndrome (SAHS). Patient/partner couples from the top (CPAP treated, n=44) or bottom (conservatively treated, n=25) of a CPAP waiting list rated marital satisfaction (evaluation and nurturing relationship issues, communication and happiness (ENRICH), behavioural questionnaire), health/functional status (Short-Form-36 Health Survey, functional outcomes of sleep questionnaire) and sleepiness (Epworth sleepiness scale). Both groups' ratings at baseline were completed while on conservative therapy. Baseline variables did not differ between groups. At follow-up, all seven summary psychosocial scores were statistically better in CPAP-treated patients, effect sizes (ES) ranging from moderate (0.5 SD: marital satisfaction) to very large (>1.0 SD: patients health, functional status and sleepiness scores). Scores in conservatively-treated patients deteriorated to a small or moderate degree (ES -0.2- -0.7 SD), while those in the CPAP-treated group improved to a larger degree (0.3-1.3 SD). Baseline polysomnographical and psychosocial scores, including marital satisfaction, did not predict objective CPAP use (r<0.3). CPAP use was modestly correlated (r=0.3-0.6) with improvement in all psychosocial areas. Continuous positive airway pressure produced statistically and clinically significant psychosocial improvements, some of large magnitude, in psychosocial function. Determinants of usage were not identified, but benefits and usage were positively correlated.

Background: The sleep apnoea/hypopnoea syndrome (SAHS) causes snoring, apnoeas, and restlessness during sleep which partners frequently complain about. A study was undertaken to determine the impact on partners of SAHS and of treatment of the patient with continuous positive airway pressure (CPAP)., Methods: Forty nine partners and patients with SAHS booked for CPAP treatment completed in house and validated questionnaires (Pittsburgh sleep quality index, Short Form 36 self-reported health status) before the patient started treatment. Twenty three couples in whom the index SAHS patient had no driving problems were recruited to a randomised crossover trial with 1 month limbs of CPAP and placebo capsule. At the end of each limb the partners' sleep was monitored by home polysomnography (PSG) and questionnaires were completed., Results: Before treatment partners frequently reported moderate to severe disturbance from patient snoring/apnoeas/restlessness and had poor sleep quality and self-reported health status. In the crossover study (22 completed) the partners' objective sleep quality did not differ between CPAP and placebo, but they reported benefit from treatment of the patients with CPAP in subjective sleep quality (p=0.05) and disturbance to sleep (p=0.03). The reported change in partners' sleep quality between pre-study and following CPAP treatment correlated positively with CPAP use (r=0.5, p=0.01)., Conclusions: Partners of patients with SAHS have poor sleep quality and self-reported health status but only subjective sleep quality benefits from treatment of the patient with CPAP.

Some patients with the sleep apnea/hypopnea syndrome (SAHS) remain subjectively and objectively sleepy despite using effective continuous positive airway pressure (CPAP) therapy. The aim of this single center study was to determine the efficacy and safety of the novel wake-promoting medication modafinil in the treatment of CPAP-resistant daytime sleepiness. Thirty sleep apneics receiving effective CPAP therapy (objective use, 6.5 +/- 1.1 h/night) received daily single doses of 400 mg modafinil or placebo for 2 wk in a double-blind randomized crossover design. Outcome measures were assessed at baseline and at the end of both 2-wk treatment periods. Treatment periods were separated by a 1-wk washout. Modafinil had no effect on sleepiness as measured by the Epworth Sleepiness Scale or the Multiple Sleep Latency Test (p > 0.1); however, significant improvements in alertness were found with the Maintenance of Wakefulness Test (modafinil 18.3 +/- 3.9 min; placebo, 16.6 +/- 5.0 min; p < 0.02). No significant treatment-related improvements in cognitive performance or quality of life were found with modafinil (all p > 0.05). There was a significant reduction in CPAP use on modafinil compared to placebo (6.3 +/- 1 h/ night; 6.5 +/- 1, p = 0.03). This study suggests that modafinil may improve some aspects of alertness in patients with SAHS who remain sleepy during CPAP therapy, but further studies are required to assess the significance of the reduction in CPAP use.

There have been relatively few robust studies of the effects of CPAP therapy on vigilance and daytime function. This article will use all known published and unpublished randomized clinical trials on this area. There is good evidence that CPAP helps subjective sleepiness, objective sleepiness, quality of life, mood and driving performance. However, CPAP does not appear to normalize objective sleepiness. Many of the improvements are directly related to the nightly use of CPAP. Recent data suggest that increasing CPAP usage improves outcomes.

The magnitude, determinants and reversibility of cognitive deficits associated with the sleep apnea/hypopnea syndrome (SAHS) are of clinical and research interest. A quantitative overview of impairment effect sizes (ESs) from case-control studies of cognitive performance in SAHS suggests that deficits broadly worsen with disease severity, with large average values for attentional (ES approximately 1.0 SD units) and executive (ES approximately 0.9 SD units) cognitive scores, and moderate values for memory-related (ES approximately 0.6 SD units) performance scores. A study of determinants of cognitive outcomes conducted in 150 patients with SAHS (AHI 5+ and > or =2 symptoms) showed significant but weak associations between a cognitive 'intellectual ability' component score (CS) and both AHI (r=-0.14) and minimum oxygen saturation (r = 0.15), linking increasing disease severity with poorer performance. A somewhat stronger correlation between a cognitive 'response slowing' CS and a 'wakefulness' CS was observed (r=-0.34). That sleepiness as well as hypoxemia might contribute to cognitive deficit has also been suggested by experimental sleep fragmentation in normals, producing small to moderate impairments (average ES approximately 0.3 SD units) in attention-biased scores. The reversibility of attentional cognitive deficits has been investigated through a meta-analysis of randomized placebo-controlled crossover studies of CPAP treatment, involving 98 SAHS patients (AHI 5+ and > or =2 symptoms). While cognitive outcomes showed at least trends towards better performance on CPAP than on placebo (p< or =0.1), the ESs of cognitive enhancements following CPAP were small (average ES approximately 0.2 SD units). This may be due either to the relatively mild study population, suboptimal CPAP use or to an irreversible component in cognitive impairment in SAHS.

Continuous positive airway pressure (CPAP) therapy improves daytime function in the sleep apnea/ hypopnea syndrome (SAHS) but it is unclear which patients benefit and what factors predict this improvement. To test the hypothesis that brief arousals from sleep predict improvements in daytime functioning with CPAP therapy, we prospectively studied 62 patients with polysomnography-defined SAHS. Each underwent daytime function assessments at baseline and after 6 mo of CPAP therapy to measure objective sleepiness, psychological well-being, quality of life, and cognitive performance. The microarousal frequency and AHI were poor predictors of improvements in daytime function with CPAP. Measures of hypoxemia predicted improvements in the mean sleep latency on the maintenance of wakefulness test, SAHS symptoms, quality of life, and reaction time, but such correlations were weak or moderate only explaining between 7% and 22% of variance. Significant relationships were found between CPAP use and improvements in self-ratings of daytime function. Results suggest that standard polysomnographic baseline variables are poor predictors of the response to CPAP therapy.

Patients with the sleep apnea/hypopnea syndrome (SAHS) treated by nasal continuous positive airway pressure (CPAP) need to use CPAP long-term to prevent recurrence of symptoms. It is thus important to clarify the level of long-term CPAP use and the factors influencing long-term use. We examined determinants of objective CPAP use in 1, 211 consecutive patients with SAHS who were prescribed a CPAP trial between 1986 and 1997. Prospective CPAP use data were available in 1, 155 (95.4%), with a median follow-up of 22 mo (interquartile range [IQR], 12 to 36 mo). Fifty-two (4.5%) patients refused CPAP treatment (these were more often female and current smokers); 1,103 patients took CPAP home, and during follow-up 20% stopped treatment, primarily because of a lack of benefit. Methods of survival analysis showed that 68% of patients continued treatment at 5 yr. Independent predictors of long-term CPAP use were snoring history, apnea/hypopnea index (AHI), and Epworth score; 86% of patients with Epworth > 10 and an AHI >/= 30 were still using CPAP at 3 yr. Average nightly CPAP use within the first 3 mo was strongly predictive of long-term use. We conclude that long-term CPAP use is related to disease severity and subjective sleepiness and can be predicted within 3 mo.

Continuous positive airway pressure (CPAP) therapy is widely prescribed for patients with the sleep apnea/hypopnea syndrome (SAHS), but the use of CPAP for such patients is disappointingly low. We postulated that providing intensive educational programs and nursing support to SAHS patients might improve CPAP use and outcomes. We also examined the hypothesis that CPAP use would be greater among patients who had initiated their own referral than among those asked to seek help by a partner. We randomized 80 consecutive, new patients with SAHS to receive either usual support or additional nursing input including CPAP education at home and involving their partners, a 3-night trial of CPAP in our institution's sleep center, and additional home visits once they had begun CPAP. The primary outcome variable was objective CPAP use; symptoms, mood, and cognitive function were also assessed after 6 mo. CPAP use over 6 mo was greater (p = 0.003) among patients receiving intensive than among those receiving standard support (5.4 +/- 0.3 versus 3.9 +/- 0. 4 h/night [mean +/- SEM]), with greater improvements (p < 0.05) in SAHS symptoms, mood, and reaction time in the intensively supported group. CPAP use was greater (p = 0.002) among patients who initiated their own referrals. CPAP use and outcomes of therapy can be improved by provision of a nurse-led intensive CPAP education and support program. CPAP use is lower among patients whose partners ask them to seek treatment.

The minimal disease severity at which patients with the sleep apnea/hypopnea syndrome (SAHS) gain benefit from treatment is not well characterized, although a pilot study of continuous positive airway pressure (CPAP) therapy showed daytime improvements in patients with 5 to 15 apneas + hypopneas per hour slept (AHI). We have thus performed a second, larger, randomized, placebo- controlled study in a prospective series of 34 patients (13 female) with mild SAHS (AHI 5 to 15) and daytime sleepiness. Patients spent 4 wk on CPAP treatment and 4 wk on an oral placebo, with randomization of treatment order, and daytime assessments on the last day of each treatment. Effective CPAP use averaged 2.8 +/- 2.1 h (mean +/- SD) per night. Compared with placebo, CPAP improved symptom score (p < 0.01), subjective (Epworth; p < 0.01) but not objective (maintenance of wakefulness test; p > 0.2) sleepiness, performances on 2 of 7 cognitive tasks (p < 0.02), depression score (p < 0.01), and five subscales of the SF-36 health/functional status questionnaire (p

Background: Patients with the sleep apnoea/hypopnoea syndrome (SAHS) report improved sleepiness, cognitive function, and psychological well being after continuous positive airway pressure (CPAP) therapy, and it is for these daytime features that CPAP is usually given. However, few randomised or controlled studies exist on the effects of CPAP on daytime function., Methods: A prospective, randomised, single blind, placebo controlled, crossover trial of daytime function after CPAP was conducted in 23 patients with SAHS, all with > or = 15 apnoeas + hypopnoeas/hour and > or = 2 symptoms of SAHS. All patients spent four weeks on CPAP therapy and four weeks on oral placebo treatment, following randomisation to treatment order. With ethics committee approval, patients were told the placebo tablet might improve upper airway function. Average effective CPAP use was monitored using hidden time clocks. Assessments of objective and subjective sleepiness, symptoms, cognitive performance, and psychological well being were performed on the last day of each treatment and compared., Results: Objective sleepiness measured by sleep onset latency on the multiple sleep latency test improved with CPAP (mean difference from placebo +2.4 min, 95% CI 0.8 to 4.0; p < 0.001) as did subjective sleepiness on the Epworth scale (mean difference -6, 95% CI -3 to -9; p = 0.001). Symptom total score also fell with CPAP (mean difference -1.6, 95% CI -2.2 to -1.0; p < 0.001). No determinants of these changes with active treatment were identified, and no significant enhancements to cognitive function or psychosocial well being were found in this small sample., Conclusions: These findings provide further evidence for clinically significant benefits to daytime function from CPAP.

Under reporting of symptoms by patients with sleep apnoea/hypopnoea syndrome (SAHS) has been reported anecdotally, but investigation of the prevalence or determinants of this is limited. To assess this, repeated ratings in 99 patients with sleep apnoea/hypopnoea syndrome of pre-treatment Epworth sleepiness score, unintended napping, driving impairment and mood were obtained, first at presentation and then after treatment with continuous positive airway pressure (CPAP) therapy of median 22 (range 2-70) weeks duration. Median Epworth score for pre-treatment sleepiness rose from 12 (range 0-24) initially to 14 (range 5-24) retrospectively (P<0.0001). More patients initially under-rated Epworth score (67%) than over-rated (29%; P<0.001). 'False negative' cases with an initially 'normal' (< or = 10) and retrospectively 'sleepy' (> or = 11) Epworth score comprised 24% of all patients and 62% of initially 'normal' scorers. Unintended napping behaviour also was rated as significantly more severe on retrospective assessment (P<0.001). Driving impairment due to sleepiness was initially reported by 23% of all drivers and retrospectively by 37% (P=0.01), with 25% of initial deniers retrospectively admitting compromised driving ability before continuous positive airway pressure. No polysomnographic predictors of symptom under reporting were found (P>0.1). These results suggest a high prevalence of symptom minimization before treatment in patients with sleep apnoea/hypopnoea syndrome.

Upper airway obstructions during sleep cause recurrent brief awakenings or microarousals. Standard criteria exist for sleep and respiratory event scoring, however, there are different definitions currently used to score microarousals. We therefore compared three definitions of microarousal (ranging from 1.5-3 s in duration) and one of awakening (>15 s). We examined their occurrence at the termination of apnoeas and hypopnoeas and their correlation with daytime sleepiness in patients with sleep apnoea/hypopnoea syndrome (SAHS). Sixty-three patients (aged 49, SD 10) had overnight polysomnography, multiple sleep latency tests (MSLT) and Epworth Sleepiness Scales (ESS). There were significantly more microarousals by any definition than there were awakenings (P<0.001) and there were more 1.5 s than 3 s microarousals (P<0.001). Significantly more apnoeas and hypopnoeas were terminated by 1.5 s microarousals (83% and 81%) than by 3 s microarousals (75%) (all P<0.001). Apnoea/ hypopnoea index (AHI) correlated significantly with objective daytime sleepiness (rho=-0.30, P<0.01). There were weakly significant relationships between all three microarousal definitions (-0.24

Background: Continuous positive airway pressure (CPAP) is an effective treatment in patients with moderate and severe sleep apnoea/hypopnoea syndrome (SAHS), but the minimum illness severity at which patients obtain benefit from CPAP is unclear. A study was therefore undertaken to investigate whether CPAP improves symptoms and daytime function in patients with mild SAHS., Methods: Sixteen consecutively recruited patients with mild SAHS (5.0-14.9 apnoeas + hypopnoeas per hour slept and two or more symptoms of SAHS) participated in a prospective placebo controlled randomised crossover trial to assess the effects of CPAP on symptoms and daytime function. Patients spent four weeks on placebo and four weeks on CPAP, undergoing assessments of sleepiness, symptoms, cognitive performance, and well being on the last day of each treatment. Data from the placebo and CPAP assessments were compared., Results: The mean (SE) objective effective use of CPAP was 2.8 (0.7) hours per night. Significant improvements in symptom score (-1.7 (0.5), p < 0.01), mental flexibility (-14 (5) seconds, p = 0.02), and depression rating (-1.6 (0.8), p = 0.03) on CPAP were observed. However, no significant differences in subjective or objective sleepiness were found. Ten of the 16 patients preferred CPAP and opted to continue with this treatment, although this proportion was non-significant (p > 0.4). The eight patients with best CPAP use showed an additional CPAP related improvement in quality of life (-4.4 (1.8), p = 0.03). Those who complied better with CPAP therapy also had a higher average microarousal frequency (p < 0.01) and apnoea+hypopnoea index (p = 0.02) than the poorer compliers., Conclusions: The results of this study provide evidence for improvements in symptoms and daytime function for patients with mild SAHS treated with CPAP.

Nocturnal cough and wheeze are common in asthma and often treated with beta2 agonists or theophyllines. As nocturnal asthma and these therapies may affect sleep and cognition, we compared 50 microg salmeterol inhaled every 12 h with individually dose-titrated sustained-release oral theophylline on sleep quality and cognitive performance in 15 patients with stable nocturnal asthma (overnight peak expiratory flow rate [PEFR] fall > or = 15%, > or = 1 asthmatic awakening/week) using a double-blind, double-dummy, crossover design with 14-d therapy limbs. Cognitive testing and polysomnography were performed on Nights 13 and 14. Trough plasma theophylline concentration after Night 14 on theophylline was median 11.1 (interquartile range 8.3, 15.2) microg/ml. Overnight PEFR falls were similar [salmeterol 2.3 (0, 10.6), theophylline 3.5 (-0.3, 9.6)%, p = 0.4] but on salmeterol there were more nights without awakenings [median difference 1 (0, 2), p < 0.01], fewer nocturnal arousals [difference -3 (-7, 2) h(-1), p < 0.05] and improved quality of life (p = 0.05). Sleep architecture did not otherwise differ. Visual vigilance improved on salmetrol (p < 0.05), but otherwise daytime cognition was unaffected. There was no patient preference for either therapy. Hence in patients with nocturnal asthma, we demonstrate no major clinical advantage, but a small benefit in sleep quality, quality of life, and daytime cognitive function with salmeterol.

Ambulatory blood pressure (BP) monitoring was performed in 13 patients with the sleep apnea/ hypopnea syndrome (SAHS) during a randomized, placebo controlled crossover trial of the effects of continuous positive airway pressure (CPAP) therapy. BP was monitored at half-hourly intervals for a 24-hour period both on CPAP and on an oral placebo, each given for a minimum of 3 weeks. Objective effective CPAP use averaged 4.3 hours per night. Weight and anti-hypertensive medications remained stable over the study period. Systolic, diastolic and mean arterial BP for 24-hour, daytime and nighttime periods were not significantly different on placebo compared to CPAP. Those patients with no significant overnight fall in BP on placebo ("non-dippers") showed a significant improvement in daytime mean arterial BP on CPAP (98 +/- 4 mm Hg) compared to placebo (102 +/- 4 mm Hg; p = 0.01). These findings, in a well-controlled trial, suggest that BP is not reduced by CPAP in a heterogeneous group of SAHS patients, but it may be selectively improved in those patients most at risk for cardiovascular morbidity and mortality.

The benefits of continuous positive airway pressure (CPAP) therapy in patients with the sleep apnea/hypopnea syndrome (SAHS) are poorly documented and patients use CPAP less than physicians recommend. To establish patients' perceptions of benefit from CPAP and to identify determinants of CPAP use, 204 CPAP users completed a questionnaire relating to use of CPAP therapy, sleepiness, and road traffic incident rate before and after CPAP, perceived change in daytime function and nocturnal symptoms with treatment, and problems with CPAP. Variables from these domains of interest were examined, reduced through principal components analysis and correlated to assess associations between these and polysomnographic measures of illness severity. Self-reported CPAP use averaged 5.8 +/- SD 2 h a night. Subjective sleepiness rated by the Epworth sleepiness scale and road traffic incident rate were significantly reduced by CPAP (p<0.0001). A broad range of function and symptom items were highly significantly improved with CPAP (p<0.0001), corroborating the cost to community and industry from SAHS and the preventive value of CPAP. Road traffic incident rate before treatment was correlated with pre-CPAP sleepiness and SAHS severity. Subjective CPAP use correlated with sleepiness before treatment but not with SAHS severity. CPAP mask problems and side effects were not associated with reduced CPAP use, but "nuisance" complaints of awakenings, noise, and sore eyes from CPAP correlated negatively with reported use. Greater reported CPAP use was associated with better resolution of sleepiness and greater improvement in daytime function and nocturnal symptoms.

Patients with the sleep apnea/hypopnea syndrome suffer from impaired daytime function. This has been attributed to both sleep fragmentation and hypoxemia. To help understand which is casual, we studied the effects of sleep fragmentation alone on daytime function. Sixteen normal subjects were studied on two pairs of two nights. The first night of each pair was for acclimatization, and on the second the subject either slept undisturbed or had sleep fragmented with sound pulses every 2 min. Sound volume and duration was titrated to cause a return to theta or alpha rhythm on the EEG for at least 3 s. Study nights were followed by daytime testing of psychometric function and mood and by a multiple sleep latency test (MSLT) and a maintenance of wakefulness test (MWT). Total sleep time did not differ between study nights (400 +/- 20 SD min undisturbed, 396 +/- 24 min fragmented; p = 0.6). Fragmentation decreased sleep latency on both the MSLT (11 +/- 3, 7 +/- 2 min; p = 0.001) and the MWT (34 +/- 8, 24 +/- 10 min; p<0.001). Energetic arousal (22 +/- 4, 19 +/- 4; p = 0.005) and hedonic tone (29 +/- 4, 27 +/- 4; p = 0.05) decreased after fragmentation. Fragmentation impaired daytime function adjudged by the Trailmaking B (p = 0.05) and PASAT 4-s tests (p<0.03). One night of sleep fragmentation makes normal subjects sleepier during the day, impairs their subjective assessment of mood, and decreases mental flexibility and sustained attention.

Background: Patients with the sleep apnoea/hypopnoea syndrome (SAHS) and their spouses often differ in their assessment of the patient's sleepiness. A study was therefore undertaken to investigate whether either the patient's or partner's rating on the Epworth sleepiness scale (ESS) was better related to illness severity., Methods: Nocturnal variables (apnoeas+hypopnoeas/hour (AHI) and arousals/hour) and patient and partner ESS scores were compared in 103 new patients attending the sleep clinic., Results: Mean patient and partner ESS scores were not different. In the whole population neither patient nor partner ESS variables correlated with AHI or arousal frequency. In the patients with SAHS (AHI > or = 15), partner ESS correlated weakly with AHI, but patient ESS did not., Conclusions: This study suggests that neither patient nor partner ESS ratings are strong predictors of SAHS severity.

Background: Continuous positive airway pressure (CPAP) therapy is the treatment of choice for the sleep apnoea/hypopnoea syndrome. Compliance with this relatively obtrusive therapy has not been well studied., Methods: Usage of CPAP was investigated in 54 patients with sleep apnoea/hypopnoea syndrome (median 36 (range 7-129) apnoeas + hypopnoeas/hour slept) over the first 1-3 months after starting CPAP therapy. In all cases CPAP usage was monitored by hidden time clocks that indicated for how long the machines were switched on--that is, the CPAP run time. In 32 patients the time at which the CPAP mask pressure was at the therapeutic level of CPAP pressure set for that patient--that is, the mask time--was also monitored. In all patients objective daytime sleepiness was assessed by multiple sleep latency before and after CPAP therapy., Results: The mean (SE) nightly CPAP run time was 4.7 (0.4) hours. There was no correlation between run time and severity of the sleep apnoea/hypopnoea syndrome as assessed by apnoea + hypopnoea frequency or multiple sleep latency, and no correlation between CPAP usage and improvement in multiple sleep latency. Thirty two patients in whom mask time was recorded had therapeutic CPAP pressures for 89% (3%) of their CPAP run times. Patients who experienced side effects from CPAP used their CPAP machines significantly less than those who did not., Conclusions: Patients with sleep apnoea/hypopnoea syndrome used CPAP for less than five hours/night on average with no correlation between severity of sleep apnoea/hypopnoea syndrome and CPAP usage. Patients who complained of side effects used their CPAP therapy less. It is recommended that, as a minimum, CPAP run time should be regularly recorded in all patients receiving CPAP therapy.

Background: Patients with the sleep apnoea/hypopnoea syndrome often receive continuous positive airway pressure to improve their symptoms and daytime performance, yet objective evidence of the effect of this treatment on cognitive performance is lacking., Methods: A prospective parallel group study was performed comparing the change in objective daytime sleepiness as assessed by multiple sleep latency, cognitive function, and mood in 21 patients (mean (SE) number of apnoeas and hypopnoeas/hour 57 (6)) who received continuous positive airway pressure for three months and 16 patients (49(6) apnoeas and hypopnoeas/hour) who received conservative treatment for a similar period., Results: Both groups showed significant within group changes in cognitive function between baseline and three months, but when comparisons were made between groups the only significant difference was a greater improvement in multiple sleep latency with continuous positive airway pressure. However, the improvement in sleep latency with continuous positive airway pressure was relatively small (3.5 (0.5) to 5.6 (0.7) min). The group treated with continuous positive airway pressure was divided into those who complied well with treatment (> 4.5 hours/night) and those who did not. Those who complied well (n = 14) showed significant improvement in mean sleep latency and also in depression score compared with the controls but no greater improvement in cognitive function., Conclusion: This study confirms significant improvements in objective sleepiness and mood with continuous positive airway pressure, but shows no evidence of major improvements in cognitive function.

The effect of theophylline on sleep quality and cognitive performance in patients with obstructive lung disease has been the subject of controversy. To examine the direct effects of theophylline on sleep quality and cognitive performance, without confounding effects from bronchodilatation, we have undertaken a study of the drug in healthy subjects. A double-blind, placebo-controlled crossover protocol was used to study the effect of oral sustained-release theophylline (Theodur) on subjective sleep quality, objective sleep quality, and cognitive performance. Overnight sleep studies were carried out on Nights 13 and 14 of each 2-wk study limb, and cognitive performance tests administered on Days 1 and 13 of each limb. A total of 18 subjects satisfactorily completed the study (8 males, median age 37, range 24 to 67 yr). Theophylline levels were median 10.2, range 2.3 to 13.3 micrograms/ml on Day 1 and 14.7, range 9.6 to 17.5 micrograms/ml on Day 13. No significant difference was observed between theophylline and placebo on subjective or objective sleep quality or on acute or medium-term cognitive performance. We conclude that theophylline does not affect sleep quality or cognitive performance in normal adults.

Magnetic resonance imaging of the brain in 69 detoxified alcoholics revealed that relaxation time (T1) in whole brain and in grey matter and parietal white matter was greater than in age-matched controls. In 48 patients, data on cognitive function and lifetime alcohol consumption were available. With age-controlled, lifetime consumption, and impairment on performance in the cognitive test (a Category Sorting Test) correlated positively with T1 whole brain and in selected regions. Impairment in the cognitive test correlated with increased T1 in whole brain and white matter independently of cerebral atrophy. Alcohol consumption patterns in the following 6 months were unrelated to changes in T1. The excess water implied by the elevated T1 values may be intra- or extracellular. It is uncertain whether or not T1 elevation in alcoholics is a marker of neuronal damage. T1 elevation appears to be a marker of one type of alcohol-related cognitive impairment.

The pressure of cerebrospinal fluid taken at lumbar puncture was recorded objectively by strain gauge pressure measurement in 35 infants and children with pyogenic meningitis. Raised pressures were found in 33 children. The median pressure was 15 mm Hg (range 4-70 mm Hg) in all age groups. The pressure level varied throughout the infection, but a higher median pressure (19 mm Hg) was found when this was measured on the day of admission. The clinical features of the meningitis in these patients suggest that many of the presenting symptoms and signs are those of pressure. These results show that high pressure is frequently present in childhood meningitis, not just in those who die from cones or who have radiological evidence of hydrocephalus. We conclude that raised cerebrospinal fluid pressure is a frequent accompaniment of childhood meningitis and may need treatment in its own right and is therefore one further important factor influencing the course and outcome of childhood meningitis.

Non-fluid displacing pressure transducers can be applied to a spinal needle at LP and direct CSF pressure recordings obtained routinely. The method is particularly applicable to children with suspected meningitis and is both a safer and a more accurate estimate of CSF pressure. Children with acute purulent meningitis frequently have raised intracranial pressure on presentation and Mannitol infusion during the LP recording is useful in returning the pressure to normal.

Twenty-seven patients had a first Magnetic Resonance Imaging (MRI) scan 1-3 days after stopping drinking and a second approximately 2 weeks later with no change in whole brain T1 or T1 in selected brain areas. Six patients whose first scan was over 36 h after the last drink underwent an increase in whole brain T1 in the interval to the second scan. The later the first scan was performed the greater was the increase in T1. These results are compatible with a very early fall in brain water immediately on cessation of drinking (perhaps due to a rebound increase of vasopressin activity) with a return to 'baseline' after two weeks. A third scan after discharge from hospital in 23 individuals who had abstained from alcohol or drank very little did not reveal any further significant change in brain T1.

CSF production rate has been measured by a drip detector method in 5 cases of childhood hydrocephalus undergoing closed ventricular drainage. The rate of production of CSF with this "real time" estimation is shown not to be constant but to be discontinuous and may vary by a factor of 10 over a one hour period, although the average rate of CSF production remains within previously established normal limits.

Magnetic resonance imaging T1 values in Alzheimer's disease (ATD) were similar to age-matched controls although frontal T1 values tended to increase intraindividually with progression of the dementia. T1 values were raised, in both cortical grey and white matter, in Korsakoff's syndrome and multi-infarct dementia. T1 values appear of little value in studying the neuropathological changes in ATD in relationship to the neuropsychological deficits, but can assist in the differential diagnosis of pre-senile dementia.