Chronic insomnia remitting after maxillomandibular advancement for mild obstructive sleep apnea: a case series.

BACKGROUND: Chronic insomnia and obstructive sleep apnea are both common sleep disorders. Chronic insomnia is thought to result from stress-related physiologic hyperarousal (somatic arousal) that makes it difficult for an individual to fall or stay asleep. Obstructive sleep apnea is thought to result from obstructive respiratory events causing arousals, sleep fragmentation, and recurrent oxygen desaturation. Although the two disorders seem different, they predispose to the same long-term, stress-related illnesses, and when they occur in the same individual, each affects the other's response to treatment; they interact. This report of three cases describes patients with both chronic insomnia and obstructive sleep apnea in whom the chronic insomnia remitted with no specific treatment following treatment of obstructive sleep apnea with maxillomandibular advancement. CASE PRESENTATIONS: Our three Caucasians patients each presented with severe, chronic insomnia associated with somatic arousal and fatigue occurring either alone, in association with bipolar disorder, or with temporomandibular joint syndrome. Polysomnography revealed that each patient also had mild obstructive sleep apnea, despite only one snoring audibly. One patient experienced a modest improvement in her somatic arousal, insomnia severity, and fatigue with autotitrating nasal continuous positive airway pressure, but the other two did not tolerate nasal continuous positive airway pressure. None of the patients received treatment for insomnia. All three patients subsequently underwent maxillomandibular advancement to treat mild obstructive sleep apnea and experienced prolonged, complete resolution of somatic arousal, chronic insomnia, and fatigue. The patient with bipolar disorder also experienced complete remission of his symptoms of depression during the 1 year he was followed postoperatively. CONCLUSIONS: These three cases lend support to the hypothesis that chronic insomnia and obstructive sleep apnea share a pathophysiology of chronic stress. Among patients with obstructive sleep apnea, the stress response is directed at inspiratory airflow limitation during sleep (hypopnea, snoring, and inaudible fluttering of the throat). Therefore, when chronic insomnia and obstructive sleep apnea occur in one individual, aggressive treatment of obstructive sleep apnea may lead to a reduction in chronic stress that causes the patient's chronic insomnia to remit.

Somatic syndromes, insomnia, anxiety, and stress among sleep disordered breathing patients.

OBJECTIVES: We tested the hypothesis that the prevalence of somatic syndromes, anxiety, and insomnia among sleep disordered breathing (SDB) patients is correlated with their levels of somatic arousal, the symptoms of increased sympathetic nervous system tone under conditions of stress. METHODS: We administered the Body Sensation Questionnaire (BSQ; a 17-item questionnaire with increasing levels of somatic arousal scored 17-85) to 152 consecutive upper airway resistance syndrome (UARS) patients and 150 consecutive obstructive sleep apnea/hypopnea (OSA/H) patients. From medical records, we characterized each patient in terms of the presence of syndromes and symptoms into three categories: somatic syndromes (six syndromes), anxiety (anxiety disorders, nightmares, use of benzodiazepines), and insomnia (sleep onset, sleep maintenance, and use of hypnotics). For the pooled sample of SDB patients, we modeled the correlation of the BSQ score with the presence of each syndrome/symptom parameter within each of the three categories, with adjustment for male vs. female. RESULTS: Mean BSQ scores in females were significantly higher than those in males (32.5 ± 11.1 vs. 26.9 ± 8.2; mean ± SD). Increasing BSQ scores significantly correlated with increasing prevalence rates of somatic syndromes (p < 0.0001), of anxiety (p < 0.0001), and of insomnia (p ≤ 0.0001). In general, females had higher prevalence rates of somatic syndromes and symptoms of anxiety than males at any BSQ score while rates of insomnia were similar. CONCLUSIONS: In patients with SDB, there is a strong association between the level of somatic arousal and the presence of stress-related disorders like somatic syndromes, anxiety, and insomnia.

Somatic arousal and sleepiness/fatigue among patients with sleep-disordered breathing.

OBJECTIVES: In a large clinical sample, we tested the hypothesis that levels of sleepiness and fatigue among upper airway resistance syndrome (UARS) patients are correlated with levels of somatic arousal (SA; reflecting the sympathetic nervous system component of the stress response). We also tested the correlations of post-treatment change in these three parameters, and we extended the investigation to obstructive sleep apnea/hypopnea (OSA/H) patients. METHODS: From 5 years of patient data, we obtained scores on the body sensation questionnaire (BSQ), measuring the level of SA, the fatigue severity scale (FSS), and Epworth sleepiness scale (ESS) for 152 consecutive UARS patients and 150 consecutive OSA/H patients. For each group, we correlated the FSS and ESS scores with the BSQ scores. Among the 45 UARS patients and 49 OSA/H patients treated with nasal CPAP who provided post-treatment data, we correlated change in FSS and ESS scores with change in BSQ scores. RESULTS: Scores on the BSQ, FSS, and ESS for UARS patients and OSA/H patients were comparable. In both UARS and OSA/H patients, both the FSS and ESS scores were positively correlated with the BSQ score. Nasal CPAP use decreased all three questionnaire scores in both patient groups. In the pooled data, changes in FSS were significantly correlated with changes in BSQ. CONCLUSIONS: Our findings confirm our preliminary observations that sleepiness and fatigue among UARS patients are correlated with their level of SA and suggest that the same is true for OSA/H patients. The decrease of SA following treatment suggests that SDB is a cause of SA among patients with UARS and OSA/H.

The association of somatic arousal with the symptoms of upper airway resistance syndrome.

OBJECTIVES: We tested the hypothesis that the symptoms of upper airway resistance syndrome (UARS) are manifestations of chronic stress. To accomplish this, we utilized the score on a self-report questionnaire for somatic arousal (a component of stress) to compare somatic arousal between UARS patients and healthy controls and, among all participants, to correlate the level of somatic arousal with the severity of UARS symptoms. METHODS: We administered the Mood and Anxiety Symptom Questionnaire anxious arousal subscale (MASQaas; a 17-item questionnaire with increasing levels of arousal scored 17-85) to 12 UARS patients and 12 healthy controls and compared scores between groups. For all participants, we correlated the MASQaas scores with scores for the Epworth Sleepiness Scale (ESS), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) scale, Pittsburgh Sleep Quality Index (PSQI), SF-36 Health Survey, and Perceived Deficits Questionnaire (PDQ; assessing cognitive function). RESULTS: Compared to healthy controls, UARS patients demonstrated increased somatic arousal (MASQaas scores of 18±2 and 28±7, respectively; p<0.0001). For all participants, the MASQaas scores correlated significantly with scores of the ESS (r=0.64; p=0.0008), the FACIT-Fatigue scale (r=-0.89; p<0.0001), the PSQI (r=0.70; p=0.0002), SF-36 Physical component (r=-0.78; p<0.0001), SF-36 Mental component (r=-0.74; p<0.0001), and the PDQ (r=0.89; p<0.0001). CONCLUSIONS: Our findings suggest that UARS patients have increased levels of the stress component, somatic arousal, proportionate to the severity of their symptoms.

A comparison of inspiratory airflow dynamics during sleep between upper airway resistance syndrome patients and healthy controls.

OBJECTIVES: A test of the hypothesis that upper airway resistance syndrome (UARS) patients have an increased prevalence of inspiratory airflow limitation (IFL) during sleep compared to healthy controls. METHODS: We compared inspiratory airflow dynamics during sleep between 12 UARS patients (nine females and three males) and 12 healthy controls matched for age, gender and obesity with maximal age limited at 45 years. A standard clinical polysomnogram (airflow measured with a nasal/oral pressure catheter) was performed to assess the impact of SDB on the participants' natural sleep. A second full-night polysomnogram with a pneumotachograph and a supraglottic pressure catheter to measure airflow and effort was performed to compare the maximal inspiratory airflow and effort and the percentage of flow-limited breaths during supine, continuous stage 2 sleep between groups. RESULTS: During clinical polysomnography, UARS participants did not differ significantly from controls in sleep architecture or fragmentation. We observed a small difference in apnea hypopnea index between UARS participants and controls (1.6 ± 1.9 vs. 0.4 ± 0.3, respectively; p = 0.035). During supine, continuous stage 2 sleep, 64.2 % (35.8; mean (SD)) of UARS participants' breaths were flow-limited compared with 34.0 % (39.3) of controls' breaths (p = 0.06). The groups did not differ in maximal inspiratory airflow or inspiratory effort. CONCLUSIONS: Our findings indicate a less-than-robust difference in respiratory parameters during sleep between UARS patients and healthy controls and no difference in standard sleep parameters or sleep fragmentation. We consider a pathophysiology of UARS that incorporates these findings.

Treatment resistant adolescent depression with upper airway resistance syndrome treated with rapid palatal expansion: a case report.

INTRODUCTION: To the best of our knowledge, this is the first report of a case of treatment-resistant depression in which the patient was evaluated for sleep disordered breathing as the cause and in which rapid palatal expansion to permanently treat the sleep disordered breathing produced a prolonged symptom-free period off medication. CASE PRESENTATION: An 18-year-old Caucasian man presented to our sleep disorders center with chronic severe depression that was no longer responsive to medication but that had recently responded to electroconvulsive therapy. Ancillary, persistent symptoms included mild insomnia, moderate to severe fatigue, mild sleepiness and severe anxiety treated with medication. Our patient had no history of snoring or witnessed apnea, but polysomnography was consistent with upper airway resistance syndrome. Although our patient did not have an orthodontic indication for rapid palatal expansion, rapid palatal expansion was performed as a treatment of his upper airway resistance syndrome. Following rapid palatal expansion, our patient experienced a marked improvement of his sleep quality, anxiety, fatigue and sleepiness. His improvement has been maintained off all psychotropic medication and his depression has remained in remission for approximately two years following his electroconvulsive therapy. CONCLUSIONS: This case report introduces the possibility that unrecognized sleep disordered breathing may play a role in adolescent treatment-resistant depression. The symptoms of upper airway resistance syndrome are non-specific enough that every adolescent with depression, even those responding to medication, may have underlying sleep disordered breathing. In such patients, rapid palatal expansion, by widening the upper airway and improving airflow during sleep, may produce a prolonged improvement of symptoms and a tapering of medication. Psychiatrists treating adolescents may benefit from having another treatment option for treatment-resistant depression.

The effects of a mid-day nap on the neurocognitive performance of first-year medical residents: a controlled interventional pilot study.

PURPOSE: Despite shorter duty hours, fatigue remains a problem among medical residents. The authors tested the effect of a short, mid-day nap on the cognitive functioning and alertness of first-year internal medicine (IM) residents during normal duty hours. METHOD: This was a controlled, interventional study performed between July 2008 and April 2010. The authors recruited a nap group of 18 residents and a rest (control) group of 11 residents. Investigators connected all participants to an ambulatory sleep monitor before the beginning of their shifts in order to monitor rolling eye movements, a proxy for attention failures. At mid-day, both groups took Conner's Continuous Performance Test (CPT II) to evaluate their cognitive functioning and then were placed in a reclining chair designed for napping. The authors instructed nap group residents to nap for up to 20 minutes and chatted with control group residents to prevent them from napping. All residents took the CPT II again immediately after the intervention. Residents' attention failures were recorded until the end of the workday. The authors compared the mean outcome parameters of the two groups through analysis of variance, using effect-of-treatment and baseline covariates. RESULTS: Nap group participants slept a mean of 8.4±3.0 minutes. Compared with controls whose cognitive functioning and number of attention failures did not change from morning to afternoon, the nap group's cognitive functioning improved and their number of attention failures decreased. CONCLUSIONS: A short, mid-day nap can improve cognitive functioning and alertness among first-year IM residents.

Functional somatic syndromes, anxiety disorders and the upper airway: a matter of paradigms.

The relationship between the functional somatic syndromes, anxiety disorders and the upper airway (particularly, sleep disordered breathing) remains ambiguous. This ambiguity, despite a growing body of research supporting a relationship, may result from the absence of a paradigm to explain how upper airway dysfunction can promote disorders commonly associated with one's mental health. This review models the functional somatic syndromes and anxiety disorders as consequences of chronically increased hypothalamic-pituitary-adrenal axis activity. It then examines the literature supporting a relationship between these disorders and upper airway dysfunction during wakefulness and sleep. Finally, building upon an existing paradigm of neural sensitization, sleep disordered breathing is linked to functional somatic syndromes and anxiety disorders through chronic activation of the hypothalamic-pituitary-adrenal axis.

The effect of nasal continuous positive airway pressure on the symptoms of Gulf War illness.

PURPOSE: We performed a pilot study to determine whether nasal continuous positive airway pressure (CPAP) alleviates the symptoms of veterans with Gulf War illness (GWI) and sleep disordered breathing (SDB). METHODS: Eighteen male veterans with GWI and SDB recruited by advertisement, participated in a randomized, single-masked, sham-controlled treatment trial. Participants received 3 weeks of treatment during sleep with either therapeutic nasal CPAP or sham nasal CPAP. Using validated questionnaires, pain, fatigue, cognitive function, sleep disturbance, and general health were assessed by self-report before and after treatment. One of the participants assigned to therapeutic CPAP was excluded from the trial before starting treatment, leaving 17 participants. RESULTS: Compared to the nine sham nasal CPAP recipients, the eight participants receiving therapeutic nasal CPAP experienced improvements in pain (34%; p = 0.0008), fatigue (38%; p = 0.0002), cognitive function (33%; p = 0.004), sleep quality (41%; p = 0.0003), physical health (34%; p = 0.0003), and mental health (16%; p = 0.03). CONCLUSIONS: Our findings in this pilot study suggest that nasal CPAP may greatly improve symptoms in veterans with GWI and SDB.

Inspiratory airflow dynamics during sleep in veterans with Gulf War illness: a controlled study.

PURPOSE: To determine whether veterans with Gulf War Illness (GWI) are distinguished by sleep-disordered breathing, we compared inspiratory airflow dynamics during sleep between veterans with GWI and asymptomatic veterans of the first Gulf War. METHODS: We recruited 18 male veterans with GWI and 11 asymptomatic male veterans of the first Gulf War by advertisement. The two samples were matched for age and body mass index. Each participant underwent a first full-night polysomnogram (PSG) while sleeping supine using standard clinical monitoring of sleep and breathing. A second PSG was performed measuring airflow with a pneumotachograph in series with a nasal mask and respiratory effort with a supraglottic pressure (Psg) catheter to assess the presence of inspiratory airflow limitation during supine N2 sleep. We determined the prevalence of flow-limited breaths by sampling continuous N2 sleep and plotting inspiratory flow against Psg for each breath in the sample. We expressed the prevalence of flow-limited breaths as their percentage in the sample. RESULTS: Compared to controls, veterans with GWI had an increased frequency of arousals related to apneas, hypopneas, and mild inspiratory airflow limitation. During supine N2 sleep, veterans with GWI had 96 ± 5% (mean ± SD) of their breaths flow-limited while controls had 36 ± 25% of their breaths flow limited (p < 0.0001). CONCLUSIONS: Veterans with GWI experience sleep-disordered breathing that may distinguish them from asymptomatic veterans of the first Gulf War.

War-related illness symptoms among Operation Iraqi Freedom/ Operation Enduring Freedom returnees.

OBJECTIVE: Our objective was to determine the pattern of war-related illness (WRI) symptoms among returnees of Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) living on Long Island, NY. METHODS: We conducted an anonymous mail survey of WRI symptoms of a random cohort of 786 returnees (718 male, 68 female) living on Long Island from among 5,500 who registered with the OIF/OEF Registry. RESULTS: From among the 786 returnees whom we surveyed, we subsequently excluded 111 whose surveys were either returned unopened or who changed address. Two hundred seventy-four of the remaining 675 returnees responded to the survey (a 41% response rate). Disabling WRI symptoms were documented in approximately 2/3 of the responders and 75% of these responders had two or more symptoms. CONCLUSION: War-related illness symptoms are very common among OIF/OEF returnees suggesting the need for management strategies targeting their symptoms. BACKGROUND: Military conflicts have produced war-related illness (WRI) among our troops and veterans since the Civil War. Common to all these WRIs are a group of symptoms including body pain, fatigue, headache, sleep disturbance, diarrhea, forgetfulness, and impaired concentration. Also common to them is the absence of a discernable pathophysiology. Because WRI is poorly understood, we cannot prevent new occurrences with each new engagement of our armed forces.

Inspiratory airflow dynamics during sleep in irritable bowel syndrome: a pilot study.

PURPOSE: This study is a preliminary test of the hypothesis that the pathophysiology of irritable bowel syndrome (IBS) derives from pharyngeal collapse during sleep. MATERIALS AND METHODS: We studied inspiratory airflow dynamics during sleep in 12 lean females with IBS and 12 healthy female controls matched for age and obesity. A standard clinical polysomnogram (airflow measured with a nasal/oral pressure catheter) was performed to assess the impact of pharyngeal collapse on the participants' natural sleep. A second polysomnogram with a pneumotachograph and a supraglottic pressure catheter to measure airflow and effort was performed to compare the maximal inspiratory airflow and effort and the prevalence of inspiratory airflow limitation (IFL) during supine stage 2 sleep between groups. RESULTS: During clinical polysomnography, IBS participants did not differ significantly from controls in sleep architecture or respiration. The difference in apnea-hypopnea index between IBS participants and controls, however, approached statistical significance (2.8 +/- 2.7 vs 1.1 +/- 1.5, respectively; p = 0.079). Although nine of the 12 IBS participants had a prevalence of IFL of at least 33% during supine stage 2 sleep, they did not differ from controls in maximal inspiratory airflow, inspiratory effort, or the prevalence of IFL. Controls, however, differed from IBS participants in having their prevalence of IFL during stage 2 sleep positively correlated with age (r = 0.86; p = 0.0003) while IBS participants demonstrated no relationship between the prevalence of IFL and age. CONCLUSIONS: Our findings, while less than definitive, suggest a prevalence pattern of pharyngeal collapse during sleep among females with IBS that differs from that of healthy females, providing necessary background to inform further work on the relationship of pharyngeal collapse during sleep to IBS.

Lower extremity edema and pulmonary hypertension in morbidly obese patients with obstructive sleep apnea.

INTRODUCTION: In 70 consecutive male patients with obstructive sleep apnea (OSA) diagnosed at the Northport VA Medical Center Sleep Disorders Center, we have characterized the association between obesity, OSA, and pulmonary hypertension (PH). MATERIALS AND METHODS: By including anthropometric, pulmonary function, and sleep study parameters in a multivariate logistic regression model, we found that a BMI of >40 kg/m(2) and the minimum oxygen saturation in non-rapid eye movement (NREM) sleep predicted the presence of pretibial edema in this sleep apnea population. We then characterized the hemodynamics of those OSA patients that had lower extremity edema. Twenty-nine of the 70 consecutive patients with sleep apnea (41%) had pretibial edema, and right heart catheterization data was obtained for 28 (97%) of these patients. RESULTS AND DISCUSSION: Ninety-three percent (26/28) of the patients had right heart failure (mean RAP > 5 mm Hg; RAP range = 0-32 mmHg) and PH (PA mean >or= 20 mm Hg) was present in 86% (24/28.) The OSA patients with lower extremity edema had an increased cardiac output (7.0 + 1.4 l/min) with a normal cardiac index (2.9 + 0.5 l/min/m(2)) in the setting of an elevated pulmonary capillary wedge pressure (PCWP 17 +/- 7 mmHg) and a normal pulmonary vascular resistance (122 + 70 dynes s cm(-5)). While PCWP, FEV(1)% predicted, and the minimum oxygen saturation in NREM sleep all independently predicted PH, PCWP was the most important predictor of PH. CONCLUSION: We conclude that pulmonary hypertension is commonly seen in patients with OSA with pretibial edema and that pretibial edema is a highly specific sign of PH in OSA patients. Pulmonary hypertension appears to result from an elevated back pressure and diastolic dysfunction with contributions from lung function and nocturnal oxygen saturation.

Hypersomnolence, insomnia and the pathophysiology of upper airway resistance syndrome.

OBJECTIVE: In order to test the hypothesis that upper airway resistance syndrome (UARS) is merely an extension of the pathophysiology of obstructive sleep apnea/hypopnea (OSA/H) to less severe pharyngeal collapse during sleep, we compared the severity of hypersomnolence and the prevalence of insomnia in UARS patients to the patterns observed for OSA/H patients. Our goal was to determine whether the severity of hypersomnolence and the prevalence of insomnia observed in UARS patients could have been predicted from the patterns observed among OSA/H patients. METHODS: We performed a retrospective study of a large consecutive patient series evaluated at an academic sleep disorders center, including 220 OSA/H patients and 137 UARS patients. Patients had no other sleep-related diagnosis and underwent an initial evaluation that included a measure of hypersomnolence [a multiple sleep latency test (MSLT); 95%] or insomnia questionnaire (87%). Patients were characterized by anthropometric data, polysomnographic descriptive measures of sleep, MSLT data and insomnia questionnaire data. RESULTS: Severity of hypersomnolence decreased over the continuum from severe to mild OSA/H. A model fit to the OSA/H patients to predict severity of hypersomnolence significantly underestimated hypersomnolence in UARS patients, which was comparable in severity to that of patients with mild OSA/H. The frequency of sleep-onset insomnia increased over the continuum from severe to mild OSA/H and increased further in UARS. CONCLUSIONS: UARS is, in some respects, an extension of OSA/H to less severe pharyngeal collapse, but this does not adequately account for the symptom profile of patients with UARS. A physical model is proposed to account for the excess somnolence in UARS relative to expectations and the increasing frequency of sleep-onset insomnia along the continuum from severe OSA/H to UARS.

Inspiratory airflow dynamics during sleep in women with fibromyalgia.

STUDY OBJECTIVES: To determine whether women with fibromyalgia have inspiratory airflow dynamics during sleep similar to those of women with upper-airway resistance syndrome (UARS). DESIGN: A descriptive study of consecutive female patients with fibromyalgia. SETTING: An academic sleep disorders center. PATIENTS OR PARTICIPANTS: Twenty-eight women with fibromyalgia diagnosed by rheumatologists using established criteria. Fourteen of the women gave a history of snoring, while 4 claimed to snore 'occasionally' and 10 denied snoring. The comparison group comprised 11 women with UARS matched for age and obesity. INTERVENTIONS: Eighteen of the 28 women with fibromyalgia and all of the women with UARS had a full-night polysomnogram. All participants had a nasal continuous positive airway pressure (CPAP) study with quantitative monitoring of inspiratory airflow and effort between atmospheric pressure and therapeutic CPAP. Fourteen patients with fibromyalgia and all patients with UARS had a successful determination of pharyngeal critical pressure. MEASUREMENTS AND RESULTS: Twenty-seven of 28 women with fibromyalgia had sleep-disordered breathing. One of the 27 had obstructive sleep apnea hypopnea while 26 had milder inspiratory airflow limitation with arousals. One patient had no apnea or hypopnea or inspiratory airflow limitation during sleep. While the patients were sleeping at atmospheric pressure, apnea-hypopnea index, arousal index, the prevalence of flow-limited breaths, and maximal inspiratory flow were similar between groups. The pharyngeal critical pressure of the patients with fibromyalgia was -6.5 +/- 3.5 cmH2O (mean +/- SD) compared to -5.8 +/- 3.5 cmH2O for patients with UARS (P = .62). Treatment of 14 consecutive patients with nasal CPAP resulted in an improvement in functional symptoms ranging from 23% to 47%, assessed by a validated questionnaire. CONCLUSION: Inspiratory airflow limitation is a common inspiratory airflow pattern during sleep in women with fibromyalgia. Our findings are compatible with the hypothesis that inspiratory flow limitation during sleep plays a role in the development of the functional somatic syndromes.

The symptoms and signs of upper airway resistance syndrome: a link to the functional somatic syndromes.

STUDY OBJECTIVES: The functional somatic syndromes are associated with a variety of symptoms/signs of uncertain etiology. We determined the prevalence of several of those symptoms/signs in patients with sleep-disordered breathing and examined the relationship between the prevalence of the symptoms/signs and the severity of sleep-disordered breathing. DESIGN: A descriptive study without intervention. SETTING: A university sleep-disorders center located in a suburban setting. PATIENTS OR PARTICIPANTS: Three groups of 25 consecutively collected patients with sleep-disordered breathing. Groups varied in their apnea hypopnea indexes (AHIs) as follows: upper airway resistance syndrome (UARS) [AHI < 10/h), mild-to-moderate obstructive sleep apnea/hypopnea (OSA/H) [AHI >or= 10 to < 40/h), and moderate-to-severe OSA/H (AHI >or= 40/h). MEASUREMENTS AND RESULTS: Patients underwent comprehensive medical histories, physical examinations, and full-night polysomnography. The diagnosis of UARS included quantitative measurement of inspiratory airflow and inspiratory effort with demonstration of inspiratory flow limitation. The percentage of women among the patients with sleep-disordered breathing (p = 0.001) and the prevalence of sleep-onset insomnia (p = 0.04), headaches (p = 0.01), irritable bowel syndrome (p = 0.01), and alpha-delta sleep (p = 0.01) was correlated with decreasing severity of AHI group. CONCLUSIONS: We conclude that patients with UARS, mild-to-moderate OSA/H and moderate-to-severe OSA/H differ in their presenting symptoms/signs. The symptoms/signs of UARS closely resemble those of the functional somatic syndromes.

Upper airway collapsibility during sleep in upper airway resistance syndrome.

STUDY OBJECTIVES: To compare upper airway collapsibility during sleep between patients with upper airway resistance syndrome (UARS), normal subjects, and patients with obstructive sleep apnea/hypopnea syndrome (OSA/H). DESIGN: A descriptive study of a series of clinical patients and a cohort of normal control subjects. SETTING: Two academic sleep-disorders centers. PATIENTS OR PARTICIPANTS: One hundred six adult patients with sleep-disordered breathing evaluated at the SUNY Sleep Disorders Center-Medicine and 12 adult subjects without habitual snoring or daytime sleepiness and with an apnea/hypopnea index (AHI) < 5/h evaluated at the Johns Hopkins Pediatric Sleep Disorders Center. INTERVENTIONS: All subjects underwent full-night polysomnography and a determination of pharyngeal critical pressure (Pcrit). All patients had a determination of therapeutic level of nasal continuous positive airway pressure (Ptherapeutic). MEASUREMENTS AND RESULTS: The mean +/- SD Pcrit of the 12 normal subjects was - 15.4 +/- 6.1 cm H(2)O; the mean Pcrit of the 22 UARS patients was - 4.0 +/- 2.1 cm H(2)O; the mean Pcrit of the 37 patients with mild-to-moderate OSA/H (AHI > or = 10/h and < 40/h) was - 1.6 +/- 2.6 cm H(2)O; and the mean Pcrit of the 47 patients with moderate-to-severe OSA/H (AHI > or = 40/h) was 2.4 +/- 2.8 cm H(2)O. The Pcrit of each group differed from that of all other groups (p < 0.01). The mean Ptherapeutic of patients with UARS was 6.9 +/- 1.7 cm H(2)O; the mean Ptherapeutic of patients with mild-to moderate OSA/H was 7.9 +/- 1.9 cm H(2)O (p = 0.08 compared with the Ptherapeutic of UARS patients); and the mean Ptherapeutic of patients with moderate-to severe OSA/H was 10.5 +/- 2.4 cm H(2)O (p < 0.0001 compared to each of the other patient groups). CONCLUSION: UARS is a syndrome of increased upper airway collapsibility during sleep. The upper airway collapsibility during sleep of patients with UARS is intermediate between that of normal subjects and that of patients with mild-to moderate OSA/H.