Are we going to deal now with Papit's Flow Limitation?
Check this about Flow Limitation (consisting of RERAs and UARs):
A source for a link:
http://www.apneaboard.com/forums/Thread ... e-Syndrome
Do you have Upper Airway Resistance Syndrome (UARS)?
Clinical Features
Patients with UARS have symptoms similar to those seen in OSAS, although there are some distinct features. Much of the research performed has attempted to identify and describe a group of patients with significant daytime sleepiness and disrupted sleep, but without the other dominant clinical features seen in OSAS. Typical symptoms reported by patients with UARS include excessive daytime sleepiness, fatigue, difficulty concentrating, morning headaches, and unrefreshing sleep. There can be also be a significant impairment in daytime functioning; a recent study demonstrated that subjects with UARS performed worse than patients with obstructive sleep apnea hypopnea syndrome and normal control individuals on different aspects of the Psychomotor Vigilance Task. In a separate study, upwards of 30% of subjects with UARS had abnormal sleep-onset latency on the Maintenance of Wakefulness Test. Individuals with abnormal airway anatomy are at increased risk, including those with a decreased retrolingual space, narrow nasal passages, or a small neck circumference. Patients are typically not obese, with a mean BMI often <25 kg/m. They are also usually younger than those in whom OSAS is diagnosed, with a mean age of approximately 38 years. Snoring is not a requisite symptom, with 10% to 15% or more of patients having never or only intermittently snored.
Patients with UARS are also more likely to report symptoms of frequent nocturnal awakening with difficulty falling back to sleep. This is thought to be a potential reason for increased complaints of insomnia amongst patients with UARS, including sleep onset and sleep maintenance problems. In addition to difficulties with acute insomnia, patients with UARS also have an increased likelihood of carrying a diagnosis of chronic insomnia. Other notable complaints include parasomnias, especially sleepwalking, sleep talking, and sleep terrors. Patients may also have symptoms of abnormal autonomic function, including lightheadedness or dizziness on rising from a supine or sitting position, cold hands and feet, and low resting blood pressures (defined as a systolic BP <105 mm Hg with a diastolic BP <65 mm Hg). In a study of 400 patients with UARS, more than 20% met criteria for low BP, a significantly higher prevalence when compared with people who have OSAS (0.6%) or insomnia (0.9%). Interestingly, all subjects in the study had evidence of a small oral cavity on examination with a narrowed airway space dimension on cephalometric radiographs, consistent with other reports. Lastly, patients with UARS have increased rates of symptoms such as gastroesophageal reflux, muscular pain, diarrhea, abdominal pain, depression, and anxiety. This has led some authors to suggest a link between UARS and functional somatic syndromes, such as irritable bowel syndrome, chronic fatigue syndrome, and fibromyalgia. In a study of 75 subjects equally divided into three groups (UARS, mild to moderate OSAS, and severe OSAS), those with UARS were more likely to report symptoms of headache, irritable bowel symptoms, and sleep-initiation insomnia. Subjects with UARS were also more likely to have alpha intrusion during slow-wave sleep, a polysomnographic finding described in a number of fatigue syndromes. In children with UARS, symptoms consistent with attention deficit disorder or attention deficit hyperactivity disorder may be present, with behavioral changes leading to poor school performance.
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Clinical Features Associated With UARS
Daytime symptoms:
Excessive daytime sleepiness
Fatigue
Morning headaches
Myalgia’s [muscle pain]
Difficulty concentrating
Sleep disturbances:
Frequent nocturnal awakenings
Difficulties initiating sleep
Insomnia
Bruxism [teeth clenching]
Restless leg syndrome
Unrefreshing sleep
Autonomic nervous system:
Hypotension
Orthostasis [maintenance of an upright standing posture]
Cold hands and feet
Functional somatic syndrome associations:
Depression
Anxiety
Chronic fatigue syndrome
Irritable bowel syndrome
Fibromyalgia
Polysomnographic abnormalities Increased RERAs:
Increased nocturnal arousals
Increased CAP rate [cyclical alternating pattern in EEG]
Alpha intrusion during sleep
Treatment
The optimal treatment for patients with UARS is not currently known. Continuous positive airway pressure (CPAP) has been quite useful in the treatment of sleep-disordered breathing and there are some notable positive results in CPAP treatment of UARS. In a study of 15 heavy snorers with clinical evidence of UARS, treatment with nasal CPAP was associated with decreases in observed nocturnal arousals on polysomnography and decreases in mean sleep latency times on multiple sleep latency testing (MSLT) after several nights of treatment. A follow-up study of 15 subjects (in the original description of UARS) with daytime sleepiness and fatigue and who had undergone a therapeutic trial of positive pressure therapy reported similar findings. After treatment with approximately a month of nasal CPAP, significant improvements were seen in mean sleep latency times on MSLT (5.3 minutes vs 13.5 minutes), Pes nadir pressure (–33.1 cm H2O vs –5.3 cm H2O), amount of slow-wave sleep (1.2% vs 9.7%), and EEG arousals (31.3 vs 7.9 events/hour of sleep). Along with an improvement in sleep latency times on MSLT, there were subjective reports of improved daytime symptoms. Lastly, in a study of 130 postmenopausal women with chronic insomnia and evidence of UARS (n=62) or normal breathing (n=68), treatment with either nasal turbinectomy or nasal CPAP was associated with improvements in subjective reports of sleep quality as measured with a visual analog scale as well as mean sleep latency times on polysomnography.19 Despite the growing body of evidence supporting the use of positive pressure therapy for UARS patients, it remains difficult to obtain therapy. In a follow-up study of more than 90 patients conducted 4 to 5 years after the initial diagnosis of UARS was made, none of the subjects were receiving CPAP treatment; the main rationale given was that their insurance provider declined to provide the necessary equipment.1 Formal follow-up clinical evaluations of these patients noted significant worsening in their sleep-related complaints, with increased reports of fatigue, insomnia, and depressive mood. More disturbingly, prescriptions for hypnotics, stimulants, and antidepressants increased more than fivefold.
Other interventions, such as surgery or oral appliances, have also been used with some success in the treatment of patients with UARS. Procedures such as uvulopalatopharyngoplasty, laser-assisted uvuloplasty (LAUP), septoplasty with turbinate reduction, genioglossus advancement, and radiofrequency ablation of the palate have all been described in the literature.37-40 A study of LAUP in nine patients with UARS who underwent uvulopalatopharyngoplasty (n=2), multilevel pharyngeal surgery (n=1), or LAUP (n=6) reported improvements in subjective daytime sleepiness as measured with Epworth Sleepiness Scale scores.37 In the two patients for whom postoperative polysomnographic data was available, significant improvements in Pes nadir pressures were seen. But patients had several interventions and it is difficult to assess which one was successful. A study of 14 patients with UARS who underwent radiofrequency ablation of the palate also reported improvement in subjective sleepiness, with concurrent improvements in Pes nadir levels and reports of snoring.40 However, prior reviews of the available literature have noted that many of the studies evaluated small numbers of patients, consisted of uncontrolled case reports or series without clear characterization of the subjects enrolled, and had no consistent end points for an adequate evaluation of efficacy.39 Further investigation is required to determine the specific role for surgical intervention in these patients. Other authors have also reported successful treatment of UARS with use of oral appliances, although these studies suffer from the same limitations as the surgical literature.41 In children, orthodontic approaches, such as maxillary distraction or use of expanders, have also shown promising results.