Prevalence and Risk Factors for Rapid Eye Movement-Related Obstructive Sleep Apnea in Children.

Objectives: Different pathophysiological mechanisms and the distribution of respiratory events among rapid eye movement (REM) and non-rapid eye movement (NREM) sleep modulate the effect of obstructive sleep apnea (OSA). We aimed to study the prevalence and risk factors for REM-related OSA in children. Study Design: Retrospective, cross-sectional study. Methods: We recruited 366 children with OSA confirmed by polysomnography (PSG) over a 5-year period. REM-related OSA is defined by an obstructive apnea-hypopnea index (OAHI) in the REM sleep ≥2× than during NREM sleep. Results: The prevalence of REM-related OSA in children was 50.3%. Children with REM-related OSA were more likely to be female (P = 0.042), and had lower prevalence of adenotonsillar hypertrophy (P = 0.043) compared with children with other OSA subtypes. Children with REM-related OSA slept longer in the supine position (P = 0.003), had shorter duration of NREM1 sleep (P = 0.018), lower nadir SpO2 (P = 0.005), and a higher oxygen desaturation index 3% (ODI3%) (P = 0.014), and lower arousal index (P = 0.034) compared with other OSA subtypes. Female gender and supine sleep was the independent risk factors for REM-related OSA. Conclusion: The prevalence of REM-related OSA was 50.3%. OAHIREM should be considered as an important parameter in future clinical research studies done in children with OSA.

Reliability and validity of the Thai version of the Pittsburgh Sleep Quality Index.

OBJECTIVE: To assess the internal consistency, test-retest reliability, and validity of the Thai version of the Pittsburgh Sleep Quality Index (Thai-PSQI), which was recently translated using a standardized method, in Thai patients with major sleep disorders. MATERIAL AND METHOD: The Thai-PSQI was developed under a standard translation protocol and administered to "bad" sleepers (i.e. patients with suspected obstructive sleep apnea [OSA], depression, or insomnia) and "good" sleepers in an academic tertiary care setting. All participants were asked to complete the same questionnaire after 2-4 weeks. RESULTS: A total of 138 participants consisting of 69 patients with OSA, 28 with major depression, 11 with primary insomnia, and 30 controls completed the questionnaire. The global scores of the Thai-PSQI revealed that it had excellent internal consistency (Cronbach's alpha = 0.837) and test-retest reliability (intraclass correlation coefficient = 0.89). An analysis of covariance demonstrated a significant difference in Thai-PSQI global score between good sleepers and bad sleepers (p < 0.001). A cut-off point of 5 out of 6 on the global score resulted in a sensitivity of 77.78% and specificity of 93.33%. CONCLUSION: The Thai-PSQI is a valid and reliable tool for screening and identifying the presence of significant sleep disturbances, and is comparable to the original English version.

Progressive multifocal cerebral infarction from intravascular large B cell lymphoma presenting in a man: a case report.

INTRODUCTION: Intravascular lymphoma is rare, and may present as ischemic stroke. Diagnosis is difficult due to the non-specific presentation and lack of lymphadenopathy, thus leading to frequent instances of autopsy-proven diagnosis. To the best of our knowledge, this is the first report of progressive stroke from intravascular lymphoma diagnosed antemortem by random skin biopsy. CASE PRESENTATION: A 42-year-old Thai man presented to our hospital with progressive multifocal cerebral infarction. Despite taking aspirin (300 mg/day), his neurological symptoms worsened. During admission, he developed an unexplained fever and hypoxemia. Magnetic resonance angiography clearly showed patency of all cerebral arteries including the internal carotid and vertebrobasilar arteries. Echocardiography, an antiphospholipid antibody test, cerebrospinal fluid cytology and a bone marrow study were normal. Other laboratory test results showed an elevated lactate dehydrogenase level, nephrotic range proteinuria (3.91 g/day), hypoalbuminemia (1.9 g/dL), a very low high-density lipoprotein level (7 mg/dL) and hypertriglyceridemia (353 mg/dL). Because of suspected vasculitis, pulse methylprednisolone was given with transiently minimal improvement. A random skin biopsy from both thighs revealed intravascular large B cell lymphoma. Chemotherapy was not given due to our patient having ventilator associated pneumonia. He died 10 days after the definite diagnosis was established. CONCLUSION: One etiology of stroke is intravascular lymphoma, in which random skin biopsy can be helpful for antemortem diagnosis.

Risk of sleep-disordered breathing in Parkinson's disease.

OBJECTIVE: The objective of this study is to assess the risk of sleep-disordered breathing (SDB) in patients with Parkinson's disease (PD) in a cross-sectional survey of PD subjects and controls in a university-based movement disorders clinic. METHODS: One hundred thirty-four consecutive PD subjects and 94 control subjects without prior diagnosis of SDB were assessed. Participants were assessed with clinical history, Unified Parkinson's Disease Rating Scale, Geriatric Depression Scale, Berlin Questionnaire to classify SDB risk, Epworth Sleepiness Scale, Parkinson's Disease Sleep Scale, and SF-36 to examine quality of life. The presence of risk for SDB was assessed by the Berlin Questionnaire. RESULTS: High risk for SDB was apparent in 66 (49.3%) of the PD patients and 32 (34.8%) of the controls. After adjustment for age, gender, and body mass index (BMI), PD subjects in comparison to controls showed higher risk for SBD (odds ratio = 2.81; 95% confidence interval, 1.36-5.82). Quality of life (physical component score) was significantly diminished in PD patients at high risk for SDB. PD severity did not correlate well with SDB risk. PD patients at high risk for SDB had higher BMIs and Epworth scores. CONCLUSIONS: PD patients have features suggesting increased risk for SDB. This frequently undiagnosed sleep disorder may have a substantial impact on quality of life of PD patients.

Fatigue, tiredness, and lack of energy improve with treatment for OSA.

OBJECTIVES: Many patients with obstructive sleep apnea complain of fatigue, tiredness, or lack of energy in addition to sleepiness, or instead of sleepiness. We explored whether self-defined fatigue, tiredness, and lack of energy improve, like sleepiness, after treatment with positive airway pressure (PAP). METHODS: We conducted a prospective survey of adults referred to a University-based sleep disorders center and confirmed to have obstructive sleep apnea on polysomnography. Surveys were mailed to 1539 patients 6 months to 3 years after they were prescribed PAP for home use. RESULTS: Participants (n = 313) included 183 who reported using PAP > or = 5 hours per night, 96 who were considered inadequately treated because they had no active treatment or used PAP < 5 hours per night, and 34 treated by surgery or other means and therefore excluded from subsequent analysis. At follow-up in comparison to baseline, subjects adherent to PAP reported less fatigue, tiredness, lack of energy, and sleepiness (p < 0.05 for each). Improvement of each symptom except for lack of energy was significantly better (p < 0.05) among PAP-adherent subjects than among inadequately treated subjects. CONCLUSIONS: Patients' complaints of fatigue, tiredness, and lack of energy, like sleepiness, can improve substantially with good adherence to PAP for obstructive sleep apnea. Therefore, patients who prefer a range of common, related terms other than sleepiness to describe their problem may benefit from investigation and treatment for any underlying sleep-disordered breathing.

Iron stores, periodic leg movements, and sleepiness in obstructive sleep apnea.

STUDY OBJECTIVES: Most clinical sleep studies are performed for suspected obstructive sleep apnea (OSA), yet one-quarter to one-half show periodic leg movements (PLMs), for reasons that remain unknown. Several other disparate sleep disorders also increase the risk for PLMs. We examined the novel hypotheses that OSA as a representative sleep disorder could promote lower body iron stores, as reflected by serum ferritin levels, and, through downstream effects on dopaminergic transmission, increase PLMs and daytime sleepiness. METHODS: Subjects were recruited as they underwent laboratory-based polysomnography for suspected OSA. Serum ferritin levels were measured the next morning. Each subject completed an Epworth Sleepiness Scale and a brief questionnaire to assess for restless legs syndrome (RLS). RESULTS: The frequency of apneic events showed no association with serum ferritin levels, before or after adjustment for age, sex, body mass index, and likely RLS (each p value > 0.3). Serum ferritin levels did not predict the frequency of PLMs (p = 0.7) or Epworth scores (p = 0.8). Iron deficiency as a dichotomous variable, determined by ferritin levels less than < 50 microg/L or in combination with low transferrin saturation or mean corpuscular volume, showed similar results. In exploratory analyses, contrary to expectations, lower minimum oxygen saturation and increased sleep-stage shifts predicted increased rather than decreased ferritin levels (p = 0.03 and p = 0.02, respectively). CONCLUSIONS: Results of this study, powered to detect small to moderate effect sizes, strongly suggest that OSA does not cause lower serum ferritin levels, which, in turn, cannot explain PLMs or daytime sleepiness in these patients.

Patterns of single photon emission tomography (SPECT) among patients with dementia in the memory clinic at Siriraj Hospital.

OBJECTIVE: The authors hypothesized that there is a pattern difference in cerebralperfusion of the 99-Technitium L, L-ethyl cysteinate dimer Single Photon Emission Computer Tomography (99-Tc ECD SPECT) between mild and moderate to severe dementia. MATERIAL AND METHOD: The authors reported a retrospective study in the Memory Clinic, Siriraj Hospital between January 2001 and October 2003 including only patients with Alzheimer's disease, vascular dementia, and mixed dementia. Clinical dementia rating (CDR) was used to document dementia severity. Patterns of hypoperfusion were classified into no definite hypoperfusion, regional hypoperfusion, and diffused hypoperfusion. RESULTS: One hundred and seven patients were included in the present study. Only mean Thai Mental State Examination (TMSE) score was different between the two groups. There was no significant correlation between pattern of hypoperfusion in brain SPECT and severity of dementia. CONCLUSION: The authors cannot demonstrate the pattern of hypoperfusion of 99-Tc ECD SPECT among patients' difference in dementia severity.