Magnetic Resonance Spectroscopy and Neurocognitive Dysfunction in Obstructive Sleep Apnea before and after CPAP Treatment

AbstractObstructive sleep apnea syndrome (OSAS) is characterized by the recurrent cessation (apnea) or reduction (hypopnea) of airflow due to the partial or complete upper airway collapse during sleep. Respiratory disturbances causing sleep fragmentation and repetitive nocturnal hypoxia are responsible for a variety of nocturnal and daytime complaints of sleep apnea patients, such as snoring, daytime sleepiness, fatigue, or impaired cognitive functions. Different techniques, such as magnetic resonance imaging, magnetic resonance spectroscopy, and positron emission tomography, are used to evaluate the structural and functional changes in OSAS patients. With quantitative electroencephalographic (qEEG) analysis, the possible existence of alterations in the brain electrical activity of OSAS patients can be investigated. We review the articles on qEEG results of sleep apnea patients and summarize the possible explanations of these qEEG measures. Finally, we review the impact of continuous positive airway pressure (CPAP) treatment on these alterations to assess whether CPAP use can eliminate alterations in the brain activity of OSAS patients.

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An fMRI study of cerebrovascular reactivity and perfusion in obstructive sleep apnea patients before and after CPAP treatment

Sleep Medicine ◽

10.1016/j.sleep.2014.04.004 ◽

2014 ◽

Vol 15 (8) ◽

pp. 892-898 ◽

Cited By ~ 35

Author(s):

Olga Prilipko ◽

Nelly Huynh ◽

Moriah E. Thomason ◽

Clete A. Kushida ◽

Christian Guilleminault

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Cerebrovascular Reactivity ◽

Cpap Treatment ◽

Fmri Study ◽

Obstructive Sleep ◽

Before And After

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Effect of obstructive sleep apnea and CPAP therapy on skeletal muscle lipid content in obese and non-obese male subjects

Journal of the Endocrine Society ◽

10.1210/jendso/bvab082 ◽

2021 ◽

Author(s):

Alexander M Koenig ◽

Ulrich Koehler ◽

Olaf Hildebrandt ◽

Hans Schwarzbach ◽

Lena Hannemann ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Magnetic Resonance ◽

Fiber Type ◽

Subcutaneous Fat ◽

Apnea Hypopnea Index ◽

Resonance Spectroscopy ◽

Vastus Lateralis Muscle ◽

Cpap Therapy ◽

Obstructive Sleep

Abstract Obstructive sleep apnea (OSA), independently of obesity (OBS), predisposes to insulin resistance (IR) for largely unknown reasons. Since OSA-related intermittent hypoxia triggers lipolysis, overnight increases in circulating free fatty acid (FFA) including palmitic acid (PA) may lead to ectopic intramuscular lipid accumulation potentially contributing to IR. Using 3-T-1H-magnetic-resonance-spectroscopy, we therefore compared intra- and extra-myocellular lipid (IMCL and EMCL) in vastus lateralis muscle at ~7:00 a.m. between 26 male patients with moderate-to-severe OSA (17 obese, 9 non-obese) and 23 healthy male controls (12 obese, 11 non-obese). Fiber type composition was evaluated by muscle biopsies. Moreover, we measured fasted FFA including PA, HbA1c, thigh subcutaneous fat volume (ScFAT, 1.5-T-magnetic-resonance-tomograpphy) and maximal oxygen uptake (VO2max). 14 patients were reassessed after continuous-positive-airway-pressure (CPAP) therapy. Total FFA and PA were significantly by 178% and 166% higher in OSA patients vs. controls and correlated with the apnea-hypopnea index (AHI) (r≥0.45, P<0.01). Moreover, IMCL and EMCL were 55% (P<0.05) and 40% (P<0.05) higher in OSA patients, i.e. 114% and 103% in non-obese, 24.4% and 8.4% in obese subjects (with higher control levels). Overall, PA, FFA (minus PA) and ScFAT significantly contributed to IMCL (multiple r=0.568, P=0.002). CPAP significantly decreased EMCL (-26%) and, by trend only, IMCL, total FFA and PA. Muscle fiber composition was unaffected by OSA or CPAP. Increases in IMCL and EMCL are detectable at ~7:00 a.m. in OSA patients and partly attributable to overnight FFA excesses and high ScFAT or BMI. CPAP decreases FFAs and IMCL by trend but significantly reduces EMCL.

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Do Obstructive Sleep Apnea Syndrome Patients Underestimate Their Daytime Symptoms before Continuous Positive Airway Pressure Treatment?

Canadian Respiratory Journal ◽

10.1155/2014/681952 ◽

2014 ◽

Vol 21 (4) ◽

pp. 216-220 ◽

Cited By ~ 4

Author(s):

Gabrielle Leclerc ◽

Yves Lacasse ◽

Diane Page ◽

Frédéric Sériès

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Continuous Positive Airway Pressure ◽

Airway Pressure ◽

Positive Airway Pressure ◽

Sleep Apnea Syndrome ◽

Cpap Treatment ◽

Obstructive Sleep ◽

Before And After ◽

Pretreatment Score

BACKGROUND: Daytime somnolence is an important feature of the obstructive sleep apnea (OSA) hypopnea syndrome and is usually subjectively assessed using the Epworth Sleepiness Scale (ESS).OBJECTIVE: To compare the scores of the ESS and different domains of the Quebec Sleep Questionnaire (QSQ) assessed before and after the first months of continuous positive airway pressure (CPAP) treatment, as well as retrospectively without treatment.METHODS: The ESS score and domain scores of the QSQ were obtained before and after a three-month period of CPAP treatment using a retrospective assessment of the pretreatment scores in 76 untreated OSA patients.RESULTS: Fifty-two patients completed the study. The ESS and QSQ scores significantly improved following CPAP therapy. Retrospective evaluation of the ESS score was significantly worse than pre- and post-treatment values (mean [± SD] pretreatment score 11.0±4.8; retrospective pretreatment score 13.5±5.1). Such differences were not observed in any domain of the QSQ, including the domain assessing hypersomnolence.CONCLUSION: OSA patients underestimated their sleepiness according to the most widely used instrument to assess hypersomnolence. This finding may not be observed with other methods used to assess OSA-related symptoms such as quality of life questionnaires.

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