fMRI responses to cold pressor challenges in control and obstructive sleep apnea subjects

2003 ◽  
Vol 94 (4) ◽  
pp. 1583-1595 ◽  
Author(s):  
Ronald M. Harper ◽  
Paul M. Macey ◽  
Luke A. Henderson ◽  
Mary A. Woo ◽  
Katherine E. Macey ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Cold Pressor ◽  
Brain Structures ◽  
Sympathetic Outflow ◽  
Intersubject Variability ◽  
Neural Responses ◽  
Cold Stimulation ◽  
Obstructive Sleep ◽  
Ventral Thalamus

Obstructive sleep apnea (OSA) patients exhibit altered sympathetic outflow, which may reveal mechanisms underlying the syndrome. We used functional MRI (fMRI) in 16 control and 10 OSA subjects who were free of cardiovascular or mood-altering drugs to examine neural responses to a forehead cold pressor challenge, which elicits respiratory slowing, bradycardia, and enhanced sympathetic outflow. The magnitude of cold-induced bradycardia was smaller, and respiratory slowing showed greater intersubject variability and reached a nadir later in OSA patients. Both groups showed similar signal changes to cold stimulation in multiple brain sites. However, signal increases emerged in OSA over controls in anterior and posterior cingulate and cerebellar and frontal cortex, whereas signals markedly declined in the ventral thalamus, hippocampus, and insula rather than rising as in controls. Anomalous responses often paralleled changes in breathing and heart rate. Medullary, midbrain areas and lentiform and cerebellar dentate nuclei also showed lower signals in OSA cases. Cold pressor physiological responses are modified in OSA and may result from both diminished and exaggerated responses in multiple brain structures.

Sleep Apnea

2017 ◽  
Author(s):  
Jennifer Accardo
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Daytime Sleepiness ◽  
Upper Airway ◽  
Brain Structures ◽  
Cognitive Effects ◽  
Common Condition ◽  
Cardiovascular Risks ◽  
Neuromuscular Activation ◽  
Obstructive Sleep

Sleep apnea is a common condition involving breathing during sleep, which nonetheless has consequences beyond the scope of either sleep or breathing. Repeated, reversible respiratory obstructions are related to abnormal ventilatory drives and decreased upper airway neuromuscular activation. They result in dysautonomia, sleep fragmentation, and increased cardiovascular risks. Obstructive sleep apnea classically presents with daytime sleepiness and snoring, and its effects on learning, cognition, and mood are pervasive. On a neuropathologic basis, corresponding damage to widespread brain structures is noted. Obstructive sleep apnea is considered treatable, but it is unclear whether its cognitive effects are fully reversible with treatment.

scholarly journals Insular functional organization during handgrip in females and males with obstructive sleep apnea

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246368
Author(s):  
Amrita Pal ◽  
Jennifer A. Ogren ◽  
Ravi S. Aysola ◽  
Rajesh Kumar ◽  
Luke A. Henderson ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Repeated Measures ◽  
Functional Organization ◽  
Blood Oxygen Level Dependent ◽  
Group Differences ◽  
Neural Responses ◽  
Blood Oxygen Level ◽  
Functional Responses ◽  
Obstructive Sleep

Study objectives Brain regulation of autonomic function in obstructive sleep apnea (OSA) is disrupted in a sex-specific manner, including in the insula, which may contribute to several comorbidities. The insular gyri have anatomically distinct functions with respect to autonomic nervous system regulation; yet, OSA exerts little effect on the organization of insular gyral responses to sympathetic components of an autonomic challenge, the Valsalva. We further assessed neural responses of insular gyri in people with OSA to a static handgrip task, which principally involves parasympathetic withdrawal. Methods We measured insular function with blood oxygen level dependent functional MRI. We studied 48 newly-diagnosed OSA (age mean±std:46.5±9 years; AHI±std:32.6±21.1 events/hour; 36 male) and 63 healthy (47.2±8.8 years;40 male) participants. Subjects performed four 16s handgrips (1 min intervals, 80% subjective maximum strength) during scanning. fMRI time trends from five insular gyri—anterior short (ASG); mid short (MSG); posterior short (PSG); anterior long (ALG); and posterior long (PLG)—were assessed for within-group responses and between-group differences with repeated measures ANOVA (p<0.05) in combined and separate female-male models; age and resting heart-rate (HR) influences were also assessed. Results Females showed greater right anterior dominance at the ASG, but no differences emerged between OSA and controls in relation to functional organization of the insula in response to handgrip. Males showed greater left anterior dominance at the ASG, but there were also no differences between OSA and controls. The males showed a group difference between OSA and controls only in the ALG. OSA males had lower left activation at the ALG compared to control males. Responses were mostly influenced by HR and age; however, age did not impact the response for right anterior dominance in females. Conclusions Insular gyri functional responses to handgrip differ in OSA vs controls in a sex-based manner, but only in laterality of one gyrus, suggesting anterior and right-side insular dominance during sympathetic activation but parasympathetic withdrawal is largely intact, despite morphologic injury to the overall structure.

scholarly journals Neural responses during Valsalva maneuvers in obstructive sleep apnea syndrome

2003 ◽  
Vol 94 (3) ◽  
pp. 1063-1074 ◽  
Author(s):  
Luke A. Henderson ◽  
Mary A. Woo ◽  
Paul M. Macey ◽  
Katherine E. Macey ◽  
Robert C. Frysinger ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Cerebellar Cortex ◽  
Valsalva Maneuver ◽  
Sleep Apnea Syndrome ◽  
Anterior Cingulate ◽  
Neural Pathways ◽  
Precentral Gyrus ◽  
Neural Responses ◽  
Obstructive Sleep

The repetitive upper airway muscle atonic episodes and cardiovascular sequelae of obstructive sleep apnea (OSA) suggest dysfunction of specific neural sites that integrate afferent airway signals with autonomic and somatic outflow. We determined neural responses to the Valsalva maneuver by using functional magnetic resonance imaging. Images were collected during a baseline and three Valsalva maneuvers in 8 drug-free OSA patients and 15 controls. Multiple cortical, midbrain, pontine, and medullary regions in both groups showed intensity changes correlated to airway pressure. In OSA subjects, the left inferior parietal cortex, superior temporal gyrus, posterior insular cortex, cerebellar cortex, fastigial nucleus, and hippocampus showed attenuated signal changes compared with controls. Enhanced responses emerged in the left lateral precentral gyrus, left anterior cingulate, and superior frontal cortex of OSA patients. The anterior cingulate, cerebellar cortex, and posterior insula exhibited altered response timing patterns between control and OSA subjects. The response patterns in OSA subjects suggest deficits in particular neural pathways that normally mediate the Valsalva maneuver and compensatory actions in other structures.

scholarly journals Obesity and upper airway control during sleep

2010 ◽  
Vol 108 (2) ◽  
pp. 430-435 ◽  
Author(s):  
Alan R. Schwartz ◽  
Susheel P. Patil ◽  
Samuel Squier ◽  
Hartmut Schneider ◽  
Jason P. Kirkness ◽  
...  
Keyword(s):  
Weight Loss ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Neuromuscular Control ◽  
Current Evidence ◽  
Central Adiposity ◽  
Neural Responses ◽  
Humoral Factors ◽  
Obstructive Sleep

Mechanisms linking obesity with upper airway dysfunction in obstructive sleep apnea are reviewed. Obstructive sleep apnea is due to alterations in upper airway anatomy and neuromuscular control. Upper airway structural alterations in obesity are related to adipose deposition around the pharynx, which can increase its collapsibility or critical pressure (Pcrit). In addition, obesity and, particularly, central adiposity lead to reductions in resting lung volume, resulting in loss of caudal traction on upper airway structures and parallel increases in pharyngeal collapsibility. Metabolic and humoral factors that promote central adiposity may contribute to these alterations in upper airway mechanical function and increase sleep apnea susceptibility. In contrast, neural responses to upper airway obstruction can mitigate these mechanical loads and restore pharyngeal patency during sleep. Current evidence suggests that these responses can improve with weight loss. Improvements in these neural responses with weight loss may be related to a decline in systemic and local pharyngeal concentrations of specific inflammatory mediators with somnogenic effects.

Treating Velopharyngeal Inadequacy Using Bilateral Buccal Flap Revision Palatoplasty

2019 ◽  
Vol 4 (5) ◽  
pp. 878-892
Author(s):  
Joseph A. Napoli ◽  
Linda D. Vallino
Keyword(s):  
Systematic Review ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
A Priori ◽  
Sufficient Evidence ◽  
Obstructive Sleep ◽  
Before And After ◽  
Buccal Flap

Purpose The 2 most commonly used operations to treat velopharyngeal inadequacy (VPI) are superiorly based pharyngeal flap and sphincter pharyngoplasty, both of which may result in hyponasal speech and airway obstruction. The purpose of this article is to (a) describe the bilateral buccal flap revision palatoplasty (BBFRP) as an alternative technique to manage VPI while minimizing these risks and (b) conduct a systematic review of the evidence of BBFRP on speech and other clinical outcomes. A report comparing the speech of a child with hypernasality before and after BBFRP is presented. Method A review of databases was conducted for studies of buccal flaps to treat VPI. Using the principles of a systematic review, the articles were read, and data were abstracted for study characteristics that were developed a priori. With respect to the case report, speech and instrumental data from a child with repaired cleft lip and palate and hypernasal speech were collected and analyzed before and after surgery. Results Eight articles were included in the analysis. The results were positive, and the evidence is in favor of BBFRP in improving velopharyngeal function, while minimizing the risk of hyponasal speech and obstructive sleep apnea. Before surgery, the child's speech was characterized by moderate hypernasality, and after surgery, it was judged to be within normal limits. Conclusion Based on clinical experience and results from the systematic review, there is sufficient evidence that the buccal flap is effective in improving resonance and minimizing obstructive sleep apnea. We recommend BBFRP as another approach in selected patients to manage VPI. Supplemental Material https://doi.org/10.23641/asha.9919352

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