# Time-Resolved MRI Method for EEG Assisted Concurrent Mapping of Cerebral Oxygen Metabolism and Airway Structure in Obstructive Sleep Apnea

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2024 · $710,082

## Abstract

PROJECT SUMMARY
Obstructive sleep apnea (OSA) is the most common sleep disorder and a recognized risk with an estimated
worldwide prevalence of one billion people. The ensuing repeated episodes of nocturnal hypoxia and hypoxemia
are at the core of the disorder’s pathogenesis, leading to upregulation of neuro inflammation and oxidative stress,
which predispose OSA patients to cardiac and neurovascular disease along with impaired cognitive function and
neurodegeneration. The investigators have previously examined the neurovascular-metabolic alterations in
terms of the cerebral metabolic rate of oxygen (CMRO2) at rest and in response to apneic challenges during
wakefulness in the form of repeated cued breath-holds mimicking the hypercapnic-hypoxic events of
spontaneous apnea, by means of temporally-resolved MRI-based brain oximetry. Although this work provided
new insights into chronic and acute neurometabolic consequences of the disorder, the response to coached
volitional apneas likely differs from that of spontaneous apneas during sleep. Also unknown are the upper
airway’s morphologic changes that occur during apneas (full airway closure) and hypopneas (partial closure)
that cause the metabolic alterations. Leading up to the proposed project we have been able to monitor cerebral
oxygen metabolism in healthy subjects in the scanner with concurrent electroencephalography (EEG) and
designed an imaging procedure that returns the vascular-metabolic parameters and upper airway morphology
during continuous scanning. We illustrate the method’s potential with model apneas induced in test subjects
involving the oropharyngeal phase of swallowing, causing airway closure and the expected hypoxic-hypercapnic
response and, more recently, in a patient with OSA during 90 minutes of continuous scanning at six seconds
temporal resolution during sleep in the scanner. The key hypothesis underlying the proposed research is that
the method can evaluate state-dependent O2 brain metabolism and airway anatomy in OSA patients during
wakefulness and sleep and during spontaneous apneas and further, that the acute airway structural
manifestations during apneas and hypopneas correlate with the metabolic response to apneas. The project
comprises three specific aims: (1) Optimize the temporally resolved interleaved structural and metabolic MRI
protocol and synchronized airway plethysmography to confirm the method’s ability to simultaneously detect the
metabolic and airway structural changes during induced apneas; (2) examine the state dependence of O2
metabolism and upper airway anatomy in OSA patients differing in disease severity, with the method of aim 1
and concurrent EEG monitoring; (3) evaluate the hypothesis that the transient brain metabolic and upper airway
changes during apnea can be predicted by baseline measurements during respiration in the awake state along
with the subjects’ biological profile obtained from blood markers of oxidative stress and neuro inflammation....

## Key facts

- **NIH application ID:** 10855884
- **Project number:** 1R01HL172928-01
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Felix W Wehrli
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $710,082
- **Award type:** 1
- **Project period:** 2024-06-01 → 2028-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10855884

## Citation

> US National Institutes of Health, RePORTER application 10855884, Time-Resolved MRI Method for EEG Assisted Concurrent Mapping of Cerebral Oxygen Metabolism and Airway Structure in Obstructive Sleep Apnea (1R01HL172928-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10855884. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*