CPAP and the Brain: Systematic Review Finds Possible but Unproven MRI Changes
A systematic review of 30 MRI studies finds CPAP treatment produces measurable but inconsistent brain changes in adults with obstructive sleep apnea.
Summary
Obstructive sleep apnea (OSA) is associated with multiple brain alterations — gray matter changes, white matter microstructural damage, and altered blood flow. CPAP, the standard treatment, opens the airway during sleep, but whether it modifies these brain changes has been unclear. This systematic review synthesized 30 longitudinal MRI studies examining brain structure, function, and metabolism before and after CPAP therapy. Post-CPAP changes were reported across multiple brain domains, including gray matter, white matter, functional connectivity, and cerebral perfusion. However, findings were highly heterogeneous, and no consistent, reproducible MRI signature of CPAP effect emerged. Most studies were small and nonrandomized. The authors conclude that CPAP may produce domain-specific brain changes, but the evidence remains exploratory and does not support routine brain imaging as a treatment monitoring tool.
Detailed Summary
Obstructive sleep apnea is far more than a snoring problem. Repeated oxygen deprivation during sleep has been associated with structural, microstructural, functional, vascular, and metabolic brain alterations. Whether CPAP therapy — the first-line treatment for OSA — can modify these brain changes is a clinically important but unresolved question.
This systematic review searched PubMed, Scopus, and Web of Science through December 2025, identifying 30 longitudinal MRI studies in adults with OSA who underwent brain imaging before and after CPAP therapy or were compared against untreated, sham-treated, best-supportive-care, or healthy control groups. MRI outcomes spanned the full spectrum: structural volumetry, diffusion imaging of white matter, functional MRI connectivity, perfusion, cerebrovascular reactivity, magnetic resonance spectroscopy, susceptibility-related imaging, and perivascular space measures. Risk of bias was assessed using an adapted Newcastle-Ottawa Scale.
Results were heterogeneous. Post-CPAP changes were reported across major MRI domains — gray matter or cortical alterations, white matter microstructural changes, modified functional connectivity and regional activity, and perfusion or cerebrovascular reactivity changes. Preliminary metabolic, susceptibility-related, and perivascular space findings were also reported. However, findings varied substantially depending on the MRI technique used, the brain regions analyzed, CPAP duration, how adherence was defined, the comparator group, and analytical methods.
The authors are explicit that the evidence is largely exploratory. Most included studies were small and nonrandomized and used heterogeneous imaging and analytical approaches. The findings do not establish reproducible MRI treatment effects and do not support routine MRI monitoring of individual CPAP response.
Larger, prospectively specified, methodologically harmonized longitudinal studies are needed before MRI can serve as a reliable biomarker of CPAP treatment response. For now, the review neither confirms nor refutes brain-level benefits of CPAP; it maps the current uncertainty and outlines what better evidence would require.
Key Findings
- 30 longitudinal MRI studies reported post-CPAP brain changes across gray matter, white matter, perfusion, functional connectivity, and metabolic domains.
- Findings were highly heterogeneous, and no reproducible MRI signature of CPAP treatment effect emerged.
- OSA is associated with structural, microstructural, functional, vascular, and metabolic brain alterations, but whether CPAP reverses them remains unproven.
- Most included studies were small and nonrandomized, limiting confidence in reported changes.
- Current evidence does not support routine brain MRI monitoring of individual CPAP treatment response.
Methodology
Systematic review of 30 longitudinal MRI studies from PubMed, Scopus, and Web of Science (inception to December 2025) in adults with OSA undergoing CPAP therapy. MRI modalities included structural, diffusion, functional, perfusion, spectroscopy, and perivascular space measures. Risk of bias was assessed with an adapted Newcastle-Ottawa Scale; qualitative synthesis was used due to substantial heterogeneity.
Study Limitations
Summary is based on the abstract only, as the full text was not available. The included studies were largely small, non-randomized, and methodologically heterogeneous, preventing firm conclusions or meta-analytic pooling. Variability in CPAP adherence definitions, imaging protocols, and analytical approaches limits comparability across studies.
Enjoyed this summary?
Get the latest longevity research delivered to your inbox every week.
Enter your email to subscribe: