This observational, cross-sectional, single-center pilot study aims to examine the
presence of "Brain Fog" - a cluster of cognitive symptoms impairing memory, attention,
and concentration - in patients with severe Obstructive Sleep Apnea Syndrome (OSA). It
compares two groups: patients who have been undergoing CPAP treatment for at least 3
months and patients who have not yet begun treatment. Patients with severe OSA (AHI >
30), evaluated by a pulmonologist for CPAP therapy adaptation or already in therapy for
at least 3 months, will be invited to participate in the study at the Sleep Center
Clinic. After reviewing and signing informed consent, participants will receive a link to
access the Qualtrics platform, where they will complete the online self-report
questionnaire under the supervision of trained staff, available to assist if needed. The
questionnaire, taking approximately 30 minutes to complete, will be administered once and
will collect sociodemographic data (gender, age, marital status, educational level,
occupational status, comorbidities, diagnosis date, CPAP adaptation start date, and
COVID-19 health status over the past 12 months), including the Brain Fog Scale, currently
undergoing Italian validation by our Research Group. Additional measures will include the
Epworth Sleepiness Scale (ESS) to assess daytime sleepiness, the Pittsburgh Sleep Quality
Index (PSQI) for sleep quality, the Fatigue Severity Scale (FSS), and Pichot's Fatigue
Scale for psychophysical fatigue. The study anticipates recruiting 80 outpatients with
severe OSA, evenly divided by age and gender into two groups: 40 patients on CPAP for at
least 3 months and 40 patients who have not yet started CPAP. As no prior studies have
investigated Brain Fog in OSA patients, conventional power calculations could not be
applied; hence, 40 patients per group were deemed sufficient to provide preliminary
estimates and identify any logistical or methodological issues for larger studies.
Statistical analyses will be conducted using Jamovi 2.5.3 software, encompassing
descriptive statistics, independent sample T-tests, Pearson's correlation to measure the
strength of linear relationships between Brain Fog and other assessment scale scores, and
a multiple regression model to examine the effect of independent variables on Brain Fog.
In cases of non-normal data distribution, appropriate non-parametric analyses will be
applied. The Brain Fog Scale, currently under Italian validation, may affect the
reliability and validity of findings. Significant differences in Brain Fog levels are
expected between CPAP-treated and untreated patients, with the hypothesis that treated
patients will show symptom reduction. CPAP treatment is anticipated to improve memory,
attention, concentration, and mental clarity in severe OSA patients. The collected data
may also reveal a positive correlation between CPAP use, sleep quality improvement, and
reduced Brain Fog symptoms. Furthermore, this study aims to provide preliminary data for
calculating the necessary sample size for larger, more rigorous future studies. Clinical
implications suggest that CPAP treatment may not only relieve respiratory symptoms of OSA
but also offer significant benefits for cognitive functions, thus enhancing the quality
of life for patients with severe OSA.