Hemodynamic Responses and Brain Activity During Dual Tasks in COPD Patients Versus Healthy Individuals

Comparison of Frontal Hemodynamic Responses and Electrical Brain Activity During Dual Tasks in COPD Patients Versus Healthy Individuals

Abstract

Cognitive dysfunction is joint in patients with chronic obstructive pulmonary disease (COPD).

In particular, there are effects in tasks that require attention, executive functions, and working memory related to the prefrontal cortex. These effects make it difficult to perform two tasks simultaneously and cause performance errors. The number of studies investigating the effects of cognitive impairments on dual-task performance in COPD is limited. In these studies, no tests were applied specifically for attention and working memory areas; therefore, the brain's neural activity was not investigated during these tests. Multimodal approaches are recommended for a comprehensive assessment of the functional activity of the brain. Multimodal approaches provide more accurate results than single-modality approaches. In the integrated electroencephalography (EEG)-functional near-infrared spectroscopy (fNIRS) approach, EEG provides adequate temporal resolution, while fNIRS offers better spatial resolution and is robust to noise. There is no study in COPD where simultaneous fNIRS-EEG measurements were made during both cognitive tests and dual tasks. In our study, the simultaneous measurement of frontal hemodynamic responses and electrical brain activity in both cognitive tests and dual-task conditions and the examination of the relationship between the results and arterial stiffness, balance, exercise capacity, anxiety, depression, and quality of life scores, which are reported to be related to cognitive function in COPD, constitute the original aspect of our study. The study will include 16 COPD and 16 healthy individuals. The same assessments will be made in both groups, and the results will be compared. General and task-specific cognitive tests, prefrontal cortex oxygenation (fNIRS), electrical brain activity (EEG), exercise capacity, muscle oxygenation, arterial stiffness, balance, respiratory function, dyspnea, depression, anxiety, and quality of life will be evaluated. As a result of this study is expected to determine the effects of cognitive function and dual-task on frontal hemodynamic responses and electrical brain activity in COPD.

This study aims to compare frontal hemodynamic responses and electrical brain activity to a dual task in individuals with COPD and healthy individuals and to investigate the relationship between frontal hemodynamic response and electrical brain activity and exercise capacity, arterial stiffness, balance, depression, anxiety, or quality of life.

The required sample size for the project was calculated as 28 individuals, 14 each for the COPD and control groups (G*Power Version 3.1.9.4, Franz Faul, Universitat Kiel, Germany), with a statistical significance of 94% test power and 0.05 error level for a difference of 3.33 points and 2.59 standard deviation (effect size 1.455) in the Mini-Mental State Examination score assessing cognitive function between the COPD and control groups. Considering a 10% dropout rate for each group, a total of 32 individuals, 16 in each group, will be included in the study.

Exercise tests will be performed with at least one day of rest breaks.

1. st Session

   • Patient file information will be recorded.
   • A respiratory function test will be performed.
   • MoCA and MMDT tests will be performed to evaluate general cognitive status.
   • 6DWT tests will be performed. Muscle oxygenation will be measured during the test.
   • An SGRQ questionnaire will be administered to the COPD Group.
   • NHP questionnaire will be performed.

2. nd Session

   • Arterial stiffness measurement will be performed.
   • TUG test will be performed.
   • The HAD scale will be applied
   • Cardiopulmonary exercise capacity will be evaluated. Muscle oxygenation will be measured during the test.

3. rd Session

   • Task-specific cognitive tests, Stroop tests, and N-back tests will be performed. fNIRS and EEG measurements will be performed during the Stroop and N-back tests.
   • fNIRS and EEG measurements will be made during single and dual tasks.

Data Collection: The researchers will collect data on frontal hemodynamic responses, electrical brain activity, exercise capacity, arterial stiffness, and balance parameters through tests. Data on dyspnea, depression, anxiety, and quality of life measurements will be collected through scales applied during face-to-face interviews.

Data Analysis: Statistical analysis of the data obtained from all volunteers included in the study will be performed using the IBM SPSS 24.0 (SPSS Inc, Chicago, USA) program. Descriptive statistics will be calculated. The conformity of the variables to normal distribution will be evaluated using visual (histogram and probability graphs) and analytical methods (Kolmogorov-Smirnov/Shapiro-Wilk tests). In comparisons between groups, Student t-test will be used when parametric test assumptions are met, and Mann Whitney U test will be used when parametric test assumptions are not met. Chi-square test will be used for comparisons of categorical variables. Correlation between data that are normally distributed will be analyzed using Pearson correlation, and those that are not normally distributed will be analyzed using Spearman correlation. The error probability will be accepted as p<0.05.

Inclusion Criteria for the COPD Group:

• Being diagnosed with COPD
• Being between the ages of 40-65
• Not having a history of exacerbations in the last 4 week
• Being willing to participate in the study

Inclusion criteria for the Control Group

• Being between the ages of 40-65
• Being willing to participate in the study

Exclusion Criteria for COPD Group :

• Known alpha-1 anti-trypsin deficiency
• Presence of ischemic heart disease, uncontrolled hypertension, and diabetes mellitus
• Presence of obstructive sleep apnea syndrome
• Untreated tumors
• Known history of dementia
• Existing musculoskeletal, neuromuscular, or neurological diseases that may prevent participation in the tests
• Not being willing to participate in the study

Exclusion criteria for the Control Group:

• Having a known chronic health problem
• Not being willing to participate in the study