VARIATION OF COGNITION AND CEREBRAL ACTIVITY WITH SEVERITY OF AIRFLOW OBSTRUCTION IN COPD

Abstract

Introduction: Cognitive dysfunction is one of the important systemic effect of Chronic Obstructive Pulmonary Disease that affects various cognitive domains in these patients. Aim: Assessment of cognitive function in specific cognitive domains in COPD with various stages of severity as observed by airflow obstruction. Methods: N=68 COPD patients and N=20 controls were matched for age and education. EEG changes, SpO2 and rSO2 were compared between COPD and control group. Cognitive scores and EEG wave patterncompared among different stages of severity in COPD group. Statistical analysis: Was done using SPSS version 18. Two independent t test was used for bivariate testing between COPD and control group. Chi square test applied to assess the frequency distribution of variables among each group. One way analysis of variance (ANOVA) was used to compare mean values of cognitive scores and Chi square test for number(%) of patients with abnormal scores in cognition and slow waves in EEG across groups with different severity of airflow obstruction (FEV1% Predicted). ResultsOncomparison of EEG slow wave, (rSO2) and (SpO2) among COPD and age matched control group, electroencephalographic(EEG) study in COPD group showed slower wave pattern than their age matched healthy counterpart which was statistically significant at p<0.001, so was true about rSO2 of right frontal region in the study group. Among the COPD groups with different severity (moderate, severe, and very severe grades), patients with severe and very severe airflow obstruction performed poorly with Folstein MMSE (statistically significant at p<0.001), more than 50 % of patients had abnormal scoring with CDT in all the three groups and with TMT-A in severe and very severe group. Conclusions:We found relative frontal hypoxemia and EEG slow wave in COPD group compared to healthy control. With severegrades of disease risk of cognitive impairment was noted. Thus, suggesting that low lung functioning may contribute to cognitive disorders by decreasing the oxygen delivery to brain neurons.