Cognition and chronic hypoxia in pulmonary diseases

Lung disease with chronic hypoxia has been associated with cognitive impairment of the subcortical type. Objectives To review the cognitive effects of chronic hypoxia in patients with lung disease and its pathophysiology in brain metabolism. Methods A literature search of Pubmed data was performed. The words and expressions from the text subitems including "pathophysiology of brain hypoxia", "neuropsychology and hypoxia", "white matter injury and chronic hypoxia", for instance, were key words in a search of reports spanning from 1957 to 2009. Original articles were included. Results According to national and international literature, patients with chronic obstructive pulmonary disease and sleep obstructive apnea syndrome perform worse on tests of attention, executive functions and mental speed. The severity of pulmonary disease correlates with degree of cognitive impairment. These findings support the diagnosis of subcortical type encephalopathy. Conclusion Cognitive effects of clinical diseases are given limited importance in congresses and symposia about cognitive impairment and its etiology. Professionals that deal with patients presenting cognitive loss should be aware of the etiologies outlined above as a major cause or potential contributory factors, and of their implications for treatment adherence and quality of life.