Study objectives: The goal of this study was to evaluate the neuropsychological and psychological functioning of emphysema patients following lung volume reduction surgery (LVRS) compared with patients receiving only medical therapy (MT).
Design: Patients with moderate-to-severe emphysema who were enrolled in the National Emphysema Treatment Trial at two sites (National Jewish Medical and Research Center and Ohio State University) were given a neuropsychological battery at baseline, 6 to 10 weeks later (following participation in pulmonary rehabilitation), and at 6 months following randomization to either LVRS or MT treatment.
Subjects and measurements: Twenty patients randomized to MT, 19 patients randomized to LVRS, and 39 matched, healthy control subjects completed a battery of tests that measured cognitive functioning, depression, anxiety, and quality of life (QoL).
Results: Controlling for practice, patients in the LVRS treatment arm at the 6-month follow-up demonstrated significant improvement compared with MT patients in cognitive tasks involving sequential skills and verbal memory. The LVRS patients also showed significant reductions in depression compared with the MT patients, as well as improved physical and psychosocial QoL. Correlational analysis indicated that improved immediate verbal memory in the LVRS group was related to improved QoL. No associations were found between changes in cognitive function and changes in depression, exercise performance, or pulmonary functioning.
Conclusion: Patients who received LVRS demonstrated improvement in specific neuropsychological functions, depression, anxiety, and QoL scores compared with patients with continued MT treatment 6 months following randomization. However, mechanisms for these neurobehavioral changes are unclear. Improved verbal memory and sequential skills following LVRS were not directly associated with depression or exercise capacity. Nonetheless, LVRS led to a strong and likely clinically significant improvement in neuropsychological functioning over and above that explained by practice effects or MT. This finding adds to the growing list of clinical benefits of LVRS over MT, and supports additional research into the underlying mechanisms of this therapeutic effect.