P50 sensory gating in hypoxemic chronic obstructive pulmonary disease patients.

PURPOSE Chronic obstructive pulmonary disease (COPD) is a condition characterized by progressive airway obstruction and recurrent attacks. Multisystem involvement with extrapulmonary manifestations has been seen in COPD patients. Numerous neurological involvement like cerebrovascular diseases, polyneuropathies, motor neuron diseases and cognitive impairement has been reported in COPD patients. Cognitive dysfunction is usually associated with hypoxia or hypercapnia in COPD patients. To our knowledge there is no study about sensory gating in COPD patients. We performed p50 test to COPD patients and we investigate sensory gating in COPD patients. PATIENTS AND METHODS 25 male patients with COPD and 17 healthy male subjects for controls included to this study. The patients were diagnosed with COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. p50 amplitude and latency, percentage of P50 suppression, N100 amplitude and latency and the N100 suppression percentage of the COPD patients and controls presented were measured and compared. RESULTS We found that the conditioning amplitudes (S1) did not differ between COPD patients and controls (p > 0.05) but (S2) amplitude was significantly increased in COPD patients (p < 0.05). COPD patients showed significantly lower P50 and N100 suppression percentage than controls (p < 0.05). CONCLUSIONS COPD patients showed a disturbance cognitive function such as attention with p50 suppression rate decrease. P50 sensory gating test can be useful to analyze the pre-attention period of cognitive impairment in the early phase of COPD patients.