The brainstem auditory evoked potential abnormalities in severe chronic obstructive pulmonary disease.

OBJECTIVE: The aim of the study was to investigate the abnormalities of brainstem auditory evoked potentials (BAEP) in patients with severe chronic obstructive pulmonary disease (COPD). METHODOLOGY: Twenty-one patients with severe COPD (16 men, five women; mean age: 64 +/- 6.5 years), in whom other causes of BAEP abnormalities had been excluded, were studied. Age-matched, non-smoking, healthy subjects acted as a control group. We performed pulmonary function tests, arterial blood gas analysis and bilateral BAEP measurements in COPD patients and control groups. RESULTS: Brainstem auditory evoked potentials were abnormal in 16 (76.1%) of the 21 COPD patients. Most prominent BAEP abnormalities were prolonged wave I peak latencies (42.8%), V wave peak latencies (38.1%), and III-V interpeak latencies (IPL) (38.1%). In five patients, a prolonged central transmission time (I-V IPL) was observed. No significant correlation was evident between the BAEP parameters and pH, PaO2, PaCO2, FEV1%, FEV1/FVC, haematocrit, duration of disease or cigarette consumption. CONCLUSION: The functions of the eighth cranial nerve and brainstem were highly impaired in severe COPD. These pathological BAEP alterations in severe COPD might be due to the chronic hypoxic-hypercapnic status occurring in the brainstem.