Evaluation of brain stem auditory evoked potentials in stable patients with chronic obstructive pulmonary disease

Though there are few studies addressing brainstem auditory evoked potentials (BAEP) in patients with chronic obstructive pulmonary disease (COPD), subclinical BAEP abnormalities in stable COPD patients have not been studied. The present study aimed to evaluate the BAEP abnormalities in this study group.

In the present study, 80 male subjects were included: COPD group comprised 40 smokers with stable COPD with no clinical neuropathy; 40 age-matched healthy volunteers served as the control group. Latencies of BAEP waves I, II, III, IV, and V, together with interpeak latencies (IPLs) of I-III, I-V, and III-V, and amplitudes of waves I-Ia and V-Va were studied in both the groups to compare the BAEP abnormalities in COPD group; the latter were correlated with patient characteristics and Mini-Mental Status Examination Questionnaire (MMSEQ) scores to seek any significant correlation.

Twenty-six (65%) of the 40 COPD patients had BAEP abnormalities. We observed significantly prolonged latencies of waves I, III, V over left ear and waves III, IV, V over right ear; increased IPLs of I-V, III-V over left ear and of I-III, I-V, III-V over right side. Amplitudes of waves I-Ia and V-Va were decreased bilaterally. Over left ear, the latencies of wave I and III were significantly correlated with FEV(1); and amplitude of wave I-Ia, with smoking pack years. A weak positive correlation between amplitude of wave I-Ia and duration of illness; and a weak negative correlation between amplitude of wave V-Va and MMSEQ scores were seen over right side.

We observed significant subclinical BAEP abnormalities on electrophysiological evaluation in studied stable COPD male patients having mild-to-moderate airflow obstruction.