Table 7.

Comparison between previous studies and our study

Study	No. of study subjects	COPD patients characteristics	BAEP parameters studied	Patients with BAEP abnormalities	BAEP parameters affected	Correlations
Kayacan et al.[4]	32 COPD subjects [male=30];	19/32 had PaO2<55mmHg	Latencies I, II, III, IV, V	Individual patients data not mentioned	Latency III	III ** PEFR, FEF25,
	no controls	Age=61±8.8 years;	IPL I-III, III-V, I-V		IPL I-III, III-V	FEF25-75
		smoking pack				IV** FVC, PEFR
		years=37.4±28.5				IPL I-III**
						FEF25-75, FEV1/FVC,
						FEF25-75
						IPL III-V** PaCO2,
						HCO3, pH
Atis et al.[5]	21 COPD patients [male=16]	Severe airflow obstruction;	Latencies I, III, V	16/21 [76.1%]	Latency I, V	No significant
	11 had clinical neuropathy	Age=64±6.5 years;	IPL I-III, III-V, I-V		IPL III-V, I-V	Correlation with pH, PaO2,
	controls=21	Only 15/21 smokers,	Amplitude wave I, III, V			PaCO2, FEV1%
		pack years = 24.59±21.21;				FEV1/FVC,
		FEV1=0.96+0.32				duration of disease or cigarette consumption
Our study	COPD patients =40, all male all male	Stable COPD patients,	Latencies I, II, III, IV, V	26/40 [65%]	Latency I, III, IV, V	Left side:
	[None had clinical neurological deficiency]	Age = 57.25±9.07	IPL I-III, III-V, I-V		IPL I-III, III-V, I-V	I, III** FEV1
	Healthy volunteers=40,	Smoking pack	Amplitude I-Ia, V-Va		Amplitude I-Ia, V-Va	Amplitude I-Ia** smoking
	all male	years= 39.95±20.94				Right side:
		FEV1= 1.48±0.50				Amplitude I-Ia**
						Duration of illness

Significant correlations between variables are shown by [**].