Evaluation of central and peripheral neuropathy in patients with chronic obstructive pulmonary disease

Figures & data

Table 1 Demographic characteristics of the patient and control groups

	Patients, n=41	Controls, n=41	P-value
Age (years)	61.88±6.6	59.22±10.1	0.164
Weight (kg)	69.51±12.7	68.75±11.6	0.779
BMI (kg/m^2)	24.5±3.6	24.9±3.7	0.586
Hemoglobin (g/dL)	13.60±1.4	14.04±1.1	0.106
Urea (mg/dL)	29.6±7.9	26.9±7.2	0.118
Creatine (mg/dL)	0.76±0.18	0.73±0.12	0.781
Iron (μg/dL)	70.46±14	76.35±13.7	0.057
Sex, male/female (n)	39/2	38/3	0.976
COPD class, moderate/severe/very severe (n)	12/29/5	–
FEV1/FVC	57.79 (31–69)	–
FEV1	44.05 (22–73)	–
Disease duration (years)	10.34 (1–34)	–

Note: Data shown as mean ± SD and mean (range).

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.

Table 2 Comparison of right-side electromyography results

	Patients	Controls	P-value
Right median motor
Amplitude (mV)	9.89±2.98 (4.45/15.6)	12.42±3.82 (5/25.6)	<0.001
Latency (ms)	4.04±0.48 (3.28/5.2)	3.41±0.56 (2.09/4.66)	<0.001
Conduction velocity (m/s)	56.51±6.06 (46.8/68.8)	59.34±7.36 (40.1/80.9)	0.061
Right median sensory
Amplitude (mV)	12.78±5.24 (5.5/26.2)	22.62±9.61 (6.9/44.10)	<0.001
Latency (ms)	3.04±0.45 (2.2/4.56)	2.66±0.36 (2.06/3.6)	<0.001
Conduction velocity (m/s)	53.22±6.40 (35.1/65.8)	57.90±6.79 (38.3/72.7)	0.002
Right ulnar motor
Amplitude (mV)	11.12±2.98 (5.76/19.8)	14.40±4.05 (7/24.4)	<0.001
Latency (ms)	3.23±0.65 (2.42/5.36)	2.75±0.24 (2.3/3.2)	<0.001
Conduction velocity (m/s)	59.83±10.1 (49.3/75.8)	67.64±8.94 (38.3/72.10)	<0.001
Right ulnar sensory
Amplitude (mV)	12.18±7.57 (2.6/43.3)	23.01±8.57 (7.6/44.10)	<0.001
Latency (ms)	2.75±0.45 (1.8/3.65)	2.34±0.31 (1.82/3.26)	<0.001
Conduction velocity (m/s)	51.81±6 (35/72.2)	55.73±5.06 (45.8/67.1)	0.002
Right peroneal motor
Amplitude (mV)	3.92±2.18 (1.6/10.3)	4.55±0.84 (1.9/17.20)	<0.001
Latency (ms)	4.55±0.84 (3/6.5)	4.01±0.88 (3/6.9)	0.006
Conduction velocity (m/s)	43.79±5.60 (30.5/58.5)	50.97±5.61 (38.3/60.2)	<0.001
Right tibial motor
Amplitude (mV)	7.78±4.18 (0.9/18.47)	13.82±5.45 (5/29)	<0.001
Latency (ms)	4.85±1.10 (2.8/8.45)	4.05±0.84 (2.7/6.5)	<0.001
Conduction velocity (m/s)	43.11±7.11 (26.5/71.9)	49.57±6.17 (35/65.3)	<0.001
Right sural sensory
Amplitude (mV)	10.52±3.92 (2.9/20.2)	15.58±4.86 (7/28.1)	<0.001
Latency (ms)	3.13±0.52 (2.02/4.2)	3.13±0.52 (1.64/4.28)	0.006
Conduction velocity (m/s)	46.40±8.57 (33/69.3)	53.07±9.11 (35.4/85.4)	0.001

Note: Data presented as mean ± SD (min/max).

Table 3 Comparison of left-side electromyography results

	Patients	Controls	P-value
Left median motor
Amplitude (mV)	9.64±2.91 (5.2/19.86)	14.66±5.15 (4.96/32.40)	<0.001
Latency (ms)	4.04±0.46 (3/5.3)	3.35±0.56 (2.13/4.7)	<0.001
Conduction velocity (m/s)	55.86±6.27 (48.7/73.3)	59.69±6.14 (43.8/79.6)	0.007
Left median sensory
Amplitude (mV)	13.84±7.02 (4/36)	22.40±9.25 (5.8/39.40)	<0.001
Latency (ms)	3.11±0.43 (2/4.87)	2.66±0.40 (1.98/4.1)	0.001
Conduction velocity (m/s)	52.48±6.12 (41.2/75)	56.92±6.98 (34.2/75.8)	0.003
Left ulnar motor
Amplitude (mV)	10.90±3.07 (5.6/17.1)	14.05±4.22 (6.95/24.6)	<0.001
Latency (ms)	3.33±0.58 (2.56/5.32)	2.76±0.39 (1.84/3.65)	<0.001
Conduction velocity (m/s)	59.41±6.70 (48.2/76.7)	69.13±9.66 (53.2/94.6)	<0.001
Left ulnar sensory
Amplitude (mV)	10.88±5.58 (1/26.8)	22.39±7.69 (7.6/38.5)	<0.001
Latency (ms)	2.87±0.61 (1.7/5.7)	2.34±0.32 (1.68/3.1)	<0.001
Conduction velocity (m/s)	51.65±5.64 (39.5/66)	56.61±5.24 (48.1/65.8)	<0.001

Note: Data presented as mean ± SD (min/max).

Table 4 Comparison of VEP parameters (P₁₀₀, N₇₅, N₁₄₅, amplitude) in patient and control groups

	Patients	Min/max	Controls	Min/max	P-value
P100 right eye (ms)	103.3±7.9	90/128	97.62±4.51	90.1/105.9	<0.001
P100 left eye (ms)	104.5±9.7	89.4/133.5	95.72±4.62	89.10/105.9	<0.001
N75 right eye (ms)	76.4±8.4	61.8/100	74.90±6.74	61.8/89	0.390
N75 left eye (ms)	77.0±9.2	60/100	75.18±8.32	60.6/90.2	0.340
N145 right eye (ms)	131.6±12.6	107.7/170.6	124.02±8.18	108.3/144.6	0.002
N145 left eye (ms)	135.4±15.5	100.2/187.5	124.6±6.9	107.7/136.6	<0.001
Amplitude right eye (μV)	5.24±0.94	4/8	5.75±0.69	4/7	0.007
Amplitude left eye (μV)	5.09±0.99	3/7	5.65±0.61	5/7	0.003

Abbreviation: VEP, visual evoked potential.

Table 5 COPD patients with VEP abnormality

	COPD patients (n=41)	Percentage
P100 right eye (ms)	14	34.1
P100 left eye (ms)	15	36.5
Amplitude right eye (μV)	3	7.3
Amplitude left eye (μV)	4	9.7
Total abnormalities	23	46.3

Notes: Abnormality defined as a variation of more than 2.5 SD from healthy-volunteer mean. Some patients had more than one abnormality.

Abbreviation: VEP, visual evoked potential.