. Author manuscript; available in PMC: 2010 Feb 28.

Published in final edited form as: Respir Physiol Neurobiol. 2008 Dec 30;165(2-3):245–253. doi: 10.1016/j.resp.2008.12.010

Table 4. Regression analysis of ipsilateral phrenic nerve burst amplitude and the histological area of cervical spinal cord injury.

Phrenic data were obtained during two conditions: baseline and hypoxic challenge. The area of remaining white matter (see Fig. 1) in the ipsilateral spinal cord at the lesion epicenter was the independent variable and was expressed relative to the area measured in the contralateral spinal cord (see methods). The amplitude of the phrenic burst was expressed as a raw voltage (V), relative to the contralateral burst (%contralateral) or as a percent of the hypoxic response or baseline output.

Dependent Variable (Y)	Coefficient of Determination (R²)	F-statistic	P-value
BL ∫Phr (V)	0.393	13.6	0.001
BL ∫Phr (% contralateral)	0.527	23.4	<0.001
BL ∫Phr (% hypoxia)	0.096	2.3	0.151
Hypoxia ∫Phr (V)	0.431	15.9	<0.001
Hypoxia ∫Phr (% contralateral)	0.539	24.5	<0.001
Hypoxia ∫Phr (% baseline)	0.063	1.4	0.249