Table 3.

Least Squares Means and Statistical Tests for Planned Group Comparisons of Pathway and Gray Matter Microstructure

		Injury groups
Pathways		TBI	EI		Group effect F (P)
Origin	Termination	Fractional anisotropy Least squares mean		Healthy comparison	Injury vs. healthy	TBI vs. EI	Age effect F (p)
Left hemisphere
Amygdala
	oPFC	0.33	0.32	0.33	0.26 (0.611)	0.70 (0.404)	0.95 (0.333)
	rACB	0.35	0.37	0.35	0.88 (0.350)	2.08 (0.152)	0.30 (0.584)
Hippocampus
	Amygdala	0.30	0.30	0.30	0.03 (0.858)	0.04 (0.837)	0.01 (0.910)
	oPFC	0.35	0.35	0.36	3.61 (0.060)	0.27 (0.605)	2.68 (0.105)
Right hemisphere
Amygdala
	oPFC	0.33	0.33	0.33	0.48 (0.491)	0.85 (0.360)	2.22 (0.139)
	rACB	0.34	0.36	0.36	3.46 (0.066)	3.56 (0.062)	1.71 (0.194)
Hippocampus
	Amygdala	0.30	0.30	0.30	0.92 (0.341)	0.00 (0.964)	3.59 (0.061)
	oPFC	0.36	0.35	0.37	5.46 (0.021)	0.27 (0.604)	5.21 (0.024)
Subcortical gray matter		Mean diffusivity Least squares mean
Left hemisphere
Amygdala		0.85	0.85	0.85	0.84 (0.361)	0.04 (0.841)	2.38 (0.126)
Hippocampus		1.03	1.02	1.01	0.61 (0.434)	0.11 (0.744)	0.72 (0.397)
Right hemisphere
Amygdala		0.83	0.84	0.83	0.89 (0.348)	2.42 (0.122)	8.47 (0.004)
Hippocampus		1.00	1.00	0.99	0.30 (0.585)	0.06 (0.800)	2.38 (0.126)

TBI, traumatic brain injury; EI, extracranial injury; oPFC, orbital pre-frontal cortex; rACB, rostral anterior cingulate bundle.