Volumetry results for different intracranial compartments^a

	Before Surgery	After Surgical Closure of Spinal Dural Tear	Difference: Absolute and Relative	P Value	Measurement Uncertainty
SIH score	6.9 ± 2.2	2.9 ± 1.7		<.001
Ventricular CSF (mL)	15.3 ± 6.3	18.0 ± 7.4	+2.7 (+18.8%)	<.001	0.2
Lateral ventricle (mL)	12.9 ± 5.9	15.2 ± 6.9	+2.3 (+18.7%)	<.001	0.2
Third ventricle (mL)	0.8 ± 0.4	1.0 ± 0.3	+0.2 (+25.5%)	<.001	0.02
Fourth ventricle (mL)	1.5 ± 0.4	1.8 ± 0.4	+0.3 (+20.9%)	.008	0.05
Total brain parenchyma (mL)	1136.9 ± 116.6	1133.1 ± 111.0	−3.8 (−0.3%)	.58	7.6
Gray matter (mL)	652.0 ± 73.7	644.8 ± 64.3	−7.2 (−0.9%)	.18	7.3
White matter (mL)	458.7 ± 53.0	462.4 ± 54.9	+3.7 (+0.8%)	.27	10.8
Brain stem	22.9 ± 3.6	22.7 ± 3.5	−0.2 (−0.9%)	.34	0.2

^aMeasurements show the mean volume in milliliters; the only exception is the SIH score in the first line.