Table 1.

Demographic information, PC-MRI-derived CSF volumetric net flow rates and directions of the iNPH patients and healthy subjects, and ICP scores of the iNPH patients.

	Healthy	iNPH cohort	iNPH cohort		Significancea
			Responders	Non-responders/Conservative	(Responders vs. Non-responders/Conservative)
Demographic information
N	4	26	17	9
Age (yrs)	30.8 ± 8.5	69.8 ± 9.6	71.1 ± 7.8	67.4 ± 12.4	ns
Gender (F/M)	1/3	11/15	7/10	4/5
MRI biomarkers
Evan's index	0.26 ± 0.02	0.38 ± 0.05	0.39 ± 0.05	0.36 ± 0.04	ns
Callosal angle (degrees)	101.5 ± 8.4	88.7 ± 26.0	84.1 ± 25.6	97.4 ± 25.8	ns
DESH (N; %)	0 (0%)	13 (50%)	9 (53%)	4 (44%)	ns
PC-MRI-derived CSFvolumetric flow rate and direction at CCJ
CSF volumetric net flow rate (mL/cycle)	0.081 ± 0.070	0.068 ± 0.10	0.073 ± 0.093	0.059 ± 0.121	ns
Estimated CSF volumetric net flow rate (L/24 h)	6.40 ± 4.88	6.86 ± 9.04	7.12 ± 8.10	6.31 ± 11.51	ns
Cranially directed net CSF flow (N)	4	17	12	5	ns
Spinally directed net CSF flow (N)	0	5	3	2
PC-MRI-derived CSF volumetric flow rate and direction in cerebral aqueduct
CSF volumetric net flow rate (mL/cycle)	−0.003 ± 0.001	0.012 ± 0.025	0.023 ± 0.021	−0.006 ± 0.02	p = 0.020
Estimated CSF volumetric net flow rate (L/24 h)	−0.26 ± 0.05	1.09 ± 2.24	2.141 ± 1.646	−0.65 ± 1.95	p = 0.016
Antegrade-directed net CSF flow (N)	4	7	3	4	ns
Retrograde-directed net CSF flow (N)	0	14	11	3
Net CSF stroke volume ratio (aqueduct/CCJ; % ratio))	2.9 ± 2.2	23.4 ± 19.8	24.5 ± 20.0	20.7 ± 21.2	p = 0.037
ICP scores
Static ICP
Mean ICP average (mmHg)		6.6 ± 3.0	7.1 ± 2.6	5.8 ± 3.6	ns
Mean ICP >15 mmHg (%)		1 ± 3	1 ± 4	2 ± 3	ns
Pulsatile ICP
MWA average (mmHg)		4.8 ± 1.5	5.2 ± 1.3	4.0 ± 1.4	p = 0.041
MWA >5 mmHg (%)		37 ± 34	46 ± 33	20 ± 32	ns

iNPH: idiopathic normal pressure hydrocephalus; CCJ: cranio-cervical junction; DESH: disproportionately enlarged subarachnoid space hydrocephalus; MWA: mean ICP wave amplitude.

^aSignificance determined by Mann-Whitney U test (ns: non-significant)