Is posture-related craniospinal compliance shift caused by jugular vein collapse? A theoretical analysis

Table 1 Parameters, distinctive for normal pressure hydrocephalus

Parameter	Symbol	Value	Unit	Reference
Elastance	\(E\)	0.23	mL⁻¹	[9, 16]*
Exponential parameter	\(p_{1}\)	4	mmHg	[16]*
Offset pressure	\(p_{0}\)	3.2	mmHg	[16]*
Rate of CSF formation	\(Q_{form}\)	0.35	mL/min	[13]
Total CSF outflow resistance	\(R_{abs}^{tot}\)	20.6	mmHg/(mL/min)	[13, 16]*
Relative spinal compliance	\(k_{V}\)	0.35	–	[17]
Spinal venous pressure	\(p_{v}^{s}\)	5.3	mmHg	[4]
Distance between spinal and cranial reference points	\(l_{sc}\)	33.8	cm	[4]
Distance between jugular veins and cranial reference point	\(l_{jug}\)	11.0	cm	[4]
Density of CSF	\(\rho_{CSF}\)	1000	kg/m³
Density of blood	\(\rho_{blood}\)	1060	kg/m³
Gravitational acceleration	\(g\)	9.81	m/s²
Relative spinal outflow conduction	\(k_{R}\)	n/a^#	–

* Computed from data given in the referenced work: \(E = \ln \left( {RPPC + 1} \right)/\Delta V_{a}\) [18], \(p_{1} = ICP_{r} - p_{0} - p_{v}^{s}\), \(p_{0} = p_{0}^{M} - p_{v}^{s}\), \(R_{abs}^{tot} = (ICP_{r} - p_{v}^{s} )/Q_{form}\) [3]
^# The value of this parameter is unknown. It is estimated in this study

ISSN: 2045-8118