Cerebrospinal fluid absorption block at the vertex in chronic hydrocephalus: obstructed arachnoid granulations or elevated venous pressure?

Table 1 Sinus blood flow and estimated sinus pressure in normal young and adult patients and in hydrocephalic patients

Group	Age	SSS outflow	ST outflow	Total outflow	Estimated sinus pressure
	Yr	ml/min	ml/min	ml/min	mmHg
Normal young n = 10
Mean	10	620	190	810	10.5
SD	4	160	60	220	3.6
Normal adult n = 20
Mean	44	360	110	470	7.7
SD	10	80	40	110	1.1
Hydrocephalus n = 20
Mean	45	280	75	355	10.2
SD	10	60	40	80	5.5
p value	0.81	0.002*	0.01*	0.001*	0.008*

Mean +/- standard deviation; SSS: superior sagittal sinus, ST: straight sinus, *: t-test p value < 0.05 normal adults versus hydrocephalic patients.

ISSN: 2045-8118