This Is MS Multiple Sclerosis Community: Knowledge & Support

Cerebral blood flow and red cell delivery in normal subjects and in multiple sclerosis.
(PMID:6140655)
Swank RL, Roth JG, Woody DC Jr
Neurological Research [1983, 5(1):37-59]

Regional cerebral blood flow (rCBF) was determined in 77 normal females and 53 normal males of different ages and in 26 men and 45 women with multiple sclerosis by the inhalation of radioactive Xe133 method. In the normal subjects the CBF was relatively high in the teens and fell, at first rapidly and then slowly in both sexes with age. During adult life the flow in females was significantly higher than in males. The delivery of packed red cells (RCD) was determined by multiplying the CBF by the percentage concentration of red cells (HCT). The RCD for both sexes was nearly the same. In the patients with multiple sclerosis there occurred a progressive generalized decrease in CBF and in RCD with age which was significantly greater than observed in normal subjects. The rate of decrease in CBF and RCD correlated directly with the rate of progress of the disease.

Stimulation of the rostral ventrolateral medullary neurons increases cortical cerebral blood flow via activation of the intracerebral neural pathway.
Saeki Y, Sato A, Sato Y, Trzebski A.
Department of Physiology, Tokyo Metropolitan Institute of Gerontology, Japan.
Abstract
In urethane-anesthetized, artificially ventilated rats, electrical or chemical (by L-glutamate) focal stimulations of the rostral ventrolateral medulla (RVLM) produced an increase in cortical cerebral blood flow (CBF). The RVLM-induced cortical vasodilative response was present in animals with spinal cords sectioned at levels of Th3-4 and with bilateral extracerebral cervical sympathetic trunks (CSTs) severed. The RVLM-induced cortical vasodilative response was totally eliminated by an alpha 2 adrenergic blocker, but not by blockers for muscarinic, nicotinic, alpha 1 and beta receptors. It was concluded that there is an intracerebral vasodilative neural pathway including an alpha 2 adrenergic receptor originating in the RVLM for regulation of cortical blood vessels.

Would increased CBF increase the rate at which CSF is drained/fed?

In the patients with multiple sclerosis there occurred a progressive generalized decrease in CBF and in RCD with age which was significantly greater than observed in normal subjects. The rate of decrease in CBF and RCD correlated directly with the rate of progress of the disease.

What do you think?
I think outflow obstructions that decrease the outflow rate will decrease the rate at which cerebrospinal fluid is drained, since the cerebrospinal fluid drains through arachnoid granulations into the sinuses which drain into the obstructed jugulars. I don't think you can do much to increase the cerebral blood flow if the outflow is obstructed.

This is the older research that shows reduced perfusion in people with MS. The explanation given by neurologists is that the diminished brain needs less blood flow, because of atrophy etc. It's a different way to consider it if the reduced perfusion is contributing to the progress of the disease.