Talk:Lesional demyelinations of the central nervous system
|WikiProject Medicine / Neurology||(Rated C-class, Low-importance)|
I am unable to find any sources other than the cited webpage supporting the jugular backflow theory on the pathophysiology underlying the Dawson's Fingers phenomenon in Multiple Sclerosis (or any other medical condition).
If the author of this article can provide a scholarly source supporting this theory, please provide it. Kazema 01:45, 12 January 2007 (UTC)
Dawson's fingers explanation preposterous
This "backpressure from the pulmonary veins" explanation is not even close to credible and must be some kind of spoof.
For one thing, the pulmonary veins carry blood from the lungs to the left atrium of the heart. Increased pressure in these veins is the kind of thing that would happen in (left) heart failure, which is not know to cause any particular brain lesion. Right heart failure or congestive heart failure can increase pressure in the veins returning to the heart from the rest of the body including the brain, but heart failure is not known for causing this kind of lesion.
MS lesions are caused by an immune-mediated attack on brain tissue. Any hypothesis purporting to explain the locations of these lesions must explain why the immune attack occurs where it does. From the (undoubtably copyrighted) 2007 Medlink Neurology article on multiple sclerosis by Anthony T. Reder MD, Associate Professor of Neurology, University of Chicago:
"The preferential periventricular location of multiple sclerosis plaques has been explained by theories including: slow blood flow in the post-capillary venules facilitates T cell adhesion; regional variation in microglia or capillary pericytes; and effects of CSF toxins or cytokines. The latter is unlikely because abluminal molecules diffuse throughout the brain within 6 minutes, facilitated by arterial pulses (Rennels et al 1985). Rapidly diffusing cytokines should activate pericytes or endothelial cells throughout the central nervous system. MRI in multiple sclerosis suggests that a flow rate through periventricular veins that is less than 50% of normal allows immune cells time to attach to endothelium (Law et al 2004). All plaques are perivenular on MRI (Tan et al 2000)."
FYI, the references cited are:
Law M, Saindans AM, Ge Y, et al. Microvascular abnormality in relapsing-remitting multiple sclerosis: perfusion MR imaging findings in normal-appearing white matter. Radiology 2004;231:645-52.
Rennels ML, Gregory TF, Blaumanis OR, Fujimoto K, Grady PA. Evidence for a “paravascular” fluid circulation in the mammalian central nervous system, provided by the rapid distribution of tracer protein throughout the brain from the subarachnoid space. Brain Res 1985;326:47-63.
Tan IL, van Schijndel RA, Pouwels PJ, et al. MR venography of multiple sclerosis. AJNR Am J Neuroradiol 2000;21:1039-42.
I'm sure there is more scholarly work on this topic, but a brief Medline search I just did failed to turn up much. —Preceding unsigned comment added by 22.214.171.124 (talk) 16:04, 5 September 2007 (UTC)