The abstracts are up from ISNVD, scorpion. I think it's always best to go to the scientists looking at this work. They don't all agree, but they are learning and sharing more now. There are 48 abstracts of work presented last week. You can read the latest research from international vascular and neurovascular specialists. Here's the link-
Here's an interesting one from Dr. Hubbard. We're learning more about hypoxia and venous undershoot via BOLD technology. BOLD stands for Blood Oxygenation Level Dependent, and it gives a good picture of how the brain uses (or doesn't use) blood. What is of interest is that after venoplasty (not calle Liberation anymore) the pwMS had the same level of respone to testing and BOLD levels as normals.
BOLD fMRI responses during cognitive tasks in Multiple Sclerosis and effects of angioplasty
Buracas G1, Ponec D2, Gooding J2, Saxon R2, Haacke M3, Sauder H4, Hubbard D4 1Dept Radiology, University of California, San Diego, 2North County Radiology, SanDiego, 3Wayne State U, Detroit MI, 4Applied fMRI Institute, San Diego
There is renewed interest in the hypothesis that multiple sclerosis may be associated with impaired clearance or insufficient CNS venous drainage - chronic cerebrospinal venous insufficiency (CCSVI). FMRI BOLD offers the possibility to evaluate both neuronal population responses and cortical hemodynamics. Specifically, venous drainage from cortex can be assessed directly by measuring the component of the BOLD hemodynamic
response (HDR) known as the venous undershoot.
20 patients with multiple sclerosis and 20 normal controls were studied by functional MRI.
The cognitive task was designed to activate a maximum number of cortical and subcortical regions while still being intuitive to an untrained person. The MS patients were re-tested after undergoing internal jugular venoplasty. MR venography, flow quantification and fMRI were conducted on a Siemens 3T scanner.
In healthy control subjects, the task evoked activation in an extensive set of brain areas (task-positive network), including visual, parietal, temporal and frontal cortices. In MS patients the task showed significantly reduced (30-70%) activations compared to normal controls. The default (task-negative) network, in particular the medial prefrontal, posterior cingulate and cuneus cortices, also showed pronounced differences in MS patients compared to the normal controls. Specifically, these areas were not suppressed during task performance in contrast to the expected suppression seen in the normal controls. The time course of the BOLD response showed greater decay and a more pronounced undershoot as compared to the control group. Venoplasty resulted in recovery of the task-negative effects in the default network such that the comparison between controls and post-venoplasty MS patients showed no significant differences (t-test, p<0.05). The pair wise t-test of pre- and
post-venoplasty activations confirmed that the default network suppression was increased post-venoplasty as compared to pre-venoplasty in the same subjects. The task-positive network on the other hand, did not show significant changes as a result of the procedure.
The finding of significant differences between normal controls and MS patients in BOLD response patterns associated with a cognitive task in both task-positive and task-negative cortical networks sheds light on neuronal mechanisms of cognitive impairment in MS patients. Most remarkably, the inhibition of the default network appears to be impaired in posterior parietal and anterior medial prefrontal cortex and this impairment is reversed and in fact normalized by venoplasty. Since BOLD response is a function of cerebral blood flow and volume, and also oxygen metabolism rate, the reduced BOLD responses in both task positive and task-negative networks may reflect not only altered neuronal function but also change in cortical venous blood volume in MS. Thus the recovery of the suppression
in the default network by angioplastic treatment may reflect recovered neuronal and/ or vascular function. Moreover the increase in the venous undershoot component of the BOLD response in MS as compared to controls and its reduction after venoplasty provides evidence of impaired clearance and CNS venous insufficiency and holds out the promise
that this method may provide an objective diagnostic test.
Buxton RB, Uluda K, Dubowitz DJ, Liu TT. (2004) Modeling the hemodynamic response to brain
activation. Neuroimage, 23 Suppl 1:S220-33.
Zamboni P, Menegatti E, Bartolomei I, Galeotti R, Malagoni AM, Tacconi G, et al.
Intracranial venous haemodynamics in multiple sclerosis. Curr Neurovasc Res 2007;4:252-8.
let us know if you want to discuss any particular paper--
Husband dx RRMS 3/07
dx dual jugular vein stenosis (CCSVI) 4/09
dual stents placed 5/09
CCSVI in MS