Thursday, 12 January 2012

Research: CCSVI and vascular abnormalities or Not

Haacke EM et al. Patients with Multiple Sclerosis with Structural Venous Abnormalities on MR Imaging Exhibit an Abnormal Flow Distribution of the Internal Jugular Veins. J Vasc Interv Radiol. 2012 Jan;23(1):60-68.e3.

PURPOSE: To evaluate extracranial venous structural and flow characteristics in patients with multiple sclerosis (MS).

MATERIALS AND METHODS: Two hundred subjects with MS from two sites (n = 100 each) were evaluated with magnetic resonance (MR) imaging at 3 Telsa. Contrast-enhanced time-resolved MR angiography and time-of-flight MR venography were used to assess vascular anatomy. Two-dimensional phase-contrast MR imaging was used to quantify blood flow. The MS population was divided into two groups: those with evident internal jugular vein (IJV) narrowing of the blood vessel = stenoses (stenotic group) and those without (nonstenotic group).

RESULTS: Of the 200 patients, 136 (68%) showed internal jugular vein (vein in neck) structural abnormalities, including unilateral or bilateral stenoses at different levels in the neck (n = 101; 50.5%) and atresia (Absence of a normal opening or failure of a structure to be tubular. n = 35; 17.5%). The total jugular vein flow normalized to the total arterial flow of the stenotic group (56% ± 22) was significantly lower than that of the nonstenotic group (77% ± 14; P <.001). The arterial/venous flow mismatch in the stenotic group (12% ± 15) was significantly greater than that in the nonstenotic group (6% ± 12; P < .001).

CONCLUSIONS: MR imaging provides a noninvasive means to separate stenotic from nonstenotic MS cases. The former group was more prevalent in the present MS population and carried significantly less flow in the IJVs than the latter.

Magnetic resonance Angiography to see the blood vessels

Two thirds of MSers have more narrowed veins and those people with apparent narrowing had a slower rate of blood flow. However, it is a shame that they did not examine 200 healthy individuals and see what the proportion or vascular abnormalities were found as it has been a increasingly consistent finding that even in health there are so-called vascular abnormalitieis.


PURPOSE:
This study aimed to evaluate the prevalence of chronic cerebrospinal venous insufficiency (CCSVI) in patients with multiple sclerosis (MS).

MATERIAL AND METHODS:From November 2009 to February 2010, 74 participants (40 MS patients and 34 healthy controls) were enrolled in a randomised singleblind prospective study. All participants underwent ultrasonography (US) to detect signs of CCSVI.

RESULTS: CCSVI was detected in 55% of patients in the MS group and 35% in the control group; the difference was not statistically significant (p=0.089).

CONCLUSIONS:In our experience, a slight difference exists in the prevalence of CCSVI between MS and healthy controls, but it is not as yet clear which parameters may be most significant. This preliminary study failed to show a statistically significant difference in the prevalence of CCSVI among patients affected by MS.

Probably one of many for the new year that casts doubt on the validity of CCSVI specificy for MS.

However, is it that we can not find CSSVI because we are not doing properly?

Zamboni P, Morovic S, Menegatti E, Viselner G, Nicolaides AN. Screening for chronic cerebrospinal venous insufficiency (CCSVI) using ultrasound - Recommendations for a protocol. Int Angiol. 2011;30:571-97.

Chronic cerebrospinal venous insufficiency (CCSVI) is a syndrome characterized by stenoses or obstructions of the internal jugular and/or azygos veins with disturbed flow and formation of collateral venous channels.

Studies using ultrasound in patients with multiple sclerosis (MS) have demonstrated a high prevalence of CCSVI (mean 70%; range 0-100%; N.=1496), whereas, in normal controls and patients without MS the prevalence was much lower (mean 10%; range 0-36%; N.=635).

Ultrasound uses a combination of physiological measurements as well as anatomical imaging and has been used for the detection of CCSVI by different centers with variable results. A high occurance ranging from 62% to 100% of obstructive lesions has been found by some teams in patients with MS compared with a lower occurence (prevalence) of 0-25% in controls. However, absence of such lesions or a lower prevalence (16-52%) has been reported by others.

This variability could be the result of differences in technique, training, experience or criteria used. The current lack of a methodology shared among experts is a confounding element in epidemiologic studies, and does not permit further analysis. In order to ensure a high reproducibility of Duplex scanning with comparable accuracy between centers, a detailed protocol with standard methodology and criteria is proposed and proposes a reporting standard of Duplex measurements and future research to answer areas of uncertainty.

This field needs a standardised protocol to see what the true occurence of CCSVI is. This should have been available very quickly to limit all ambiguity in the deluge of pages that will be appearring.

I think I'll save them up and post occassionally, unless there is something earth shattering, rather than doing this as they arrive.