bifrostlake wrote:Well, so much for that theory.
Results: We found an age-related increase of iron in the white matter of controls as well as in patients with short disease duration. In chronic MS, however, there was a significant decrease of iron in the normal appearing white matter (NAWM) with disease duration, when corrected for age. This decrease of iron in oligodendrocytes and myelin was associated with an up-regulation of iron-exporting ferroxidases. In active MS lesions, iron was apparently released from dying oligodendrocytes, resulting in extracellular accumulation of iron and uptake into microglia and macrophages. Iron-containing microglia showed signs of cell degeneration. At lesion edges and within centers of lesions, iron accumulated in astrocytes and axons.
Interpretation: Iron decreases in the NAWM of MS patients with increasing disease duration. Cellular degeneration in MS lesions leads to waves of iron liberation, which may propagate neurodegeneration together with inflammatory oxidative burst.
Patients with CIS showed significantly increased content and volume of iron, as determined by abnormal SWI-phase measurements, in the various sub-cortical deep gray matter structure, suggesting that iron depostion may precede structure-specific atrophy.
Brain iron accumulation has been shown histologically in MS and recently, an iron increase from 24% to 39.5% was reported in the deep gray matter in MS patients compared to control subjects (25,26).
The source of iron deposition may be myelin/oligodendrocyte debris (17), concentrated iron in the macrophages (that phagocytize the destructed myelin/oligodendrocyte), or the product of hemorrhages from damaged brain vessels.
The amount of iron deposition could reflect the extent of tissue damage, thus iron could be used as a biomarker to predict clinical outcome. This is a reasonable hypothesis given recent findings (27), which show very clear iron deposition encircling dilated veins in MS. The source of this iron is still unclear, but it could result from microhemorrhaging and hemosiderin buildup
Pediatric MS patients, at an early stage of the disease, showed significantly increased iron content and atrophy in the SDGM compared to HC, with regional predilection for the pulvinar nucleus of the thalamus.
OBJECTIVE: Chronic cerebrospinal venous insufficiency (CCSVI) was hypothesized to play a causative role in multiple sclerosis (MS). The assessment of pediatric-onset MS (POMS) may provide a unique window of opportunity to study hypothesized risk factors in close temporal association with the onset of the disease.
METHODS: Internal jugular veins, vertebral veins and intracranial veins were evaluated with extracranial and intracranial ultrasound in 15 POMS and 16 healthy controls. Assessor's blinding was maintained during the study. We considered subjects positive to CCSVI when at least two criteria were fulfilled.
RESULTS: CCSVI frequency was comparable between POMS and controls (p > 0.05). Clinical features were not significantly different between CCSVI-positive and CCSVI-negative patients.
CONCLUSIONS: Our findings add to previous data pointing against a causative role of CCSVI in MS.
BACKGROUND AND PURPOSE:Chronic cerebrospinal venous insufficiency is a postulated etiologic factor for multiple sclerosis, but the higher frequency with longer disease duration and progressive disability suggests that chronic cerebrospinal venous insufficiency is secondary to chronic disease. We evaluated the presence of chronic cerebrospinal venous insufficiency in pediatric-onset MS.
MATERIALS AND METHODS:Twenty-six pediatric patients with MS (18 years of age or younger), 26 age-matched healthy controls, and 13 young adults with pediatric-onset MS underwent sonography of the internal jugular, vertebral, and deep cerebral veins. Five venous hemodynamic criteria were assessed, with 2 criteria required for chronic cerebrospinal venous insufficiency. MR imaging studies, performed in the pediatric patients with MS and healthy control groups, included intracranial 2D time-of-flight MR venography and velocity-sensitive phase-contrast sequences. Contrast-enhanced brain MR images were obtained in pediatric patients with MS to further evaluate venous patency. We used paired t tests, Wilcoxon matched pairs, McNemar tests, and exact conditional logistic regression to estimate the association of chronic cerebrospinal venous insufficiency with MS.
RESULTS:Fifty participants (73.5%) had normal ultrasound findings, 15 (23.1%) met 1 venous hemodynamic criterion, and 2 pediatric patients with MS and 1 young adult with pediatric-onset MS met chronic cerebrospinal venous insufficiency criteria. Chronic cerebrospinal venous insufficiency was not associated with MS (odds ratio, 2.41; 95% CI, 0.19-infinity). Demographic and disease characteristics did not differ between the patients with MS meeting chronic cerebrospinal venous insufficiency criteria (n = 3) and those who did not (n = 36; all, P > .05). The mean (SD) MR imaging measures of intracerebral flow did not differ between the 2 pediatric patients with MS meeting chronic cerebrospinal venous insufficiency criteria (0.85 ± 0.11) and healthy controls (0.87 ± 0.16, P = .50); no child demonstrated venous obstruction.
CONCLUSIONS:Chronic cerebrospinal venous insufficiency is rarely observed in children or young adults with pediatric-onset MS. Venous anatomy and flow rates indicate that venous outflow is intact in pediatric patients with MS. Our findings argue against chronic cerebrospinal venous insufficiency as a component of MS etiology.
DrGeoff wrote:What causes anyone to get MS?
What can be done to moderate it?
Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular phenomenon recently described in multiple sclerosis (MS) that is characterized by stenoses affecting the main extracranial venous outflow pathways and by a high rate of cerebral venous reflux that may lead to increased iron deposition in the brain. Aim of this study was to investigate the relationship between CCSVI and iron deposition in the brain of MS patients by correlating venous hemodynamic (VH) parameters and iron concentration in deep-gray matter structures and lesions, as measured by susceptibility-weighted imaging (SWI), and to preliminarily define the relationship between iron measures and clinical and other magnetic resonance imaging (MRI) outcomes.
Sixteen (16) consecutive relapsing-remitting MS patients and 8 age- and sex-matched healthy controls (HC) were scanned on a GE 3T scanner, using SWI.
All 16 MS patients fulfilled the diagnosis of CCSVI (median VH=4), compared to none of the HC. In MS patients, the higher iron concentration in the pulvinar nucleus of the thalamus, thalamus, globus pallidus, and hippocampus was related to a higher number of VH criteria (P<0.05). There was also a significant association between a higher number of VH criteria and higher iron concentration of overlapping T2 (r=-0.64, P=0.007) and T1 (r=-0.56, P=0.023) phase lesions. Iron concentration measures were related to longer disease duration and increased disability as measured by EDSS and MSFC, and to increased MRI lesion burden and decreased brain volume.
The findings from this pilot study suggest that CCSVI may be an important mechanism related to iron deposition in the brain parenchyma of MS patients. In turn, iron deposition, as measured by SWI, is a modest-to-strong predictor of disability progression, lesion volume accumulation and atrophy development in patients with MS.
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