We have been discussing how the loss of gray matter is important in MS progression. Gray matter loss is more difficult to quantify than white matter lesions, since it has been harder to see. But new MRI technology is noting gray matter loss, and showing the seriousness of this aspect of MS disease progression. Gray matter loss of the thalamus has been linked to CCSVI in published research.
Here's the note I wrote up in May on the importance of following gray matter loss vs. the white matter lesions which are easier to see---
https://www.facebook.com/note.php?note_id=10150185662517211
Here's new research announced today:
Cognitive impairment linked to reduced brain size in children with MS: York U study
http://news.yorku.ca/2011/06/16/cognitive-impairment-linked-to-reduced-brain-size-in-children-with-ms-york-u-study/
TORONTO, June 16, 2011 – Children who suffer cognitive impairment from Multiple Sclerosis (MS) are more likely to have less brain matter, according to a study by researchers from York University, The Hospital for Sick Children, and McGill University.
Researchers found that cognitive impairment occurs in approximately 30 percent of children and teens with MS; reduced processing speed is most commonly observed, even early in the disease process. These deficits can impact overall efficiency of cognitive networks and disrupt learning of new information, the study says.
“More significantly, we found the severity of cognitive dysfunction to be strongly correlated to a reduction in size in key brain regions, including the thalamus and corpus callosum, and less strongly influenced by inflammatory activity, as detected by lesion volume in the brain,” says the study’s lead author, Christine Till, assistant professor of psychology in York’s Faculty of Health. “This suggests a link between cognitive impairment and the neurodegenerative component of MS, and highlights the important impact of the disease on deep grey matter structures and related neural networks,” she says.
Detailed neuropsychological evaluations and high-quality MRI scans were performed on 35 patients with pediatric onset MS who were recruited from the Pediatric Demyelinating Disease Clinic at Toronto’s Hospital for Sick Children. Researchers compared their findings to results from healthy children, who were of similar
age, sex, and parental education level.
MRI results showed that children with MS have overall smaller brain volumes than expected for their age. Regional analysis taking into account differences in head size showed that the thalamus, a key brain structure involved in attention, arousal, and memory, was reduced by 11.9 percent in the MS patients. The corpus callosum, which is the largest white matter tract in the brain and important for transmitting information between brain hemispheres, was reduced by five percent.
“A key component of MS onset during childhood relates to its effect on the developing brain,” says Till. “Overall, our findings suggest that the young age of childhood-onset MS patients does not protect them from the negative impact of the disease.
Approximately 24 to 40 percent of MS patients in the study showed impaired cognitive performance on measures of processing speed and visuomotor integration (e.g. copying designs). Impairments were also noted in complex attention (e.g. simultaneously attending to multiple stimuli), visual-spatial abilities, expressive language, and executive functions such as shifting attention back and forth between two stimuli, planning and organizing.
“Interestingly, physical disability did not correlate with cognitive impairment, suggesting that cognitive dysfunction can be present in the absence of physical disability,” Till says
The current research is part of a three-year study investigating the long-term effects of MS on cognitive performance. Serial analyses of MRI scans are currently underway to examine whether cognitive decline reflects the progressive neurodegenerative aspect of MS in children and teens.
“MS is increasingly diagnosed in childhood, which makes the need to understand pediatric implications of the disease all the more pressing,” says Till. “We need to fully comprehend how the disease functions in its earliest stages in order to devise interventions that can help [pediatric patients].”
The paper, “ in May 2011. Researchers from the Hospital for Sick Children and the Montreal Neurological Institute contributed to this study, which was supported by the MS Society of CanadaMRI Correlates of Cognitive Impairment in Childhood-Onset Multiple Sclerosis,” was published in the journal
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Important things to note:
1. Gray matter loss occurs early in the MS disease process, often before physical disability accrues. It is not related to inflammation, but to neurodegeneration. What does this mean? It means that the structures deep inside the brain, the thalmus, is suffering first. There is cellular death before immune activation.
2. The thalmus is the structure affected by the deep cerebral veins. It is the area of the brain that shows the most iron deposition in Dr. Zivadinov's and Dr. Haacke's SWI iron studies. Here is the study where the doctors noted that CCSVI was affecting the thalamus and decreasing brain volume.
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.
CONCLUSION:
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.
http://www.ncbi.nlm.nih.gov/pubmed/20351672
More research showing the importance of looking at gray matter loss, which occurs without immune activation. More research providing the link to the veins.
Joan