Sunday, 11 May 2014

Size Doesn't Matter for the spinal cord

Daams M, Weiler F, Steenwijk MD, Hahn HK, Geurts JJ, Vrenken H, van Schijndel RA, Balk LJ, Tewarie PK, Tillema JM, Killestein J, Uitdehaag BM, Barkhof F. Mean upper cervical cord area (MUCCA) measurement in long-standing multiple sclerosis: Relation to brain findings and clinical disability.
Mult Scler. 2014 May 8. [Epub ahead of print]

BACKGROUND: The majority of patients with multiple sclerosis (MS) present with spinal cord pathology. Spinal cord atrophy is thought to be a marker of disease severity, but in long-disease duration its relation to brain pathology and clinical disability is largely unknown.
OBJECTIVE:Our aim was to investigate mean upper cervical cord area (MUCCA) in patients with long-standing MS and assess its relation to brain magnetic resonance imaging (MRI) measures and clinical disability.
METHODS: MUCCA was measured in 196 MS patients and 55 healthy controls using 3DT1-weighted cervical images obtained at 3T MRI. Clinical disability was measured using the Expanded Disability Status Scale (EDSS), Nine-Hole-Peg test (9-HPT), and 25 feet Timed Walk Test (TWT). Stepwise linear regression was performed to assess the association between MUCCA and MRI measures, and between MUCCA and clinical disability.
RESULTS: MUCCA was smaller (mean 11.7%) in MS patients compared with healthy controls (72.56±9.82 and 82.24±7.80 mm2 respectively; p<0.001), most prominently in male patients. MUCCA was associated with normalized brain volume, and number of cervical cord lesions. MUCCA was independently associated with EDSS, TWT, and 9-HPT.
CONCLUSION: MUCCA was reduced in MS patients compared with healthy controls. It provides a relevant marker for clinical disability in long-standing disease, independent of other MRI measures.

The spinal cord is the nervous highway between your brain and limbs and lesions are going to affect your normal nerve function. In this study they used MRI to measure spinal cord volume and found that the spinal cord had shrunk relative to none-MSers suggesting some nerve loss. This was associated with lesion load but not other functions such as EDSS and some other movement activities. 

However we have to remember the iceberg effect, The small amount of spinal cord shrinkage is only a fraction of what probably is occurring. The real amount of nerve content is probably being masked by swelling in the spinal cord and replacement of lost tissue by astrocytes causing gliosis such that the MRI is missing loads and so may not correlate with disability. 

DrKlaus may have more to say on this in MS but in EAE it is pretty clear. If you look, not at the MRI, but the histology you can see that whilst the spinal cord is not shrinking much in terms of area loss, there is can be a 40% total nerve loss and in some places 60%.  Nerve loss then correlates with the accumulation of disability. Therefore it is probably that spinal cord area MRI is missing a lot.

3 comments:

  1. Is there anything in the pipeline to protect or repair the spinal cord? Years ago I read of a Professor Raisman in the UK who was looking st stem cels for spinal cord injuries, but it all seems to have gone quiet.

    ReplyDelete
    Replies
    1. Protection yes repair yes and stem cells yes. Studies h have started or are iminent.
      Dr Raisamann was a stem cell guy transplanting stem cells has immense potential but also problems

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    2. However spinal injury is a good place to test the strategy as there is often a single lesion to deal with.

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