This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Background: The MRI incidental finding in asymptomatic subjects of brain white matter (WM) changes meeting the Barkhof criteria for the diagnosis of multiple sclerosis (MS) has been recently characterized as the radiologically isolated syndrome (RIS). This entity needs to be more specifically defined to allow risk stratification of these subjects. We used brain proton magnetic resonance spectroscopic imaging (1H-MRSI) to assess metabolic changes in an RIS population.
Methods: Twenty-three RIS subjects who were classified according to the Okuda Criteria underwent 1H-MRSI examination with a central brain (CB) volume of interest (VOI) to measure levels of N-acetylaspartate (NAA) and choline (Cho) normalized to creatine (Cr) in the whole CB-VOI, in lesional/perilesional and normal-appearing WM regions, and in the cortical gray matter (CGM). The 1H-MRSI data were compared with those of 20 demographically matched healthy controls (HC).
Results: NAA/Cr levels were significantly lower in RIS than in HC in all regions (p < 0.005 for all). No differences in Cho/Cr levels were found in either brain region. A single-subject analysis showed that NAA/Cr levels were at least 2 SDs below the HC mean in the 44% of RIS in the normal-appearing WM and in the 61% of RIS in the CGM.
Conclusion: Decreased brain NAA/Cr levels in a group of RIS subjects indicates that brain metabolic abnormalities suggestive of axonal damage can be significant even at this early disease stage. This information could be useful for stratifying RIS individuals with a high risk of progression to MS.
GLOSSARY
- CB=
- central brain;
- CGM=
- gray matter of the occipito-parietal cortex;
- Cho=
- choline;
- Cr=
- creatine;
- DIT=
- dissemination in time;
- 1H-MRSI=
- proton magnetic resonance spectroscopic imaging;
- HC=
- healthy controls;
- LL=
- lesion load;
- MR=
- magnetic resonance;
- MS=
- multiple sclerosis;
- NAA=
- N-acetylaspartate;
- NAWM=
- normal-appearing white matter;
- NBV=
- normalized brain volume;
- RIS=
- radiologically isolated syndrome;
- VOI=
- volume of interest;
- WM=
- white matter
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
Editorial, page 2084
- Received October 29, 2012.
- Accepted in final form February 12, 2013.
- © 2013 American Academy of Neurology
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Disputes & Debates: Rapid online correspondence
- Early metabolic effects in axonal damage
NOTE: All authors' disclosures must be entered and current in our database before comments can be posted. Enter and update disclosures at http://submit.neurology.org. Exception: replies to comments concerning an article you originally authored do not require updated disclosures.
- Stay timely. Submit only on articles published within the last 8 weeks.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- 200 words maximum.
- 5 references maximum. Reference 1 must be the article on which you are commenting.
- 5 authors maximum. Exception: replies can include all original authors of the article.
- Submitted comments are subject to editing and editor review prior to posting.