ANNALS of Neurology TABLE 1: 2010 McDonald MRI Criteria for Demonstration of DIS 1 T2 Lesiona in at DIS Can Be Demonstrated by Least 2 of 4 Areas of the CNS: Periventricular Juxtacortical Infratentorial Spinal cordb Based on Swanton et al 2006, 2007.22,27 aGadolinium enhancement of lesions is not required for DIS. bIf a subject has a brainstem or spinal cord syndrome, the symptomatic lesions are excluded from the Criteria and do not contribute to lesion count. MRI ¼ magnetic resonance imaging; DIS ¼ lesion dissemi- nation in space; CNS ¼ central nervous system. nonimaging specialists.25,26 The European MAGNIMS multicenter collaborative research network, which studies MRI in MS, compared the Barkhof/Tintore´ criteria for DIS4,6 with simplified criteria developed by Swanton and colleagues.22,27 In the MAGNIMS work, DIS can be demonstrated with at least 1 T2 lesion in at least 2 of 4 locations considered characteristic for MS and as speci- fied in the original McDonald Criteria (juxtacortical, periventricular, infratentorial, and spinal cord), with lesions within the symptomatic region excluded in patients with brainstem or spinal cord syndromes. In 282 CIS patients, the Swanton-based DIS criteria were shown to be simpler and slightly more sensitive than the origi- nal McDonald Criteria for DIS, without compromising specificity and accuracy.22 The Panel accepted these MAGNIMS DIS Criteria, which can simplify the diag- nostic process for MS while preserving specificity and improving sensitivity (Table 1). MAGNETIC RESONANCE IMAGING CRITERIA FOR DIT. The 2005 revision of the McDonald Criteria sim- plified the MRI evidence required for DIT, basing it on the appearance of a new T2 lesion on a scan compared to a reference or baseline scan performed at least 30 days after the onset of the initial clinical event.9 In clinical practice, however, there is reason not to postpone a first MRI until after 30 days of clinical onset, which would result in an extra MRI scan to confirm a diagnosis. Aban- doning the requirement for an extra reference MRI after 30 days does not compromise specificity,28 and therefore the Panel, in its current revision of the McDonald Crite- ria, allows a new T2 lesion to establish DIT irrespective of the timing of the baseline MRI. 294 More recently, the MAGNIMS group confirmed earlier studies29,30 by showing that, in patients with typi- cal CIS, a single brain MRI study that demonstrates DIS and both asymptomatic gadolinium-enhancing and non- enhancing lesions is highly specific for predicting early development of clinically definite MS (CDMS) and reli- ably substitutes for prior imaging criteria for DIT.23,24 After review of these data, the Panel accepted that the presence of both gadolinium-enhancing and nonenhancing lesions on the baseline MRI can substitute for a follow-up scan to confirm DIT (Table 2), as long as it can be reli- ably determined that the gadolinium-enhancing lesion is not due to non-MS pathology. By using the recommended simplified MAGNIMS criteria to demonstrate DIS22 and allowing DIT to be demonstrated by a scan containing both enhancing and nonenhancing lesions in regions of the CNS typical for MS,23 a diagnosis of MS can be made in some CIS patients based on a single MRI.24 The Panel felt this is justified because it simplifies the diagnostic process with- out reducing accuracy. However, a new clinical event or serial imaging to show a new enhancing or T2 lesion will still be required to establish DIT in those patients who do not have both gadolinium-enhancing and nonenhanc- ing lesions on their baseline MRI. THE VALUE OF CEREBROSPINAL FLUID FINDINGS IN DIAGNOSIS. The Panel reaffirmed that positive cere- brospinal fluid (CSF) findings (elevated immunoglobulin G [IgG] index or 2 or more oligoclonal bands) can be important to support the inflammatory demyelinating nature of the underlying condition, to evaluate alternative diagnoses, and to predict CDMS.15,31 In the 2001 and 2005 McDonald Criteria, a positive CSF finding could be used to reduce the MRI requirements for reaching DIS criteria (requiring only 2 or more MRI-detected lesions consistent with MS if the CSF was positive).8,9 However, when applying the simplified MAGNIMS TABLE 2: 2010 McDonald MRI Criteria for Demonstration of DIT DIT Can Be Demonstrated by: 1. A new T2 and/or gadolinium-enhancing lesion(s) on follow-up MRI, with reference to a baseline scan, irrespective of the timing of the baseline MRI 2. Simultaneous presence of asymptomatic gadolinium-enhancing and nonenhancing lesions at any time Based on Montalban et al 2010.24 MRI ¼ magnetic resonance imaging; DIT ¼ lesion dissemi- nation in time. Volume 69, No. 2