Katherine A. Miszkiel

Gray matter atrophy is related to long‐term disability in multiple sclerosis

To determine the relation of gray matter (GM) and white matter (WM) brain volumes, and WM lesion load, with clinical outcomes 20 years after first presentation with clinically isolated syndrome suggestive of multiple sclerosis (MS).

MRI criteria for multiple sclerosis in patients presenting with clinically isolated syndromes: a multicentre retrospective study.

BACKGROUND The 2001 and 2005 McDonald criteria allow MRI evidence for dissemination in space (DIS) and dissemination in time (DIT) to be used to diagnose multiple sclerosis in patients who present with clinically isolated syndromes (CIS). In 2006, new criteria were proposed in which DIS requires at least one T2 lesion in at least two of four locations (juxtacortical, periventricular, infratentorial, and spinal-cord) and DIT requires a new T2 lesion on a follow-up scan. We applied all three criteria in a large cohort of CIS patients to assess their performance by use of conversion to clinically definite multiple sclerosis (CDMS) as the outcome. METHODS Patients who had two MRI scans within 12 months of CIS onset were identified in four centres in the Magnims European research network. The specificity and sensitivity of MRI criteria for CDMS after 3 years was assessed in 208 patients. A Cox proportional hazards model was applied in a larger cohort of 282 patients that included all patients irrespective of length of follow-up. FINDINGS The specificity of all criteria for CDMS was high (2001 McDonald, 91%; 2005 McDonald, 88%; new, 87%). Sensitivity of the new (72%) and 2005 McDonald (60%) criteria were higher than the 2001 McDonald criteria (47%). The Cox proportional hazards model showed a higher conversion risk for all three criteria in those with both DIS and DIT than those with either DIS or DIT alone. When all three criteria were included in the model, only the new criteria had an independent significant effect on conversion risk. INTERPRETATION The new criteria are simpler than the McDonald criteria without compromising specificity and accuracy. The presence of both DIS and DIT from two MRI scans has a higher specificity and risk for CDMS than either DIS or DIT alone.

Application of the new McDonald criteria to patients with clinically isolated syndromes suggestive of multiple sclerosis.

Traditionally, multiple sclerosis (MS) has been diagnosed on the basis of clinical evidence of dissemination in time and space. Previously, it could not be diagnosed in patients with single clinical episodes of demyelination known as clinically isolated syndromes. New diagnostic criteria from the International Panel of McDonald and colleagues incorporate MRI evidence of dissemination in time and space to allow a diagnosis of MS in patients with clinically isolated syndromes. From clinical and MRI examinations performed prospectively at baseline, 3 months, 1 year, and 3 years of follow‐up, the frequency of developing MS was ascertained by the application of both the new McDonald criteria and the Poser criteria for clinically definite MS. The specificity, sensitivity, positive and negative predictive value, and accuracy of the new criteria for the development of clinically definite MS were assessed. At 3 months, 20 of 95 (21%) patients had MS with the McDonald criteria, whereas only 7 of 95 (7%) had developed clinically definite MS. After 1 year, the corresponding figures were 38 of 79 (48%) and 16 of 79 (20%), and after 3 years, they were 29 of 50 (58%) and 19 of 50 (38%). The development of MS with the new MRI criteria after 1 year had a high sensitivity (83%), specificity (83%), positive predicative value (75%), negative predictive value (89%), and accuracy (83%) for clinically definite MS at 3 years. Use of the new McDonald criteria more than doubled the rate of diagnosis of MS within a year of presentation with a clinically isolated syndrome. The high specificity, positive predictive value, and accuracy of the new criteria for clinically definite MS support their clinical relevance.

Modification of MRI criteria for multiple sclerosis in patients with clinically isolated syndromes

Background: The McDonald criteria include MRI evidence for dissemination in space and dissemination in time for the diagnosis of multiple sclerosis in young adult patients who present with clinically isolated syndromes (CIS) typical of the disease. Although a major advance, the criteria have limited sensitivity for making an early diagnosis. Objective: To compare the performance of McDonald criteria and modified McDonald criteria for dissemination in space and time for assessing the development of clinically definite multiple sclerosis. Methods: McDonald criteria were modified using the combination of a less stringent definition for dissemination in space and allowing a new T2 lesion per se after three months as evidence for dissemination in time. Modified and McDonald criteria were applied in 90 CIS patients at baseline and at three month follow up scans. Results: Both criteria were highly specific (>90%) but the modified criteria were more sensitive (77% v 46%) and more accurate (86% v 73%). Conclusions: These modified criteria should be evaluated in other CIS cohorts.

Progressive ventricular enlargement in patients with clinically isolated syndromes is associated with the early development of multiple sclerosis

Background: In patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS), the extent of brain magnetic resonance imaging (MRI) lesion load influences the probability and time to development of clinically definite MS. Cerebral atrophy is recognised in established MS, but its time of onset and whether, in early disease, it is related to MRI lesion load or clinical outcome is less certain. Objectives: This study investigated ventricular enlargement over one year in CIS patients and explored its relation with lesion load and clinical outcome. Methods: A semi-automated thresholding technique for measuring ventricular volume (MIDAS) was applied to MRI scans in a cohort of 55 patients with CIS, recruited consecutively and imaged within three months of the onset of symptoms and again after one year. Results: Clinical MS had developed after one year in 16 of 40 patients with an abnormal baseline T2 scan and 2 of 15 with a normal scan. Significant ventricular enlargement was seen in 27 of 55 patients who fulfilled the new McDonald MRI criteria for MS using all available MRI at clinical follow up (median increase 0.3 cm3, p=0.005) Significant increase in ventricular volume was also seen in the 18 of 55 patients who developed clinical MS over the follow up period (median increase 0.5 cm3, p=0.006). There were significant but modest correlations between baseline lesion measures and subsequent ventricular enlargement. Conclusions: (1) Lesions and atrophy are both associated with early relapse leading to a diagnosis of clinical MS; (2) while lesions contribute to the development of atrophy, atrophy may also develop by other mechanisms. This suggests that MR measures have a complementary role in monitoring the course of MS, even from the earliest clinical stage.

Effect of natalizumab on conversion of gadolinium enhancing lesions to T1 hypointense lesions in relapsing multiple sclerosis

Abstract.Background:Natalizumab, a humanized monoclonal anti-adhesion molecule antibody, reduces the frequency of new gadolinium (Gd) enhancing lesions and relapses in multiple sclerosis (MS). Its effect on evolution of new Gd enhancing lesions to T1 hypointense lesions is unknown.Methods:213 patients were randomized to receive 3 mg/kg or 6 mg/kg natalizumab or placebo monthly for 6 months and then followed for a further 6 months. A subset of patients who had one or more new gadolinium enhancing lesions from Month 0 to Month 6 and available electronic data were analysed. Each new Gd enhancing lesion that developed during treatment (months 1–6) was investigated for conversion to a new T1 hypointense lesion at month 12. Lesions were classified as large or small if their cross-sectional area was greater or less than 20mm2. Because of the similarity of both doses of natalizumab on the frequency of new Gd enhancing lesions, the two natalizumab arms were combined in all analyses.Results:Compared with the placebo group, the natalizumab group exhibited significant decreases in: (i) the proportion of patients with new Gd enhancing lesions that evolved to T1-hypointense lesions (10/38 [26 %] versus 27/40 [68 %]; p < 0.01); (ii) the proportion of patients who developed large T1 hypointense lesions (2/38 [5 %] versus 16/40 [40 %]; p < 0.01); (iii) the proportion of new Gd enhancing lesions that became T1 hypointense (11/75 [15 %] versus 118/466 [25 %]; p = 0.045); (iv) the mean proportion per patient of new Gd enhancing lesions that converted to T1-hypointense lesions (0.15 versus 0.28; p = 0.005), and (v) the odds ratio (OR) of converting from Gd enhancing to T1-hypointense lesions (OR = 0.48; 95% CI = 0.24, 0.94, p = 0.031)).Conclusion:Natalizumab significantly suppresses the evolution of new Gd enhancing to T1-hypointense lesions. This may reflect several mechanisms including reduced cell migration across the blood brain barrier, reduced T cell activation within lesions, an inhibitory effect on subsequent axonal damage within the new central nervous system lesion, and a reduced likelihood of recurrent lesion inflammation.

A Single, Early Magnetic Resonance Imaging Study in the Diagnosis of Multiple Sclerosis

BACKGROUND A diagnosis of multiple sclerosis in patients who present for the first time with a clinically isolated syndrome (CIS) can be established with brain magnetic resonance imaging (MRI) if the MRI demonstrates demyelinating lesions with dissemination in space (DIS) and dissemination in time (DIT). OBJECTIVE To investigate the diagnostic performance of a single MRI study obtained within the first 3 months after symptom onset in a cohort of patients with a CIS suggestive of multiple sclerosis at presentation. DESIGN Multicenter inception cohort with a follow-up of at least 24 months. SETTING Referral hospitals. Patients Patients with CIS onset between April 1, 1995, and September 30, 2004, who fulfilled the following criteria were included: (1) age of 14 to 50 years and (2) clinical follow-up for at least 24 months after CIS onset or until development of clinically definite multiple sclerosis (CDMS), if this occurred within 2 years. Main Outcome Measure All patients underwent 2 comparable brain MRI examinations, the first within 3 months (early) and the second between 3 and 12 months (delayed) after CIS onset. We defined DIS using several existing MRI criteria, and DIT was inferred when there were simultaneous gadolinium-enhancing and nonenhancing lesions on a single MRI. RESULTS Two hundred fifty patients were included in the study. The comparison of the diagnostic performance of various MRI criteria for identifying early converters to CDMS showed similar sensitivity and specificity between early and delayed MRIs. In addition, the use of less stringent criteria for DIS yielded better sensitivity and similar specificity, particularly when assessed in the first weeks after CIS onset. CONCLUSION A single brain MRI study that demonstrates DIS and shows both gadolinium-enhancing and nonenhancing lesions that suggest DIT is highly specific for predicting the early development of CDMS, even when the MRI is performed within the first 3 months after the onset of a CIS.

Measurement of spinal cord area in clinically isolated syndromes suggestive of multiple sclerosis

Atrophy of the spinal cord is known to occur in multiple sclerosis but the cause and the timing of its onset are not clear. Recent evidence suggests that atrophy may start to occur early in the disease. The aim was to determine whether atrophy of the spinal cord could be detected in vivo using MRI techniques, in patients presenting with a clinically isolated syndrome, which in many cases is the earliest clinical stage of multiple sclerosis.  The cross sectional area of the spinal cord was measured in 43 patients presenting with a clinically isolated syndrome and 15 matched controls. T2 weighted imaging of the brain was also performed to determine the number and volume of high signal lesions consistent with disseminated demyelination. Both patients and controls were restudied after 1 year.  The spinal cord area was significantly smaller in the 74% of patients with an abnormal brain MRI at presentation than in controls (mean areas 73.9 mm2 and 78.1 mm2 respectively, p=0.03). No significant difference was found in the spinal cord area between controls and patients with normal baseline brain imaging. The annual rate of change in patients did not differ significantly from controls.  In conclusion, the finding of a smaller cord area in the subgroup of patients with clinically isolated syndrome with the highest risk of developing multiple sclerosis—that is, with an abnormal brain MRI, suggests that atrophy has developed in some patients with multiple sclerosis even before their first clinical symptoms. However, the lack of a detectable change in cord area over 1 year of follow up contrasts strikingly with the results of an earlier study of patients with relapsing-remitting multiple sclerosis, suggesting that the rate of atrophy increases as the disease becomes more established.

Multisequence MRI in clinically isolated syndromes and the early development of MS

Objective: To apply multisequence MRI techniques to patients with clinically isolated syndromes, to document the pattern and frequency of abnormalities at baseline and early follow-up, and to determine their predictive values for the early development of clinical MS. Background: Disseminated lesions on T2-weighted brain MRI confer an increased risk of progression to clinically definite MS. Newer MRI techniques increase detection of lesions in both brain and spinal cord, and clarify further their pathology. The predictive value of such techniques for the development of clinical MS needs to be defined. Methods: Brain and spinal MRI were performed on 60 patients after their first demyelinating event. A total of 50 patients were followed for 1 year, and 49 underwent repeat brain MRI 3 months after the initial scan. Results: At baseline, 73% of patients had lesions on T2-weighted fast spin-echo (FSE) brain images and 42% had asymptomatic spinal cord lesions. Fast fluid-attenuated inversion-recovery brain did not improve detection of brain lesions. Repeat brain MRI demonstrated new FSE lesions in 43% of patients. After 1 year, 26% of patients developed MS. The MRI features that provided the best combination of sensitivity and specificity for the development of MS were the presence of new FSE lesions at follow-up and enhancing lesions at baseline. The frequency of developing clinical MS was higher for those with both brain and spinal cord lesions at baseline (48%) than brain lesions alone (18%). Conclusions: The combination of baseline MRI abnormalities and new lesions at follow-up, indicating dissemination in space and time, was associated with a high sensitivity and specificity for the early development of clinical MS. These data suggest a potential role for new diagnostic criteria for MS based on early MRI activity. Such criteria may be useful in selecting patients for therapeutic trials at this early clinical stage.

Adaptive cortical plasticity in higher visual areas after acute optic neuritis

The ability to distinguish adaptive cortical reorganization may help to target future therapeutic strategies after neurological insult. We investigated cortical plasticity by prospectively applying visual functional magnetic resonance imaging (fMRI) and optic nerve MRI to 20 patients with acute optic neuritis at baseline, 1, 3, 6, and 12 months. We performed three types of correlation analyses to investigate the relationships between fMRI activity, clinical function, and optic nerve structure. The first analysis directly correlated the fMRI response to clinical function or optic nerve structure and found dynamic relations especially within the first 3 months. The second analysis used a novel technique that modeled the fMRI response and optic nerve structure together with clinical function, to determine the contribution fMRI made to clinical function after accounting for structural factors. Significant effects were found at baseline only, within the right peristriate cortex, and bilaterally in the lateral occipital complexes, which are normally involved in higher order visual processing. The third analysis investigated the relation between the modeled visual recovery rate and fMRI response but found no significant effects. The key findings of this study are from the second analysis and suggest a genuine adaptive role for cortical reorganization within extrastriate visual areas early after optic neuritis. Ann Neurol 2005;57:622–633