Proposed modifications to the McDonald criteria for use in Asia

Lesion Activity on Brain MRI in a Chinese Population with Unilateral Optic Neuritis

Longitudinal studies have shown that brain white matter lesions are strong predictors of the conversion of unilateral optic neuritis to multiple sclerosis (MS) in Caucasian populations. Consequently brain MRI criteria have been developed to improve the prediction of the development of clinically definite multiple sclerosis (CDMS). In Asian populations, optic neuritis may be the first sign of classical or optic-spinal MS. These signs add to the uncertainty regarding brain MRI changes with respect to the course of unilateral optic neuritis. The aim of this study was to examine the association between brain lesion activity and conversion to CDMS in Chinese patients with unilateral optic neuritis. A small prospective cohort study of 40 consecutive Chinese patients who presented with unilateral optic neuritis was conducted. Brain lesion activity was recorded as the incidence of Gd-enhanced lesions and new T2 lesions. Brain lesions on MRI that were characteristic of MS were defined according to the 2010 revisions of the McDonald criteria. The primary endpoint was the development of CDMS. We found that nineteen patients (48%) had brain lesions that were characteristic of MS on the initial scan. One of these patients (3%) had Gd-enhanced brain lesions. A significantly lower percentage of the patients (10%, p<0.001) presented with new T2 brain lesions on the second scan. During a median of 5 years of follow-up, seven patients (18%) developed CDMS. There was no significant difference in the conversion rate to CDMS between patients with and without brain lesions that were characteristic of MS (4/19 and 3/21, respectively; Fisher exact test, one-sided, p = 0.44). We conclude that brain lesions characteristic of MS are common in Chinese patients with unilateral optic neuritis; however, these patients exhibit low lesion activity. The predictive value of brain lesion activity for CDMS requires investigation in additional patients.

Updates on clinically isolated syndrome and diagnostic criteria for multiple sclerosis

Clinically isolated syndrome (CIS) is a central nervous system demyelinating event isolated in time that is compatible with the possible future development of multiple sclerosis (MS). Early risk stratification for conversion to MS helps with treatment decisions. Magnetic resonance imaging (MRI) is currently the most useful tool to evaluate risk. Cerebrospinal fluid studies and evoked potentials may also be used to assess the likelihood of MS. Four clinical trials evaluating the benefits of either interferon β (IFN-β) or glatiramer acetate (GA) within the first 3 months after a high-risk CIS demonstrate decreased rates of conversion to clinically definite MS (CDMS) and a lesser degree of MRI progression with early treatment. In the 3-, 5-, and 10-year extension studies of 2 formulations of IFN-β, the decreased conversion rate to CDMS remained meaningful when comparing early treatment of CIS to treatment delayed by a median of 2 to 3 years. Diagnostic criteria have been developed based on the clinical and MRI follow-up of large cohorts with CIS and provide guidance on how to utilize clinical activity in combination with radiographic information to diagnose MS. The most recent 2010 McDonald criteria simplify requirements for dissemination in time and space and allow for diagnosis of MS from a baseline brain MRI if there are both silent gadolinium-enhancing lesions and nonenhancing lesions on the same imaging study. The diagnostic criteria for MS require special consideration in children at risk for acute disseminated encephalomyelitis (ADEM), in older adults who may have small vessel ischemic disease, and in ethnic groups that more commonly develop neuromyelitis optica (NMO).

Spinal cord lesions and disability in Hispanics with multiple sclerosis

Longitudinally extensive spinal cord lesions (LESCLs) are believed to occur predominantly with opticospinal multiple sclerosis (OSMS) and are associated with disability. The purpose of this study is to describe the prevalence and patterns of spinal cord lesions in Hispanics with multiple sclerosis (MS) and OSMS and their association with disability. A cross-sectional study of 164 patients with complete MRIs was used. In each case the spinal cord was classified: LESCLs, scattered spinal cord lesions (sSCLs) or no spinal cord lesions (noSCLs). Clinical course was defined as classical MS or OSMS. Risk of disability (Expanded Disability Status Scale ≥4.0) was adjusted for age, disease duration and sex using logistic regression. A total of 125/164 (73 %) MS patients had spinal cord lesions (sSCLs, 57 %; LESCLs, 19 %), but only 11 (7 %) had OSMS. LESCLs were associated with disability (p < 0.0001), longer disease duration (p < 0.0001) and MS (n = 21 vs. n = 10 OSMS; p < 0.0001). LESCLs were also associated with the greatest risk to disability (OR 7.3, 95 % CIs 1.9-26.5; p = 0.003; sSCLs OR 2.5, 95 % CIs 0.9-7.1; p = 0.09) compared with noSCLs. LESCLs are more common than OSMS and are associated with worse disability even in patients with MS. These results suggest that LESCLs are a more important marker of disability in MS than OSMS and may be an early indicator of more aggressive disease in this population.

Diagnostic criteria for multiple sclerosis: 2010 revisions to the McDonald criteria

New evidence and consensus has led to further revision of the McDonald Criteria for diagnosis of multiple sclerosis. The use of imaging for demonstration of dissemination of central nervous system lesions in space and time has been simplified, and in some circumstances dissemination in space and time can be established by a single scan. These revisions simplify the Criteria, preserve their diagnostic sensitivity and specificity, address their applicability across populations, and may allow earlier diagnosis and more uniform and widespread use.

Relapsing demyelinating CNS disease in a Korean pediatric population: Multiple sclerosis versus neuromyelitis optica

Background and Objective:Our objective was to characterize the clinical and radiologic features of Korean pediatric patients with relapsing central nervous system (CNS) demyelination disease.

Methods:Twenty-one patients with relapsing CNS demyelinating events were classified as having multiple sclerosis (MS, 18 patients) or neuromyelitis optica (NMO, three patients) according to the international consensus definitions. Retrospective analysis of clinical and radiologic features was conducted. Anti-aquaporin-4 antibody (AQP4 Ab) test was performed in six patients (including three NMO patients) who showed selective involvement of optic nerve and spinal cord.

Results: Median age at the initial episode in patients with MS was 7.0 years (range, 4.4–13.6 years). Three of 18 MS patients (3/18, 17%) showed selective involvement of the optic nerve and spinal cord during the clinical course. Five patients (31%) at the initial episode and nine patients (50%) at relapse met the McDonald magnetic resonance imaging criteria for dissemination in space. Oligoclonal bands detected with a silver staining method were positive in only one patient of 16 patients tested. Two NMO patients positive for AQP4 Ab showed frequent relapses and early disabilities that were unresponsive to interferon treatment.

Conclusions:We conclude that Korean pediatric patients with relapsing CNS demyelination disease were characterized by preferential involvement of the optic nerve or spinal cord. The AQP4 Ab test seems to be useful for predicting clinical courses in the setting of heterogeneous opticospinal presentations.

Modifications to the McDonald MRI dissemination in space criteria for use in Asians with classic multiple sclerosis: the Taiwanese experience

Background: The McDonald MRI dissemination in space criteria have been found to be less sensitive when applied to Asians with classic multiple sclerosis. The Asian neurological community thus proposed modifications to the criteria with reduction of minimal number of T2 lesions from nine to four, and removal of restriction on spinal cord lesion length and morphology for use in Asians.

Objective: The study is to examine the accuracy of modified MRI dissemination in space criteria for prediction of conversion from clinically isolated syndrome to definite multiple sclerosis according to patients’ baseline MRI.

Methods: From 2001 to 2007, we recruited 67 patients with clinically isolated syndrome. They had been followed-up until development of definite multiple sclerosis or remaining as clinically isolated syndrome for more than 2 years. The non-converters were taken as negative cases. The 67 patients’ baseline MRIs were evaluated by two radiologists and determined as either fulfilling or not fulfilling McDonald and modified MRI criteria for dissemination in space.

Results: Thirty-two patients converted to definite multiple sclerosis and 35 did not. The modified criteria are slightly more sensitive (53.1% vs. 50.0%) and accurate (77.6% vs. 76.1%) as compared with McDonald criteria. However, further reduction of the cutoff of abnormal MRI criteria from three of four to two of four criteria yields best sensitivity (71.9%) and accuracy (83.6%).

Conclusions: Modifications to the McDonald MRI dissemination in space criteria (by using fewer T2 lesions, removal of the restriction on the spinal cord lesion and reduction of the cutoff of MRI criteria) are more appropriate for use in the Taiwanese population for the diagnosis of classic multiple sclerosis.

[Recent advances of multiple sclerosis research in Japan]

Multiple sclerosis (MS) is rare in Asians, but selective and severe involvement of the optic nerve and spinal cord is characteristic when it does occur. Recent epidemiological studies have demonstrated an increase in the prevalence of MS in Japan. Moreover, while there are two distinct phenotypes of MS in Asians, opticospinal (OSMS) and conventional (CMS), it is important to determine if MS phenotypes in Japanese are presently undergoing change. Four nationwide surveys of MS have been conducted in Japan: 1972, 1982, 1989, and 2004. The most recent survey demonstrated: (1) a four-fold increase in the estimated number of clinically definite MS patients in 2003 (9.900; crude MS prevalence. 7.7/100.000) compared to the numbers in 1972; (2) a shift in the peak age at onset from the early 30s in 1989 to the early 20s in 2003; (3) a successive proportional decrease in optic-spinal involvement; (4) a significant north-south gradient for the CMS/OSMS ratio: (5) after dividing the mainland (30-45 degrees North) into northern and southern parts at 37 degrees N, northern-born northern-residents (northern patients) showed a significantly higher CMS/OSMS ratio and higher frequency of brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) than southern-born southern-residents; (6) among northern patients, the absolute numbers of CMS patients and those with Barkhof brain lesions rapidly increased with advancing birth year; (7) further classifications based on MRI findings demonstrated distinct demographic features with not only the CMS/OSMS phenotype but also the presence or absence of longitudinally extensive spinal cord lesions (LESCLs). In northern patients, the incidence of OSMS with LESCLs had decreased with advancing year of birth, while incidences of intermediate phenotypes, such as CMS with LESCLs and OSMS without LESCLs, had increased. Although phenotypic changes appeared to be mostly attributable to the increase in CMS patients with Barkhof brain lesions in younger northern populations, the emergence of such intermediate phenotypes may support the notion that CMS and OSMS represent opposite ends of a single spectrum of disease. These findings suggest that phenotype is drastically altered by environmental factors, such as latitude and "Westernization". The recent discovery of a specific IgG against neuromyelitis optica (NMO) suggests that NMO is a disease entity distinct from MS. NMO-IgG targeting aquaporin-4 (AQP4) is present in 30 to 60% of Japanese OSMS patients with LESCLs. MS patients with anti-AQP4 antibodies were not responsive to interferon beta-1b while those without anti-AQP4 antibody did respond. In CSF, IL-17, IFN-gamma, granulocyte-colony stimulating factor, and IL-8 were markedly upregulated in OSMS patients, irrespective of the presence or absence of the anti-AQP4 antibody. Pathological studies of autopsy specimens of OSMS patients disclose that there are two subtypes of OSMS, with or without showing a selective AQP4 loss; although both subtypes had severe necrotic spinal cord lesions. There are also OSMS cases showing both pathological patterns at different lesions. These findings indicate that both anti-AQP4 autoimmunity-related and -unrelated OSMS occur in Japanese. Th17/Th1 cells are involved in both conditions, while additional humoral factors also act in the former.