E. Ann Yeh

Clinical features and viral serologies in children with multiple sclerosis: a multinational observational study

BACKGROUND The full spectrum of clinical manifestations and outcome, and the potential importance of regional or demographic features or viral triggers in paediatric multiple sclerosis (MS), has yet to be fully characterised. Our aim was to determine some of these characteristics in children with MS. METHODS 137 children with MS and 96 control participants matched by age and geographical region were recruited in a multinational study. They underwent structured clinical-demographic interviews, review of academic performance, physical examination, disability assessment (MS patients only), and standardised assays for IgG antibodies directed against Epstein-Barr virus, cytomegalovirus, parvovirus B19, varicella zoster virus, and herpes simplex virus. FINDINGS MS was relapsing-remitting at diagnosis in 136 (99%) children. The first MS attack resembled acute disseminated encephalomyelitis (ADEM) in 22 (16%) of the children, most under 10 years old (mean age 7.4 [SD 4.2] years). Children with ADEM-like presentations were significantly younger than were children with polyfocal (11.2 [4.5] years; p<0.0001) or monofocal (12.0 [3.8] years; p=0.0005) presentations. Permanent physical disability (EDSS>or=4.0) developed within 5 years in 15 (13%) of the 120 children for whom EDSS score was available. 23 (17%) had impaired academic performance, which was associated with increasing disease duration (p=0.02). Over 108 (86%) of the children with MS, irrespective of geographical residence, were seropositive for remote EBV infection, compared with only 61 (64%) of matched controls (p=0.025, adjusted for multiple comparisons). Children with MS did not differ from controls in seroprevalence of the other childhood viruses studied, nor with respect to month of birth, sibling number, sibling rank, or exposure to young siblings. INTERPRETATION Paediatric MS is a relapsing-remitting disease, with presenting features that vary by age at onset. MS in children might be associated with exposure to EBV, suggesting a possible role for EBV in MS pathobiology.

Pediatric multiple sclerosis

Pediatric multiple sclerosis (MS) accounts for up to 5% of all MS cases. Work conducted over the past 5 years has provided new information about the treatment, pathogenesis, demographics, and natural history of this disorder. Genetic and environmental factors seem to exert critical influences on its development. Clinical, MRI and laboratory data from prepubertal and postpubertal children suggest differences between the immune response and/or CNS environment in younger compared with older children and adults with MS. Randomized, controlled treatment trials for pediatric MS have not yet been performed, but therapies used in adult MS have been evaluated in this population, and their use seems to be safe. This article provides a comprehensive review of current knowledge regarding pediatric MS, highlighting new advances in the field.

Multiple Sclerosis Therapies in Pediatric Patients With Refractory Multiple Sclerosis

BACKGROUND Currently available disease-modifying therapies (DMTs) are known to be only partially effective in adults with multiple sclerosis (MS). Little is known about pediatric patients with MS who experience refractory disease while receiving first-line DMTs. OBJECTIVE To assess the occurrence and management of refractory disease in a group of pediatric patients with MS treated with first-line DMTs approved for adult patients within a network of pediatric MS centers in the United States. DESIGN, SETTING, AND PATIENTS A multicenter, retrospective, longitudinal, open-label study design involving record review of 258 patients with pediatric-onset MS (68.6% female; mean [SD] age at disease onset, 13.2 [3.5] years; range of age at onset, 2.0-17.9 years) who were seen at 6 pediatric MS centers in the United States. INTERVENTION We evaluated medication changes owing to refractory disease in cases of pediatric-onset MS. MAIN OUTCOME MEASURE Disease stability as represented by lack of medication change for breakthrough disease. RESULTS Records of 258 children with a confirmed diagnosis of MS and exposure to DMTs were reviewed. Interferon beta (prescribed to 200 of 258 children [77.5%]) and glatiramer acetate (prescribed to 53 of 258 children [20.5%]) were the 2 most frequently used first-line DMTs. Overall, 144 children (55.8%) continued receiving 1 therapy, while 65 (25.2%), 29 (11.2%), and 20 (7.8%) received 2, 3, or 4 or more sequential therapies, respectively, during a mean (SD) observation period of 3.9 (2.8) years. Second-line DMT use was restricted to interferon beta and glatiramer acetate in 203 children (78.7%), whereas other treatments such as broad-spectrum chemotherapies (cyclophosphamide, mitoxantrone hydrochloride), natalizumab, corticosteroids (monthly), and daclizumab were used at some point during the observation period for disease management in 55 children (21.3%). Hispanic children were more likely to experience breakthrough disease while receiving first-line DMTs than non-Hispanic children. CONCLUSION Although switching between first-line DMTs may be effective in pediatric patients with disease that is refractory to initial treatment, a subset of patients may require second-line therapeutic interventions.

Fatigue and Depression in Children With Demyelinating Disorders

Fatigue and depression have been shown to be significant problems in children with multiple sclerosis. The rate at which these conditions occur in children with other acquired demyelinating syndromes is unknown. In this cross-sectional study, the authors evaluated 49 children with demyelinating disorders (multiple sclerosis and acute disseminated encephalomyelitis) and 92 healthy controls for depression and/or fatigue using the Behavior Assessment System for Children, Second Edition behavior and mood rating scale and Varni PedsQL Multidimensional Fatigue Scale. The parents of acquired demyelinating syndrome patients were more likely to report elevated depressive symptoms (30.8% vs 10.8%, P = .008). Elevated parent and self-reported total fatigue (25% vs 0%, P < .001, 26.7% vs 8.6%, P = .024) was seen in the patient cohort. The authors conclude that fatigue and depression are far more common in children with acquired demyelinating syndromes than in controls. Clinical attention to and implementation of effective therapies oriented toward these conditions in children with acquired demyelinating syndromes is needed.

Natalizumab in pediatric multiple sclerosis patients.

Pediatric multiple sclerosis (MS) comprises 2-5% of all cases of MS. Although first-line disease-modifying therapy (DMT) including interferons and glatiramer acetate appear to be well tolerated in this population, recent work has suggested that a growing number of children suffer from disease which is resistant to treatment with these therapies. Natalizumab is a therapy which, although associated with a 1 : 1000 risk for progressive multifocal leukoencephalopathy (PML), has been shown to be well tolerated in the adult population and may lead to disease remission in adults with highly active disease. Reports of use of this therapy in the pediatric population with highly active disease have been published. This paper reviews current experience with the use of natalizumab in the pediatric MS population, with attention to potential risks and possible long-term outcomes in this population.

Lower physical activity is associated with higher disease burden in pediatric multiple sclerosis

Objective: To evaluate the association between physical activity (PA) and multiple sclerosis (MS) disease activity, depression, and fatigue in a cohort of children with MS and monophasic acquired demyelinating syndrome (mono-ADS). Methods: In this cross-sectional study of consecutive patients attending a specialized pediatric MS clinic, we administered the PedsQL Multidimensional Fatigue Scale, Center for Epidemiological Studies Depression Scale, and Godin Leisure-Time Exercise Questionnaire. Quantitative MRI analysis was performed to obtain whole brain and T2 lesion volume in a subset of participants (n = 60). Results: A total of 110 patients (79 mono-ADS; 31 MS; 5–18 years; M:F 1:1.2) were included. Patients with MS reported less strenuous (33.21 ± 31.88 metabolic equivalents [METs] vs 15.97 ± 22.73 METs, p = 0.002) and total (44.48 ± 39.35 METs vs 67.28 ± 59.65 METs; p = 0.0291) PA than those with mono-ADS. Patients with MS who reported greater amounts of moderate PA METs had fewer sleep/rest fatigue symptoms (r = −0.4). Participation in strenuous PA was associated with smaller T2 lesion volumes (r = −0.66) and lower annualized relapse rate (r = −0.66). No associations were found between total brain volume and participation in PA. Conclusions: Children with MS are less physically active than children with mono-ADS. Reasons for this are unclear, but may be related to ongoing disease activity, perceived limitations, or symptoms such as depression or fatigue. Children with MS reporting higher levels of strenuous PA had lower T2 lesion volumes and lower relapse rates, suggesting a potential protective effect of strenuous PA in this population. Further longitudinal studies are needed to establish the relationship of PA to MS symptoms and disease activity in this population.

Contribution of the cerebellum to cognitive performance in children and adolescents with multiple sclerosis

Background: Posterior fossa lesions are common in pediatric-onset multiple sclerosis (MS), which is of concern, given the known role of the cerebellum in cognition. Objectives: To investigate the relationship between cerebellar pathology and cognitive function in youth with pediatric-onset MS. Methods: Twenty-eight pediatric-onset relapsing–remitting MS patients (21 girls; mean age 16.2 years; mean disease duration 4.3 years, median Expanded Disability Status Scale 1.25) were compared to 33 age- and sex-matched healthy controls. Participants underwent structural magnetic resonance imaging (MRI) and neuropsychological evaluation to assess intelligence, attention, processing speed, language, visuo-motor integration, and fine-motor dexterity. Associations between cognitive outcomes and cerebellar volume independent of cerebral volume were examined. Results: Cognitive and motor performance of the MS group was reduced relative to controls (all p<0.003). While cerebellar volumes did not differ between groups, cerebellar posterior lobe volume and infratentorial lesion volume accounted for extra variance on measures of information processing (R2=0.43; p=0.02) and vocabulary (R2=0.56; p=0.04) in patients (controlling for cerebral volume and sex), but not in controls. Conclusion: Smaller cerebellar posterior lobe volume, a known region for cognitive processing, and increased lesion burden in the posterior fossa adversely impact cognitive function, an important functional consequence of MS onset during childhood.

Iron content of the pulvinar nucleus of the thalamus is increased in adolescent multiple sclerosis

Objective: The objective of this paper is to assess abnormal phase values, indicative of increased iron content, using susceptibility-weighted imaging (SWI)-filtered phase of the subcortical deep gray matter (SDGM) in adolescent multiple sclerosis (MS) and other neurological disorders (OND) patients, and in healthy controls (HC). Methods: Twenty adolescent MS and eight adolescent OND patients and 21 age- and sex-matched HC were scanned on a 3T GE scanner. Mean phase of abnormal phase tissue (MP-APT), MP-APT volume, normal phase tissue volume (NPTV) and normalized volume measurements were obtained for total SDGM, as well as specific structures separately. Results: Significantly increased MP-APT (28.2%, p<.001) and MP-APT volume (82.7%, p<.001), and decreased NPTV (−23.3%, p<.001) and normalized volume (−15.5%, p<.001) in the pulvinar nucleus of the thalamus was found in MS patients compared to HC. MP-APT in MS patients was also increased in total SDGM (p=.012) and thalamus (p=.044). Compared to OND patients, MS patients had increased MP-APT volume in the pulvinar nucleus of the thalamus (p=.044) and caudate (p=.045). Increased MP-APT of the SDGM structures were associated with increased T2 and T1 lesion burden and brain atrophy in MS patients. Conclusion: Adolescent MS patients showed increased iron content in the SDGM compared to OND patients and HC.

Antibody response to common viruses and human leukocyte antigen-DRB1 in pediatric multiple sclerosis

Background: As remote infections with common herpes viruses are associated with modulation of the risk of multiple sclerosis (MS), we hypothesized that antibody concentrations against these viruses may further modify risk. As many common viruses are first encountered during childhood, pediatric MS offer a unique opportunity to investigate more closely their influence on susceptibility. Our aim was to determine if MS patients who were positive for these viruses had higher levels of antibodies to these viruses. We also assessed whether human leukocyte antigen (HLA)-DRB1*1501 genotype influenced viral antibody levels. Methods: Antibody response levels toward Epstein Barr virus (EBV), cytomegalovirus (CMV), and herpes simplex virus (HSV)-1, and HLA-DRB1*1501 status were determined in pediatric MS patients (n=189) and controls (n=38). Multivariate analyses were used, adjusted for age, gender, race, ethnicity and use of disease-modifying therapies. Results: The antibody concentrations against EBV (Epstein-Barr nuclear antigen 1 (EBNA-1), viral capsid antigen (VCA) and early antigen (EA)), CMV and HSV-1 were similar between pediatric MS patients and controls positive for seroconversion against the virus of interest. EBNA-1 humoral responses were higher in HLA-DRB1 positive individuals (p=0.005) whereas other viral humoral responses were similar in HLA-DRB1 positive and negative individuals. Conclusion: Among those positive for EBNA-1, MS patients did not have higher levels of antibody response to EBNA-1: however, titers for EBNA-1 were higher in those who were HLA-DRB1 positive. This suggests that genotype might influence the humoral response to EBV. Whether other genotypes influence antibody response to other viruses remains to be determined.

Cerebellar Mutism in Pediatric Acute Disseminated Encephalomyelitis

Acute disseminated encephalomyelitis is a demyelinating process affecting multiple areas of the central nervous system, frequently including the cerebellum. Cerebellar insult may lead to absence of speech or cerebellar mutism. Cerebellar mutism often occurs in young children after posterior fossa tumor resection, and generally appears as part of a larger subset of neurobehavioral signs and personality changes known as posterior fossa syndrome. Information on the impact of widespread cerebellar involvement on speech production, behavior, and long-term outcomes in acute disseminated encephalomyelitis is limited. We describe cases of acute disseminated encephalomyelitis with predominantly cerebellar involvement, with specific attention to cerebellar mutism. We conducted a retrospective chart review of children diagnosed with acute disseminated encephalomyelitis between 2005-2009 at a pediatric multiple sclerosis and demyelinating disorders clinic. Of 19 patients diagnosed with acute disseminated encephalomyelitis, six (32%) manifested primary cerebellar involvement. Of these six, four (67%) exhibited acute language disturbance, with three (50%) exhibiting mutism. The three patients with cerebellar mutism experienced protracted speech and language deficits after follow-ups from 6 months to 4 years. Widespread cerebellar involvement in acute disseminated encephalomyelitis may result in cerebellar mutism, in addition to persistent neurocognitive and behavioral problems.