Faculty Bibliography

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated demyelinating CNS disorder with predilection to early childhood. ADEM is generally considered a monophasic disease. However, recurrent ADEM has been described and defined as multiphasic disseminated encephalomyelitis. ADEM often occurs postinfectiously, although a causal relationship has never been established. ADEM and multiple sclerosis are currently viewed as distinct entities, generally distinguishable even at disease onset. However, pathologic studies have demonstrated transitional cases of yet unclear significance. ADEM is clinically defined by acute polyfocal neurologic deficits including encephalopathy. MRI typically demonstrates reversible, ill-defined white matter lesions of the brain and often also the spinal cord, along with frequent involvement of thalami and basal ganglia. CSF analysis may reveal a mild pleocytosis and elevated protein, but is generally negative for intrathecal oligoclonal immunoglobulin G synthesis. In the absence of a specific diagnostic test, ADEM is considered a diagnosis of exclusion, and ADEM mimics, especially those requiring a different treatment approach, have to be carefully ruled out. The role of biomarkers, including autoantibodies like anti-myelin oligodendrocyte glycoprotein, in the pathogenesis and diagnosis of ADEM is currently under debate. Based on the presumed autoimmune etiology of ADEM, the current treatment approach consists of early immunotherapy. Outcome of ADEM in pediatric patients is generally favorable, but cognitive deficits have been reported even in the absence of other neurologic sequelae. This review summarizes the current knowledge on epidemiology, pathology, clinical presentation, neuroimaging features, CSF findings, differential diagnosis, therapy, and outcome, with a focus on recent advances and controversies.

The emotional and behavioral problems associated with pediatric multiple sclerosis remain unclear. Participants with pediatric multiple sclerosis or clinically isolated syndrome (n = 140; ages 5-18 years) completed self- and parent ratings using the Behavioral Assessment System for Children, Second Edition, neurologic exam, the Fatigue Severity Scale, and neuropsychological assessment. Mean self- and parent-ratings on the Behavioral Assessment System for Children, Second Edition, were in the typical range across all scales. However, 33.1% indicated a clinically significant problem on a least 1 scale. Although the type of clinical problems varied across participants, attention problems, somatization, and anxiety were found to be most common. Disease features including duration, age of onset, neurologic disability, and fatigue did not distinguish those with and without clinical problems. However, cognitive functioning significantly predicted the presence of a clinical problem (P = .02). Pediatric multiple sclerosis is associated with a range of nonspecific emotional and behavioral clinical problems, occurring more frequently in those patients with cognitive involvement.

OBJECTIVES: To describe the demographic and clinical characteristics of pediatric multiple sclerosis (MS) in the United States. METHODS: This prospective observational study included children and adolescents with MS. Cases were evaluated across 9 geographically diverse sites as part of the US Network of Pediatric MS Centers. RESULTS: A total of 490 children and adolescents (324 girls, 166 boys) were enrolled; 28% developed symptoms before 12 years of age. The proportion of girls increased with age from 58% (<12 years) to 70% (>/=12 years). Race and ethnicity as self-identified were: white, 67%; African American, 21%; and non-Hispanic, 70%. Most (94%) of the cases were born in the United States, and 39% had 1 or both foreign-born parents. Fifty-five percent of cases had a monofocal presentation; 31% had a prodrome (most frequently infectious), most often among those aged <12 years (P < .001). Children aged <12 years presented more commonly with encephalopathy and coordination problems (P < .001). Sensory symptoms were more frequently reported by older children (ie, those aged >/=12 years) (P < .001); 78% of girls had MS onset postmenarche. The initial Expanded Disability Status Scale score for the group was <3.0, and the annualized relapse rate was 0.647 for the first 2 years. Interval from symptom onset to diagnosis and from diagnosis to initiation of disease-modifying therapy was longer among those <12 years of age. CONCLUSIONS: Pediatric MS in the United States is characterized by racial and ethnic diversity, a high proportion of children with foreign-born parents, and differences in clinical features and timing of treatment among those <12 years of age compared with older children.

We explored the association between baseline gut microbiota (16S rRNA biomarker sequencing of stool samples) in 17 relapsing-remitting pediatric MS cases and risk of relapse over a mean 19.8 months follow-up. From the Kaplan-Meier curve, 25% relapsed within an estimated 166 days from baseline. A shorter time to relapse was associated with Fusobacteria depletion (p=0.001 log-rank test), expansion of the Firmicutes (p=0.003), and presence of the Archaea Euryarchaeota (p=0.037). After covariate adjustments for age and immunomodulatory drug exposure, only absence (vs. presence) of Fusobacteria was associated with relapse risk (hazard ratio=3.2 (95% CI: 1.2-9.0), p=0.024). Further investigation is warranted. Findings could offer new targets to alter the MS disease course.

BACKGROUND: High salt intake may be associated with pro-inflammatory changes in the immune response, and increased clinical and MRI activity in adults with relapsing-remitting multiple sclerosis. OBJECTIVE: We sought to determine if dietary salt intake is associated with pediatric-onset MS risk in a multicenter, case-control study. METHODS: Pediatric-onset CIS/MS cases within four years of onset and controls less than 22 years old recruited from 14 pediatric-MS centers were studied. Dietary sodium intake was assessed using the validated Block Kids Food Screener (NutritionQuest). Sodium intake, excess sodium, and sodium terciles were compared between cases and controls. Logistic regression models were adjusted for age, gender, ethnicity, body mass index, and socioeconomic status. RESULTS: Among 170 cases (mean age=15.2+/-3.5) and 331 controls (mean age=14.0+/-3.7), no significant difference in unadjusted mean sodium intake was found between cases (2044mg/d) and controls (2030mg/d, p=0.99). The proportion of subjects consuming excess sodium, based on the adequate intake for age and gender, was similar between cases and controls (65% versus 69%, p=0.34). There were no increased odds of higher sodium intake among cases as compared to controls (for each 100mg/d increase in sodium, OR=1.00, 95% CI 0.98, 1.02; p=0.93, for excess sodium intake, OR=1.05, 95% CI 0.67, 1.64; p=0.84). CONCLUSIONS: Our results show no strong association between dietary salt intake and pediatric-onset MS risk, suggesting that salt intake may not play a prominent role in susceptibility to MS in children.

OBJECTIVE: To compare clinical features of pediatric neuromyelitis optica (NMO) to other pediatric demyelinating diseases. METHODS: Review of a prospective multicenter database on children with demyelinating diseases. Case summaries documenting clinical and laboratory features were reviewed by an adjudication panel. Diagnoses were assigned in the following categories: multiple sclerosis (MS), acute disseminated encephalomyelitis, NMO, and recurrent demyelinating disease not otherwise specified. RESULTS: Thirty-eight cases of NMO were identified by review panel, 97% of which met the revised International Panel on NMO Diagnosis NMO-SD 2014 criteria, but only 49% met 2006 Wingerchuk criteria. Serum or CSF NMO immunoglobulin G (IgG) was positive in 65% of NMO cases that were tested; however, some patients became seropositive more than 3 years after onset despite serial testing. No patient had positive CSF NMO IgG and negative serum NMO IgG in contemporaneous samples. Other than race (p = 0.02) and borderline findings for sex (p = 0.07), NMO IgG seropositive patients did not differ in demographic, clinical, or laboratory features from seronegatives. Visual, motor, and constitutional symptoms (including vomiting, fever, and seizures) were the most common presenting features of NMO. Initiation of disease-modifying treatment was delayed in NMO vs MS. Two years after onset, patients with NMO had higher attack rates, greater disability accrual measured by overall Expanded Disability Status Scale score, and visual scores than did patients with MS. CONCLUSION: The new criteria for NMO spectrum disorders apply well to the pediatric setting, and given significant delay in treatment of NMO compared to pediatric MS and worse short-term outcomes, it is imperative to apply these to improve access to treatment.