Neuropsychological outcomes of pediatric demyelinating diseases: a review

The Impact of Neuroimmunologic Disease and Developing Nervous System

Over the last two decades, neuroimmunologic disorders of childhood have been increasingly described, phenotyped, and treated. These disorders remain rare in the general population and while sharing common therapeutic interventions due to their immune pathophysiology, are heterogeneous with regard to presentation and risk of recurrence. As such, the impact of these disorders on the developing brain has come into the forefront of emerging research in pediatric neuroimmunology. Investigations into the singular impact of monophasic disease on long-term development and the impact of early and aggressive disease-modifying therapy in relapsing conditions are quickly becoming areas of ripe investigation as the field's most optimal way to treat and monitor these conditions over time. Although critically important in evaluating the developing brain, research has been heterogeneous among these diseases and limited by small cohort size. This narrative review details the role of common neuroimmunologic disorders in long-term neurological and cognitive outcomes in children as they develop.

Evaluation, Treatment, and Outcomes of Viral and Autoimmune Encephalitis in Children

Viral encephalitis and autoimmune encephalitis are currently the most common causes of encephalitis. Determining the causative agent is helpful in initiating medical treatment that may help reduce long-term sequelae. Cerebrospinal fluid, neuroimaging, serologic, and electroencephalogram in combination with clinical manifestations play a role in determining the cause of the encephalitis. Although motor dysfunction tends to improve, there is a significant risk of long-term neurologic and cognitive sequelae. These persistent deficits that occur in childhood indicate the importance for ongoing rehabilitative services to maximize functional skills, improve cognitive deficits, and assist with community integration.

Neuropsychological Phenotypes of Pediatric Anti-Myelin Oligodendrocyte Glycoprotein Associated Disorders: A Case Series

Emerging research has demonstrated that anti-myelin oligodendrocyte associated disorders (MOG-AD) are associated with a less severe clinical course than demyelinating conditions associated with the presence of aquaporin-4 antibodies. While a heterogeneity of neuropsychological outcomes in pediatric demyelinating conditions have been described in the literature, no studies to date have investigated the neuropsychological sequelae of pediatric MOG-AD specifically. The objective of the present case series was to describe the clinical and neuropsychological phenotypes of seven pediatric patients (ages 3-15 years) with MOG-AD of different diagnoses (e.g., acute disseminated encephalomyelitis, optic neuritis, multiple sclerosis, and neuromyelitis spectrum disorders). Neuropsychological outcomes were evaluated by retrospective chart review. Results indicated largely intact neuropsychological profiles in five of the seven patients, with mild weaknesses in attention, executive functioning, processing speed, visual-motor/fine-motor skills, and mood concerns being observed. Two patients with a Kurtzke Extended Disability Status Scale of 0 still demonstrated findings on neuropsychological testing. Of the other two patients, one demonstrated higher levels of impairment in the context of a complex medical history and premorbid learning difficulties, while the other demonstrated declines in functioning likely associated with an earlier age of onset. Findings suggest that neuropsychological outcomes may be correspondingly less severe in this population compared with what has previously been described in the pediatric demyelinating disease literature. This differential impact may contribute to the heterogeneity of neuropsychological outcomes found in previous studies, and future research should separate participants with myelin oligodendrocyte antibodies given the difference in clinical course, treatment outcomes, and neuropsychological sequelae.

Therapeutic potential of the target on NLRP3 inflammasome in multiple sclerosis

Inflammasomes are multi-protein macromolecular complexes that typically comprise of three units, a sensor, an adaptor and procaspase-1. The assembly of each inflammasome is dictated by a unique pattern recognition receptors (PRRs) in response to pathogen-associated molecular patterns (PAMPs) or other endogenous danger-associated molecular patterns (DAMPs) in the cytosol of the host cells, and promote the maturation and secretion of IL-1β and IL-18 during the inflammatory process. Specific inflammasomes are involved in the host defense response against different pathogens, and the latter have evolved multiple corresponding mechanisms to inhibit inflammasome activation. The nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome is the best understood in terms of molecular mechanisms, and is a promising therapeutic target in immune-related disorders. Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demyelination of white matter in the central nervous system, increased levels of IL-1β in the cerebrospinal fluid (CSF) of relapsed patients, and deposition of caspase-1 in the spinal cord. The direct involvement of the NLRP3 inflammasome in the occurrence and development of MS was ascertained in the experimental autoimmune encephalomyelitis (EAE) animal model. In this review, we have focused on the mechanisms underlying activation of the NLRP3 inflammasome in MS or EAE, as well as inhibitors that specifically target the complex and alleviate disease progression, in order to unearth new therapeutic strategies against MS.

Psychosocial impact of paediatric demyelinating disorders: a scoping review

AIM

To: (1) provide greater insight into the psychological and social impact of a range of demyelinating disorders, (2) explore differences between disorders, and (3) provide direction for future research.

METHOD

Studies were identified by searching online databases. Studies that explored the psychological, emotional, or social impact of a range of demyelinating disorders in childhood, including acute disseminated encephalomyelitis (ADEM), optic neuritis, transverse myelitis, and multiple sclerosis, were included and screened independently by three authors. Data on the design, sample characteristics, psychosocial measures, key findings, and methodological strengths and limitations were extracted. Twenty-five studies were included in the narrative synthesis.

RESULTS

Demyelinating disorders are associated with lower quality of life, affecting young people's emotional, social, school, and behavioural functioning. There is a high prevalence of psychiatric disorders and fatigue, particularly in multiple sclerosis. Subtle differences exist in the psychological presentation between different demyelinating disorders, with clear gaps in the research for the long-term psychosocial impact of monophasic conditions.

INTERPRETATION

The difference between the impact of monophasic and relapsing demyelinating disorders on psychosocial functioning is unclear. Future research should aim to identify the psychosocial impact across disorders and over time, ensure that services are capturing those patients who may benefit from tailored interventions.

WHAT THIS PAPER ADDS

Prevalence of psychiatric diagnoses in paediatric demyelinating disorders is higher than controls. Depression and emotional concerns are elevated in paediatric demyelinating disorders. Demyelinating disorders impact children's quality of life across school, social, and physical functioning.

Serial neuropsychological testing in MOG antibody-associated disease to improve understanding of outcomes

Neurocognitive outcomes data in patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease are limited. Within MOG-positive cohorts, outcomes data typically utilize gross psychological, cognitive, or physical disability measures. Here, we report a pediatric patient who presented with two clinically heterogeneous events and was found to have MOG-associated encephalomyelitis. We administered detailed neuropsychological test batteries to obtain a robust understanding of the patient's neurocognitive profile over time. This case exemplifies the need to perform systematic and serial neuropsychological testing in patients with MOG-associated disease to better understand neurocognitive outcomes, facilitate multidisciplinary management, and improve recovery.

The Multiple Sclerosis Inventory of Cognition for Adolescents (MUSICADO): A brief screening instrument to assess cognitive dysfunction, fatigue and loss of health-related quality of life in pediatric-onset multiple sclerosis

OBJECTIVE

Screening for cognitive impairment (CI), fatigue and also Health-related quality of life (HRQoL) in patients with pediatric-onset multiple sclerosis (POMS) is of utmost importance in clinical practice. The aim of this study was to establish a new and validated pediatric screening tool "MUSICADO" that is easy to use and time economical.

METHODS

106 patients with POMS aged 12-18 years and 210 healthy controls (HCs) stratified for age and education underwent neuropsychological testing including a screening test "Multiple Sclerosis Inventory of Cognition" for adults and 8 standardized cognitive tests and established scales to assess fatigue and HRQoL.

RESULTS

The phonemic verbal fluency task (RWT "s-words"), the Trail Making Test A (TMT-A), and the Digit Span Forward discriminated significantly between patients and HCs (p = 0.000, respectively) and showed the highest proportion of test failure in patients (24.5%, 17.9%; 15.1%, respectively). Therefore, they were put together to form the cognitive part of the "MUSICADO". After applying a scoring algorithm with balanced weighting of the subtests and age and education correction and a cut-off score for impairment, 35.8% of patients were categorized to be cognitively impaired (specificity: 88.6%). Fatigue was detected in 37.1% of the patients (specificity: 94.0%) and loss of HRQoL in 41.8% (specificity 95.7%) with the screening version, respectively.

CONCLUSION

The MUSICADO is a newly designed brief and easy to use screening test to help to early identify CI, fatigue, and loss of HRQoL in patients with POMS as cut scores are provided for all three items. Further studies will have to show its usability in independent samples of patients with POMS.

Pronounced Structural and Functional Damage in Early Adult Pediatric-Onset Multiple Sclerosis with No or Minimal Clinical Disability

Pediatric-onset multiple sclerosis (POMS) may represent a model of vulnerability to damage occurring during a period of active maturation of the human brain. Whereas adaptive mechanisms seem to take place in the POMS brain in the short-medium term, natural history studies have shown that these patients reach irreversible disability, despite slower progression, at a significantly younger age than adult-onset MS (AOMS) patients. We tested for the first time whether significant brain alterations already occurred in POMS patients in their early adulthood and with no or minimal disability (n = 15) in comparison with age- and disability-matched AOMS patients (n = 14) and to normal controls (NC, n = 20). We used a multimodal MRI approach by modeling, using FSL, voxelwise measures of microstructural integrity of white matter tracts and gray matter volumes with those of intra- and internetwork functional connectivity (FC) (analysis of variance, p ≤ 0.01, corrected for multiple comparisons across space). POMS patients showed, when compared with both NC and AOMS patients, altered measures of diffusion tensor imaging (reduced fractional anisotropy and/or increased diffusivities) and higher probability of lesion occurrence in a clinically eloquent region for physical disability such as the posterior corona radiata. In addition, POMS patients showed, compared with the other two groups, reduced long-range FC, assessed from resting functional MRI, between default mode network and secondary visual network, whose interaction subserves important cognitive functions such as spatial attention and visual learning. Overall, this pattern of structural damage and brain connectivity disruption in early adult POMS patients with no or minimal clinical disability might explain their unfavorable clinical outcome in the long term.