Trends and tenets in relapsing and progressive opsoclonus-myoclonus syndrome

Five Years Follow-up of Opsoclonus-Myoclonus-Ataxia Syndrome-Associated Neurogenic Tumors in Children

AIM

 Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare autoimmune disorder. Approximately half of the cases are associated with neuroblastoma in children. This study's aim is to review management of our cases with OMAS-associated neuroblastoma for treatment approach as well as long-term follow-up.

METHODS

 Age at onset of symptoms and tumor diagnosis, tumor location, histopathology, stage, chemotherapy, OMAS protocol, surgery, and follow-up period were evaluated retrospectively in six patients between 2007 and 2022.

RESULTS

 Mean age of onset of OMAS findings was 13.5 months and mean age at tumor diagnosis was 15.1 months. Tumor was located at thorax in three patients and surrenal in others. Four patients underwent primary surgery. Histopathological diagnosis was ganglioneuroblastoma in three, neuroblastoma in two, and undifferentiated neuroblastoma in one. One patient was considered as stage 1 and rest of them as stage 2. Chemotherapy was provided in five cases. The OMAS protocol was applied to five patients. Our protocol is intravenous immunoglobulin (IVIG) 1 g/kg/d for 2 consecutive days once a month and dexamethasone for 5 days (20 mg/m2/d for 1-2 days, 10 mg/m2/d for 3-4 days, and 5 mg/m2/d for the fifth day) once a month, alternatively by 2-week intervals. Patients were followed up for a mean of 8.1 years. Neuropsychiatric sequelae were detected in two patients.

CONCLUSION

 In tumor-related cases, alternating use of corticosteroid and IVIG for suppression of autoimmunity as the OMAS protocol, total excision of the tumor as soon as possible, and chemotherapeutics in selected patients seem to be related to resolution of acute problems, long-term sequelae, and severity.

Neuroblastic Tumor Recurrence Associated With Opsoclonus Myoclonus Ataxia Syndrome Relapse a Decade After Initial Resection and Treatments

Opsoclonus myoclonus ataxia syndrome (OMAS) is a rare disorder that causes significant neurodevelopmental sequelae in children. Approximately half of pediatric OMAS cases are paraneoplastic, typically associated with localized neuroblastic tumors. Since early persistence or relapse of OMAS symptoms is common even after tumor resection, OMAS relapses may not routinely prompt reevaluation for recurrent tumors. We report a 12-year-old girl with neuroblastic tumor recurrence associated with OMAS relapse a decade after initial treatment. Providers should be aware of tumor recurrence as a trigger for distant OMAS relapse, raising intriguing questions about the role of immune surveillance and control of neuroblastic tumors.

Clinical features and outcomes of opsoclonus myoclonus ataxia syndrome

OBJECTIVES AND METHODS

Opsoclonus myoclonus ataxia syndrome (OMAS) is a rare neuroinflammatory disorder. We aimed to retrospectively evaluate clinical and laboratory data and outcomes of 23 children diagnosed with OMAS in two children's hospitals between 2010 and 2021.

RESULTS

There were 14 boys and 9 girls aged 4-113 months, median 24 months. Ten (43.5%) children had paraneoplastic causes: neuroblastoma/ganglioneuroblastoma (n = 9), acute lymphoblastic leukemia (n = 1). Three children had a postinfectious cause (upper respiratory tract infection in 2, EBV infection in 1) and two had a history of vaccination (varicella in 1, hepatitis A and meningococcal in 1). No underlying factor was identified in 8 (34.8%) children. Speech disorders were more frequent in patients with neural tumors than in those without (p = 0.017). Intravenous immunoglobulin and steroids were effective as initial treatment in most children. Rituximab resulted in at least mild improvement in all 6 children with persistent or recurrent symptoms. Nine (39%) children experienced at least one relapse. Neurological sequelae were detected in 13 (57%) children. There was no significant correlation between clinical characteristics and outcome, except for higher risk of relapse in case of incomplete recovery after first attack (p = 0.001).

CONCLUSIONS

Acute lymphoblastic leukemia, vaccines against hepatitis A and meningococci can be included among antecedent factors in OMAS. Among clinical symptoms, speech problems might point to the likelihood of an underlying neoplasm in OMAS. Intravenous immunoglobulin and steroids may be chosen for initial treatment while rituximab can increase the chance of recovery in case of persistent or recurrent symptoms. The presence of relapse was associated with poor outcome.

Monocentric retrospective clinical outcome in a group of 13 patients with opsoclonus myoclonus syndrome, proposal of diagnostic algorithm and review of the literature

BACKGROUND

Dancing eye syndrome or opsoclonus-myoclonus syndrome (OMS) is a very rare disease (incidence <1/5,000,000 per year), which is more prevalent in young children. Although it is not usually a cause of mortality, the aftermaths are not rare.

METHODS

We performed an observational retrospective review of children diagnosed with OMS in our neuropediatric department from 1996 to 2020, with the objective of assessing the prognostic value of initial clinical features. All medical data from diagnosis to last follow-up were reviewed. We defined unfavorable evolution of OMS as persistence or worsening of symptoms. Subsequently, based on a literature review, our results and experience, a diagnostic algorithm was developed.

RESULTS

A total of 13 OMS patients were included: 61.5% were male (n = 8), median age at diagnosis was 18 months (IR = 76), median treatment delay was 14 days (IR = 146) and OMS score at onset was 8 (IR = 11). The most frequent etiologies were neuroblastoma-associated and idiopathic OMS (38.46%; n = 5) of the patients, followed by post-infectious OMS (n = 3). All the patients were treated with corticosteroids, five required a surgical intervention (neuroblastoma group), and three required adjunctive immune therapy (immunoglobulins, cyclophosphamide and/or rituximab). We detected neurodevelopmental disorders in 38.46% (n = 5) of the patients, mainly attention deficit (n = 4), and persistent sleep disturbances (n = 4). The median OMS score at the end of follow-up was 1 (IR = 3). An important diagnostic delay, OMS score of ≥10 and age >1 year at onset may correlate with a higher risk of aftermaths. We detected a better prognosis in the post-infectious OMS, with full recovery occurring in 2/3 of patients.

CONCLUSIONS

Early clinical suspicion is key to guarantee maximum response of treatment.

Profile and Outcome of Children with Opsoclonus Myoclonus Ataxia: A Tertiary Care Hospital Experience from India

Opsoclonus myoclonus ataxia syndrome (OMAS) is a rare but treatable, often paraneoplastic neuroimmunologic condition. This is a retrospective chart review of 8 patients diagnosed in the past 11 years at a tertiary care hospital. The mean age of children with OMAS was 21.2 ± 8 months. There was a female preponderance (62.5%). Median symptom duration was 24.5 days (interquartile range [IQR] 12.7; 97.5). All patients had ataxia and irritability; 6 had opsoclonus.

An underlying neurogenic tumor was identified in 87.5% (⅞) of the patients by computed tomography (CT)/magnetic resonance imaging. Neuroblastoma was detected in ⅘ with normal 24-hour urinary vanillylmandelic acid and 2 had negative metaiodobenzylguanidine scan.

All patients received adrenocorticotropic hormone/steroids for a median of 9.5 months (IQR 5.3; 13.5) with clonazepam. Five received intravenous immunoglobulin (IVIG), including repeated cycles in ⅘. Two received rituximab. One child with relapsing-remitting course received pulse dexamethasone and cyclophosphamide, resulting in improvement. Clonazepam restored ambulation in one with delayed diagnosis and failure of response to steroids. Six patients underwent tumor resection and four needed chemotherapies.

Median follow-up was 15 months (IQR 10.7; 23.2). Mean OMAS-severity scale reduced from 10 to 1.4 in the IVIG group and 10.6 to 5.3 in those who did not receive IVIG. Cognitive delay and behavioral issues were seen in 100% treated with steroids only; 50 and 25%, respectively, treated with multimodal immunotherapy. Five had relapses, one with tumor recurrence.

Thorax and abdomen CT scan was found to be a sensitive tool for tumor detection. Better motor and cognitive behavioral outcome were noted in patients who received adjunctive IVIG.

Future studies on optimum investigation and treatment protocol in various resource settings are needed.

Diagnosis and Management of Opsoclonus-Myoclonus-Ataxia Syndrome in Children: An International Perspective

BACKGROUND AND OBJECTIVES

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare disorder of the nervous system that classically presents with a combination of characteristic eye movement disorder and myoclonus, in addition to ataxia, irritability, and sleep disturbance. There is good evidence that OMAS is an immune-mediated condition that may be paraneoplastic in the context of neuroblastoma. This syndrome may be associated with long-term cognitive impairment, yet it remains unclear how this is influenced by disease course and treatment. Treatment is largely predicated on immune suppression, but there is limited evidence to indicate an optimal regimen.

METHODS

Following an international multiprofessional workshop in 2004, a body of clinicians and scientists comprising the International OMS Study group continued to meet biennially in a joint professionals and family workshop focusing on pediatric OMAS. Seventeen years after publication of the first report, a writing group was convened to provide a clinical update on the definitions and clinical presentation of OMAS, biomarkers and the role of investigations in a child presenting with OMAS, treatment and management strategies including identification and support of long-term sequelae.

RESULTS

The clinical criteria for diagnosis were reviewed, with a proposed approach to laboratory and radiologic investigation of a child presenting with possible OMAS. The evidence for an upfront vs escalating treatment regimen was reviewed, and a treatment algorithm proposed to recognize both these approaches. Importantly, recommendations on monitoring of immunotherapy response and longer-term follow-up based on an expert consensus are provided.

DISCUSSION

OMAS is a rare neurologic condition that can be associated with poor cognitive outcomes. This report proposes an approach to investigation and treatment of children presenting with OMAS, based on expert international opinion recognizing the limited data available.

Autosomal dominant ADAR c.3019G>A (p.(G1007R)) variant is an important mimic of hereditary spastic paraplegia and cerebral palsy

BACKGROUND

The type 1 interferonopathy, Aicardi-Goutières syndrome 6 (AGS6), is classically caused by biallelic ADAR mutations whereas dominant ADAR mutations are associated with dyschromatosis symmetrica hereditaria (DSH). The unique dominant ADAR c.3019G>A variant is associated with neurological manifestations which mimic spastic paraplegia and cerebral palsy (CP).

CASE SUMMARIES

We report three cases of spastic paraplegia or CP diagnosed with AGS6 caused by the ADAR c.3019G>A variant. Two children inherited the variant from an asymptomatic parent, and each child had a different clinical course. The youngest case demonstrated relentless progressive symptoms but responded to immunomodulation using steroids and ruxolitinib.

CONCLUSION

The ADAR c.3019G>A variant has incomplete penetrance and is a likely underrecognized imitator of spastic paraplegia and dystonic CP. A high level of clinical suspicion is required to diagnose this form of AGS, and disease progression may be ameliorated by immunomodulatory treatment with selective Janus kinase inhibitors.

Opsoclonus-Myoclonus Syndrome in Children and Adolescents: A Therapeutic Challenge

Opsoclonus-myoclonus syndrome (OMS) is a neurological non-fatal disease that usually responds to immunotherapies. However, the real challenge is to counteract the high frequency of relapses and long-term developmental sequelae. Since the OMS is extremely rare, a common consensus regarding therapeutic guidelines is still lacking. The goals of this study were to test whether ACTH was superior to other immunotherapies and to investigate whether an early treatment could improve the outcome. Sixteen children affected by OMS were retrospectively reviewed. Eight children had a neuroblastic tumor. The other eight patients were affected by non-paraneoplastic OMS. Overall, the most commonly used treatment was corticotherapy (n = 11). However, ACTH (n = 10), rituximab (n = 7), immunoglobulins (n = 4), cyclophosphamide (n = 3), and mycophenolate (n = 2) were also administered. ACTH was associated with a high percentage of patients who healed (80%) and, as a first-line therapy, was associated with a lower incidence of relapses. An early treatment was associated with a favorable long-term outcome. Long-term sequelae occurred in 42% of patients who were treated early and in all of those who were treated late. It is advisable for the affected children to be identified at an early time, as they may benefit from an early treatment. ACTH represents an effective treatment with a high probability of recovery and low rate of relapses.

Opsoclonus-myoclonus-ataxia syndrome in children

Opsoclonus-myoclonus-ataxia syndrome is a rare neuroimmunologic disorder typically presenting in previously healthy infants and toddlers. It is characterized by a clinical triad of (1) erratic saccadic intrusions; (2) myoclonus and/or ataxia; (3) behavioral features, typified by developmental plateauing, irritability and insomnia. About half of cases are associated with an underlying neuroblastoma and diagnostic imaging is essential once OMAS is suspected. A thorough workup, including serum, urine, and cerebrospinal fluid studies is critical to identify underlying biomarkers of OMAS itself or neuroblastoma. Historically, many children had relatively poor long-term outcomes, with residual neurologic and/or neuropsychiatry sequelae typical. More recent concepts have emphasized combined immunotherapy regimens that offer hope for better outcomes in children with this remarkable, challenging disease.

Immunotherapy responsive SARS-CoV-2 infection exacerbating opsoclonus myoclonus syndrome

The global pandemic of SARS-CoV-2 has been known to have diverse neurologic complications among adult patients. The neurologic effects of SARS-CoV-2 in the pediatric population is poorly described, especially in those with rare underlying neurologic conditions. We describe the first known case of SARS-CoV-2 in a pediatric patient with refractory opsoclonus-myoclonus syndrome. A 25-month-old female with progressive opsoclonus-myoclonus syndrome secondary to metastatic neuroblastoma status-post resection and chemotherapy presented with worsening opsoclonus, tremor, and breakthrough seizures. She had no fever or respiratory symptoms at presentation. Urine catecholamines were unchanged, with low suspicion for tumor recurrence. She was found to have SARS-CoV-2 via nasopharnygeal PCR assay. She received intravenous immunoglobulin and dexamethasone therapy with improvement in opsoclonus-myoclonus syndrome symptoms and was discharged home at her neurologic baseline. Patients with opsoclonus-myoclonus syndrome may present with exacerbation of symptoms in the context of SARS-CoV-2. This case describes a sentinel report of a child with opsoclonus-myoclonus syndrome presenting with worsening symptoms with concomitant SARS-CoV-2. Improvement in symptoms was achieved with standard of care therapies.

IQ predictors in pediatric opsoclonus myoclonus syndrome: a large international cohort study

AIM

To determine predictors of full-scale IQ (FSIQ) in an international pediatric opsoclonus myoclonus syndrome (OMS) cohort.

METHOD

In this retrospective and prospective cohort study at three academic medical centers (2006-2013), the primary outcome measure, FSIQ, was categorized based on z-score: above average (≥+1), average (+1 to -1), mildly impaired (-1 to -2), and impaired (<-2). Univariate analysis and multivariable linear regression modeling using stepwise selection with Akaike's information criterion was performed to understand the relationship between exposures and FSIQ.

RESULTS

Of 81 participants, 37 with sufficient data had mean FSIQ 84.38 (SD 20.55) and median 90 (40-114) at latest available evaluation (mean age 8y 5mo). Twenty (54%), nine (24.3%), and eight (21.6%) had normal, mildly impaired, and impaired FSIQ respectively. The final multivariable linear regression model included 34 participants with evaluable data: number of relapses occurring before neuropsychological testing (p<0.001) and OMS severity score at last follow-up (p<0.001) predicted FSIQ (adjusted R² =0.64). There was a mean decrease of 2.4 FSIQ points per OMS relapse.

INTERPRETATION

Number of relapses negatively correlates with FSIQ in pediatric OMS. Demographic and clinical measures available at OMS onset did not predict FSIQ. Strategies to reduce OMS relapses may improve intellectual outcomes.

The Treatment of Opsoclonus-Myoclonus Syndrome Secondary to Neuroblastic Tumours-Single-Centre Experience and Literature Review

Background and Objectives: The opsoclonus-myoclonus syndrome (OMS) is characterised by opsoclons, myoclons and impaired balance, often concomitant with sleep disorder and behavioural difficulties. The symptoms develop as a result of autoimmune response triggered by a neuroblastic tumour (NT). OMS can also develop secondarily to a viral infection or as an immune response triggered by an unknown agent. This leads to the activation of B- and T-cells, which produce and release autoantibodies or cytokines directly within the central nervous system (CNS), thus damaging the neurons within the cerebellum and the brain stem. The available OMS treatments aim at decreasing lymphocyte, cytokine and autoantibody production or accelerating the utilisation of the latter. Another treatment option for OMS involves using cytostatic agents, which damage T- and B-cells causing their depletion and impaired function, which reduces their ability to produce antibodies and cytokines. Materials and Methods: We present a single-centre experience in treating OMS secondary to NT in 7 children. Results: The combined treatment with cyclophosphamide plus dexamethasone resulted in a complete resolution of OMS symptoms in 4 children, and a significant improvement in the 3 children. Two of them periodically present hyperactivity, and one girl requires an additional support at school due to special educational needs (SEN). Conclusions: NT resection does not resolve OMS in children with OMS secondary to NT. The combined treatment with dexamethasone plus cyclophosphamide seems to be an effective treatment of OMS.

Opsoclonus-myoclonus syndrome: clinical characteristics, therapeutic considerations, and prognostic factors in a Spanish paediatric cohort

INTRODUCTION

Opsoclonus-myoclonus-ataxia syndrome is a rare neuroinflammatory disorder with onset during childhood; aetiology may be paraneoplastic, para-infectious, or idiopathic. No biomarkers have yet been identified, and diagnosis is clinical. Better cognitive prognosis appears to be related to early onset of immunomodulatory therapy.

METHODS

We describe the epidemiological, clinical, therapeutic, and long-term prognostic characteristics of a cohort of 20 Spanish patients.

RESULTS

The mean age of onset was 21 months (range, 2-59). Ataxia and opsoclonus were the most frequent symptoms both at disease onset and throughout disease progression. The mean time from onset to diagnosis was 1.1 months. Neuroblast lineage tumours were detected in 45% of patients; these were treated with surgical resection in 7 cases and chemotherapy in 2. Cerebrospinal fluid analysis revealed pleocytosis in 4 cases (25%) and neither antineuronal antibodies nor oligoclonal bands were detected in any patient. Immunomodulatory drugs were used in all cases. Nine patients started combined immunomodulatory treatment at the time of diagnosis, and 5 patients after a mean of 2.2 months. In the long term, 6 of the 10 patients followed up for more than 5 years presented mild or moderate cognitive sequelae. Four patients presented relapses, generally coinciding with the decrease of corticosteroid doses.

CONCLUSIONS

Early initiation of immunotherapy, as well as triple combination therapy, where needed, was associated with a lower frequency of cognitive impairment 2 years after onset.

Standardised guidelines and reference networks for treating neuroinflammatory conditions in children are lacking

AIM

To investigate whether local or national guidelines are used in treating neuroinflammatory conditions in children and if there is a perceived need for more guidelines and forums of cooperation.

METHODS

A web-based questionnaire sent to all university hospitals in the Nordic countries (n = 21) between March and July 2015.

RESULTS

All 21 centres replied to the survey. Markers of neuronal or glial damage and markers of inflammation were used at varying rates. Neuronal antibodies were used at all sites except two. Only three hospitals collaborated with their laboratories in developing new assays for biomarkers. Although most centres used some form of guideline for neuroinflammatory conditions, no single disease had a guideline prevalence over 60%. For some diagnoses, access to guidelines was as low as 10%. Standardised follow-up programs were lacking in 50-95%. A clear majority of the centres perceived a need for more guidelines. Also, forums of cooperation were few. However, there was a great interest in developing paediatric neuroinflammatory guidelines and to create platforms for further consensus work and discussion.

CONCLUSION

There is a need for developing treatment guidelines within the field of paediatric neuroinflammation to aid in clinical decision-making, and to establish forums of cooperation.

Current therapies and therapeutic decision making for childhood-onset movement disorders

Movement disorders differ in children to adults. First, neurodevelopmental movement disorders such as tics and stereotypies are more prevalent than parkinsonism, and second, there is a genomic revolution which is now explaining many early-onset dystonic syndromes. We outline an approach to children with movement disorders starting with defining the movement phenomenology, determining the level of functional impairment due to abnormal movements, and screening for comorbid psychiatric conditions and cognitive impairments which often contribute more to disability than the movements themselves. The rapid improvement in our understanding of the etiology of movement disorders has resulted in an increasing focus on precision medicine, targeting treatable conditions and defining modifiable disease processes. We profile some of the key disease-modifying therapies in metabolic, neurotransmitter, inflammatory, and autoimmune conditions and the increasing focus on gene or cellular therapies. When no disease-modifying therapies are possible, symptomatic therapies are often all that is available. These classically target dopaminergic, cholinergic, alpha-adrenergic, or GABAergic neurochemistry. Increasing interest in neuromodulation has highlighted that some clinical syndromes respond better to DBS, and further highlights the importance of "disease-specific" therapies with a future focus on individualized therapies according to the genomic findings or disease pathways that are disrupted. We summarize some pragmatic applications of symptomatic therapies, neuromodulation techniques, and some rehabilitative interventions and provide a contemporary overview of treatment in childhood-onset movement disorders. © 2019 International Parkinson and Movement Disorder Society.

[Psychological development of children with opsoclonus myoclonus syndrome and its correlation with age and disease onset]

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder with unknown etiology and pathogenesis. There is not enough knowledge about psychological development of children with OMS.

AIM

To study an influence of the time of disease onset and children's age and type of disease course on psychological development of children with OMS.

MATERIAL AND METHODS

The study included 26 children with OMS of age between 1 year 7 months and 13 years, 10 boys and 16 girls. The following methods were used: analysis of patient's development records, psychological interview with parents, assessment of emotional, behavioral, motion state and interpersonal relations.

RESULTS AND CONCLUSION

The disease onset at the early stage of ontogenesis (before 3 years) results into severe psychological disorders. Patients at the age between 3 and 5 years demonstrate the maximal number of developmental delays with possibilities of compensation. The article discusses a possible role of psychotraumatic and psychosocial factors in psychological disorders in children with OMS. The influence of age should be taken into account in planning of treatment and rehabilitation and evaluation of disease prognosis.

Evaluation of Responsiveness to Reduced-Dose Rituximab in Corticotropin/Intravenous Immunoglobulin/Rituximab Combination Immunotherapy for Opsoclonus-Myoclonus Syndrome

BACKGROUND

Rituximab (anti-CD20) has been used as B-cell-targeted intervention to treat opsoclonus-myoclonus syndrome. Due to isolated reports of chronic hypogammaglobulinemia and B lymphopenia following rituximab in several disorders, and rapid B-cell depletion after a few doses, we reduced the dosage 20% in our clinical practice.

METHODS

In this Institutional Review Board-approved retrospective study, 32 children with opsoclonus-myoclonus syndrome and cerebrospinal fluid B-cell expansion had received front-loaded adrenocorticotropic hormone, intravenous immunoglobulin, and rituximab combination immunotherapy for de novo opsoclonus-myoclonus syndrome. Parametric statistical analysis compared 10 children receiving 1200 mg/m² of rituximab (300 mg/m² × 4) and 22 receiving 1500 mg/m² (375 mg/m² × 4). Clinical response had been video documented and scored by a blinded observer.

RESULTS

In both groups, motor severity (total score) lessened by ≥76% and cerebrospinal fluid B cells were similarly depleted (≥95%) six months after treatment. None of the treated patients remained unable to walk independently. Serum IgM depletion was analogous in the 1200 mg/m² (-73%) and 1500 mg/m² group (-64%). The relapse frequency was similar in both groups. Side effects were principally steroidal, tolerable, and transient. Circulating B-cell repopulation was comparable.

CONCLUSIONS

The reduced-dose of rituximab in rituximab combination immunotherapy was as effective and well tolerated as the standard dose, and provided rapid, early therapeutic intervention in opsoclonus-myoclonus syndrome. Pending a long-term prospective study, these are proof-of-concept data in support of challenging the dose of rituximab in various disorders, which may have different dose requirements.

Autologous stem cell transplantation for refractory opsoclonus myoclonus ataxia syndrome

Opsoclonus, myoclonus, ataxia syndrome (OMA) is a severe neurologic disorder often associated with neuroblastoma. It is challenging to treat and can have long-term neurologic sequelae. Current recommended therapies include intravenous immunoglobulin, corticosteroids, rituximab, and chemotherapy (cyclophosphamide). We present two cases who were refractory to conventional therapy and underwent autologous stem cell transplantation (ASCT). One patient had complete resolution of symptoms following ASCT and the other patient had minimal change in symptoms with this therapy. These findings support consideration of ASCT as a therapeutic option for patients with refractory OMA after failure of known effective therapies.

Effect of low-dose cyclophosphamide, ACTH, and IVIG combination immunotherapy on neuroinflammation in pediatric-onset OMS: A retrospective pilot study

INTRODUCTION

Flow cytometric cerebrospinal fluid (CSF) lymphocyte subset analysis has improved the diagnosis of neuroinflammation and identified multiple markers of inflammation in opsoclonus-myoclonus syndrome (OMS). The aim of this exploratory, retrospective study was to analyze the effect of immunotherapy on these markers to determine which agents are disease modifying.

METHODS

Cross-sectional immunological observations were made in an IRB-approved case-control study, and patients were treated empirically. Ten different CSF lymphocyte subpopulations from 18 children with persistent OMS had been measured by flow cytometry before and after clinical treatment with cyclophosphamide/ACTH/IVIG combination (n = 7) or ACTH/IVIG alone (n = 11). Clinical severity of OMS was scored from videotapes by a blinded observer using the OMS Evaluation Scale.

RESULTS

Only cyclophosphamide combination therapy (mean dose 26 ± 3 mg/kg or 922 ± 176 mg/m² x 6 cycles) significantly decreased the percentage of CSF B cells. The mean reduction was 65%, with CSF B cell frequency normalized at 7-8 months in 70%. Other abnormalities of the CSF immunophenotype, such as the low CD4/CD8 T cell ratio, persisted, and there were no therapeutic changes in T cell activation/maturation markers. Effects on relative and absolute size of PBMC subsets were similar. Clinical improvement was 70% and 55% in respective treatment groups. The relapse rates of the two groups did not significantly differ.

DISCUSSION

The main effect of cyclophosphamide combination therapy on neuroinflammation in OMS was moderate reduction in CSF B cell expansion. Though exploratory, it may provide a steroid sparer option in partially-responsive OMS.

Cerebrospinal fluid γδ T cell frequency is age-related: a case-control study of 435 children with inflammatory and non-inflammatory neurological disorders

Studies of cerebrospinal fluid (CSF) γδ T cells in children are limited, due especially to the lack of control data. In adults, gamma/delta T cells (TCR-γδ) residing in the intrathecal space are sometimes involved in neuroinflammation. To evaluate the possible role of γδ T cells in paediatric neuroinflammation, we immunophenotyped cerebrospinal fluid (CSF) and blood lymphocytes using flow cytometry in a case-control study of 100 children with non-inflammatory neurological disorders (NIND), 312 with opsoclonus-myoclonus (OMS) and 23 with other inflammatory neurological disorders (OIND). In NIND, the negative correlation between CSF γδ T cell frequency and patient age was striking: median frequency of 27% in infants and 3·3% in teens. Interindividual variations were largest in the youngest. There was no gender effect. In all OMS, after correcting for age, only a small effect of OMS severity remained. Measurement of markers for γδ T cell activation [human leucocyte antigen D-related (HLA-DR)], maturation (CD45RA, CD45RO) or intracellular cytokine staining [interleukin (IL)-4, interferon (IFN)-γ] failed to discriminate OMS and NIND groups. Of seven OMS immunotherapies/combinations, none altered the frequency of total CSF γδ T cells or subsets significantly. In OIND, the CSF γδ T cell frequency was < 10% for single samples of other paraneoplastic disorders [anti-neuronal nuclear antibody (ANNA)-1, PCA-1, teratoma-associated syndrome], cerebellar ataxia (post-infectious, ataxia-telangiectasia), acute disseminated encephalomyelitis, neuroborreliosis and encephalitis. This study provides new insights into CSF γδ T cells in the paediatric population. Although their role in CSF remains elusive, the negative age correlation, resistance to immunotherapy and our age cut-off references for NIND are important findings for the design of future paediatric studies.

The efficacy of adrenocorticotropic hormone in a girl with anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND

Immunomodulatory therapy has shown some therapeutic benefits in patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis. In this report, we describe the use of adrenocorticotropic hormone (ACTH) immunotherapy with good outcome in a patient with anti-NMDAR encephalitis.

SUBJECT AND METHODS

A 4-year-old girl developed convulsions in her right arm and leg without impaired consciousness. These convulsions occurred frequently in clusters of 10-20 events of 10-20 s duration. She was admitted to our hospital on the 6th day following her initial series of convulsions. Flaccid paralysis of the right hand and leg was also found. Interictal electroencephalography showed high-amplitude slow waves. No abnormal findings were shown on MRI. ^99mTc-ECD brain SPECT on the 14th day showed hyperperfusion in the left hemisphere, including the left basal ganglia. The convulsions ceased following the oral administration of valproic acid on the 10th day; however, paralysis associated with choreic dyskinesia of the right arm and leg remained. ACTH immunotherapy was then performed on the 15th day. We identified the presence of N-methyl-D-aspartate receptor antibody in CSF samples taken on the 6th day. After ACTH therapy, the patient fully recovered from the paralysis associated with choreic dyskinesia of the right arm and leg. She has not had a relapse and has not required medication for over a year.

CONCLUSION

ACTH immunotherapy may be a useful treatment option for patients with anti-NMDAR encephalitis, although further evaluation is required.

Principles and approaches to the treatment of immune-mediated movement disorders

Immune mediated movement disorders include movement disorders in the context of autoimmune encephalitis such as anti-NMDAR encephalitis, post-infectious autoimmune movement disorders such as Sydenham chorea, paraneoplastic autoimmune movement disorders such as opsoclonus myoclonus ataxia syndrome, and infection triggered conditions such as paediatric acute neuropsychiatric syndrome. This review focuses on the approach to treatment of immune mediated movement disorders, which requires an understanding of the immunopathogenesis, whether the disease is destructive or 'altering', and the natural history of disease. Factors that can influence outcome include the severity of disease, the delay before starting therapy, use of multimodal therapy and whether the course is monophasic or relapsing. Although the four main conditions listed above have different pathophysiological processes, there are general themes that broadly apply including: early diagnosis and treatment is better, minimise the severity of disease, escalate treatment if the patient is not responding to initial treatments, and minimise relapse.

Therapeutic plasma exchange for a case of refractory opsoclonus myoclonus ataxia syndrome

Opsoclonus myoclonus ataxia syndrome (OMAS) can be refractory to standard therapies and devastating. Alternative treatments are imperative. A 14-month-old male diagnosed with neuroblastoma and paraneoplastic OMAS achieved complete cancer remission with chemotherapy. The OMAS, however, persisted over the subsequent 4 years despite numerous immune-modulatory and immunosuppressive therapies. The patient ultimately achieved complete remission following therapeutic plasma exchange (TPE) combined with rituximab and intravenous immunoglobulin. After three asymptomatic years, he relapsed. Upon reintroducing TPE and rituximab plus oral prednisolone, the patient rapidly achieved a second complete remission. This case offers proof-of-principle for the potential efficacy of TPE for neuroblastoma-associated OMAS.

Brain volumetric analysis and cortical thickness in adults with saccadic intrusions (ocular flutter or opsoclonus-myoclonus syndrome)

OBJECTIVES

Ocular flutter (OF) and opsoclonus are considered a continuum with a similar pathogenesis. Due to the rarity of this disease in the adult population, little is known about the brain morphological changes in the chronic phase of the disease.

PATIENTS AND METHODS

Six magnetic resonance imaging from adults with previous history of OF/Opsoclonus and 12 healthy patients (paired by age and sex) were analyzed in order to identify the long term cortical thickness pattern in this rare disease by using Freesurfer.

RESULTS

Patients with OF/Opsoclonus showed reduced cerebellum cortical volume with a subsequent diminution in total cerebellar volume. White mater cerebellum volume was not modified. In addition, we have also identified a significant supratentorial gray matter volume decrease in OF/Opsoclonus patients, involving both the cortical and the subcortical gray matter.

CONCLUSIONS

OF/Opsoclonus in adults may be associated with cortical and subcortical gray matter atrophy, as well as decreased cerebellar cortical volume. Further larger prospective studies are necessary to confirm these results.

Demographic, Clinical, and Immunologic Features of 389 Children with Opsoclonus-Myoclonus Syndrome: A Cross-sectional Study

Pediatric-onset opsoclonus-myoclonus syndrome (OMS) is a devastating neuroinflammatory, often paraneoplastic, disorder. The objective was to characterize demographic, clinical, and immunologic aspects in the largest cohort reported to date. Cross-sectional data were collected on 389 children in an IRB-approved, observational study at the National Pediatric Myoclonus Center. Non-parametric statistical analysis was used. OMS manifested in major racial/ethnic groups, paralleling US population densities. Median onset age was 1.5 years (1.2–2 interquartile range), inclusive of infants (14%), toddlers (61%), and youngsters (25%). The higher female sex ratio of 1.2 was already evident in toddlers. Time to diagnosis was 1.2 months (0.7–3); to treatment, 1.4 months (0.4–4). Irritability/crying dominated prodromal symptomatology (60%); overt infections in <35%. Acute cerebellar ataxia was the most common misdiagnosis; staggering appeared earliest among 10 ranked neurological signs (P < 0.0001). Some untreated youngsters had no words (33%) or sentences (73%). Remote neuroblastic tumors were detected in 50%; resection was insufficient OMS treatment (58%). Age at tumor diagnosis related to tumor type (P = 0.004) and stage (P = 0.002). A novel observation was that paraneoplastic frequency varied with patient age—not a mere function of the frequency of neuroblastoma, which was lowest in the first 6 months of life, when that of neuroblastoma without OMS was highest. The cerebrospinal fluid (CSF) leukocyte count was minimally elevated in 14% (≤11/mm³) with normal differential, and commercially screened serum autoantibodies were negative, but CSF oligoclonal bands (OCB) and B cells frequency were positive (58 and 93%). Analysis of patients presenting on immunotherapy revealed a shift in physician treatment practice patterns from monotherapy toward multi-agent immunotherapy (P < 0.001); the number of agents/sequences varied. In sum, a major clinical challenge is to increase OMS recognition, prevent initial misdiagnosis, and shorten time to diagnosis/treatment. The index of suspicion for an underlying tumor must remain high despite symptoms of infection. The disparity in onset age of neuroblastoma frequency with that of neuroblastoma with OMS warrants further studies of potential host/tumor factors. OMS neuroinflammation is best diagnosed by CSF OCB and B cells, not by routine CSF or commercial antibody studies.

6-Mercaptopurine modifies cerebrospinal fluid T cell abnormalities in paediatric opsoclonus-myoclonus as steroid sparer

The purpose of this study was to evaluate the capacity of 6-mercaptopurine (6-MP), a known immunosuppressant, to normalize cerebrospinal fluid (CSF) lymphocyte frequencies in opsoclonus-myoclonus syndrome (OMS) and function as a steroid sparer. CSF and blood lymphocytes were immunophenotyped in 11 children with OMS (without CSF B cell expansion) using a comprehensive panel of cell surface adhesion, activation and maturation markers by flow cytometry, and referenced to 18 paediatric controls. Drug metabolites, lymphocyte counts and liver function tests were used clinically to monitoring therapeutic range and toxicity. In CSF, adjunctive oral 6-MP was associated with a 21% increase in the low percentage of CD4⁺ T cells in OMS, restoring the CD4/CD8 ratio. The percentage of CD4⁺ T cells that were interferon (IFN)-γ⁺ was reduced by 66%, shifting the cytokine balance away from T helper type 1 (Th1) (proinflammatory) predominance. The percentage of natural killer (NK) cells decreased significantly in CSF (-32%) and blood (-67 to -82%). Low blood absolute lymphocyte count was more predictive of improvement in CSF lymphocyte proportions (correlated with % CD4⁺ T cells) than the 6-thioguanine level (no correlation). 6-MP was difficult to titrate: 50% achieved the target absolute lymphocyte count (< 1·5 K/mm); 20%, the 'therapeutic' 6-thioguanine level; and 40% the non-toxic 6-methylmercaptopurine level. Side effects and transaminase elevation were mild and reversible. Clinical steroid-sparing properties and lowered relapse frequency were demonstrated. 6-MP displayed unique pharmacodynamic properties that may be useful in OMS and other autoimmune disorders. Its steroid sparer capacity is limited to children in whom the therapeutic window can be reached without limiting pharmacokinetic factors or side effects.

Immunotherapeutics in Pediatric Autoimmune Central Nervous System Disease: Agents and Mechanisms

Beyond the major advances produced by careful clinical-radiological phenotyping and biomarker development in autoimmune central nervous system disorders, a comprehensive knowledge of the range of available immune therapies and a deeper understanding of their action should benefit therapeutic decision-making. This review discusses the agents used in neuroimmunology and their mechanisms of action. First-line treatments typically include corticosteroids, intravenous immunoglobulin, and plasmapheresis, while for severe disease second-line "induction" agents such as rituximab or cyclophosphamide are used. Steroid-sparing agents such as mycophenolate, azathioprine, or methotrexate are often used in potentially relapsing or corticosteroid-dependent diseases. Lessons from adult neuroimmunology and rheumatology could be translated into pediatric autoimmune central nervous system disease in the future, including the potential utility of monoclonal antibodies targeting lymphocytes, adhesion molecules for lymphocytic migration, cytokines or their receptors, or complement. Finally, many agents used in other fields have multiple mechanisms of action, including immunomodulation, with potential usefulness in neuroimmunology, such as antibiotics, psychotropic drugs, probiotics, gut health, and ketogenic diet. All currently accepted and future potential agents have adverse effects, which can be severe; therefore, a "risk-versus-benefit" determination should guide therapeutic decision-making.

Dexamethasone, Intravenous Immunoglobulin, and Rituximab Combination Immunotherapy for Pediatric Opsoclonus-Myoclonus Syndrome

BACKGROUND

Although pulse-dose dexamethasone is increasingly favored for treating pediatric opsoclonus-myoclonus syndrome (OMS), and multimodal immunotherapy is associated with improved clinical response, there have been no neuroimmunologic studies of dexamethasone-based multimodal disease-modifying therapy.

METHODS

In this observational retrospective study, 19 children with OMS (with or without associated neuroblastoma) underwent multibiomarker evaluation for neuroinflammation. Nine children of varying OMS severity, duration, and treatment status were treated empirically with pulse dexamethasone, intravenous immunoglobulin (IVIg), and rituximab combination immunotherapy (DEXIR-CI). Another 10 children on dexamethasone alone or with IVIg at initial evaluation only provided a comparison group. Motor severity (total score) was scored rater-blinded via videotapes using the validated OMS Evaluation Scale.

RESULTS

DEXIR-CI was associated with a 69% reduction in group total score (P = 0.004) and was clinically well tolerated. Patients given the dexamethasone combination exhibited significantly lowered B cell frequencies in cerebrospinal fluid (-94%) and blood (-76%), normalizing the cerebrospinal fluid B cell percentage. The number of patients with positive inflammatory markers dropped 87% (P = 0.002) as did the number of markers. Cerebrospinal fluid oligoclonal bands were positive in four of nine pretreatment patients but zero of six post-treatment patients. In the comparison group, partial response to dexamethasone alone or with IVIg was associated with multiple positive markers for neuroinflammation despite an average of seven months of treatment.

CONCLUSIONS

Multimechanistic dexamethasone-based combination immunotherapy increases the therapeutic armamentarium for OMS, providing a viable option for less severely affected individuals. Partial response to dexamethasone with or without IVIg is indicative of ongoing neuroinflammation and should be treated promptly and accordingly.

Case-control, exploratory study of cerebrospinal fluid chemokines/cytokines and lymphocyte subsets in childhood Tourette syndrome with positive streptococcal markers

A longstanding question is whether neuroinflammation is present in children symptomatic for Tourette syndrome (TS) with positive streptococcal serology and throat cultures. The objective was to directly test for it using modern hypothesis-driven approaches. Profiling studies for 14 immune cell types (flow cytometry), 7 chemokines/cytokines (ELISA), oligoclonal bands, and other immunoglobulins were performed in this IRB-approved study of 5 children with TS and streptococcal markers compared to data from 26 non-inflammatory pediatric neurological controls. Subjects were well-characterized clinically and with standardized scales for tics and obsessions/compulsions. Three subjects with TS (60%) had positive throat cultures for Group A beta-hemolytic strep, five had elevated anti-deoxyribonuclease-B titers (mean=444), and 4 (80%) had elevated anti-streptolysin O titers (981). There were no significant differences between groups in the frequency of CSF B and T cell subsets or NK cells; the proportion of intracellularly-stained T helper type 1 (IFN-γ) or type 2 (IL-4) cells; the concentrations of B cell chemoattractants CXCL13, CXCL10; the B cell proliferation/survival cytokines BAFF and APRIL, or other chemokines (CCL19, CCL21, CCL22). None of the patients had positive CSF oligoclonal bands or an abnormal IgG index/synthesis rate. Parallel blood studies were negative. This novel study found no group CSF lymphocyte phenotypic abnormalities or elevated inflammatory mediators in childhood TS despite positive serology and throat cultures for Group A beta-hemolytic streptococci. It demonstrates feasibility of the methodology, and should serve as the basis for a larger study of putative streptococcal-associated neuroimmunological disorders.