A nationwide survey of opsoclonus-myoclonus syndrome in Japanese children

Late cognitive and adaptive outcomes of patients with neuroblastoma-associated opsoclonus-myoclonus-ataxia-syndrome: A report from the Children's Oncology Group

BACKGROUND

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare autoimmune disorder of the nervous system presenting with abnormal eye and limb movements, altered gait, and increased irritability. Two to four percent of children diagnosed with neuroblastoma have neuroblastoma-associated OMAS (NA-OMAS). These children typically present with non-high-risk neuroblastoma that is cured with surgery, with or without chemotherapy. Despite excellent overall survival, patients with NA-OMAS can have significant persistent neurological and developmental issues.

OBJECTIVE

This study aimed to describe long-term neurocognitive and adaptive functioning of patients with NA-OMAS treated with multimodal therapy, including intravenous immunoglobulin (IVIG) on Children's Oncology Group (COG) protocol ANBL00P3.

METHODS

Of 53 children enrolled on ANBL00P3, 25 submitted evaluable neurocognitive data at diagnosis and at least one additional time point within 2 years and were included in the analyses. Adaptive development was assessed via the Vineland Adaptive Behavior Scale, and validated, age-appropriate measures of intellectual function were also administered.

RESULTS

Twenty-one of the 25 patients in this cohort ultimately received IVIG. Descriptive spaghetti plots suggest that this cohort demonstrated stable long-term cognitive functioning and adaptive development over time. This cohort also demonstrated decreased OMAS scores over time consistent with improved OMAS symptoms.

CONCLUSIONS

While statistical significance is limited by small sample size and loss to follow-up over 10 years, findings suggest stable long-term cognitive and adaptive functioning over time in this treated cohort.

Characteristics of Opsoclonus-Myoclonus Syndrome in Patients of the Largest Pediatric Hospital in Latin America

BACKGROUND

Opsoclonus-myoclonus syndrome (OMS) is a rare neuroinflammatory disorder characterized by ataxia, opsoclonus, and myoclonus. Clinical diagnosis of OMS has been challenging; therefore, we sought to determine the clinical and treatment profiles of patients with OMS at the largest pediatric hospital in Latin America.

METHODS

We analyzed the data of patients diagnosed with OMS between 2010 and 2020 at Pequeno Principe Hospital (Brazil) to determine the corresponding clinical profile more accurately.

RESULTS

Of the approximately 50,000 visitors to our pediatric neurology department from 2010 to 2020, 10 patients with OMS were observed. Five nontumor cases included three parainfectious and two idiopathic cases. The median time from symptom onset to diagnosis was 34 days. All patients with diagnostic OMS criteria in the idiopathic, nontumor group underwent whole-exome sequencing, with potentially pathogenic mutations identified in two cases. Nine patients were treated with methylprednisolone pulse, followed by oral steroids; eight received one or more intravenous immunoglobulin treatments; and six received azathioprine and cyclophosphamide. Complete symptomatic recovery was observed in only one patient.

CONCLUSIONS

OMS diagnosis remains challenging. Diagnostic suspicion is necessary to improve the management of these patients and allow early immunosuppressive treatment. Paraneoplastic etiology is the most prevalent. In idiopathic patients who do not respond to immunosuppressive treatment, tests, such as whole-exome sequencing, may reveal a differential diagnosis. Genetic alterations that increase the risk of tumors may be an important clue to the pathophysiology of OMS.

Diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography imaging in pediatric opsoclonus myoclonus ataxia syndrome presenting with neuroblastoma

BACKGROUND

Early precision diagnosis and effective treatment of opsoclonus myoclonus ataxia syndrome (OMAS) patients presenting with neuroblastoma can prevent serious neurological outcomes.

OBJECTIVE

To assess the diagnostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging in pediatric OMAS with neuroblastoma.

MATERIALS AND METHODS

A retrospective evaluation of 45 patients diagnosed with OMAS who underwent 18F-FDG PET/CT was performed. A univariate analysis was performed to compare clinical characteristics between OMAS with and without neuroblastoma. Univariate and multivariate logistic regression analyses were applied to identify independent risk factors for OMAS with neuroblastoma and to develop the clinical model. Finally, independent risk factors and PET/CT were fitted to build the combined model for the diagnosis of OMAS with neuroblastoma and presented as a nomogram. Receiver operating characteristic curve, decision curve, and calibration curve analyses were conducted to evaluate the performance of the models.

RESULTS

Among 45 patients, 27 were PET/CT-positive, 23/27 lesions were neuroblastoma, and four were false positives. One of the false positive patients was confirmed to be adrenal reactive hyperplasia by postoperative pathology, and the symptoms of OMAS disappeared in the remaining three cases during clinical follow-up. The average maximal standardized uptake value of PET/CT-positive lesions was 2.6. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT were 100%, 81.8%, 85.2%, 100%, and 91.1%, respectively. Age at diagnosis, lactate dehydrogenase, and neuron-specific enolase showed statistically significant differences between OMAS with and without neuroblastoma. Lactate dehydrogenase was identified as the independent risk factor to develop the clinical model, and the clinical model demonstrated an area under the curve (AUC) of 0.82 for the diagnosis of OMAS with neuroblastoma, with an AUC as high as 0.91 when combined with PET/CT. The decision curve analysis and calibration curve demonstrated that the nomogram had good consistency and clinical usefulness.

CONCLUSION

In patients with OMAS, 18F-FDG PET/CT has a high diagnostic accuracy in detecting tumors of the neuroblastoma, especially when combined with the independent risk factor serum lactate dehydrogenase.

Benign paraspinal ganglioneuroma with paraneoplastic opsoclonus myoclonus syndrome

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare immune-mediated movement disorder occurring as a paraneoplastic manifestation of neuroblastic tumours (NTs), especially neuroblastoma in infancy. Ganglioneuroma (GN), the benign tumour in the spectrum, is rarely associated with OMAS. We report the case of a child in her second year of life presenting with acute onset of progressive paraplegia and OMAS. MRI showed diffuse and infiltrating left paraspinal mass from T3-T9 levels with differentials of neuroblastoma or ganglioneuroblastoma. Histopathological and immunohistochemistry examination of the excised tumour showed maturing GN. The OMAS was managed with intravenous immunoglobulin and steroids. In the 6-month follow-up, the child has a residual motor weakness with myelomalacia in neuroimaging. The case report substantiates the occurrence of OMAS as paraneoplastic manifestation in NTs, including benign, in children younger than 2 years with a female predilection.

Paraneoplastic Neurologic Syndromes

OBJECTIVE

Progress is ongoing in understanding paraneoplastic neurologic disorders, with new syndromes and antibodies being described and more detailed evidence available to guide workup for diagnosis and treatment to improve outcomes. Many excellent reviews have summarized the molecular features of different antibodies, but this article emphasizes the clinical features of each syndrome that may help guide initial diagnosis and treatment, which often should occur before an antibody or cancer is found to confirm the diagnosis.

LATEST DEVELOPMENTS

Recent findings include updated diagnostic criteria with validated sensitivity and specificity, discovery of novel antibodies, and clinical findings that increase the likelihood of an underlying paraneoplastic disorder. Suggestive syndromes that have been recently identified include faciobrachial dystonic seizures and pilomotor auras in anti-leucine-rich glioma inactivated protein 1 encephalitis, extreme delta brush on EEG in N-methyl-d-aspartate (NMDA)-receptor encephalitis, déjà vu aura in anti-glutamic acid decarboxylase 65 (GAD65) encephalitis, and sleep disturbances in several disorders. In addition, there is confirmed utility of brain positron emission tomography (PET) and CSF markers, including carcinoembryonic antigen and oligoclonal bands, as well as improved tests for the presence of leptomeningeal cancer cells in CSF. Associations of cancer immunotherapies with paraneoplastic syndromes and herpes simplex virus encephalitis (and COVID-19) with NMDA-receptor encephalitis have been described.

ESSENTIAL POINTS

All neurologists should be aware of advances regarding paraneoplastic neurologic syndromes, as patients can present with a wide variety of neurologic symptoms and earlier diagnosis and treatment can improve outcomes.

Benign paroxysmal vertigo of childhood

Benign paroxysmal vertigo of childhood (or recurrent vertigo of childhood) is the most common cause of vertigo in young children. It is considered a pediatric migraine variant or precursor disorder, and children with the condition have an increased likelihood of developing migraine later in life than the general population. Episodes are typically associated with room-spinning vertigo in conjunction with other migrainous symptoms (e.g. pallor, nausea, etc.), but it is rarely associated with headaches. Episodes typically only last for a few minutes and occur with a frequency of days to weeks without interictal symptoms or exam/test abnormalities. Treatment is rarely necessary, but migraine therapy may be beneficial in cases where episodes are particularly severe, frequent, and/or prolonged. An appreciation of the typical presentation and characteristics of this common condition is essential to any provider responsible for the care of children with migraine disorders and/or dizziness. This chapter will review the current literature on this condition, including its proposed pathophysiology, clinical presentation, and management. This chapter also includes a brief introduction to pediatric vestibular disorders, including relevant anatomy, physiology, embryology/development, history-taking, physical examination, testing, and a review of other common causes of pediatric dizziness/vertigo.

Opsoclonus-myoclonus syndrome associated with neuroblastoma: Insights into antitumor immunity

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder. Half of these cases occur in children with neuroblastoma. Neuroblastoma patients with OMS usually have better oncological outcomes than those without OMS even after stratification by tumor stage and age, indicating that factors mediating OMS may also inhibit tumor cell proliferation. Although the mechanisms underlying OMS remain undefined, the cytokines and lymphocytes alterations in the cerebrospinal fluid support the concept that it is a pattern of neuroinflammation due to an autoimmune effect. The presence of lymphoid follicles consisting of follicular dendritic cells, CD20⁺ B lymphocytes, CD3⁺ T lymphocytes, and CD68⁺ macrophages in the tumor microenvironment in OMS-associated neuroblastoma support the autoimmune nature of this disorder. This review focuses on the clinical and genetic features of OMS-associated neuroblastoma, and we update readers on immune features of neuroblastoma with or without OMS to gain insights into antitumor immunity as it relates to tumor biology and prognosis.

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.

Long-term neurological outcomes of children with neuroblastoma with opsoclonus-myoclonus syndrome

BACKGROUND

Neuroblastoma with opsoclonus-myoclonus syndrome (OMS-NB) is a rare disease in children. Few studies of long-term outcome of children with OMS-NB were conducted. This study aimed to review the rate of recovery of neurological symptoms and the long-term neurological outcomes of children with OMS-NB.

METHODS

This study retrospectively assessed 14 children with OMS-NB diagnosed at Peking University First Hospital from May 2011 to November 2019. Demographic data, neurological symptoms, oncological status and treatments were retrospectively reviewed from the records. Neurological sequelae were recorded by clinical and remote follow-up.

RESULTS

During the acute stage, myoclonus and ataxia were observed in all children while opsoclonus was observed in 10/14 children. The median durations of neurological symptoms were 15 months (range, 5-48 months). Approximately 93% (13/14) children revealed neurological sequelae. Significant correlations were as follows: motor retardation with female gender (P<0.001) and residual tumors (P<0.05); language impairment with non-adrenal-gland-located tumors (P<0.05). There were no obvious factors that had a statistical relationship with cognitive disorder or behavioral changes.

CONCLUSIONS

Children with OMS-NB have favorable outcomes in terms of neurological symptoms. Neurological sequelae occurred in almost all children. Children with different features tend to reveal different sequalae. Features of female gender and residual tumors tend to reveal motor retardation while that of non-adrenal-gland-located tumors tend to reveal language impairment.

Movement disorders, cerebral palsy and vaccination

This review focused on vaccination in children with movement disorders, including cerebral palsy and the movement disorders triggered by vaccination in children with and without neurological disabilities. The following clinical questions were addressed: 1) Can children with movement disorders be vaccinated? 2) Can vaccination trigger movement disorders in children without neurological disabilities? 3) Can vaccination trigger movement disorders in children with neurological disabilities? and 4) Is there any consensus of care concerning vaccination in children with movement disorders? Following the PRISMA reporting guidelines, 1096 records were identified and 34 relevant papers were included. No evidence that vaccinations are contraindicated for children with movement disorders was noticed. Several reports of neurological adverse events, including movement disorders in children without neurological disabilities after various types of vaccination, were found. The reporting rates were low, the causality was controversial, and patient outcomes were mostly favourable. There was limited (if any) evidence in our search that any vaccination leads to any movement disorder exacerbation. Finally, no generally accepted consensus or standards of care concerning vaccination in patients with movement disorders were found. In summary, we found few precautions for vaccination in this group of patients and concluded that general best practice guidelines for immunization should be followed. In addition, influenza and pneumococcal vaccines are recommended because they can reduce morbidity and mortality in individuals severely affected by movement restrictions.

Clinical Analysis of Pediatric Opsoclonus-Myoclonus Syndrome in One of the National Children's Medical Center in China

Objective: To study the clinical characteristics and treatment of pediatric opsoclonus-myoclonus syndrome (OMS).

Methods: We analyzed the clinical data of nine children OMS between June 2017 and Nov 2020.

Results: Nine children (M/F = 3:6, median onset age was 18 months) diagnosed with OMS were included in the study. Before onset, human rhinovirus and respiratory syncytial virus were seen in one patient, respectively. And one patient received Japanese encephalitis vaccination. Three patients had neuroblastoma, and one patient had ganglioneuroblastoma. All patients' symptoms were improved after receiving surgery (for four patients with tumor), intravenous human immunoglobulin and pulsed methylprednisolone. However, four patients without mass relapsed and became relapse free after rituximab treatment. The relapse rate was 44.4% (4/9). The OMS severity score at the last follow-up was significantly lower than the OMS severity score at onset (3.0 ± 1.0 vs. 11.0 ± 2.2, paired-samples t-test, P < 0.001). All patients had at least one item of neurological symptoms or neuropsychological disturbances.

Conclusion: For pediatric OMS, human rhinovirus infection and respiratory syncytial virus infection can be seen before onset. Rituximab is effective in reducing relapse. Improving recognition and long-term prognosis in OMS is urgent.

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.

Diagnostic values of 68Ga-labelled DOTANOC PET/CT imaging in pediatric patients presenting with paraneoplastic opsoclonus myoclonus ataxia syndrome

OBJECTIVES

Opsoclonus myoclonus ataxia (OMA) syndrome, also known as "Kinsbourne syndrome" or "dancing eye syndrome," is a rare, paraneoplastic entity which may be associated with pediatric neuroblastic tumors and carry a grave prognosis. We aimed to evaluate the role of ⁶⁸Ga DOTANOC PET/CT for detecting neuroblastic tumors in patients with OMA syndrome.

METHODS

We retrospectively evaluated the ⁶⁸Ga-DOTANOC PET/CT data of pediatric patients presenting with OMA syndrome from March 2012 to November 2018. A somatostatin receptor (SSTR)-expressing lesion with corresponding morphological change on CT image was considered PET-positive, while no abnormal SSTR expression or lesion was noticed in PET-negative patients. Histopathology and/or clinical/imaging follow-up (minimum one year) was considered a reference standard for comparing the PET/CT findings. The results of ⁶⁸Ga-DOTANOC PET/CT were also compared with ¹³¹I MIBG whole-body scintigraphy, which was available in five patients.

RESULTS

Of 38 patients (13 males, 25 females, aged 3-96 months), 18 (47.3%) had SSTR-expressing lesions (PET-positive), and histopathology revealed neuroblastic tumors in 17/18 lesions (neuroblastoma 14, ganglioneuroblastoma 2, and ganglioneuroma 1) and reactive hyperplasia in 1/18. The remaining 20/38 (52.6%) patients did not demonstrate SSTR-expressing lesions (PET-negative) and had an uneventful follow-up. The average SUVmax of the PET-positive lesions was 10.3 (range 2.8-34.5). The PET/CT results revealed 17 true-positive, one false-positive, 20 true-negative, and zero false-negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 100%, 95.2%, 94.4%, 100%, and 97.3% respectively.

CONCLUSIONS

⁶⁸Ga-DOTANOC PET/CT identified neuroblastic tumors with a high diagnostic accuracy in our cohort compared to histology and follow-up.

KEY POINTS

• Opsoclonus myoclonus ataxia (OMA) syndrome or "dancing eye syndrome" is a rare paraneoplastic entity which may be associated with pediatric neuroblastic tumors with a grave prognosis. • ¹²³I/¹³¹I MIBG imaging has a proven role for functional imaging in neuroblastoma or patients with OMA, but the role of ⁶⁸Ga-DOTANOC PET/CT is not yet studied. • 68Ga-labelled DOTANOC PET/CT (SSTR) imaging, in our cohort, was able to positively identify neuroblastic tumors with high diagnostic accuracy when compared with histology.

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-ataxia syndrome and mature ovarian teratoma in an adolescent

•Ovarian teratomas have been implicated in multiple paraneoplastic syndromes.•Opsoclonus-ataxia syndrome is a rare entity that may be secondary to a paraneoplastic, infectious, or idiopathic process.•Opsoclonus-ataxia syndrome may be associated with ovarian teratoma in both children and adults.•Prompt gynecologic involvement for teratoma resection is warranted.

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.

Serum IgG-induced microglial activation enhances neuronal cytolysis via the NO/sGC/PKG pathway in children with opsoclonus-myoclonus syndrome and neuroblastoma

Background

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disease. Some children with OMS also have neuroblastoma (NB). We and others have previously documented that serum IgG from children with OMS and NB induces neuronal cytolysis and activates several signaling pathways. However, the mechanisms underlying OMS remain unclear. Here, we investigated whether nitric oxide (NO) from activated microglias and its cascade contribute to neuronal cytolysis in pediatric OMS.

Methods

The activation of cultured cerebral cortical and cerebellar microglias incubated with sera or IgG isolated from sera of children with OMS and NB was measured by the expression of the activation marker, cytokines, and NO. Neuronal cytolysis was determined after exposing to IgG-treated microglia-conditioned media. Using inhibitors and activators, the effects of NO synthesis and its intracellular cascade, namely soluble guanylyl cyclase (sGC) and protein kinase G (PKG), on neuronal cytolysis were evaluated.

Results

Incubation with sera or IgG from children with OMS and NB increased the activation of cerebral cortical and cerebellar microglias, but not the activation of astrocytes or the cytolysis of glial cells. Moreover, the cytolysis of neurons was elevated by conditioned media from microglias incubated with IgG from children with OMS and NB. Furthermore, the expression of NO, sGC, and PKG was increased. Neuronal cytolysis was relieved by the inhibitors of NO signaling, while neuronal cytolysis was exacerbated by the activators of NO signaling but not proinflammatory cytokines. The cytolysis of neurons was suppressed by pretreatment with the microglial inhibitor minocycline, a clinically tested drug. Finally, increased microglial activation did not depend on the Fab fragment of serum IgG.

Conclusions

Serum IgG from children with OMS and NB potentiates microglial activation, which induces neuronal cytolysis through the NO/sGC/PKG pathway, suggesting an applicability of microglial inhibitor as a therapeutic candidate.

Clinical Profile, Prognostic Indicators, and Therapeutic Outcomes of Pediatric Opsoclonus-Myoclonus-Ataxia Syndrome: A Single-Center Experience from South India

Background:

Opsoclonus myoclonus syndrome (OMS) is a neuroinflammatory disorder. Indian literature on its clinical profile and outcome is sparse.

Objectives:

The objective of this study is to describe the clinical profile and analyze outcomes and prognostic predictors in a cohort of children with OMS.

Materials and Methods:

This was a retrospective study of children with OMS between 2007 and 2017.

Results:

Twenty-two children were included in the study. The mean age at onset of symptom was 20.9 months (standard deviation [SD]: 7.5). The mean duration of delay in diagnosis was 8.4 months (SD 1.26) with acute cerebellitis being the most common misdiagnosis. Eleven children (50%) were diagnosed with tumor during evaluation and follow-up and 11 children (50%) belonged to idiopathic/postinfectious group. Magnetic resonance imaging brain was normal in all children except for one revealing cerebellar atrophy on follow-up. One child in the paraneoplastic group (neuroblastoma) had a positive PNMA2/Ta onconeural antibody. Children in the tumor group had an earlier age of onset (mean 15.5 vs. 26.3 months), shorter time to onset of opsoclonus from initial symptom (2.54 vs. 7.27 weeks), and higher severity score at presentation (13.7 vs. 11.3) compared to the nontumor group. Children in the nontumor group attained their first remission with treatment earlier (10.9 weeks, SD: 4.5) than the children with tumor (18.72 weeks, SD: 5.8). There was no significant difference in the outcome between the groups. Children with multiple relapses (>3) and late surgical intervention for tumor (>6 months after symptom onset) had a poor outcome.

Discussion:

A high index of suspicion coupled with early diagnosis and periodic tumor surveillance (even in the initially negative cases) along with aggressive combined multimechanistic immunotherapies is the key in improving outcomes.

Conclusion:

A high index of suspicion in appropriate clinical circumstances and early aggressive immunomodulation might lead to a better outcome.

IGF-1 alleviates serum IgG-induced neuronal cytolysis through PI3K signaling in children with opsoclonus-myoclonus syndrome and neuroblastoma

BACKGROUND

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder, usually accompanied by neuroblastoma (NB). There is no targeted treatment and animal model of OMS. We aimed to investigate whether insulin-like growth factor 1 (IGF-1)/phosphoinositide 3-kinase (PI3K) signaling alleviates neuronal cytolysis in pediatric OMS.

METHODS

Cultured rat cerebral cortical neurons and cerebellar neurons were incubated with sera or IgG isolated from sera of children with OMS and NB. Cytolysis and PI3K expression were measured by the lactate dehydrogenase assay and enzyme-linked immunosorbent assay, respectively. Using inhibitors and activators, the effects of IGF-1 and PI3K on cytolysis were investigated.

RESULTS

The incubation of sera or IgG from children with OMS and NB increased cytolysis in not only cerebellar neurons, but also cerebral cortical neurons. Furthermore, the IGF-1 receptor antagonist NVP-AEW541 exaggerated cytolysis in children with OMS and NB. IGF-1 alleviated cytolysis, which was blocked by the PI3K inhibitor LY294002. Additionally, sera or IgG from children with OMS and NB compensatively elevated PI3K expression. LY294002 exacerbated cytolysis; whereas, the PI3K activator 740 Y-P suppressed cytolysis.

CONCLUSION

IGF-1/PI3K signaling alleviates the cytolysis of cultured neurons induced by serum IgG from children with OMS and NB, which may be innovation therapy targets.

Intravenous immunoglobulin with prednisone and risk-adapted chemotherapy for children with opsoclonus myoclonus ataxia syndrome associated with neuroblastoma (ANBL00P3): a randomised, open-label, phase 3 trial

Purpose

No previous clinical trial has been conducted for patients with neuroblastoma associated opsoclonus myoclonus ataxia syndrome (OMA), and current treatment is based on case reports. To evaluate the OMA response to prednisone and risk-adapted chemotherapy and determine if the addition of intravenous gammaglobulin (IVIG) further improves response, the Children’s Oncology Group designed a randomized therapeutic trial.

Patient and Methods

Eligible subjects were randomized to receive twelve cycles of IVIG (IVIG+) or no IVIG (NO-IVIG) in addition to prednisone and neuroblastoma risk-adapted chemotherapy. All low-risk patients were treated with cyclophosphamide. The severity of OMA symptoms was evaluated at 2, 6, and 12 months using a scale developed by Mitchell and Pike and baseline versus best response scores were compared. A single patient who did not undergo neurologic assessment was excluded from OMA response analysis. This study is registered with Clinical Trials.gov (identifier NCT00033293).

Results

Of the 53 patients enrolled in the study, 62% (33/53) were female. There were 44 low-risk, 7 intermediate-risk, and 2 high-risk neuroblastoma patients. Twenty-six subjects were randomized to receive IVIG+ and 27 were randomized to NO-IVIG. The neuroblastoma 3-year event-free survival (95% confidence interval (CI)) was 94.1% (87.3%, 100%) and overall survival was 98.0% (94.1%, 100%). Significantly higher rates of OMA response were observed in patients randomized to IVIG+ compared to NO-IVIG [21/26=80.8% for IVIG+; 11/27=40.7% for NO-IVIG (odds ratio=6.1; 95% CI: (1.5, 25.9), p=0.0029)]. For the majority of patients, the IVIG+ OMA regimen combined with cytoxan or other risk-based chemotherapy was well tolerated, although there was one toxic death in a high-risk subject.

Conclusion

This is the only randomized prospective therapeutic clinical trial in children with neuroblastoma-associated OMA. The addition of IVIG to prednisone and risk-adapted chemotherapy significantly improves OMA response rate. IVIG+ constitutes a back-bone upon which to build additional therapy.

Clinicopathological features of neuroblastic tumors with opsoclonus-myoclonus-ataxia syndrome: Follicular structure predicts a better neurological outcome

Neuroblastic tumors (NT) with opsoclonus-myoclonus syndrome (OMS) display characteristic histological features, such as lymphocytic infiltration with lymphoid follicles, indicating an underlying immune response. We retrospectively assessed NT patients from 2001 to 2016. Five cases of NT with OMS and 76 cases of NT without OMS were histopathologically reviewed in this study. The grade of lymphocytic infiltration was evaluated. The number of follicles was counted and the presence or absence of lymphoid follicles was recorded for each case. We also confirmed the presence or absence of follicular dendritic cells (FDCs). We investigated the relationship between the histopathological and clinical findings of NT with OMS. Lymphocytic infiltration was observed in all cases; however, the precise follicular structure was occasionally unclear. Patients with clear follicular structures displayed germinal centers including tingible body macrophages and FDCs. All patients without neurological sequelae demonstrated a clear follicular structure with a FDC meshwork pattern. The interval between OMS onset and the detection and initial treatment of NT was typically longer in patients with neurological sequelae compared to those without neurological sequelae. Early detection and treatment of NT with OMS at the phase of a clear follicular formation with multiple FDC may provide favorable neurological outcomes.

Childhood opsoclonus-myoclonus syndrome: A case series from Tunisia

INTRODUCTION

Opsoclonus myoclonus syndrome (OMS) is a rare immune-mediated disorder characterized by opsoclonus, myoclonus, ataxia and behavioral changes. The aim of our study was to investigate the epidemiology, clinical features, etiological aspects and outcome of OMS in Tunisian children.

METHODS

We conducted a retrospective study over 11years (2005-2016) including all patients aged under 18years who were managed for newly diagnosed OMS in a tertiary care research centre for children with neurological symptoms. Epidemiological and clinical data were analyzed.

RESULTS

Fifteen patients were included. The male-female ratio was 7:8. Median age of onset was 4.32years (range: 14months-16years). Time to diagnosis ranged between 2days and 10months. Median follow-up period was 3.8years (range: 2-6years). Acute ataxia was the preponderant inaugural feature. Mean severity score was 9 (range: 3-14). In "Tumor group" (n=7), the main underlying malignancy was neuroblastoma identified in 5 patient. In "No tumor group" (n=8), parainfectious and idiopathic OMS were identified in 5 and 3 patients, respectively. All patients received immunomodulatory treatment. Complete recovery of OMS symptoms was obtained in 12 children. Comparing the "Tumor group" and the "No tumor group", there were no differences in age of onset, sex ratio, main presenting symptom, median OMS severity score or responsiveness to treatment. However, sleep and behavioral disturbances were more frequent in the "No tumor group" (p=0.04). Neurological sequelae were equally found in both groups.

CONCLUSION

Annual incidence of OMS in Tunisia could be estimated as 0.6 patients in children per million per year. Diagnosis may be challenging especially when the triad is incomplete. Although behavioral disturbances seem to be more frequent in the "No tumor group", our study suggests that there is no specific features differentiating paraneoplastic OMS from non paraneoplastic OMS. Acute symptoms are responsive to immunomodulatory treatment but long term follow up can reveal neurological (mainly cognitive) sequelae.

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.

Opsoclonus-Myoclonus Syndrome: A New Era of Improved Prognosis?

BACKGROUND

Opsoclonus-myoclonus syndrome is an autoimmune neurological disorder characterized by opsoclonus, myoclonus, ataxia, and behavioral changes. Although long-term outcomes have historically been poor, including motor and cognitive disabilities, the advent of new and more aggressive immunotherapy regimens may be improving prognosis in opsoclonus-myoclonus syndrome.

METHODS

We retrospectively reviewed the records of all children diagnosed with opsoclonus-myoclonus syndrome at BC Children's Hospital from 2000 to 2010. Neurological outcomes were compared with those previously reported in the literature.

RESULTS

Twelve children with opsoclonus-myoclonus syndrome were identified, four of whom had an associated neuroblastoma. Two thirds of patients received initial treatment with a combination of corticosteroids, intravenous immunoglobulin (IVIG), and an additional immunosuppressant agent. After a median follow-up of three years from diagnosis, ten patients had no or minimal neurological abnormalities. Two patients had poor outcome with significant cognitive impairment.

CONCLUSIONS

Most patients in this series were treated with early multimodal immunotherapy, and neurological outcomes were better than those in most historical reports. This finding is consistent with recent studies that suggest multimodal immunotherapy regimens may be improving the prognosis in this challenging disease. However, some individuals did well with less aggressive treatment, and further studies are required to determine optimal treatment approach.

The "neuro" of neuroblastoma: Neuroblastoma as a neurodevelopmental disorder

Neuroblastoma is a childhood cancer derived from cells of neural crest origin. The hallmarks of its enigmatic character include its propensity for spontaneous regression under some circumstances and its association with paraneoplastic opsoclonus, myoclonus, and ataxia. The neurodevelopmental underpinnings of its origins may provide important clues for development of novel therapeutic and preventive agents for this frequently fatal malignancy and for the associated paraneoplastic syndromes. Ann Neurol 2016;80:13-23.

Rituximab treatment for relapsed opsoclonus-myoclonus syndrome

INTRODUCTION

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder that is associated with paraneoplastic diseases. Because OMS can frequently relapse, patients may be inflicted with neurological problems for a long time. Recently, rituximab (RTX) was introduced as a drug to treat OMS. To assess RTX treatment, we studied a patient who experienced recurrence of OMS.

CASE REPORT

A 2-year-old Japanese boy, who had left adrenal neuroblastoma, suddenly showed OMS symptoms, including ataxia and opsoclonus. Surgical resection of the tumor and subsequent steroid therapy ameliorated his symptoms. When OMS relapsed during the time when prednisolone was reduced, he was treated with full-dose RTX therapy (375 mg/m2/week) for 4 consecutive weeks. However, 1year later, he presented again with OMS symptoms. This time, we only administered an additional single dose of RTX treatment (375 mg/m2), allowing remission of OMS symptoms. During 2 years after the additional RTX treatment, OMS symptoms did not appear, even when prednisolone was reduced. He had no adverse events associated with RTX during the whole treatment period.

CONCLUSIONS

An additional single-dose RTX therapy might be effective for relapsed OMS patients who were previously treated with full-dose RTX therapy.

The diagnostic value of saccades in movement disorder patients: a practical guide and review

Saccades are rapid eye movements designed to shift the fovea to objects of visual interest. Abnormalities of saccades offer important clues in the diagnosis of a number of movement disorders. In this review, we explore the anatomy of horizontal and vertical saccades, discuss practical aspects of their examination, and review how saccadic abnormalities in hyperkinetic and hypokinetic movement disorders aid in diagnosis, with video demonstration of classic examples. Documentation of the ease of saccade initiation, range of motion and conjugacy of saccades, speed and accuracy of saccades, dynamic saccadic trajectory, and the presence or absence of saccadic intrusions and oscillations are important components of this exam. We also provide a practical algorithm to demonstrate the value of saccades in the differential diagnosis of the movement disorders patient.