Long-term outcome of ten children with 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.

Opsoclonus Myoclonus Syndrome in a Case of Severe Acute Malnutrition in Children: A Case Report

Opsoclonus myoclonus syndrome (OMS) is a rare (1 in 10 million people per year) but nonfatal autoimmune disorder characterized by involuntary oscillating eye movements, multifocal muscular jerky movements, severe ataxia, and neuropsychological and behavioral changes. It usually manifests as a paraneoplastic condition but has other etiologies also. To the best of our knowledge, this is the first case of OMS seen in a patient with severe acute malnutrition (SAM). Parents brought a three-year-old female child with complaints of being unable to sit, stand, and hold her neck for the past 18 months. The patient has had involuntary eyeball movements for three months and has shown regression in milestones. Our study aimed to understand the pathophysiology, etiology, and clinical course of OMS in a child with SAM. However, relapses and long-term developmental sequelae are common due to the lack of a common consensus regarding therapeutic guidelines.

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.

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.

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.

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.

A review of psychiatric co-morbidity described in genetic and immune mediated movement disorders

Psychiatric symptoms are an increasingly recognised feature of movement disorders. Recent identification of causative genes and autoantibodies has allowed detailed analysis of aetiologically homogenous subgroups, thereby enabling determination of the spectrum of psychiatric symptoms in these disorders. This review evaluates the incidence and type of psychiatric symptoms encountered in patients with movement disorders. A broad spectrum of psychiatric symptoms was identified across all subtypes of movement disorder, with depression, generalised anxiety disorder and obsessive-compulsive disorder being most common. Psychosis, schizophrenia and attention deficit hyperactivity disorder were also identified, with the psychiatric symptoms often predating onset of the motor disorder. The high incidence of psychiatric symptoms across such a wide range of movement disorders suggests a degree of common or overlapping pathogenic mechanisms. Our review demonstrates the need for increased clinical awareness of such co-morbidities, which should facilitate early neuropsychiatric intervention and allied specialist treatment for patients.

Altered functional brain connectivity in children and young people with opsoclonus-myoclonus syndrome

AIM

Opsoclonus-myoclonus syndrome (OMS) is a rare, poorly understood condition that can result in long-term cognitive, behavioural, and motor sequelae. Several studies have investigated structural brain changes associated with this condition, but little is known about changes in function. This study aimed to investigate changes in brain functional connectivity in patients with OMS.

METHOD

Seven patients with OMS and 10 age-matched comparison participants underwent 3T magnetic resonance imaging (MRI) to acquire resting-state functional MRI data (whole-brain echo-planar images; 2mm isotropic voxels; multiband factor ×2) for a cross-sectional study. A seed-based analysis identified brain regions in which signal changes over time correlated with the cerebellum. Model-free analysis was used to determine brain networks showing altered connectivity.

RESULTS

In patients with OMS, the motor cortex showed significantly reduced connectivity, and the occipito-parietal region significantly increased connectivity with the cerebellum relative to the comparison group. A model-free analysis also showed extensive connectivity within a visual network, including the cerebellum and basal ganglia, not present in the comparison group. No other networks showed any differences between groups.

INTERPRETATION

Patients with OMS showed reduced connectivity between the cerebellum and motor cortex, but increased connectivity with occipito-parietal regions. This pattern of change supports widespread brain involvement in OMS.

Opsoclonus-myoclonus syndrome after adenovirus infection

Autoimmune and paraneoplastic movement disorders are rare in childhood. Diagnosis often relies on clinical manifestations and clinicians' recognition. A 22-month-old girl at onset of opsoclonus-myoclonus syndrome (OMS) was followed for 8 years. Adenovirus (type C subtype 3) infection coincided with manifestation. Data on treatment, imaging and follow-up are provided. In the spinal fluid, elevated anti-rubella antibodies and oligoclonal bands were detected. An autoimmune process affecting mainly cerebellar neurons was revealed immunohistochemically. Moderately intense long-term immunosuppressive therapy resulted in a favorable clinical outcome. A video demonstrated severe OMS manifestations at onset, followed by nearly complete recovery after treatment. We describe the association of a parainfectious OMS and adenovirus infection; laboratory results indicate a non-specific humoral process affecting mainly cerebellar neurons. Our video documentation will aid to recognize this rare movement disorder and to initiate early treatment.

A nationwide survey of opsoclonus-myoclonus syndrome in Japanese children

BACKGROUND

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disease characterized by opsoclonus, myoclonus, ataxia, and behavioral changes. The aim of our study was to investigate the epidemiological characteristics of OMS in Japan and to clarify the association between therapy and prognosis.

METHODS

We retrospectively collected the data from 626 Japanese medical institutions from 2005 to 2010, and analyzed the clinical features of pediatric patients with OMS based on the data.

RESULTS

In this survey, there were 23 patients (10 males and 13 females). The median ages at the disease onset and the time of study were 16.5 months (range: 11-152 months) and 54 months (range: 24-160 months), respectively. The principal symptoms were opsoclonus (23 patients, 100%), myoclonus (21 patients, 91.3%), and ataxia (23 patients, 100%). The related factors were neuroblastoma (10, 43.5%), infection (9, 39.1%), and immunization (2, 8.7%). The treatments for OMS were included intravenous immunoglobulin (17, 73.9%), methylprednisolone pulse (13, 56.5%), oral prednisolone (12 patients, 52.2%), and chemotherapy and/or operation for the underlying tumors (6, 26.1%), and rituximab (2, 8.7%). Complete remissions were obtained in 35.3%, 23.1%, 33.3%, 66.7%, and 100% of these treatments, respectively. At the latest follow-up period, 8 (34.8%) and 17 patients (73.9%) showed neurological sequelae of motor and intellectual functions, respectively. Patients whose treatment was started more than 30 weeks after the disease onset suffered from the severest neurological sequelae (OMS severity 4) more frequently than those less than 30 weeks (p=0.022).

CONCLUSION

The annual incidence of OMS was estimated to be 0.27-0.40 cases per million in Japanese children. More than 70% of OMS patients had neurological sequelae, especially intellectual function. Early effective treatments within 30 weeks after the onset may be required to prevent the serious neurological outcome.

Effect of Increased Immunosuppression on Developmental Outcome of Opsoclonus Myoclonus Syndrome (OMS)

Opsoclonus myoclonus syndrome (OMS) produces long-term cognitive, behavioral, and motor deficits. Objective was to see if more aggressive treatment improved outcome. Assessment included opsoclonus myoclonus syndrome rating, developmental/cognitive and motor assessment, and adaptive behavior. Fourteen subjects completed testing. Nine had neuroblastoma. Onset was at 10 to 35 months; onset to diagnosis: 2 days to 14 months, and onset to first treatment: 5 days to 15 months. Initial treatment was corticotropin (12), oral steroids (3), plus intravenous immunoglobulin in all. Ten received rituximab, 5 cyclophosphamide. Age at testing ranged from 2.5 to 10.3 years. Adaptive Behavior Score (11 subjects), mean 93.5; estimated Intelligence Quotient/Developmental Quotient mean 93.5; Motor: mean 92.8. Residual opsoclonus myoclonus syndrome symptoms at the time of the evaluation were generally minor; opsoclonus myoclonus syndrome scores ranged from 0 to 6. Comparison to previously reported opsoclonus myoclonus syndrome subjects showed improved outcomes: Adaptive behavior, cognitive and motor scores were significantly higher (P < .001) in new subjects. Outcomes have improved with more aggressive immunosuppression, with most opsoclonus myoclonus syndrome survivors now functioning at or near normal.

Paraneoplastic disorders of the central and peripheral nervous systems

Paraneoplatic neurologic syndromes (PNS) have been seminally defined as acute or subacute neurological syndromes resulting from nervous system dysfunction that is remote from the site of a malignant neoplasm or its metastases. However, in respect to our current understanding of their pathogenesis we may redefine these disorders as cancer-related dysimmune neurologic syndromes. We first deal with the epidemiology and the pathogenesis of PNS, then the different classic PNS are reviewed with clinical features according to the associated onconeuronal antibodies. Finally, therapeutic approaches are discussed.

Autoimmune encephalitis in children

The causes of encephalitis are numerous, and extensive investigations for infectious agents and other etiologies are often negative. The discovery that many of these encephalitis are immune mediated has changed the approach to the diagnosis and treatment of these disorders. Moreover, the broad spectrum of symptoms including, psychosis, catatonia, alterations of behavior and memory, seizures, abnormal movements, and autonomic dysregulation usually requires a multidisciplinary treatment approach. This review focuses in several forms of encephalitis that occur in children, and for which an autoimmune etiology has been demonstrated (eg, anti-N-methyl-d-aspartate receptor encephalitis) or is strongly suspected (eg, Rasmussen encephalitis, limbic encephalitis, opsoclonus-myoclonus). The authors also review several disorders that may be immune mediated, such as the rapid onset obesity with hypothalamic dysfunction, hypoventilation and autonomic dysregulation (ROHHAD) syndrome and some encephalopathies with fever and status epilepticus. Recognition of novel immune-mediated encephalitis is important because some of these disorders are highly responsive to immunotherapy.

Active comparator-controlled, rater-blinded study of corticotropin-based immunotherapies for opsoclonus-myoclonus syndrome

To test the efficacy and safety of corticotropin-based immunotherapies in pediatric opsoclonus-myoclonus syndrome, 74 children received corticotropin alone or with intravenous immunoglobulin (groups 1 and 2, active controls); or both with rituximab (group 3) or cyclophosphamide (group 4); or with rituximab plus chemotherapy (group 5) or steroid sparers (group 6). There was 65% improvement in motor severity score across groups (P < .0001), but treatment combinations were more effective than corticotropin alone (P = .0009). Groups 3, 4, and 5 responded better than group 1; groups 3 and 5 responded better than group 2. The response frequency to corticotropin was higher than to prior corticosteroids (P < .0001). Fifty-five percent had adverse events (corticosteroid excess), more so with multiagents (P = .03); and 10% had serious adverse events. This study demonstrates greater efficacy of corticotropin-based multimodal therapy compared with conventional therapy, greater response to corticotropin than corticosteroid-based therapy, and overall tolerability.

Cognitive and psychiatric phenotypes of movement disorders in children: a systematic review

AIM

The cognitive and psychiatric aspects of adult movement disorders are well established, but specific behavioural profiles for paediatric movement disorders have not been delineated. Knowledge of non-motor phenotypes may guide treatment and determine which symptoms are suggestive of a specific movement disorder and which indicate medication effects.

METHOD

The goal of this review is to outline the known cognitive and psychiatric symptoms associated with paediatric movement disorders. We used a systematic approach, via PubMed, and reviewed over 400 abstracts of studies of selected disorders, of which 88 papers reporting paediatric non-motor symptoms are summarized.

RESULTS

Obsessive-compulsive disorder was manifest in children with paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections and Sydenham chorea. Children with opsoclonus-myoclonus syndrome had, for the most part, cognitive and behavioural problems, and attention-deficit-hyperactivity disorder was reported as a major comorbidity in Tourette syndrome, stereotypies, and restless legs syndrome. Symptoms of depression and anxiety were more frequent in individuals with idiopathic dystonia. Affective disorders were suggestive of Wilson disease. Cognitive decline was common in children with juvenile Huntington disease. A limitation of this review was the lack of systematic assessment in paediatric movement disorders for evaluation and uniform definitions.

INTERPRETATION

Although the literature in non-motor phenomena is still emerging, recognition of salient cognitive and psychiatric phenomena may facilitate management of paediatric movement disorders.

Movement disorder emergencies in childhood

The literature on paediatric acute-onset movement disorders is scattered. In a prospective cohort of 52 children (21 male; age range 2mo-15y), the commonest were chorea, dystonia, tremor, myoclonus, and Parkinsonism in descending order of frequency. In this series of mainly previously well children with cryptogenic acute movement disorders, three groups were recognised: (1) Psychogenic disorders (n = 12), typically >10 years of age, more likely to be female and to have tremor and myoclonus (2) Inflammatory or autoimmune disorders (n = 22), including N-methyl-d-aspartate receptor encephalitis, opsoclonus-myoclonus, Sydenham chorea, systemic lupus erythematosus, acute necrotizing encephalopathy (which may be autosomal dominant), and other encephalitides and (3) Non-inflammatory disorders (n = 18), including drug-induced movement disorder, post-pump chorea, metabolic, e.g. glutaric aciduria, and vascular disease, e.g. moyamoya. Other important non-inflammatory movement disorders, typically seen in symptomatic children with underlying aetiologies such as trauma, severe cerebral palsy, epileptic encephalopathy, Down syndrome and Rett syndrome, include dystonic posturing secondary to gastro-oesophageal reflux (Sandifer syndrome) and Paroxysmal Autonomic Instability with Dystonia (PAID) or autonomic 'storming'. Status dystonicus may present in children with known extrapyramidal disorders, such as cerebral palsy or during changes in management e.g. introduction or withdrawal of neuroleptic drugs or failure of intrathecal baclofen infusion; the main risk in terms of mortality is renal failure from rhabdomyolysis. Although the evidence base is weak, as many of the inflammatory/autoimmune conditions are treatable with steroids, immunoglobulin, plasmapheresis, or cyclophosphamide, it is important to make an early diagnosis where possible. Outcome in survivors is variable. Using illustrative case histories, this review draws attention to the practical difficulties in diagnosis and management of this important group of patients.

Outcome and prognostic features in opsoclonus-myoclonus syndrome from infancy to adult life

OBJECTIVE

Opsoclonus-myoclonus syndrome (OMS) is a serious and often chronically disabling neurologic illness with onset in early childhood. Our aim was to identify long-term neurologic sequelae of OMS and predictors for disease outcome.

METHODS

We retrospectively assessed the case records of 101 patients diagnosed with OMS over a 53-year period. Clinical data were obtained from medical record review; we documented age at onset, severity of symptoms, response to treatment, and neurocognitive sequelae.

RESULTS

Overall, 21% of the patients had a neuroblastoma detected; however, in those born after 1990, this figure rose to 40%. Sixty-one percent of the patients had a chronic-relapsing course, 32% experienced several acute exacerbations, and 7% had a monophasic course. At the most recent review, 60% had residual motor problems, 66% speech abnormalities, 51% learning disability, and 46% behavior problems. One-third of the patients had normal intellectual outcome and cessation of symptoms. A severe initial presentation predicted a chronic disease course (odds ratio [OR]: 2.77 [95% confidence interval (CI): 1.47-5.23]; P = .002) and later learning disability (OR: 2.03 [95% CI: 1.08-3.79]; P = .026). Those with cognitive impairment were younger at disease onset (15.0 vs 19.5 months; P = .029). A chronic-relapsing disease course was associated with motor (P < .001), speech (P = .001), cognitive (P < .001), and behavior (P = .006) problems.

CONCLUSIONS

OMS is a chronic and debilitating illness; those with severe initial symptoms and those who are very young at disease onset are at increased risk of developing long-term sequelae. It is important for affected children to be identified early, because they might benefit from targeted immunomodulating therapy in specialist centers.

Neural bases of childhood speech disorders: lateralization and plasticity for speech functions during development

Current models of speech production in adults emphasize the crucial role played by the left perisylvian cortex, primary and pre-motor cortices, the basal ganglia, and the cerebellum for normal speech production. Whether similar brain-behaviour relationships and leftward cortical dominance are found in childhood remains unclear. Here we reviewed recent evidence linking motor speech disorders (apraxia of speech and dysarthria) and brain abnormalities in children and adolescents with developmental, progressive, or childhood-acquired conditions. We found no evidence that unilateral damage can result in apraxia of speech, or that left hemisphere lesions are more likely to result in dysarthria than lesion to the right. The few studies reporting on childhood apraxia of speech converged towards morphological, structural, metabolic or epileptic anomalies affecting the basal ganglia, perisylvian and rolandic cortices bilaterally. Persistent dysarthria, similarly, was commonly reported in individuals with syndromes and conditions affecting these same structures bilaterally. In conclusion, for the first time we provide evidence that longterm and severe childhood speech disorders result predominantly from bilateral disruption of the neural networks involved in speech production.

Update on diagnosis, treatment, and prognosis in opsoclonus-myoclonus-ataxia syndrome

PURPOSE OF REVIEW

Opsoclonus-myoclonus-ataxia syndrome (OMS) is a severe autoimmune central nervous system disorder, which predominantly affects young children and causes lifelong neurological disability. Early recognition and treatment may yield better outcomes.

RECENT FINDINGS

Appreciation of the spectrum of clinical presentations of OMS, awareness of common misdiagnoses, and utilization of diagnostic criteria may facilitate the timely diagnosis of OMS. Approximately 50% of patients have an associated neuroblastoma, which may escape detection by traditional methods and require MRI or computed tomography of the torso for diagnosis. In nonparaneoplastic cases, many associated infections have been reported. Although there has been progress in autoantibody identification and cerebrospinal fluid B cell expansion is a common finding, there is no diagnostic biomarker for OMS currently. Approximately 80% of reported patients, typically treated with conventional therapies such as adrenocorticotropin hormone, corticosteroids, and/or intravenous immunoglobulin, develop long-term neurological morbidity. Newer treatment approaches using early, aggressive therapy with cyclophosphamide or rituximab are promising.

SUMMARY

The diagnosis of OMS requires a high level of suspicion and a systematic approach for diagnostic testing, particularly for neuroblastoma. Future collaborative studies are required to determine whether early, aggressive therapy will improve the typically poor long-term neurological outcome.

Neuropsychological decline/improvement in opsoclonus myoclonus ataxia

Opsoclonus myoclonus ataxia (OMA) is a rare neurological disorder (incidence = approximately 1/5 million) primarily associated with involuntary conjugate saccadic eye movements, involuntary muscle jerks, cerebellar ataxia, and neuropsychological impairments. Unfortunately, there is limited published data regarding the nature and course of neuropsychological impairments following OMA diagnosis and treatment. This study presents neuropsychological data obtained at 1, 4, and 18 months post-diagnosis of a 52-year-old male with OMA. The patient initially demonstrated significant global neurocognitive, psychomotor, and psychological difficulties with substantial improvement over time. Treatment included medication management, physical rehabilitation, and psychological intervention.

Update on paraneoplastic neurologic disorders

When patients with cancer develop neurologic symptoms, common causes include metastasis, infections, coagulopathy, metabolic or nutritional disturbances, and neurotoxicity from treatments. A thorough clinical history, temporal association with cancer therapies, and results of ancillary tests usually reveal one of these mechanisms as the etiology. When no etiology is identified, the diagnosis considered is often that of a paraneoplastic neurologic disorder (PND). With the recognition that PNDs are more frequent than previously thought, the availability of diagnostic tests, and the fact that, for some PNDs, treatment helps, PNDs should no longer be considered diagnostic zebras, and when appropriate should be included in the differential diagnosis early in the evaluation.

Mycoplasma pneumoniae associated opsoclonus-myoclonus syndrome in three cases

Opsoclonus-myoclonus syndrome (OMS) is a rare acquired movement disorder occurring in all age groups, predominantly in infants. Although the exact pathogenesis is still undefined, there is strong evidence for a paraneoplastic or parainfectious immune process resulting in central nervous system dysfunction. Mycoplasma pneumoniae has been implicated in a number of immune-mediated neurologic diseases [28]. However, the association of M. pneumoniae and opsoclonus-myoclonus-ataxia syndrome is not well established so far. We present three cases with opsoclonus-myoclonus-ataxia syndrome in adolescents following an infection with M. pneumoniae. Monophasic disease course and full recovery correspond to the favorable prognosis known from parainfectious cases in young adults. This should affect therapeutic consideration. OMS should be added to the spectrum of M. pneumoniae-associated neurologic complications. Nevertheless, neuroblastoma has to be ruled out in all cases of OMS.

Update on paraneoplastic neurological syndromes

PURPOSE OF REVIEW

To describe specificities and new advances in treatment of paraneoplastic neurological syndromes (PNS).

RECENT FINDINGS

PNS are defined as neurological syndromes of unknown cause that often antedate the diagnosis of an underlying cancer that is usually not clinically evident. The clinical signs of PNS are accurately described and 'classical' PNS have been established. Within the context of these syndromes, the concept of limbic encephalitis has evolved dramatically in the last 2 years due to the description of new auto-antibodies. The diagnosis and treatment of the associated cancer remains the key goal of the clinical management of PNS. However, the specific treatment of the neurological symptoms primarily depends on the immunological findings.

SUMMARY

There is increasing recognition of an extensive array of PNS and of several paraneoplastic antibodies as biological markers of these disorders. Basic immunological studies support the pathogenic role of some of these antibodies. Others are only markers of the disease.

Improvement of neurological status and quality of life in children with opsoclonus myoclonus syndrome at long-term follow-up

BACKGROUND

Kinsbourne syndrome or opsoclonus myoclonus syndrome (OMS) is characterized by rapid, involuntary, irregular conjugate eye movements (opsoclonus), myoclonic jerking of the limbs and trunk, ataxia, and behavioral disturbances. In general, the outcome of neurologic and behavioral symptoms is poor. Studies on quality of life (Qol) and recovery after very long-term follow-up of children with OMS are lacking.

METHODS

We studied long-term cancer survival, neurologic recovery, and Qol of a consecutive series of eight patients with OMS that were treated in our center. Two cross-sectional follow-up evaluations were conducted at a 3-year interval (T1 and T2).

RESULTS

In four out of eight children with OMS a neuroblastoma (NBL) was diagnosed and surgically removed completely. All children received immuno-modulatory therapy, consisting of prednisone (three children), prednisone and ACTH (four children), or prednisone, ACTH, and gammaglobulin (one child). At T1, median follow-up time was 9.5 years (range 3-14 years) after OMS onset and at T2, 11.6 years (range 6-17 years). Neurologic functioning improved in all children, reflected by a significant improvement of the mean Z-score in the motor domain of the Qol questionnaire at T2 as compared to T1. In contrast, seven children continued to have a severe developmental delay at T2. No significant difference in any of the variables was found between NBL survivors and OMS patients without NBL.

CONCLUSION

Cognitive and behavioral impairments and not a motor impairment, such as ataxia, appear to be predominant at long-term in children with OMS.

Immunoglobulin therapy in idiopathic hypothalamic dysfunction

Idiopathic hypothalamic dysfunction is a rare disorder presenting at age 3-7 years. Severe hypothalamic and brainstem dysfunction leads to death in 25% of patients. The disease is presumed to be autoimmune, or in some cases paraneoplastic. No successful treatment has been reported. Patient V. developed hyperphagia, hypersomnia, and extreme aggression at age 7 years, accompanied by episodes of hyperthermia, hypothermia, sinus bradycardia, hypernatremia, hyponatremia, persistent hyperprolactinemia, hypothyroidism, and growth-hormone deficiency. At age 9 years, a diagnosis of idiopathic hypothalamic dysfunction was rendered, and immunoglobulin therapy was commenced. Nine courses of immunoglobulins, at a dose of 2 g/kg every 4 weeks, were administered. Reproducible improvements in behavior and no further episodes of hyponatremia or hypernatremia and sinus bradycardia were evident. The endocrinologic abnormalities and poor thermoregulation remained. Administration of immunoglobulins during late stages of idiopathic hypothalamic dysfunction led to improvement in some but not all signs. Assuming an autoimmune basis for this disorder, treatment during early stages of disease should be more effective. To facilitate such early treatment, increased awareness of this disorder is necessary, to allow for early diagnosis.

Response to rituximab and prednisolone for opsoclonus-myoclonus-ataxia syndrome in a child with ganglioneuroblastoma

Opsoclonus-myoclonus-ataxia (OMA) syndrome is a rare neurobehavioral paraneoplastic disorder in children with neuroblastic tumors. The neurologic symptoms are generally treated with a number of immunosupressive and immunomodulating agents. A 4-year-old previously healthy male patient was admitted to the authors' center with progressive ataxia, gait disturbance, difficulty of speech, and opsoclonus. He had a diagnosis of ganglionueroblastoma at the thoracal paraspinal region. Following surgery, the patient received IVIG and prednisolone but his cerebellar symptoms progressed. Rituximab therapy was started and continued for total 8 weeks without any side effect. The authors observed excellent neurologic response in the patient at the 4th week of treatment. Rituximab is a new, promising, and safe therapy for OMA syndrome in children with neuroblastoma.

Neurometabolic effects of ACTH on free amino compounds in opsoclonus-myoclonus syndrome

To evaluate the possible role of central free amino compounds in pediatric opsoclonus-myoclonus syndrome (OMS), 21 cerebrospinal fluid (CSF) amino compounds were measured by an amino acid analyzer or mass spectroscopy in 74 anesthetized children, 54 with OMS and 20 age-matched neurological controls. In OMS, only phosphoethanolamine was increased compared to controls; OMS severity and duration had significant converse effects on alanine and phosphoethanolamine. In contrast, corticotropin (ACTH) treatment was associated with increased alanine and phenylalanine, and decreased taurine compared to controls and untreated OMS, and increased glutamine, lysine, ornithine, and tyrosine compared to untreated OMS. Other than low taurine, these effects were not found with corticosteroid treatment, and non-steroidogenic immunotherapy had no effect. The ACTH dose-association was most apparent for alanine and phosphoethanolamine, but lysine and ornithine were also higher in the high-dose ACTH group. There were no significant disease- or treatment-associated perturbations in GABA, glycine, or other amino acids. These data suggest a unique pattern of ACTH effects on non-neurotransmitter CSF amino compounds, for the most part not shared by steroids.

Differential diagnosis of cerebellar atrophy in childhood

Starting from the imaging appearance of cerebellar atrophy (CA) we provide checklists for various groups of CA: hereditary CA, postnatally acquired CA, and unilateral CA. We also include a list of disorders with ataxia as symptom, but no evidence of CA on imaging. These checklists may be helpful in the evaluation of differential diagnosis and planning of additional investigations. However, the complete constellation of clinical (including history and neurological examination), imaging, and other information have to be considered. On the basis of a single study distinction between prenatal onset atrophy, postnatal onset atrophy, and cerebellar hypoplasia is not always possible. Apart from rare exceptions, neuroimaging findings of CA are nonspecific. A pattern-recognition approach is suggested, considering isolated (pure) CA, CA and hypomyelination, CA and progressive white matter abnormalities, CA and basal ganglia involvement, and cerebellar cortex hyperintensity.