Clinical Presentation, Management, and Diagnostic Performance of 2021 Criteria for Paraneoplastic Neurologic Syndromes in Childhood

BACKGROUND AND OBJECTIVES

Paraneoplastic neurologic syndromes (PNSs) are remote neurologic immune-related effects of tumors. The clinical characteristics of pediatric PNSs remain unclear. We retrospectively examined the clinical characteristics of cases of pediatric PNSs and assessed the performance of the 2021 diagnostic criteria in children.

METHODS

Patients hospitalized in the Beijing Children's Hospital between June 2015 and June 2023 and fulfilling the description of definite by 2004 diagnostic criteria of PNSs were included. A retrospective analysis of clinical characteristics was conducted, and the 2021 diagnostic criteria were applied to rediagnostic stratification.

RESULTS

Among the 42 patients included, the most common neurologic syndrome was opsoclonus-myoclonus syndrome (OMS) (62%), followed by rapidly progressive cerebellar syndrome (26%). Most tumors were neuroblastomas (88%), with few being ovarian teratomas (10%). Approximately 71% (30/42) of patients were classified as definite and 24% (10/42) as probable according to the 2021 criteria. All cases judged as probable exhibited rapidly progressive cerebellar ataxia with neuroblastoma. For OMS, chemotherapy was administered based on the tumor's risk stage, accompanied by regular infusion of IV gamma globulin and oral steroids following tumor diagnosis. Twenty-one patients underwent regular follow-ups over 4.92 (0.58-7.58) years. The initial hospitalization recorded a median score of 12 (7-14) on the Mitchell and Pike OMS rating scale, decreasing to 0 (0-5) at the final follow-up. In cases of rapidly progressive cerebellar syndrome, a similar therapeutic regimen was used. Nine patients underwent regular follow-ups over 4.42 (1.17-7.50) years. The mean modified Rankin scale score at first hospitalization was 4 (3-4), reducing to 1 (0-4) at the final follow-up. Only 17% (5/30) of patients across both groups exhibited poor response to this regimen. Among these 5 patients, 4 belonged to the low-risk group (without chemotherapy).

DISCUSSION

OMS followed by rapidly progressive cerebellar ataxia are the most common forms of PNSs in children and are associated with neuroblastoma. An aggressive approach with multiple immunotherapies may improve the prognosis of neuroblastoma-associated PNSs. The 2021 criteria perform well in pediatric PNSs. However, we propose upgrading the classification of antibody-negative rapidly progressive cerebellar ataxia with neuroblastoma to definite diagnosis. This adjustment aims to further improve the diagnostic efficacy of this diagnostic criterion in childhood.

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.

Successful use of tacrolimus for treatment-refractory neuroblastoma-associated opsoclonus-myoclonus-ataxia syndrome: A case series

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is an autoimmune central nervous system disorder, primarily manifesting as a paraneoplastic sequalae to neuroblastoma, and characterized by motor disorders and behavioral disturbances. OMAS is typified by aberrant B-cell and T-cell activation. Current treatment involves immunosuppression using corticosteroids, intravenous immunoglobulin, and rituximab. However, these approaches often lead to treatment-related toxicities and symptomatic recurrences with chronic neurocognitive impairment. We treated three children with refractory neuroblastoma-associated OMAS with tacrolimus, a T-cell-targeting calcineurin inhibitor, effectively controlling symptoms within a month and enabling the discontinuation of immunosuppression with minimal side effects. Tacrolimus shows promise as a therapeutic option for refractory OMAS.

A rare clinical presentation of COVID 19: opsoclonus-myoclonus ataxia syndrome

INTRODUCTION

Coronavirus disease 2019 (COVID-19) can have symptoms like many neurological diseases, and one of the rare forms of these presentations is opsoclonus-myoclonus ataxia syndrome (OMAS). The pathogenesis of OMAS in adults has not been clearly elucidated and OMAS can be fatal.

CASE PRESENTATION

We present a 71-year-old male patient who was admitted to the emergency department with complaints of involuntary tremor-like movements in his hands, feet and mouth, and speech impediment for three days, and was followed up with COVID-19. The patient was diagnosed with OMAS and clonazepam treatment was started. He died three days later due to respiratory arrest. Our case is the first case diagnosed with COVID-19-associated OMAS in Turkey.

DISCUSSION

OMAS has no definitive treatment. Early diagnosis and initiation of corticosteroids and intravenous immunoglobulin (IVIG) therapy, if necessary, can be life-saving. In COVID-19 patients with unexplained clinical findings, awareness of different and rare diseases and a multidisciplinary approach has vital importance.

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.

[Clinical analysis of adult oculomoclonus-myoclonus syndrome with vertigo]

The clinical manifestation, physical and laboratory examination, electrophysiological, and imaging data of 2 female adult OMS patients with vertigo were analyzed at the Department of Neurology of the First Medical Center of Chinese PLA General Hospital from February 2021 to March 2022. The treatment strategy and clinical outcome were followed up. The two female patients were aged 42 and 66 years. Anti-NMDA receptor antibody and anti-GABAB receptor antibody were detected in serological screening, respectively. The two patients met the diagnostic criteria for OMS, and one was screened for breast tumor. The clinical symptoms of the two patients were relieved after immunomodulation therapy. OMS is a group of rare clinical syndromes; its clinical evaluation process should be standardized and the etiology should be actively searched for.

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

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

Anti-SOX1 Antibody-positive Small-cell Lung Cancer That Triggered Opsoclonus

A 72-year-old woman with opsoclonus visited our hospital and was diagnosed with small-cell lung cancer. Blood tests revealed anti-SOX1 antibodies, so the patient was diagnosed with paraneoplastic opsoclonus-myoclonus syndrome. After steroid pulse therapy was started, chemotherapy of treatment, the opsoclonus showed an improving trend. Anti-Ri and anti-Hu antibodies have been reported as autoantibodies associated with neoplastic opsoclonus-myoclonus syndrome; however, there are no such reports concerning anti-SOX1 antibody. Therefore, this is a valuable case.

Opsoclonus-myoclonus Syndrome with Neuroblastoma in Children and their Anaesthetic Management

Opsoclonus-myoclonus syndrome (OMS) or the dancing eye syndrome, is a rare inflammatory neurological disorder often with paraneoplastic aetiology. It has an incidence of 1 in 1000,000 population worldwide. Opsoclonus-myoclonus syndrome is associated with 2-3% of patients having neuroblastoma. The authors present 5 cases of OMS in children who had neuroblastoma and underwent surgical resection. The median age was 26 (14-36) months. Male: female ratio was 1:1.5. All the patients had moderate to severe symptoms. Duration of symptoms at presentation varied from 3 days to one and half years. The possibility of OMS should be considered in all children presenting with probable neurological symptoms. Pharmacological therapy combined with surgery results in a good outcome. Balanced anaesthesia with the most commonly used drugs can be safely administered in the patients with opsoclonus-myoclonus syndrome. Key Words: Opsoclonus, Myoclonus, Neuroblastoma, Child, Anaesthesia.

Postinfectious SARS-CoV-2 Opsoclonus-Myoclonus-Ataxia Syndrome

BACKGROUND

The opsoclonus-myoclonus-ataxia syndrome (OMAS) represents a pathophysiology and diagnostic challenge. Although the diverse etiologies likely share a common mechanism to generate ocular, trunk, and limb movements, the underlying cause may be a paraneoplastic syndrome, as the first sign of cancer, or may be a postinfectious complication, and thus, the outcome depends on identifying the trigger mechanism. A recent hypothesis suggests increased GABAA receptor sensitivity in the olivary-oculomotor vermis-fastigial nucleus-premotor saccade burst neuron circuit in the brainstem. Therefore, OMAS management will focus on immunosuppression and modulation of GABAA hypersensitivity with benzodiazepines.

METHODS

We serially video recorded the eye movements at the bedside of 1 patient with SARS-CoV-2-specific Immunoglobulin G (IgG) serum antibodies, but twice-negative nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR). We tested cerebrospinal fluid (CSF), serum, and nasopharyngeal samples. After brain MRI and chest, abdomen, and pelvis CT scans, we treated our patient with clonazepam and high-dose Solu-MEDROL, followed by a rituximab infusion after her formal eye movement analysis 10 days later.

RESULTS

The recordings throughout her acute illness demonstrated different eye movement abnormalities. While on high-dose steroids and clonazepam, she initially had macrosaccadic oscillations, followed by brief ocular flutter during convergence the next day; after 10 days, she had bursts of opsoclonus during scotopic conditions with fixation block but otherwise normal eye movements. Concern for a suboptimal response to high-dose Solu-MEDROL motivated an infusion of rituximab, which induced remission. An investigation for a paraneoplastic etiology was negative. CSF testing showed elevated neuron-specific enolase. Serum IgG to Serum SARS-CoV2 IgG was elevated with negative RT-PCR nasopharyngeal testing.

CONCLUSION

A recent simulation model of macrosaccadic oscillations and OMAS proposes a combined pathology of brainstem and cerebellar because of increased GABAA receptor sensitivity. In this case report, we report 1 patient with elevated CSF neuronal specific enolase, macrosaccadic oscillations, ocular flutter, and OMAS as a SARS-CoV-2 postinfectious complication. Opsoclonus emerged predominantly with fixation block and suppressed with fixation, providing support to modern theories on the mechanism responsible for these ocular oscillations involving cerebellar-brainstem pathogenesis.

Delayed Opsoclonus-Myoclonus Syndrome After Ovarian Teratoma Resection

ABSTRACT

Opsoclonus-myoclonus syndrome (OMS) is a rare syndrome characterized by opsoclonus, which is irregular, spontaneous, multivectorial saccadic eye movements, along with diffuse or focal myoclonus and sometimes ataxia. OMS is associated with paraneoplastic etiologies in 20%-40% of cases, with small-cell lung and breast cancers the most common associated primary neoplasms in adults, whereas neuroblastoma is more common in children and ovarian teratoma may occur in women younger than 30 years. Onconeural antibodies are often not identified. In existing literature, paraneoplastic OMS precedes identification of the neoplasm, and neurological recovery depends on treatment of the underlying cancer. We describe a 27-year-old woman with the delayed onset of OMS one month after resection of ovarian teratoma, likely due to immune trigger from antigen exposure at the time of resection. She was treated with intravenous methylprednisolone, immunoglobulins, and eventually rituximab with resolution of her symptoms. Identification of OMS after tumor resection and prompt immunotherapy are critical for neurologic recovery. At 30-month follow-up, this patient had not experienced recurrence of OMS.

Paraneoplastic Opsoclonus-myoclonus Syndrome with Anti-Hu and Anti-SOX-1 Antibodies after Immune-checkpoint Inhibitor Treatment Combined with Chemotherapy in a Patient with Small-cell Lung Cancer

A 69-year-old man with advanced small-cell lung cancer achieved partial remission after 3 courses of immunochemotherapy that included atezolizumab. Ten days after the last treatment, he developed paraneoplastic opsoclonus-myoclonus syndrome and required mechanical ventilation. Serology testing detected anti-Hu and anti-SOX-1 antibodies. Despite steroid pulse therapy, various anticonvulsants, continuous intravenous sedation, and a fourth course of chemotherapy without atezolizumab, his condition failed to improve. Paraneoplastic opsoclonus-myoclonus syndrome with autoantibodies after immune-checkpoint inhibitor treatment has not been reported previously. Although a causal relationship between immune-checkpoint inhibitors and paraneoplastic syndromes has been suggested, the mechanism remains unknown.

Opsoclonus-Myoclonus-Ataxia Syndrome Related to the Novel Coronavirus (COVID-19)

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Neurological complications of pediatric cancer

Both the onset of various malignancies as well as the treatment of cancer can lead to neurologic symptoms which can be difficult to diagnose. In this review, we highlight the varied ways in which neurologic sequelae of cancer and its treatment manifest in children. Initial neurologic presentation may be secondary to mass effect or to immune-mediated paraneoplastic syndromes. Treatment effects on the nervous system may arise from surgery, chemotherapy, radiation, or bone marrow transplantation. In addition, the rapidly expanding field of immunotherapies for cancer has generated numerous new approaches to eradicating cancer including monoclonal antibodies, checkpoint inhibitors, and chimeric antigen receptor T cells (CAR-T cells), which have neurologic side effects mediated by immune responses that are also being recognized. Here we review common consult questions to the neurologist and our general approach to these scenarios including altered mental status, headaches, seizures, and sensorimotor complaints, considering the multifactorial nature of each.

Update on opsoclonus-myoclonus syndrome in adults

Opsoclonus-myoclonus syndrome in adults is a rare and heterogeneous disorder with the clinical features of opsoclonus, myoclonus, ataxia, and behavioral and sleep disturbances. The pathophysiology is thought to be immunological on the basis of paraneoplastic or infectious etiologies. Immunomodulatory therapies should be performed although the response may be incomplete. A number of autoantibodies have been identified against a variety of antigens, but no diagnostic immunological marker has yet been identified. This review focuses on underlying mechanisms of opsoclonus-myoclonus syndrome, including findings that have been identified recently, and provides an update on the clinical features and treatments of this condition.

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.

Adult-onset opsoclonus-myoclonus syndrome due to West Nile Virus treated with intravenous immunoglobulin

A 63-year-old female with no significant past medical history was presented with a 5-day history of progressive opsoclonus-myoclonus, headaches, and fevers. Her workup was significant only for positive West-Nile Virus serum serologies. She received a 2-day course of intravenous immunoglobulin (IvIG). At an 8-week follow up, she had a complete neurological remission. Adult-onset opsoclonus-myoclonus syndrome is a rare condition for which paraneoplastic and infectious causes have been attributed. To our knowledge, this is the first case reported of opsoclonus-myoclonus secondary to West-Nile Virus treated with intravenous immunoglobulin monotherapy.

[Comprehensive treatment of neuroblastoma in children associated with opsoclonus-myoclonus-ataxia syndrome]

OBJECTIVE

To investigate the efficacy of combined modality therapy for neuroblastoma in children associated with opsoclonus-myoclonus syndrome (OMS-NB).

METHOD

From May 2011 to December 2013, 6 consecutive patients (4 boys and 2 girls) diagnosed as OMS-NB underwent surgery and chemotherapy in the First Hospital, Peking University. The median age of onset was 19.5 months (range 13-24 months) and misdiagnosis occurred 7.5 months (range 2-14 months) ago. A retrospective analysis for the location, stage, pathological type, treatment way and outcome of neuroblastoma was done.

RESULT

(1) All patients were misdiagnosed as simply opsoclonus-myoclonus syndrome (OMS) at the time of onset. They had been receiving treatment with adrenocorticotropic hormone and intravenous immunoglobulin within 1-13 months.OMS-NB was diagnosed by means of enhanced abdominal CT image which was delayed to be given after the poor efficacy or relapse. (2) The primary tumors were almost all small, stage I-II, located in adrenal, retroperitoneal or pelvis. The pathology of tumors included ganglioneuroblastoma (5/6) and neuroblastoma (1/6). (3) All these cases underwent surgery, 4/6 cases with complete tumor resection, 2/6 cases with tumor around the aorta and induced local residue. Preoperative and postoperative chemotherapy was given to 2 and 5 cases, respectively. (4) The patients were followed up for 3-31 months, except 1 patient lost, the other 5 are currently surviving disease-free (3 having been at the end of chemotherapy, 1 still in chemotherapy, and another had local recurrence and is receiving radiotherapy and chemotherapy after the second operation and now also stopped taking the medicine). The symptoms of nervous system have been significantly improved during postoperative chemotherapy.

CONCLUSION

To reduce the misdiagnosis, regular CT imaging of the abdomen or pelvic should be ordered for all cases with OMS. The children with OMS-NB need to be actively treated with the combined modality therapy including surgery, chemotherapy or radiotherapy, to reduce recurrence and reduce the symptoms of nervous system.

[Gustavo Pittaluga and the expedition to study sleeping sickness in the Spanish territories of the Gulf of Guinea (1909)]

INTRODUCTION

Sleeping sickness, or human African trypanosomiasis, caused an important mortality at the beginnings of the twentieth century. For this reason the European colonial countries organized several scientific expeditions which contributed decisively to the knowledge of the disease.

AIM

To study the first investigation performed in Spain on African trypanosomiasis and in the field of tropical medicine, which was accomplished by a scientific expedition to the Spanish territories in the Gulf of Guinea organized by Cajal in 1909.

DEVELOPMENT

The parasitologist Gustavo Pittaluga, who became one of the most outstanding figures in Spanish medicine and public health during the first third of the twentieth century, commanded the expedition. Other members were Luis Rodriguez Illera and Jorge Ramon Fananas, Cajal's son. Along four months they travelled through the Spanish territories of Guinea, collecting clinical and epidemiological information on sleeping sickness and other diseases, and examining a great number of patients, who had hematological and parasitological studies performed. In the clinical description of the 14 cases of trypanosomiasis studied we have found the first description of the opsoclonus-myoclonus syndrome. A pathological study of the brain was performed in one case. In addition, important entomological studies and experimental investigations on trypanosomiasis were also performed.

CONCLUSIONS

This expedition took place in the context of the impulse of renovation of Spanish science headed by Cajal through the Junta de Ampliacion de Estudios, recently created. In the investigations performed in Guinea, Pittaluga demonstrated a high scientific standard in the fields of clinical medicine, hygiene, parasitology and entomology, comparable with other contemporary European studies.

Opsoclonus-myoclonus syndrome following influenza a infection

A 60-year-old woman developed opsoclonus-myoclonus syndrome (OMS) a week after being diagnosed with influenza A infection by a rapid antigen test. She had no loss of consciousness. Opsoclonus, myoclonus, and truncal ataxia were noted. Two weeks after treatment with intravenous immunoglobulin and corticosteroids, her opsoclonus, myoclonus, and truncal ataxia disappeared. No malignant tumors were detected during the 3-year follow-up period. There has been no previous report of postinfectious OMS following confirmed influenza A infection. OMS without a loss of consciousness has been reported to be statistically less common in cases of non-paraneoplastic OMS. This finding was consistent with the present patient's clinical manifestations.

[Opsoclonus-myoclonus syndrome in a 2 year old boy with prenatally diagnosed retroperitoneal tumour]

Opsoclonus-myoclonus syndrome, also named Myoclonic Encephalopathy of Infants, Opsoclonus- Myoclonus Ataxia, Dancing Eyes - Dancing Feet Syndrome, Dancing Eyes Syndrome, Kinsbourne syndrome, is a rare, paraneoplastic or possibly post-viral chronic neurological disorder. The age of presentation ranges from 6 months to 3 years. In 50% of affected children the syndrome is associated with an underlying occult or clinically apparent neuroblastoma. In most patients the tumour is localized, small and well differentiated, with no NMYC gene copy number amplification. The syndrome may also occur after tumour resection or at relapse. The opsoclonus-myoclonus syndrome can occur in children without neuroblastoma, in such idiopathiccases, the onset of neurological symptoms is related to infection. It is assumed, that in idiopathic cases the syndrome could have developed in the course of neuroblastoma which had undergone a complete spontaneous regression. The most characteristic clinical features of opsoclonus-myoclonus syndrome are: opsoclonus, myoclonus, ataxia, irritability, mutism and sleep disturbances. The disease course is usually long-term with episodes of remission and relapses. Approximately 80% of children with opsoclonus-myoclonus syndrome suffer from mild to severe neurological handicaps, mainly cognitive impairment. The authors present a 2-year old boy with opsoclonus-myoclonus syndrome preceded by involution of prenatally documented retroperitoneal area tumour.

[Paraneoplastic opsoclonus-myoclonus syndrome--a review]

The aim of this article is to review the paraneoplastic opsoclonus-myoclonus syndrome (POMS). Opsoclonus is characterized by involuntary, arrhythmic, chaotic, multi-directional saccades with horizontal, vertical and torsional components, and it is commonly accompanied by cerebellar ataxia and myoclonic jerks in the trunk and limbs. Parainfectious brainstem encephalitis, toxic-metabolic disturbances and others condition should be considered as potential causes of these symptoms. In adults, POMS is most commonly associated with small-cell lung cancer, breast cancer, and ovarian cancer. In children, a neuroblastoma is detected in approximately 50% of cases. Many autoantibodies have been detected in patients with POMS: this finding suggests the involvement of a humoral immune mechanism. However, most patients are seronegative for these autoantibodies. This implies that a cell-mediated immune mechanism may also be involved in the pathogenesis of opsoclonus. Although the exact pathophysiology mechanism of opsoclonus remains unclear, recent reports suggest that disinhibition of the fastigial nucleus of the cerebellum is involved. In children, the immunotherapy with corticosteroids, intravenous immunoglobulin, adrenocorticotropic hormone, plasma exchange, cyclophosphamide, or rituximab is used. Although opsoclonus is often responsive to therapy, the high incidence of sequelae related to motor function, speech, behavior, and sleep is an important problem. In adults, POMS is less responsive to immunotherapy and improves only with tumor resection. In order to develop novel and effective therapeutic strategies, further studies on the immunopathogenesis and pathophysiology of POMS are required.

[Opsoclonus-myoclonus syndrome in children with neuroblastoma: description of 3 cases]

Neuroblastoma (NBL) is one of the most common childhood malignancies. Presence of untypical symptoms is characteristic for this malignancy; therefore it may mimic many other illnesses, both malignant and nonmalignant. Particular attention should be focused on opsoclonus-myoclonus syndrome (OMS, Kinsbourne's syndrome). In this paper three children with NBL previously diagnosed with OMS are presented. There is a need to test children with OMS for NBL as more than 30% of them are diagnosed with a tumor of neural origin. Children with NBL suffering from OMS have usually a favorable outcome with respect to their malignancy. However, the neurological and cognitive deficits are present for a long time and even they may become more intensive in spite of immunosuppressive therapy.

[Small cell lung cancer complicated by opsoclonus myoclonus syndrome]

Opsoclonus myoclonus syndrome, one of the paraneoplastic neurological syndromes involving several neurological symptoms that result from "remote effects" of cancer, is a rare disease characterized by opsoclonus, cerebellar ataxia and myoclonus of the trunk and extremities. A 53-year-old man was admitted with dizziness and difficulty walking. Medical examinations led to a diagnosis of opsoclonus myoclonus syndrome. CT scans showed mediastinal and cervical lymphadenopathy, and a diagnosis of small cell lung cancer was made. Steroid therapy and chemotherapy (carboplatin + etoposide) produced significant improvement in the neurological symptoms.

[Opsoclonus-myoclonus-ataxia syndrome: two anatomo-clinical case reports]

INTRODUCTION

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is characterised by the acute or subacute development of chaotic eye movements and diffuse myoclonus. On some occasions it is associated with ataxia and encephalopathy. In adults there are multiple causations and a possible paraneoplastic origin must always be taken into account.

CASE REPORTS

We report two cases of OMAS of a paraneoplastic origin with a post mortem study. In the first case, the syndrome was associated to a small-cell carcinoma in the lungs, and in the second patient it was associated to a digestive lymphoma. Neuroimaging studies did not reveal any kind of alterations in either of the two cases. In our cases, none of the antibodies that are relatively frequently associated to this syndrome were found. In both of them, an immunomodulator treatment regimen was established; only the patient with the lymphoma showed an initial improvement with antineoplastic therapy. In the pathological study, alterations were observed in the brain stem, and in the second patient alterations were also found in the cerebellum.

CONCLUSIONS

This is a rare condition that obliges the specialist to think in order to reach a correct diagnosis, and to search for the primary tumour and establish early treatment in order to bring about an improvement and even the remission of the neurological signs and symptoms. The pathological findings are not pathognomonic, but they are typical of this syndrome.

[Opsoclonus-myoclonus syndrome]

The opsoclonus-myoclonus syndrome in children is a rare entity which is characterized by irritability, chaotic ocular movements with vertical, horizontal, rotatory components (opsoclonus) along with myoclonus and ataxia. In a high proportion of cases, it is associated with neuroblastoma although other etiologies involving infectious or toxic agents have been reported. An autoimmune mechanism would be responsible for the dysfunction of structures in brain stem and cerebellum thus explaining some of the cardinal symptoms such as opsoclonus, myoclonus and ataxia. However, encephalopathic symptoms and the high percentage of patients with neurocognitive and psychiatric sequels are in favor of a wider dysfunction. Treatment with steroids, ACTH, immunomodulatory or immunosuppressive drugs is being used although prospective studies are needed to determine whether the prolonged use of these drugs influences favorably the evolution of these patients.

An adult case of hand, foot, and mouth disease caused by enterovirus 71 accompanied by opsoclonus myoclonica

We reported a 23-year-old female who was treated for rash due to hand, foot, and mouth disease (HFMD). On day 4 of hospitalization, the patient showed opsoclonus (jerky eye movements in all directions), myoclonus of the neck, trunk, and extremities, and cerebellar ataxia. Based on the changes in serum viral antibody titer, the patient was diagnosed as enterovirus 71 infection. No obvious abnormal findings were noted in head MRI. Immunoglobulin 5 g/day was administered for 3 days in the early stages of infection, and administration of methylprednisolone 500 mg/day for 3 days was repeated twice. Afterwards, oral corticosteroids were given, resulting in neurological improvements a month. Including our case, there are only 2 cases within opsoclonus myoclonica associated with enterovirus 71 infection. Our case suggests, based on the course of treatment, possible involvement of direct viral action or autoimmune response in opsoclonus myoclonica.

Treatment of neuroblastoma-related opsoclonus-myoclonus-ataxia syndrome with high-dose dexamethasone pulses

Opsoclonus-myoclonus-ataxia-syndrome (OMS) represents a rare neuroblastoma-associated paraneoplastic syndrome that commonly results in neurologic deficits despite tumor resection and immunosuppressive therapy. We describe the response of five such children to high-dose dexamethasone pulses including two patients in whom previous glucocorticoids, rituximab, and cytostatic drugs were not successful. All patients had MYCN non-amplified tumors that were detected 1 to 7 months after the onset of the OMS or ataxia. This treatment resulted in a good partial response in three and in complete remission in two patients. Our results show that dexamethasone pulses are likely to be useful for both, first-line- and salvage-therapy for OMS-patients.

Rituximab for treatment of opsoclonus-myoclonus syndrome in neuroblastoma

Opsoclonus-myoclonus syndrome (OMS) is a rare paraneoplastic syndrome that occurs in 2%-3% of patients with neuroblastoma. The cause of this syndrome is believed to be immune mediated, but the exact mechanism still remains unclear. There is an urgent need to improve our current strategies for treating patients with OMS, as many patients have significant long-term neurologic deficits and behavior disorders with current treatment approaches. Therapies that have shown to improve symptoms in these patients have ranged from ACTH and corticosteroids, to intravenous gammaglobulin and plasmapheresis. We report our experience with Rituximab in a patient with neuroblastoma and OMS.

Response to rituximab in a child with neuroblastoma and opsoclonus-myoclonus

Opsoclonus-myoclonus (OM) is a paraneoplastic syndrome of probable autoimmune origin. Despite current therapies aimed at decreasing autoantibody formation, OM is difficult to control and may impact long-term neurologic outcome. We present a case of a 19-month-old patient who initially presented with OM, neuroblastoma and a constitutional cytogenetic abnormality t(5;12)(q11.2;q15). The patient's OM was recalcitrant to conventional therapies, but showed significant improvement following treatment with rituximab.

Neuroblastoma and opsoclonus-myoclonus-ataxia syndrome--clinical and pathological characteristics

INTRODUCTION

Opsoclonus-myoclonus-ataxia (OMA) syndrome is the most common paraneoplastic neurological syndrome in childhood.

MATERIALS AND METHODS

We reviewed the literature and reported on clinical and pathological characteristics of four children with OMA and peripheral neuroblastic tumours. In two of the children the onset of neurological symptoms was connected with a vaccination and in one with viral infection. The suprarenal gland was the primary localization of the tumour in 3 of the children and in one the tumour was located in the retroperitoneal area. All cases were in stage II or III of the disease, with no metastases or MYCN amplification. The group included two ganglioneuroblastomas, one ganglioneuroma and one differentiating neuroblastoma. The tumours were characterized by the presence of lymphocytic infiltrations with lymphadenoplasia. Immunohistochemical analysis of inflammatory infiltrations revealed mixed type populations of lymphocytes with prevalence of the cytotoxic type (CD8 and CD56-positive cells). The participation of dendritic cells and macrophages was also detected. All patients were treated by surgery alone or with adjuvant chemotherapy with a positive outcome. In 3 cases persistent neurological disorders were observed with exacerbations during infections.

CONCLUSION

In some patients the onset of OMA is related to vaccination or infection. Children with OMA and neuroblastoma despite a good oncological prognosis often present permanent neurological and developmental deficits. The inflammatory infiltrations within the tumours are combined, with predominant participation of cytotoxic cells.

Opsoclonus-myoclonus syndrome associated with group a streptococcal infection

This report describes the unusual syndrome of opsoclonus-myoclonus associated with group A streptococcal infection in a 9-year-old Nepalese boy.

Epstein-Barr virus related opsoclonus-myoclonus-ataxia does not rule out the presence of occult neuroblastic tumors

Opsoclonus-myoclonus-ataxia (OMA) secondary to Epstein-Barr virus (EBV) infection has only been described in three pediatric patients. Previous reports suggested that evidence for a recent EBV infection in the absence of an occult neoplasm would predict a favorable prognosis for OMA as well as no tumor development. We present the case of a 20-month-old child with OMA associated with a microbiologically documented acute EBV infection and an occult thoracic ganglioneuroblastoma diagnosed 5 months later.

Opsoclonus-myoclonus syndrome: a clinicopathological confrontation

Opsoclonus-myoclonus syndrome (OMS), a movement disorder characterised by chaotic eye movements and myoclonus, is a rare clinical entity. We present two cases of opsoclonus-myoclonus syndrome of paraneoplastic origin. In the first patient the syndrome was associated with a breast carcinoma and in the second patient with a non small cell lung carcinoma. However none of the commonly associated antibodies were found in these cases. From the neuropathological findings from the first patient we find arguments that support the current hypothesis on the pathophysiology of OMS namely a dysfunction in brainstem and cerebellum. We conclude that in adults with OMS one has to be very suspicious of a possible neoplastic origin of the syndrome. The antibodies associated with some cases of OMS are thought to play a role in the pathophysiology of the syndrome although the exact immunologic mechanism remains unknown. Research into the neuropathological substrate of OMS yields a broad range of abnormalities in brain stem and cerebellum. However none of these findings seem to be pathognomonic. As for the possible therapy of OMS, several immunomodulating strategies can be used with varying success. At present there is no established standard therapy.