Opsoclonus-Myoclonus With Anti-YO Antibodies Revealing Breast Cancer: A Case Report.

Opsoclonus myoclonus syndrome (OMS) is a rare neurological disorder characterized by irregular, continuous, and chaotic eye saccades accompanied by myoclonus, defined by brief, shock-like muscle spasms in the arms or legs. This syndrome often presents with additional features such as cerebellar syndrome, nycthemeral rhythm disorders, hallucinosis, and irritability-type behavioral disorders. In adults, OMS is predominantly paraneoplastic, necessitating screening for onconeural antibodies (ONA). While specific medications for OMS are lacking, addressing the underlying cause may ameliorate its clinical manifestations. The presence of opsoclonus-myoclonus should prompt urgent and thorough investigation for an underlying cancer, given its frequent association with paraneoplastic neurological syndrome (PNS). Here, we present the case of a 39-year-old patient with opsoclonus associated with cerebellar ataxia, revealing a breast neoplasm with positive anti-YO antibodies. Through the review of the literature, we discuss the epidemiological, clinical, diagnostic, and therapeutic aspects of this rare situation.

Drug- and Toxin-Induced Opsoclonus - a Systematized Review, including a Case Report on Amantadine-Induced Opsoclonus in Multiple System Atrophy.

Background: Opsoclonus is a rare disorder characterized by conjugate multidirectional, horizontal, vertical, and torsional saccadic oscillations, without intersaccadic interval, resulting from dysfunction within complex neuronal pathways in the brainstem and cerebellum. While most cases of opsoclonus are associated with autoimmune or paraneoplastic disorders, infectious agents, trauma, or remain idiopathic, opsoclonus can also be caused by medications affecting neurotransmission. This review was prompted by a case of opsoclonus occurring in a patient with Multiple System Atrophy, where amantadine, an NMDA-receptor antagonist, appeared to induce opsoclonus. Methods: Case report of a single patient and systematized review of toxic/drug-induced opsoclonus, selecting articles based on predefined criteria and assessing the quality of included studies. Results: The review included 30 articles encompassing 158 cases of toxic/drug-induced opsoclonus. 74% of cases were attributed to bark scorpion poisoning, followed by 9% of cases associated with chlordecone intoxication. The remaining cases were due to various toxics/drugs, highlighting the involvement of various neurotransmitters, including acetylcholine, glutamate, GABA, dopamine, glycine, and sodium channels, in the development of opsoclonus. Conclusion: Toxic/drug-induced opsoclonus is very rare. The diversity of toxics/drugs impacting different neurotransmitter systems makes it challenging to define a unifying mechanism, given the intricate neuronal pathways underlying eye movement physiology and opsoclonus pathophysiology.

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.

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.

Scrub typhus with opsoclonus-myoclonus-ataxia-seizure as primary presentations.

Scrub typhus is a simple acute febrile illness with rash or an eschar, with up to one-fifth of the patients complicated with the nervous system. Hence, certain cases present to physicians with rather a different systemic manifestation and incidentally have been diagnosed with scrub typhus. We present two such cases of scrub typhus with neurological manifestations. The first case was of a 14-year-old boy with no previous history of any comorbidities who presented with bilateral opsoclonus with multifocal spontaneous myoclonus with cerebellar ataxia with a preceding history of fever and acute gastroenteritis. The second case of a 30-year-old gentleman with no previous history of any comorbidities presented to us with generalized tonic-clonic seizures and spontaneous multifocal myoclonus with a preceding history of fever. Both cases had no motor, sensory, cerebellar, or autonomic involvement. The pathophysiology of central nervous system (CNS) infections in scrub typhus is attributed to three major mechanisms of vasculitis, direct invasion, and immune-mediated. CNS involvement in scrub typhus is a significant marker for risk of mortality or morbidity. The most common CNS manifestations in scrub include meningitis, encephalitis, and seizures. Opsoclonus, myoclonus, and parkinsonism are comparatively rare manifestations.Scrub typhus infection must be considered in the differential diagnosis of clinical neurological features with even a remote history of acute febrile illnesses in endemic regions like ours, despite the absence of any eschar, rashes, and unremarkable neuroimaging.

Review of Opsoclonus-Myoclonus Ataxia Syndrome in Pediatric Patients.

Opsoclonus-myoclonus ataxia syndrome (OMAS), also known as Kinsbourne syndrome, is a rare disorder that presents with myoclonus, ataxia, abnormal eye movements, irritability, and sleep disruptions, often in young children. We report a case of an infant barely 6 months old, with no significant past medical history, who presented to the emergency department with tremors, jerking motions of the head and arms, and rapid eye movements. After an extensive workup, she was found to have a neuroblastoma, which was subsequently surgically removed via thoracotomy. Despite an initial improvement in symptoms post-resection, the patient's symptoms recurred. She was subsequently treated with dexamethasone, intravenous immunoglobulin (IVIG), and rituximab. After treatment, the patient was noted to have mild global developmental delays but was otherwise well. This case report highlights the rare occurrence of OMAS in an infant barely 6 months old at diagnosis. Using the PubMed database, a systematic review was conducted to highlight the clinical presentation, diagnosis, and management of 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.

Paraneoplastic cerebellar and brainstem disorders.

Paraneoplastic cerebellar and brainstem disorders are a heterogeneous group that requires prompt recognition and treatment to help prevent irreversible neurologic injury. Paraneoplastic cerebellar degeneration is best characterized by Yo antibodies in patients with breast or ovarian cancer. Tr (DNER) antibodies in patients with Hodgkin lymphoma can also present with a pure cerebellar syndrome and is one of the few paraneoplastic syndromes found with hematological malignancy. Opsoclonus-myoclonus-ataxia syndrome presents in both pediatric and adult patients with characteristic clinical findings. Other paraneoplastic brainstem syndromes are associated with Ma2 and Hu antibodies, which can cause widespread neurologic dysfunction. The differential for these disorders is broad and also includes pharmacological side effects, infection or postinfectious processes, and neurodegenerative diseases. Although these immune-mediated disorders have been known for many years, mechanisms of pathogenesis are still unclear, and optimal treatment has not been established.

Overview of treatment strategies in paraneoplastic neurological syndromes.

Treatment strategies in paraneoplastic neurological syndromes rely on the three pillars of tumor treatment, immunotherapy, and symptomatic treatment, the first one being by far the most important in the majority of patients and syndromes. Classically, antibodies against extracellular antigens are directly pathogenic, and patients with these syndromes are more responsive to immunomodulatory or immunosuppressive treatments than the ones with antibodies against intracellular targets. This chapter first discusses some general principles of tumor treatment and immunotherapy, followed by a closer look at specific treatment options for different clinical syndromes, focusing on symptomatic treatments.

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.

Rare Presentation and Diagnostic Challenge of a Germ Cell Tumor of the Yolk Sac Type.

Opsoclonus-ataxia paraneoplastic syndrome (OAPS) is a rare neurological disorder often associated with malignancies. This case report highlights an unusual instance of OAPS linked to a yolk sac (germ cell) tumor, a correlation underrepresented in the medical literature. The patient presented with distinct neurological symptoms alongside mediastinal lymphadenopathies. The subsequent diagnostic journey revealed a yolk sac germ cell tumor. Following incisional biopsies and treatment, the patient experienced fluctuations in mental status, leading to challenges in initiating chemotherapy. Despite these complications, a multidisciplinary approach involving neurologists, oncologists, and hematologists was pivotal. The case emphasizes the complexities of managing OAPS in tandem with a germ cell tumor, underscoring the need for further research and highlighting the significance of specialized neurological evaluation in similar cases.

KCTD7-related progressive myoclonic epilepsy: Report of 42 cases and review of literature.

OBJECTIVE: KCTD7-related progressive myoclonic epilepsy (PME) is a rare autosomal-recessive disorder. This study aimed to describe the clinical details and genetic variants in a large international cohort. METHODS: Families with molecularly confirmed diagnoses of KCTD7-related PME were identified through international collaboration. Furthermore, a systematic review was done to identify previously reported cases. Salient demographic, epilepsy, treatment, genetic testing, electroencephalographic (EEG), and imaging-related variables were collected and summarized. RESULTS: Forty-two patients (36 families) were included. The median age at first seizure was 14 months (interquartile range = 11.75-22.5). Myoclonic seizures were frequently the first seizure type noted (n = 18, 43.9%). EEG and brain magnetic resonance imaging findings were variable. Many patients exhibited delayed development with subsequent progressive regression (n = 16, 38.1%). Twenty-one cases with genetic testing available (55%) had previously reported variants in KCTD7, and 17 cases (45%) had novel variants in KCTD7 gene. Six patients died in the cohort (age range = 1.5-21 years). The systematic review identified 23 eligible studies and further identified 59 previously reported cases of KCTD7-related disorders from the literature. The phenotype for the majority of the reported cases was consistent with a PME (n = 52, 88%). Other reported phenotypes in the literature included opsoclonus myoclonus ataxia syndrome (n = 2), myoclonus dystonia (n = 2), and neuronal ceroid lipofuscinosis (n = 3). Eight published cases died over time (14%, age range = 3-18 years). SIGNIFICANCE: This study cohort and systematic review consolidated the phenotypic spectrum and natural history of KCTD7-related disorders. Early onset drug-resistant epilepsy, relentless neuroregression, and severe neurological sequalae were common. Better understanding of the natural history may help future clinical trials.

Retrospective analysis of COVID-19 patients with Guillain-Barre, Miller-Fisher, and opsoclonus-myoclonus-ataxia syndromes-a case series.

BACKGROUND: In accordance with the rising number of SARS-CoV­2 infections, reports of neurological complications have also increased. They include cerebrovascular diseases but also immunological diseases such as Guillain-Barre syndrome (GBS), Miller-Fisher syndrome (MFS), and opsoclonus-myoclonus-ataxia syndrome (OMAS). While GBS and MFS are typical postinfectious complications, OMAS has only recently been described in the context of COVID-19. GBS, MFS, and OMAS can occur as para- and postinfectious, with different underlying pathomechanisms depending on the time of neurological symptom onset. The study aimed to describe clinical features, time between infection and onset of neurological symptoms, and outcome for these diseases. METHODS: All COVID-19 patients treated in the neurological ward between January 2020 and December 2022 were screened for GBS, MFS, and OMAS. The clinical features of all patients, with a particular focus on the time of onset of neurological symptoms, were analyzed. RESULTS: This case series included 12 patients (7 GBS, 2 MFS, 3 OMAS). All GBS and one MFS patient received immunomodulatory treatment. Three patients (2 GBS, 1 OMAS) had a severe COVID-19 infection and received mechanical ventilation. In patients with OMAS, only one patient received treatment with intravenous immunoglobulin and cortisone. The remaining two patients, both with disease onset concurrent with SARS-COV­2 infection, recovered swiftly without treatment. In all subgroups, patients with concurrent onset of neurological symptoms and COVID-19 infection showed a trend toward shorter disease duration. CONCLUSION: All patient groups displayed a shorter disease duration if the onset of neurological symptoms occurred shortly after the COVID-19 diagnosis. In particular, both the OMAS patients with symptom onset concurrent with COVID-19 showed only abortive symptoms followed by a swift recovery. This observation would suggest different pathomechanisms for immune-mediated diseases depending on the time of onset after an infection.

Opsoclonus Induced by Head-Shaking in Vestibular Migraine.

Opsoclonus refers to saccadic oscillations without an intersaccadic interval occurring in multiple planes. Opsoclonus mostly indicates dysfunction of the brainstem or cerebellum. We report opsoclonus induced by horizontal head-shaking without other signs of brainstem or cerebellar dysfunction in two patients with vestibular migraine (VM). The development of opsoclonus after horizontal head-shaking indicates unstable or hyperactive neural circuits between the excitatory and inhibitory saccadic premotor burst neurons in these patients with VM.

Adult-onset idiopathic opsoclonus-myoclonus syndrome / Síndrome de opsoclonia-mioclonia idiopática de início adulto

ABSTRACT Purpose: Opsoclonus-myoclonus syndrome is extremely uncommon in adults with an autoimmune pathophysiology. Because of the rarity of the syndrome, international recognition of opsoclonus-myoclonus-ataxia syndrome needs to be improved urgently. Therefore, the goal of this study was to raise the awareness of the opsoclonus-myoclonus-ataxia syndrome and help doctors in better diagnosing and using immunotherapy. Methods: We present a case study of an adult-onset case of idiopathic opsoclonus-myoclonus syndrome characterized by spontaneous arrhythmic multidirectional conjugate eye movements, myoclonus, ataxia, sleep disorders, and intense fear. Additionally, we conduct a literature search and summarize the pathophysiology, clinical presentation, diagnosis, and treatment of opsoclonus-myoclonus-ataxia syndrome. Results: Immunotherapies successfully treated the patient's opsoclonus, myoclonus, and ataxia. Further, the article also includes an update summary of the opsoclonus-myoclonus-ataxia syndrome. Conclusion: The prevalence of residual sequela in adults with opsoclonus-myoclonus-ataxia syndrome is low. Early diagnosis and treatment may result in a better prognosis. Furthermore, combined immunotherapy is expected to reduce the incidence of refractory and reoccurring opsoclonus-myoclonus-ataxia syndrome.

RESUMO Objetivo: A síndrome de opsoclonia-mioclonia é extremamente rara em adultos e tem uma fisiopatologia autoimune. Devido à raridade dessa síndrome, o reconhecimento da síndrome de opsoclonia-mioclonia-ataxia precisa melhorar urgentemente em todo o mundo. Assim sendo, este estudo visou aumentar a conscientização sobre a síndrome de opsoclonia-mioclonia-ataxia e ajudar os médicos para um melhor diagnóstico e o uso correto da imunoterapia. Métodos: Este é o relato de um caso adulto de síndrome de opsoclonia-mioclonia idiopática com movimentos oculares conjugados, multidirecionais, arrítmicos e espontâneos, mioclonia, ataxia, distúrbios do sono e medo intenso. Além disso, foram pesquisadas as publicações recentes relevantes e resumiu-se a fisiopatologia, a apresentação clínica, o diagnóstico e o tratamento da síndrome de opsoclonia-mioclonia-ataxia. Resultados: A paciente recuperou-se totalmente da opsoclonia, da mioclonia e da ataxia através de imunoterapia. O artigo também fornece um resumo atualizado sobre a síndrome de opsoclonia-mioclonia-ataxia. Conclusão: Adultos com síndrome de opsoclonia-mioclonia-ataxia têm uma baixa frequência de sequelas residuais. O diagnóstico e o tratamento precoces podem levar a melhores prognósticos. Espera-se que a imunoterapia combinada reduza a incidência da síndrome de opsoclonia-mioclonia-ataxia refratária e recorrente.

A Case of Paraneoplastic Neurological Syndrome Leading to the Diagnosis of Large Cell Neuroendocrine Carcinoma From Opsoclonus-Myoclonus Syndrome.

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder characterized by myoclonus, ataxia, and tremors. It can be classified as neoplastic or idiopathic, with small cell lung cancer being commonly associated. Herein, we present a rare case of refractory paraneoplastic neurological syndrome (PNS) caused by large cell neuroendocrine carcinoma (LCNEC), a rare form of non-small cell lung cancer (NSCLC). A 60-year-old otherwise healthy man presented with acute-onset dysarthria, gait instability, and numbness on the right side of his body. According to the clinical symptoms and neurological examination, we initially suspected cerebellar infarction; however, brain imaging revealed no abnormal findings. After a few days, the patient developed worsening horizontal nystagmus, irregular ocular rhythms, and generalized involuntary movements, indicative of OMS. A systemic evaluation revealed a solitary nodule in the lower lobe of the right lung, leading to a clinical diagnosis of PNS. The patient underwent segmentectomy to treat an early-stage LCNEC nodule after one month from onset. Despite all therapeutic interventions, OMS was refractory, and after consulting with the person himself and the family, palliative care was selected. However, the patient showed a clinical response belatedly five months after surgery. This case highlights the importance of considering PNS, and that it may be associated with a rare malignancy when cerebellar symptoms are observed, and the challenges in managing refractory PNS associated with rare forms of NSCLC.

"The Red Flags" in Clinical Approach to Acute Ataxia-the Experience in Cohort of 76 Children.

The aim of our study is to define the most frequent etiology, clinical presentation, and predictive factors of outcome in children with acute ataxia (AA) and to determine "the red flags" in the diagnostic approach to children with AA. The retrospective study included the patients with AA treated in the institute from 2015 to 2021. The inclusion criteria were children aged 1-18 years, evolution time of ataxia within 72 h, and diagnosis made by a physician. The exclusion criteria were anamnestic data about ataxia without confirmation by any physician, chronic/persistent ataxia, and psychogenic or postictal ataxia. Clinical presentation was divided into two categories: (1) isolated cerebellar signs (CS): ataxic gait, dysmetria, dysdiadochokinesia, intention tremor, dysarthria, and nystagmus; (2) CS-plus symptoms which included CS associated with any of other symptoms such as encephalopathy (GCS < 15), awareness disturbances, vomiting, headache, a new onset limb or facial paresis, torticollis, hypotonia, and opsoclonus. The outcome was assessed at the end of hospitalization and was defined as complete or incomplete recovery. The study included 76 children, with a mean age of 5.7 years (IQR 2.1-8.3). The most frequent causes of AA were immune-mediated/infective cerebellar ataxia in 27 (35.5%), and intoxication in 24 (31.6%) cases, followed by vestibular ataxia, opsoclonus-myoclonus-ataxia syndrome, and intracranial expansive process. Forty-two (56%) cases experienced isolated CS, and 35 (46%) cases had CS-plus. Complete recovery was experienced by 62 (81.6%) patients. Analysis of some risk factors (sex, age, presence of previous infection, "cerebellar plus symptoms," and structural abnormalities/neuroimaging abnormalities) and their relation to outcome was performed. Analysis showed that presence of additional symptoms to ataxia, so called "cerebellar plus symptoms" (p = 0.002) and structural abnormalities (p < 0.001), had statistically higher frequency of poor outcome. Statistical significance remained in the univariate analysis. Significant data was included in multivariate logistic regression analysis which also showed that presence of "cerebellar plus symptoms" (p = 0.021) and structural abnormalities (p = 0.002) is related to a poor outcome. Most of the children with AA have "benign" etiology such as intoxication and post/parainfectious cerebellar ataxia with favorable outcomes. On the other hand, AA might be the first manifestation of CNS neoplasm or paraneoplastic phenomena. "The red flags" associated with cerebellar signs are limbs or facial palsy, hypotonia, GCS < 15, vomiting, opsoclonus, headache, myoclonus, visual impairment, torticollis, and vertigo. The presence of those signs and/or structural brain abnormalities was related to poor outcomes in children with AA.