Anti-recoverin antibodies in a cerebellar syndrome without retinal involvement

Anti-recoverin antibodies are typically found in cancer-associated retinopathy or autoimmune diseases. We present a case of anti-recoverin positive cerebellar syndrome without any signs of malignancy or retinopathy. The patient was treated with steroids and intravenous immunoglobulins, resulting in improvements in both cognitive and motor symptoms.

Rickettsial Cerebellitis: A Rare Neurological Manifestation

Scrub typhus is a vector-borne disease caused by gram-negative bacilli, Orientia tsutsugamushi. The vector of scrub typhus is the mite. The clinical manifestations often present with either a simple fever or life-threatening multi-organ dysfunction. Neurological manifestations also vary, and the incidence of neurological manifestations is unknown. Cerebellitis is one of the rare neurological manifestations associated with scrub typhus. In this case report, we present the case of a 35-year-old man who tested positive for scrub typhus (IgM enzyme-linked immunosorbent assay (ELISA) blood test) with a history of fever and cerebellar signs and symptoms. He was managed with antibacterial agents and made a good recovery.

Neuroimaging Spectrum in COVID-19 Infection: A Single-Center Experience

Background and Purpose  The ongoing coronavirus disease 2019 (COVID-19) pandemic is a multisystemic disease and involvement of the nervous system is well established. The neurological and neuroimaging features of the disease have been extensively evaluated. Our study aimed to elucidate the neuroradiological findings in COVID-19 infected patients admitted to our institute during the first and second waves of the pandemic in India. Methods  This was a single-center retrospective study of all COVID-19 positive patients who underwent neuroimaging between March 2020 and May 2021. The presenting neurological complaints, the imaging findings in computed tomography (CT) imaging, and/or magnetic resonance imaging (MRI) were recorded. They recorded the findings in the subheadings of ischemic stroke, hemorrhagic stroke, parainfectious demyelination, acute encephalitis syndrome, and changes of global hypoxic changes. Patients with age-related, chronic, and incidental findings were excluded. Results  The study comprised of 180 COVID-19 positive patients who underwent neuroimaging. CT scan was performed for 169 patients, MRI for 28, and a combination of both CT and MRI was performed for 17 patients. Seventy percent of patients were males, and median age was 61.5 years (interquartile range: 48.25-70.75). Out of the 180 patients, 66 patients had nonspecific findings that could not be attributed to COVID-19 infection. In the remaining 114 patients, 77 (42.7%) had ischemic findings, while 22 (12.2%) had hemorrhagic stroke. Hypoxic ischemic changes were noted in five patients. The rest of the patients had a spectrum of changes including, cerebellitis (3), tumefactive demyelination (1), COVID-19-associated encephalitis (1), hemorrhagic acute demyelinating encephalomyelitis (1), transverse myelitis (1), cytotoxic lesions of corpus callosum (1), Guillain-Barre syndrome (1), and COVID-19-associated microhemorrhages (1). Conclusion  Neurological manifestations of COVID-19 infection are not uncommon, and our understanding of this topic is expanding. A complex interplay of neurotropism and direct central nervous system invasion, immune activation and cytokine storm, vasculitis, and parainfectious processes are implicated in the pathophysiology. While the most common imaging finding was ischemic stroke, followed by hemorrhagic stroke, a diverse range of parainfectious findings was also noted in our study.

Neurological complications of rotavirus infection in children: a systematic review and meta-analysis

AIM

To systematically review the clinical features and outcomes of pediatric patients developing neurological complications associated with a rotavirus infection.

METHODS

A systematic literature review and meta-analysis was performed, including articles published from 1984 to 2020. Neurological complications were classified into four groups: encephalitis, cerebellitis, encephalo-cerebellitis and benign convulsions with mild gastroenteritis (CwG).

RESULTS

Out of 68 reports that fulfilled the research criteria, 99 cases of CwG, 39 cases of encephalitis, 18 cases of encephalo-cerebellitis and five cases of cerebellitis were collected. Ninety-five patients were from Asia. Median age was 22 (IQR 14-29) months, and the children who developed CwG were significantly younger (19, IQR 12-24 months, p<0.0001) than the others. Status epilepticus was observed in 23% and 5% of the encephalitis and CwG groups, respectively. The most frequently described neuroimaging finding were lesions of the splenium of corpus callosum. Four deaths were reported in the encephalitis group, whereas no fatal events were described in the other groups. Among the surviving children, the encephalo-cerebellitis group showed the most severe long-term outcome. All cases of CwG recovered completely.

CONCLUSION

Older age at diagnosis and the development of encephalo-cerebellitis are associated with a higher risk of long-term complications.

Cerebellar involvement associated with immune checkpoint inhibitors: A systematic review

BACKGROUND AND PURPOSE

Immune checkpoint inhibitors (ICIs) targeting programmed death receptor 1 (PD-1), cytotoxic T-lymphocyte-associated-4 (CTLA-4) and programmed cell death ligand 1 can be associated with immune-related adverse events (iRAEs). Amongst neurological iRAEs, cerebellar involvement seems to be rare and currently lacks a proper characterization. The aim of this study was to phenotype cerebellar iRAEs.

METHODS

A systematic review was performed according to PRISMA guidelines including reported patients with cerebellar involvement related to ICIs and with available individual data.

RESULTS

After screening 2765 records, 32 studies with 46 patients were included. Median age was 63 years (20-82), and most patients were male (63.0%). Isolated cerebellitis was observed in 32.6% of cases, whilst the remaining cases had "cerebellitis plus", mostly associated with encephalitis/encephalopathy. Associated tumors included most frequently lung cancer, melanoma and Merkel cell carcinoma. PD-1 inhibitor was the most administered treatment (n = 29, 64.4%), whilst exposure to CTLA-4 inhibitor was rare (n = 2, 4.5%). Magnetic resonance imaging was abnormal in 43.2% of patients and inflammatory cerebrospinal fluid findings were frequently observed. Autoantibodies were detected in 61.9% of patients and included novel reactivities. Amongst treatment strategies, the most common were steroids (n = 36) and ICI discontinuation (n = 28, 90.3%). Relapses were reported in 10% of patients. Most patients showed improvement/remission (n = 31) but, at last follow-up, 12 had died. Isolated cerebellitis versus cerebellitis-plus differed in terms of outcomes, whilst seropositive versus seronegative patients had distinct tumor associations.

DISCUSSION

Cerebellar iRAEs are usually multifocal, have heterogeneous tumor associations, are most associated with PD-1 inhibitor exposure and are related to autoantibodies, including novel reactivities.

Central nervous system manifestations of dengue infection: data from a tertiary care Centre in South India

BACKGROUND

Dengue fever is the second most common mosquito-borne disease affecting human beings and neurological manifestations (NMs) of this arboviral infection are increasingly being reported.

METHODS

In this retrospective study, conducted in a tertiary care centre in south India, we sought to describe the spectrum of NMs of dengue fever. The records of all patients admitted in the Department of Internal Medicine over 8 years, with a diagnosis of dengue-based on clinical symptoms and the detection of dengue IgM antibodies or detection of NS1 antigen or nucleic acid by reverse transcriptase-polymerase chain reaction (RT-PCR); with Glasgow coma score (GCS) ≤14, neck stiffness, focal neurological signs, seizures, or visual disturbances-were explored.

RESULTS

Of 1121 patients admitted with dengue fever, 341 (30%) had severe dengue and 23 (2%) had NMs. Encephalopathy was seen in 9 patients (39%), encephalitis in 6 (27%), cerebellitis in 4 (17%), acute disseminated encephalomyelitis (ADEM) in 2 (9%), ischaemic stroke in 1 (4%) patient, and neuro-ophthalmological manifestations in 1 (4%) patient. The median duration of hospital stay was 7 days. Nine (39% of) patients required intensive care unit (ICU) admission and 5 (22%) had fatal outcomes. There was no association between thrombocytopenia, metabolic acidosis, transaminitis, hyponatremia, the type of dengue infection, and the various NMs described.

CONCLUSIONS

The NMs of dengue infection are varied, and a high index of suspicion is needed to identify them in patients who present with lethargy or altered sensorium on the background of an acute febrile illness suggestive of dengue.

Post-infectious cerebellar ataxia following COVID-19 in a patient with epilepsy

Background

Various neurological manifestations have been described in relation to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19). However, the development of cerebellar ataxia after recovery from COVID-19 is rare. We present a case of cerebellar ataxia 3 weeks after recovery from COVID-19.

Case Presentation

A 70-year-old male patient from an urban area of India presented with ataxia. He was hypertensive and had been receiving treatment for post-traumatic epilepsy for the previous 3 years. He had previously had laboratory-confirmed COVID-19 infection with mild symptoms that resolved within 2 weeks. However, 3 weeks after symptom improvement, he developed severe pan-cerebellar ataxia. Investigations were suggestive of post-infectious cerebellar ataxia. Other causes of ataxia were excluded. He responded well to pulse methylprednisolone therapy and was discharged with mild tremor and ataxia.

Conclusion

Post-infectious cerebellar ataxia is an unusual presentation after COVID-19. The clinician should be aware of such complications following COVID-19 infection as early diagnosis and proper management leads to better outcomes in many patients.

Acute Cerebellitis in MIS-C: A Case Report

BACKGROUND

Coronavirus disease-2019 (COVID-19) is characterized predominantly by respiratory symptoms and has affected a small subset of children. Multisystem inflammatory syndrome in children (MIS-C) has been reported in children following COVID-19. There is increasing report that COVID-19 may also lead to neurologic manifestations. Cerebellar lesions may be observed in viral infections.

CASE REPORT

We report a child with MIS-C related to severe acute respiratory syndrome coronavirus 2, who developed cerebellar lesion during the disease course. Encephalopathy was the first central nervous system symptom. His consciousness improved but he developed clinical signs of cerebellar dysfunction including ataxia, dysarthria and nystagmus. Brain magnetic resonance imaging (MRI) revealed symmetrical pathological signal changes in both cerebellar hemispheres.

CONCLUSION

We demonstrated the first child with MIS-C to develop cerebellar lesion on brain MRI, suggestive of cerebellitis.

Lupus Cerebellitis Presenting With Ataxia: A Case Report

We report a case of a woman with a history of systemic lupus erythematosus who developed persistent ataxia and was diagnosis with lupus cerebellitis. Magnetic resonance imaging of the brain showed T2/FLAIR signal hyperintensity within the cerebellar vermis without mass effect. The patient's condition improved with pulse IV methylprednisolone. This case highlights unique imaging findings within the cerebellum, our diagnostic and treatment regimen, and compares this case to previous literature on similar cases.

Anti-GFAP-antibody positive postinfectious acute cerebellar ataxia and myoclonus after COVID-19: a case report

We present a case of acute cerebellar ataxia and myoclonus with detected anti-GFAP-antibodies in a patient recently recovered from COVID-19. Main symptoms consisted of acute gait and limb ataxia and myoclonus. The patient improved considerably upon treatment with high-dose intravenous (IV) steroids. While cerebrospinal fluid (CSF) and magnetic resonance imaging (MRI) findings were unremarkable, anti-GFAP-antibodies were detected in the patient’s serum and disappeared upon clinical remission at a 3-month follow-up. This case suggests that anti-GFAP-antibodies might be associated with some of the increasingly observed cases of postinfectious acute cerebellar ataxias in COVID-19 patients and aid in the diagnosis of this autoimmune complication. We recommend searching for these antibodies in serum and CSF in suspected cases. Early steroid treatment may prove beneficial for these patients.

Acute cerebellitis following SARS-CoV-2 infection: A case report and review of the literature

Novel coronavirus disease (COVID‐19) first described in Wuhan, China in December 2019, has rapidly spread across the world and become a global public health emergency. Literature on the neurological manifestations of COVID‐19 is limited. We report a 24‐year‐old male, who presented with vertigo, dysarthria, and bradyphrenia 3 weeks after being diagnosed with COVID‐19 on nasopharyngeal reverse transcription polymerase chain reaction. The patient was diagnosed with acute cerebellitis based on magnetic resonance imaging features and showed improvement posttreatment with intravenous methylprednisone for 5 days. The scope of this article is to highlight the importance of early identification of neurological symptoms and timely management as the outcomes may be catastrophic.

CD8 T-cell-mediated cerebellitis directed against Purkinje cell antigen after ipilimumab for small cell lung cancer

We report a rapidly progressive and fatal CD8 T-cell-mediated cerebellitis after ipilimumab (cytotoxic T-lymphocyte-associated protein 4 inhibitor) for small cell lung cancer. Clinical features and histopathology were consistent with an accelerated form of paraneoplastic cerebellar degeneration. A patchy CD8 T-cell infiltrate spatially corresponded to areas of Purkinje cell loss, with occasional CD8 polarisation towards Purkinje cells. CD20-positive B cells were sparse. CD8 T-cell-mediated cerebellitis after immune checkpoint inhibitor treatment may recapitulate the early stages of paraneoplastic cerebellar degeneration.

Acute Cerebellar Ataxia in COVID-19 Infection: A Case Report

Background

The outbreak of coronavirus disease 2019 (COVID-19) has been widely reported to cause symptoms such as fever, cough, sore throat, fatigue, and shortness of breath. Neurologic complications have not been widely reported without associated respiratory symptoms. These neurologic manifestations have been found mostly in the elderly. There has been no report of ataxia or COVID-19 cerebellitis in the young adult population without associated respiratory symptoms.

Case Report

Here we report the case of a 30-year-old patient who presented with isolated cerebellar symptoms and was diagnosed with COVID-19 cerebellitis.

Why Should an Emergency Physician Be Aware of This?

It is important for emergency physicians to know that COVID-19 can have many clinical manifestations and to have a high level of suspicion with acute neurologic symptoms.

Acute Cerebellitis or Postinfectious Cerebellar Ataxia? Clinical and Imaging Features in Acute Cerebellitis

Acute cerebellitis is a rare condition often considered within the group of acute postinfectious cerebellar ataxia despite its distinctive clinical and imaging features. We retrieved clinical, laboratory, and follow-up data of 15 children diagnosed with acute cerebellitis in our department between 2011 and 2019. There were 10 boys and 5 girls aged 3-15 years, median 9.5 years. The most common first symptoms were ataxia, vomiting, and headache. Magnetic resonance imaging (MRI) generally showed bilateral symmetrical T2 hyperintense changes with moderate swelling in the cerebellar cortex. Tonsillar herniation was present in 73.3% and obstructive hydrocephalus in 26.6%. Etiologic workup for infectious pathogens revealed Mycoplasma pneumoniae, influenza A virus, cytomegalovirus, and varicella zoster virus in 1 case each. Fourteen of 15 patients were treated with intravenous and/or oral steroids and 8 cases with intravenous immunoglobulin. No patient required surgical decompression. Neurologic examination median 12 months later revealed ataxia and dysmetria in 4 cases (27%), accompanied by memory difficulties, dysarthria or tremor. Follow-up magnetic resonance imaging (MRI; n = 12) showed diffuse cerebellar cortical T2-hyperintense signal changes in 11 cases and cerebellar atrophy in 9. The diagnosis of acute cerebellitis rather than acute postinfectious cerebellar ataxia should be considered when headache and vomiting accompany ataxia in a child. Acute cerebellitis heals with sequelae in about one-third of cases. The absence of fatalities in our series suggests early diagnosis, and steroid treatment can increase the chance of recovery. MRI results were not found to be predictive of outcome.

An Unusual Etiology of Cerebellar Ataxia

Cerebellar ataxia, which is the lack of coordination, has a number of causes none of which are as uncommon or unheard of as Scrub typhus. Scrub typhus very rarely presents itself with CNS manifestations. Here, we present the case of a 7-year-old girl from the Hooghly district in West Bengal, who presented to us with the history of fever, cerebellar signs, and sudden onset of visual loss. She was ultimately diagnosed with scrub typhus cerebellitis.

Methadone-induced Toxic Encephalopathy In Pediatric Patients: Two Case Reports

Toxic encephalopathy is a wide spectrum of encephalopathy secondary to insult from toxic substances, with variable clinical presentations from minor cognitive impairment to severe neurological dysfunction and death. Methadone-induced toxic encephalopathy is an extremely rare form of toxic encephalopathy which typically demonstrates abnormal imaging findings in the dentate nuclei or cerebellum. This is a report of methadone-induced toxic encephalopathy in two toddlers secondary to accidental ingestion. They were brought in unconscious to the emergency department of a tertiary hospital and were found to be cyanotic and pulseless, requiring cardiopulmonary resuscitation and mechanical ventilation. Magnetic resonance imaging (MRI) of the brain of both patients showed similar findings of symmetrical hyperintense foci in bilateral cerebellar hemispheres on T2-weighted and fluid-attenuated inversion recovery (FLAIR) sequences. These areas also demonstrated diffusion restriction on diffusion weighted imaging (DWI). Blood and urine toxicology results confirmed the presence of methadone in both patients. As the exact substance of accidental ingestion may not be known at the time of presentation, early radiological diagnosis of methadone-induced encephalopathy may prompt early initiation of treatment to prevent further life-threatening complications, particularly in vulnerable pediatric population.

Acute ataxia in paediatric emergency departments: a multicentre Italian study

OBJECTIVES

To evaluate the causes and management of acute ataxia (AA) in the paediatric emergency setting and to identify clinical features predictive of an underlying clinically urgent neurological pathology (CUNP).

STUDY DESIGN

This is a retrospective medical chart analysis of children (1-18 years) attending to 11 paediatric emergency departments (EDs) for AA in an 8-year period. A logistic regression model was applied to identify clinical risk factors for CUNP.

RESULTS

509 patients (mean age 5.8 years) were included (0.021% of all ED attendances). The most common cause of AA was acute postinfectious cerebellar ataxia (APCA, 33.6%). Brain tumours were the second most common cause (11.2%), followed by migraine-related disorders (9%). Nine out of the 14 variables tested showed an OR >1. Among them, meningeal and focal neurological signs, hyporeflexia and ophthalmoplegia were significantly associated with a higher risk of CUNP (OR=3-7.7, p<0.05). Similarly, the odds of an underlying CUNP were increased by 51% by each day from onset of ataxia (OR=1.5, CI 1.1 to 1.2). Conversely, a history of varicella-zoster virus infection and vertigo resulted in a significantly lower risk of CUNP (OR=0.1 and OR=0.5, respectively; p<0.05).

CONCLUSIONS

The most frequent cause of AA is APCA, but CUNPs account for over a third of cases. Focal and meningeal signs, hyporeflexia and ophthalmoplegia, as well as longer duration of symptoms, are the most consistent 'red flags' of a severe underlying pathology. Other features with less robust association with CUNP, such as seizures or consciousness impairment, should be seriously taken into account during AA evaluation.

Atypical Autoimmune Encephalitis With Neuropil Antibodies Against a Yet Unknown Epitope

Autoimmune encephalitis often causes acute psychiatric symptoms and epileptic seizures. However, it is becoming increasingly clear that depending on the target antigen both symptoms and disease severity may vary. Furthermore, the identification and characterization of antibody subtypes are highly relevant for personalizing the treatment and to prevent relapses. Here we present an atypical case of encephalitis with cerebellar and temporal dysfunction but without seizures associated with high levels of cerebrospinal fluid neuropil antibodies against a yet unknown epitope on the neuronal surface in the cerebellum, hippocampus, thalamus, and the olfactory bulb. We treated the patient successfully with corticosteroids, plasmapheresis, and rituximab.

Acute Cerebellitis in Children: A Variable Clinical Entity

Acute cerebellar ataxia is the most common cause of acute ataxia in children and it usually runs a self-limiting and ultimately benign clinical course. A small proportion of children have evidence of inflammatory swelling in the cerebellum. Many of these children suffer more severe and potentially life-threatening forms of cerebellar ataxia and may need more intensive treatments including urgent neurosurgical treatments. This more severe form of acute cerebellar ataxia is often termed acute cerebellitis. Many children with acute cerebellitis have long-term neurological sequela and evidence of structural cerebellar changes on follow-up imaging. Several patterns of cerebellar inflammation have been described. The authors describe the variabilities in the clinical and radiological patterns of disease in the cases that have been described in the literature.

Involvement of Cerebellum in Leigh Syndrome: Case Report and Review of the Literature

BACKGROUND

Leigh syndrome is an early-onset progressive neurodegenerative disorder typically involving lesions of the bilateral basal ganglia, thalami, and brainstem. Isolated involvement of the cerebellum is uncommon.

PATIENT DESCRIPTION

We present a six-year-old boy with Leigh syndrome who presented with recurrent episodes of ataxia and dysarthria. He was diagnosed with Leigh syndrome at two years of age with bilateral basal ganglia lesions on brain magnetic resonance imaging (MRI). Genetic testing confirmed a diagnosis of Leigh syndrome secondary to a homoplasmic mitochondrial DNA mutation (m.9176T>C). He experienced regressive episodes (ages five and six years). Each regressive episode had a similar presentation with worsening of baseline ataxia and dysarthria. The first episode mimicked infectious cerebellitis, with elevated cerebral spinal fluid (CSF) protein and white blood cell count. No organisms were isolated from the CSF/blood during any of the regressive episodes. Brain MRI consistently showed cerebellar lesions, however cerebellar spectroscopy during the second episode found an elevated lactate peak, a decrease of the N-acetylaspartate peak, and elevation of the choline peak; consistent with an acute exacerbation of Leigh syndrome.

CONCLUSIONS

Leigh syndrome can present primarily with involvement of the cerebellum, and it should be considered in the differential diagnosis for acute cerebellitis.

The Complex Diagnostic Challenge in Children With Non-Central Nervous System Cancer and Cerebellar Mutism

Multiple etiologies should be considered in the differential diagnosis of immunocompromised patients with non-central nervous system cancer and viral infections who develop mutism. Acute cerebellitis, caused by infections or by neurotoxicity resulting from chemotherapy; paraneoplastic cerebellar degeneration; atypical posterior reversible encephalopathy syndrome; and acute disseminated encephalomyelitis may all cause mutism in such patients. This condition warrants prompt recognition and may require treatment with immunotherapy, as it may be an immune-mediated process. We present 2 patients with leukemia and viral illness who developed cerebellar mutism in the setting of acute cerebellitis and responded to immunotherapy, suggesting that the condition involved a parainfectious immune-mediated response.

Epilepsy with myoclonic atonic seizures and chronic cerebellar symptoms associated with antibodies against glutamate receptors N2B and D2 in serum and cerebrospinal fluid

A 3-year-old boy with normal development presented with acute cerebellitis at one year and 10 months of age. His truncal ataxia resolved without treatment. He experienced a relapse of truncal ataxia and atonic seizures at 2 years and one month of age. Five months later, he experienced myoclonic atonic seizures. By 3 years of age, the truncal ataxia had become severe, and the frequency of myoclonic atonic seizures increased. Compared to controls, we found higher levels of anti-C-terminal GluN2B and anti-N terminal GluD2 antibodies in the serum, and anti-N terminal GluN2B and anti-C terminal GluD2 antibodies in the cerebrospinal fluid (CSF). A cell-based assay revealed the presence of anti-NMDA-type glutamate receptor antibody in the serum, but absence in the CSF. Ictal EEG of myoclonic atonic seizures showed generalized spike and wave complexes. The patient was diagnosed with myoclonic atonic epilepsy. Adrenocorticotrophic hormone therapy resolved the truncal ataxia and myoclonic atonic seizures, along with the decreased serum anti-C-terminal GluN2B and anti-N-terminal GluD2 antibodies, and CSF anti-N-terminal GluN2B and anti-C-terminal anti-GluD2 antibodies. Our results suggest that the anti-GluN2B and anti-GluD2 antibodies may be associated with myoclonic atonic epileptic seizures and chronic cerebellitis.

An Adult Case of Acute EBV Cerebellitis

Acute neurological manifestations of infectious mononucleosis are uncommon and have been predominantly reported in the paediatric population. We report a case of acute Epstein-Barr virus cerebellitis in an adult in whom spontaneous resolution of symptoms and signs occurred after 2 weeks of supportive treatment. An infective cause for an acute cerebellar syndrome in an adult must always be considered in the differential diagnosis when appropriate.

LEARNING POINTS

A high index of suspicion is needed in adults who present with a febrile syndrome and cerebellar signs.An acute cerebellar syndrome may be the only manifestation of Epstein-Barr virus infection.In certain cases, conservative management may be sufficient depending on the clinical severity.

Acute Cerebellitis in Children: A Many-Faceted Disease

Acute cerebellitis is a rare inflammatory condition. It may have a benign, self-limiting course or present as a fulminant disease resulting in severe cerebellar damage or even sudden death. We present the clinical, laboratory, and radiologic data in 9 children diagnosed with acute cerebellitis, who were identified by database search in our pediatric medical center from January 2000 to November 2014. The main presenting symptom was headache, and the main presenting sign was ataxia. Bilateral diffuse hemispheric involvement was the most common imaging finding at presentation. Mycoplasma pneumoniae was the most common infectious pathogen found. Treatment included steroids in all cases, antibiotics in 4, and intravenous immunoglobulins in 6. Six patients had a full recovery, and 3 had residual neurologic complications. Magnetic resonance imaging (MRI) is the modality of choice for diagnosis. The course of acute cerebellitis varies from a commonly benign and self-limiting disease to an occasionally fulminant disease, resulting in severe cerebellar damage or sudden death.

Neurologic Complications Caused by Epstein-Barr Virus in Pediatric Patients

We retrospectively analyzed the medical documentation of 194 children infected with Epstein-Barr virus. The diagnosis was based on clinical symptoms and the presence of the viral capsid antigen IgM antibody. Patients with severe neurologic complications also underwent neurologic examination, magnetic resonance imaging (MRI), and electroencephalography (EEG). There were 2 peaks in incidence of infection; the first one in young children aged 1 to 5 years represented 62.0% of cases. The second peak (24.6% of patients) occurred in teenagers. Febrile seizures were confirmed in 3.1% of affected children younger than 5 years and headaches in 24.2% patients, mostly older children. Ten children presented severe, neurologic complications: meningoencephalitis, acute encephalitis, acute cerebellitis, transverse myelitis, and myeloradiculitis. Our study identified a variety of Epstein-Barr virus-related neurologic complications. Epstein-Barr virus should be routinely tested for when a child presents with an apparent neuroinfection as it is a common pathogen that can induce a wide variety of signs and symptoms.

Neuronal central nervous system syndromes probably mediated by autoantibodies

In the last few years, a rapidly growing number of autoantibodies targeting neuronal cell-surface antigens have been identified in patients presenting with neurological symptoms. Targeted antigens include ionotropic receptors such as N-methyl-d-aspartate receptor or the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, metabotropic receptors such as mGluR1 and mGluR5, and other synaptic proteins, some of them belonging to the voltage-gated potassium channel complex. Importantly, the cell-surface location of these antigens makes them vulnerable to direct antibody-mediated modulation. Some of these autoantibodies, generally targeting ionotropic channels or their partner proteins, define clinical syndromes resembling models of pharmacological or genetic disruption of the corresponding antigen, suggesting a direct pathogenic role of the associated autoantibodies. Moreover, the associated neurological symptoms are usually immunotherapy-responsive, further arguing for a pathogenic effect of the antibodies. Some studies have shown that some patients' antibodies may have structural and functional in vitro effects on the targeted antigens. Definite proof of the pathogenicity of these autoantibodies has been obtained for just a few through passive transfer experiments in animal models. In this review we present existing and converging evidence suggesting a pathogenic role of some autoantibodies directed against neuronal cell-surface antigens observed in patients with central nervous system disorders. We describe the main clinical symptoms characterizing the patients and discuss conflicting arguments regarding the pathogenicity of these antibodies.

Opioid overdose in a child: case report and discussion with emphasis on neurosurgical implications

In environments in which opioids are increasingly abused for recreation, children are becoming more at risk for both accidental and nonaccidental intoxication. In toxic doses, opioids can cause potentially lethal acute leukoencephalopathy, which has a predilection for the cerebellum in young children. The authors present the case of a 2-year-old girl who suffered an accidental opioid overdose, presenting with altered mental status requiring cardiorespiratory support. She required emergency posterior fossa decompression, partial cerebellectomy, and CSF drainage due to cerebellar edema compressing the fourth ventricle. To the authors' knowledge, this is the first report of surgical decompression used to treat cerebellar edema associated with opioid overdose in a child.

'Medusa head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 2: Anti-PKC-gamma, anti-GluR-delta2, anti-Ca/ARHGAP26 and anti-VGCC

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa head antibodies' due their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects, and provides a summary and outlook.

'Medusa head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 3: Anti-Yo/CDR2, anti-Nb/AP3B2, PCA-2, anti-Tr/DNER, other antibodies, diagnostic pitfalls, summary and outlook

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.

'Medusa-head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 1: Anti-mGluR1, anti-Homer-3, anti-Sj/ITPR1 and anti-CARP VIII

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa-head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.

A case of acute cerebellitis with a unique sequential change on magnetic resonance imaging

BACKGROUND

Acute cerebellitis with unilateral onset is rare, and magnetic resonance imaging (MRI) is a useful method for demonstrating cerebellar involvement.

PATIENT

We report a 12-year-old girl with acute cerebellitis with a unique sequential change on her MRI.

RESULTS

The patient's brain MRI first revealed cortical lesions mainly in the right cerebellar hemisphere. These subsequently disappeared, and at the same time, new lesions appeared in the opposite cerebellar hemisphere. All the lesions were confined to gray matter in the cerebellum and were isotense on diffusion-weighted imaging and had high signal intensity on the apparent diffusion coefficient map, consistent with the characteristic of vasogenic edema.

CONCLUSION

The sequential MRI demonstrates conversion of hemicerebellitis to bilateral cerebellitis during subacute phase, and vasogenic edema might be contributing to the pathogenesis of acute cerebellitis in this patient.

Acute cerebellitis following hemolytic streptococcal infection

BACKGROUND

Acute cerebellitis is a rare inflammatory syndrome in children, with either infectious or autoimmune etiologies.

PATIENT

We describe a 7-year-old girl with a presentation of cerebellitis following group A streptococcal infection.

RESULTS

Magnetic resonance imaging showed diffuse symmetrical swelling and edema of the cerebellum resulting in compression of the fourth ventricle and hydrocephalus. Autoantibodies against glutamate receptor δ2 were detected in the cerebrospinal fluid, suggesting that the cerebellum might be injured by postinfectious immunologic reaction. The most common causes of cerebellitis are acute viral infection, postinfection, and following vaccination. No examples of acute cerebellitis following group A streptococcal infection have been documented.

CONCLUSION

Our report demonstrates that group A streptococcal can lead to acute cerebellitis.

Complications of varicella zoster virus reactivation

OPINION STATEMENT

Varicella zoster virus (VZV) is an exclusively human neurotropic alphaherpesvirus. Primary infection causes varicella (chickenpox), after which virus becomes latent in ganglionic neurons along the entire neuraxis. With advancing age or immunosuppression, cell-mediated immunity to VZV declines and virus reactivates to cause zoster (shingles), which can occur anywhere on the body. Skin lesions resolve within 1-2 weeks, while complete cessation of pain usually takes 4-6 weeks. Zoster can be followed by chronic pain (postherpetic neuralgia), cranial nerve palsies, zoster paresis, meningoencephalitis, cerebellitis, myelopathy, multiple ocular disorders and vasculopathy that can mimic giant cell arteritis. All of the neurological and ocular disorders listed above may also develop without rash. Diagnosis of VZV-induced neurological disease may require examination of cerebrospinal fluid (CSF), serum and/ or ocular fluids. In the absence of rash in a patient with neurological disease potentially due to VZV, CSF should be examined for VZV DNA by PCR and for anti-VZV IgG and IgM. Detection of VZV IgG antibody in CSF is superior to detection of VZV DNA in CSF to diagnose vasculopathy, recurrent myelopathy, and brainstem encephalitis. Oral antiviral drugs speed healing of rash and shorten acute pain. Immunocompromised patients require intravenous acyclovir. First-line treatments for post-herpetic neuralgia include tricyclic antidepressants, gabapentin, pregabalin, and topical lidocaine patches. VZV vasculopathy, meningoencephalitis, and myelitis are all treated with intravenous acyclovir.

Transient tonic upgaze deviation: a neuro-ophthalmological complication of acute cerebellitis

Acute cerebellitis in children is an inflammatory syndrome with symptoms of cerebellar dysfunction. We describe a 3-year-old boy with acute cerebellitis who had cerebellar tonsillar herniation, hydrocephalus, and transient tonic bilateral upward gaze deviation. Although no etiology for his acute cerebellitis was determined, he fully recovered with high-dose corticosteroids, intravenous immunoglobulin, and antimicrobial therapy. We propose that there was tonic irritation of the upward gaze generator cells in the superior colliculus as an explanation for temporary disturbance of his ocular gaze.

Reversible neurological syndromes with atypical pneumonia

Simultaneous or sequential involvement of lungs is frequently encountered with neurological syndromes like meningoencephalitis, cerebellitis, aseptic meningitis, transverse myelitis, or multiple cranial nerve palsies. However, pulmonary involvement is frequently overlooked when all the attention of physician is diverted to neurological disorder. Prompt and early recognition of such potentially treatable association is required to improve diagnostic and therapeutic outcome. We report six patients presenting with various neurological manifestations like meningitis, meningoencephalitis, and myelits associated with atypical pneumonia. With proper clinical correlation and relevant investigations, all of them were diagnosed in time and had remarkable recovery with appropriate treatment.

Herniation to foramen magnum in the course of cerebellitis in a 4-year-old boy, as shown by CT and MRI - case report

BACKGROUND

Acute cerebellitis is an uncommon but dangerous complication of infectious diseases. Besides neurological examination, neuroimaging (especially MR imaging) is very useful for diagnosing cerebellitis.

CASE REPORT

A 4-year-old boy was admitted to the hospital with a 1-week history of fever, vomiting and headache. His past medical history was unremarkable. The physical examination revealed disturbance of consciousness and truncal ataxia. He underwent urgent CT and MRI examinations which demonstrated isolated swelling of the cerebellar hemispheres and the vermis, with increased signal intensity in T2-weighted, FLAIR, and DWI sequence and a significant mass effect associated with tonsillar herniation. An emergent life-saving suboccipital craniectomy was performed with removal of the C1 vertebral arch. There was a gradual clinical improvement, and a follow-up brain MRI revealed disappearance of cerebellar swelling and of mass effect.

CONCLUSIONS

Magnetic resonance (MR), including diffusion-weighted imaging (DWI) sequence, plays an important role in the diagnostic work-up of cerebellitis in children. This imaging method is very useful for detecting cerebellitis, evaluating its severity and monitoring the disease.