Two Cases of Autoimmune Encephalitis with Multiple Anti-neuronal Antibodies

Autoimmune encephalitis(AE)can arise from various etiologies and present with complex clinical manifestations,especially in cases involving multiple anti-neuronal antibodies.This report presents two cases of AE with multiple anti-neuronal antibodies admitted to Ningbo Medical Center Li Huili Hospital on October 9,2020,and March 12,2024.Case 1 is a 15-year-old boy with positive anti-N-methyl-D-aspartate receptor(NMDAR)and anti-metabotropic glutamate receptor 5(mGluR5)antibodies in his serum and cerebrospinal fluid(CSF).Case 2 is a 14-year-old boy with positive NMDAR and myelin oligodendrocyte glycoprotein(MOG)antibodies in his CSF.Patients with AE who have multiple anti-neuronal antibodies present significant diagnostic and therapeutic challenges,warranting close clinical attention.

Autoimmune encephalitis after surgery for appendiceal cancer:A case report

BACKGROUND Primary cancer of the appendix is rare and often difficult to diagnose preoperatively due to the lack of specific clinical symptoms. Autoimmune encephalitis(AIE) is the most common cause of non-infectious encephalitis. The etiologies of AIE include tumors(paraneoplastic), infections(parainfections), or recessive infections. The tumors that have been reported to cause AIE include thymomas, ovarian teratomas, lung cancers, and breast cancers. However, there are no reports of AIE occurring after surgery for appendiceal cancer. This report describes the diagnosis and treatment of a patient with an appendiceal cancer and postoperative AIE.CASE SUMMARY We report the case of a 47-year-old man who was transferred to our hospital due to a recurrent low intestinal obstruction. Abdominal enhanced computed tomography was used to consider the possibility of a terminal ileal tumor with serous infiltration and lymph node metastasis. A right hemi-colectomy was performed under general anesthesia with an ileo-transcolon anastomosis and laparoscopic exploration. The postoperative pathologic evaluation revealed a high-grade goblet cell carcinoma of the appendix, accompanied by mesangial and abdominal lymph node metastases, and neural tube and vascular infiltration. The operation was completed without complication. The patient developed restlessness on postoperative day 4, and gradually developed a disturbance of consciousness on postoperative day 6. He was transferred to West China Hospital of Sichuan University and diagnosed with AIE.CONCLUSION Albeit rare, the occurrence of neurologic and psychiatric symptoms in patients with an appendiceal cancer postoperatively suggests the possibility of AIE.

Epidemic Japanese B encephalitis combined with contactinassociated protein-like 2 antibody-positive autoimmune encephalitis:A case report

BACKGROUND It is not uncommon to develop viral encephalitis.Epidemic Japanese B encephalitis infection combined with contactin-associated protein-like 2(CASPR-2)antibody-positive autoimmune encephalitis has not been reported at present.In clinical work,we need to consider more options.CASE SUMMARY A 32-year-old male worker presented with headache,fever and call-unresponsive presentation.Complete cranial magnetic resonance image showed symmetrical abnormal signals in bilateral medial temporal lobe,bilateral thalamus and basal ganglia.Improved lumbar puncture showed that cerebrospinal fluid protein and cell count increased significantly.Viral encephalitis was considered,and the patient's consciousness still increased rapidly after antiviral treatment.Further detection of Cerebrospinal fluid Japanese B encephalitis virus Polymerase Chain Reaction positive,serum autoimmune encephalitis antibody showed CASPR-2 antibody positive(1:320),the patient's condition gradually improved after plasma exchange treatment.3 mo later,the serum CASPR-2 antibody was negative and the patient's condition was stable.CONCLUSION This article reports the world’s first case of Epidemic Japanese B encephalitis infection combined with CASPR-2 antibody-positive autoimmune encephalitis,with a view to raising awareness.

Can Autoimmune Encephalitis Occur with Negative Markers? A Rare Case Report

In our case, we present a case of a 27-year-old male who presented with progressively worsening altered mental status and seizures. Over the course of his admission to the hospital and intensive care unit, laboratory testing failed to find an offending agent to his presentation. Testing did result in the diagnosis of encephalitis, but an underlying cause was not found. After careful exclusion of bacterial, viral, and other types of encephalopathy, autoimmune encephalopathy was diagnosed despite the absence of commonly used markers of autoimmune encephalopathy. The presentation and symptoms of our patient led to a wide range of differentials, and a high index of suspicion was needed throughout his admission in order to obtain the appropriate tests. Although appropriate testing might be ordered, due to the sensitivities and specificities of all laboratory tests, these objective tests do produce false negative results at times. It is in these times that one must weigh the physical exam, clinical judgment, and the process of elimination to diagnose an underlying pathology. Autoimmune Encephalitis diagnosis can be broken down into possible, probable, and definitive diagnoses based on antibody testing results. In this case, we present a patient with probable autoimmune encephalitis that failed to yield positive autoimmune markers after extensive testing of other possible causes of encephalitis.

Stiff-Person Syndrome Associated with Anti-Glutamic Acid Decarboxylase Autoimmune Encephalitis in a Young Woman: A Case Report

A 34-year-old female with stiff-person syndrome(SPS)is reported in this paper.She experienced short-term memory impairment and was diagnosed with anti-glutamic add decarboxylase(GAD)autoimmune encephalitis(AE)at the local hospital.However,after the treatment with intravenous immunoglobulin and highdose glucocorticoids,her symptoms unchanged.Two months later,she was admitted to our hospital due to an unstable gait and persistent leg stiffness,at which point she was diagnosed as anti-GAD AE concomitant with SPS.Her clinical symptoms improved with an increased dose of y-aminobutyric acid(GABA)-enhancing drug and plasma exchange.Anti-GAD antibody-associated AE combined with SPS is extremely rare.Treatment with GABA-enhancing drugs and appropriate immunotherapy can improve the neurological function of patients suffering from the combination of SPS and limbic encephalitis.

Autoimmune encephalitis with posterior reversible encephalopathy syndrome:A case report

BACKGROUND Posterior reversible encephalopathy syndrome(PRES)is a neuroimaging-based syndrome and is associated with multifocal vasogenic cerebral edema.Patients with PRES frequently demonstrate headache,seizure,encephalopathy,altered mental function,visual loss and so on.We here report a patient who showed persistent neurologic deficits after PRES and was ultimately diagnosed with autoimmune encephalitis(AE).CASE SUMMARY This case exhibits a rare imaging manifestation of anti-casper 2 encephalitis which was initially well-matched with PRES and associated vasogenic edema.CONCLUSION AE should be further considered when the etiology,clinical manifestations,and course of PRES are atypical.

Glutamic acid decarboxylase 65-positive autoimmune encephalitis presenting with gelastic seizure, responsive to steroid: A case report

BACKGROUND Anti-glutamic acid decarboxylase(GAD)antibody is known to cause several autoimmune-related situations.The most known relationship is that it may cause type I diabetes.In addition,it was also reported to result in several neurologic syndromes including stiff person syndrome,cerebellar ataxia,and autoimmune encephalitis.Decades ago,isolated epilepsy associated with anti-GAD antibody was first reported.Recently,the association between temporal lobe epilepsy and anti-GAD antibody has been discussed.Currently,with improvements in examination technique,many more autoimmune-related disorders can be diagnosed and treated easier than in the past.CASE SUMMARY A 44-year-old female Asian with a history of end-stage renal disease(without diabetes mellitus)under hemodialysis presented with diffuse abdominal pain.The initial diagnosis was peritonitis complicated with sepsis and paralytic ileus.Her peritonitis was treated and she recovered well,but seizure attack was noticed during hospitalization.The clinical impression was gelastic seizure with the presentation of frequent smiling,head turned to the right side,and eyes staring without focus;the duration was about 5–10 s.Temporal lobe epilepsy was recorded through electroencephalogram,and she was later diagnosed with anti-GAD65 antibody positive autoimmune encephalitis.Her seizure was treated initially with several anticonvulsants but with poor response.However,she showed excellent response to intravenous methylprednisolone pulse therapy.Her consciousness returned to normal,and no more seizures were recorded after 5 d of intravenous methylprednisolone treatment.CONCLUSION In any case presenting with new-onset epilepsy,in addition to performing routine brain imaging to exclude structural lesion and cerebrospinal fluid studies to exclude common etiologies of infection and inflammation,checking the autoimmune profile has to be considered.In the practice of modern medicine,autoimmune-related disorders are relatively treatable and should not be missed.

Heterogeneity of clinical features, EEG and brain imaging findings in anti‑leucine‑rich glioma‑inactivated protein 1 autoimmune encephalitis: a retrospective case series study and review of the literature

Background Anti-leucine-rich glioma-inactivated 1(LGI-1)autoimmune encephalitis(AE),characterized by rapid decline of memory,seizures,and neuropsychiatric abnormalities,is a rare but devastating disorder.Early diagnosis and treatment are essential to prevent long-term sequelae.In this report,we provide a detailed description of clinical characteristics,laboratory test results,imaging,and electroencephalography(EEG)findings,as well as treatment responses of eight patients with anti-LGI-1 AE treated at our center.Case presentation At the onset,all eight patients presented with confusion/memory deterioration,seizures(including faciobrachial dystonic seizures or other types of seizure),and behavioral changes such as hallucination,paranoia,and anxiety.Four patients were found with severe hyponatremia.Anti-LGI1 antibodies were detected in the cerebrospinal fluid and/or serum of all patients.For patients with faciobrachial dystonic seizures,no discernible scalp EEG change was detected,while EEG recording of patients experiencing other types of seizure showed focal slowing,focal epileptiform discharges,and focal onset seizures.All patients showed abnormal brain magnetic resonance imaging signals,mainly involving the mesial temporal lobe and the hippocampus.In addition,one patient also experienced fulminant cerebral edema during the acute phase of the illness.All patients received immunotherapy and anti-seizure medications and achieved good seizure control.Nevertheless,these patients continued to experience cognitive impairment during their long-term follow-ups.Conclusions The care of anti-LGI1 AE patients requires rapid evaluation,prompt initiation of immunotherapy,and long-term follow-up.The long-term presence of neurocognitive complications observed in these patients underline the importance of developing reliable biomarkers that can distinguish between different subtypes of this disease with heterogeneous clinico-electrographico-radiological features.Further research is needed to understand the molecular mechanisms underlying the heterogeneity,in order to facilitate development of more effective treatments for anti-LGI1 AE.

Anti-contact protein-associated protein 2 antibody encephalitis in children:A case report

BACKGROUND Anti-contactin-associated protein-like 2(CASPR2)antibody encephalitis is an autoimmune disorder characterized by the presence of antibodies against the voltage-gated potassium channel.This leads to neurological symptoms,such as seizures,cognitive decline,and neuropathic pain,primarily affecting the limbic system.The prognosis of this disorder varies among individuals.CASE SUMMARY The patient,a girl aged nine years and nine months,underwent treatment for 14 to 21 d.The main clinical manifestations were vomiting and unclear consciousness,positive pathological signs,normal cranial computed tomography and magnetic resonance imaging,and abnormal electroencephalogram.The child was discharged after receiving immunoglobulin and hormone treatment.Subsequent follow-up over a period of 15 months after discharge,conducted through telephone and outpatient visits,showed no recurrence of symptoms.CONCLUSION Anti-CASPR2 antibody autoimmune encephalitis in children is rare,mainly manifested as convulsions,mental abnormalities,cognitive impairment,and neuropathic pain,among others.Timely evaluation for autoimmune encephalitis antibodies is crucial,especially in cases of recurrent central nervous system involvement in children.

Anti-N-methyl-D-aspartate receptor-associated encephalitis: A review of clinicopathologic hallmarks and multimodal imaging manifestations

Anti-N-methyl-D-aspartate receptor-associated encephalitis(NMDARE)is a rare immune-mediated neuroinflammatory condition characterized by the rapid onset of neuropsychiatric symptoms and autonomic dysfunction.The mechanism of pathogenesis remains incompletely understood,but is thought to be related to antibodies targeting the GluN1 subunit of the NMDA receptor with resultant downstream dysregulation of dopaminergic pathways.Young adults are most frequently affected;the median age at diagnosis is 21 years.There is a strong female predilection with a female sex predominance of 4:1.NMDARE often develops as a paraneoplastic process and is most commonly associated with ovarian teratoma.However,NMDARE has also been described in patients with small cell lung cancer,clear cell renal carcinoma,and other benign and malignant neoplasms.Diagnosis is based on correlation of the clinical presentation,electro-encephalography,laboratory studies,and imaging.Computed tomography,positron emission tomography,and magnetic resonance imaging are essential to identify an underlying tumor,exclude clinicopathologic mimics,and predict the likelihood of long-term functional impairment.Nuclear imaging may be of value for prognostication and to assess the response to therapy.Treatment may involve high-dose corticosteroids,intravenous immunoglobulin,and plasma exchange.Herein,we review the hallmark clinicopathologic features and imaging findings of this rare but potentially devastating condition and summarize diagnostic criteria,treatment regimens,and proposed pathogenetic mechanisms.

Autoimmune Encephalitis： An Expanding Frontier of Neuroimmunology

INTRODUCTIONDiscovery of the spectrum ofautoimmune encephalitis （ALE） is among the most attractive events of neurology in the past decade. AIE includes a heterogeneous group of encephalitic syndromes, which generally include two major categories： classic paraneoplastic limbic encephalitis （LE） associated with the so-called well-characterized onconeural autoantibodies against intracellular neuronal antigens （e.g., Hu, Ma2, etc.） and new-type AIE associated with autoantibodies to the neuronal surface or synaptic antigens.

Leucine-rich glioma-inactivated protein 1 antibody-mediated autoimmune encephalitis in a 4-year-old girl:a case report

Background:Leucine-rich glioma-inactivated protein 1(LGI1)antibody-mediated encephalitis is a rare subtype of autoimmune encephalopathy,which is associated with autoimmunity against the neuronal plasma membrane proteins.The characteristic symptoms of this disease are memory dysfunction,seizures,faciobrachial dystonic seizures,cognitive deficits,neuropsychiatric disturbances,and intractable hyponatremia.The diagnosis of this disease mainly depends on the presence of anti-LGI1 antibody in serum or cerebrospinal fluid of patients.LGI1 antibody encephalitis has been reported mostly in adults,with rare occurrences in children.Case presentation:In this report,we described a 4-year-old girl with typical seizures.Seizure types included focal seizures and generalized tonic-clonic seizures.The electroencephalogram findings showed focal discharges.Brain magnetic resonance imaging(MRI)showed normal.The cerebrospinal fluid(CSF)levels of cells,glucose,and chloride were within the normal range,and the culture did not reveal growth of any pathogen.Test of serum LGI1-Ab was positive,while the tests for autoimmune encephalitis antibody series in CSF were negative.The seizures of the patient were completely controlled after the therapy of immunoglobulin,methylprednisolone and antiepileptic drugs(AEDs),and the mental state almost returned to normal.Conclusion:To our knowledge,the patient described here may be the youngest case of LGI1 antibody encephalitis reported to date.Children with the LGI1 antibody-associated encephalitis may present only with single symptoms such as epileptic seizures and have good response to the therapy of immunoglobulin,methylprednisolone and antiepileptic drugs.Our case report will provide hints for pediatricians in the diagnosis and treatment of LGI1-antibody encephalitis.

Psychotic and nonpsychotic mood disorders in autoimmune encephalitis:diagnostic issues and research implications

Recent research on autoimmune disorders suggests additional links between systemic and central nervous system(CNS)pathophysiology,among which the identification of antibody-induced limbic encephalitis provided the strongest evidence for the potential involvement of autoimmunity in the pathogenesis of severe mood and psychotic symptoms.In these illnesses,psychiatric symptoms predominate in the initial phase of the disorder in up to 70%of the cases,and they often lead patients to early psychiatric evaluation.For this reason,it is very important to increase the limited knowledge among psychiatrists about these autoimmune neuropsychiatric diseases,which can mimic psychiatric syndromes,in particular,those typically presented in severe mood disorders and schizophrenia.On the other hand,similarities in clinical presentation suggest that neuroinflammation and systemic immune dysregulation may play a role in the pathophysiology of severe mood and psychotic disorders.A complex interaction between periphery and immune cells of the CNS may result in cellular damage through mechanisms involving excitotoxicity,oxidative stress,and mitochondrial dysfunction.These pathways are possibly shared between comorbid medical disorders and severe mood and psychotic disorders and may reflect common underlying vulnerability.

Anti-leucine-rich glioma inactivated protein 1 encephalitis with sleep disturbance as the first symptom: A case report and review of literature

BACKGROUND Anti-leucine-rich glioma inactivated protein 1(anti-LGI1) encephalitis is an infrequent type of autoimmune encephalitis(AE) characterized by acute or subacute cognitive and psychiatric disturbance, facio-brachial dystonic seizures(FBDSs), and hyponatremia. Anti-LGI1 AE has increasingly been considered a primary form of AE. Early identification and treatment of this disease are clearly very important.CASE SUMMARY Here, we report that a male patient developed severe anti-LGI1 encephalitis, which was initially misdiagnosed as a sleep disturbance. He was hospitalized for epileptic seizures and typical FBDSs half a month after he developed sleep disturbances. LGI1 antibodies were detected in his cerebrospinal fluid and serum(1:100 and 1:3.2, respectively), which led to the diagnosis of classic anti-LGI1 AE. No obvious abnormality was observed on brain computed tomography images. T2-weighted fluid-attenuated inversion recovery and T2-weighted scans of brain magnetic resonance imaging(MRI) showed slightly elevated signals within the left basal ganglia area. No tumor was detected within the brain of this patient using MRI. After hormone and antiepileptic drug treatment, the patient’s symptoms improved significantly.CONCLUSION Anti-LGI1 antibody-associated encephalitis has characteristic clinical manifestations, such as cognitive impairment, psychiatric symptoms, seizures, sleep disorders, hyponatremia, and FBDSs. LGI1 antibodies are present in the serum and/or cerebrospinal fluid, but their production is sensitive to immunosuppressants, and this disease has a relatively good prognosis. In particular, we should be aware of the possibility of anti-LGI1 antibody-associated encephalitis in adolescents with sleep disorders to avoid missed diagnoses and misdiagnoses.

Diagnostic algorithms in autoimmune encephalitis

Over the past decade the discovery of novel forms of encephalitis associated with neuronal surface antibodies had changed the paradigms for diagnosing and treating disorders that were previously mischaracterized.Recognition of clinical syndromes,consistent methods of diagnosis,and early targeted immunotherapy can lead to a favorable outcome in diseases that may be associated with significant disability or death if left untreated.Here the conditions associated with neuronal surface antibodies are briefly reviewed,some general aspects of these syndromes are considered and guidelines that could help in the recognition of these disorders are suggested.Furthermore,a diagnostic algorithm to detect and characterize neuronal cell surface autoantibodies is suggested and some of the caveats of serum testing are outlined.Future directions will involve the identification of novel autoantibodies,the standardization of methods to detect and characterize them,as well as evaluation of the most efficacious therapeutic strategies in patients with established diagnosis of autoimmune encephalitis.

Unremitting diarrhoea in a girl diagnosed anti-N-methyl-D-aspartatereceptor encephalitis:A case report

BACKGROUND Asymptomatic cytomegalovirus(CMV)infection is common in children;in contrast,in children with a weakened immune system,invasive CMV can occur.This is the first case report of a severe manifestation of CMV esophagoenterocolitis in a girl diagnosed with anti-N-methyl-D-aspartate-receptor(antiNMDAR)encephalitis who received only a moderate dose of corticosteroid therapy.CASE SUMMARY A 12-year-old-Thai girl presented with acute behavioural change and headache for 6 d.Electroencephalogram and positivity for NMDAR autoantibodies were compatible with anti-NMDAR encephalitis.Hence,she received pulse methylprednisolone 10 mg/kg per day for 4 d and continued with prednisolone 1.2 mg/kg per day.On day 42 of corticosteroid therapy,she developed unremitting vomiting and diarrhoea.Endoscopy showed multiple ulcers and erythaematous mucosa along the gastrointestinal tract.Tissue CMV viral load and viral-infected cells confirmed CMV esophago-enterocolitis.Therefore,the patient received ganciclovir 5 mg/kg per dose every 12 h for 3 wk and then 5 mg/kg per dose once daily for 3 wk.Unremitting diarrhoea slowly improved from stool output 1-4 L per day to 1-2 L per day after 3 wk of treatment.Pulse methylprednisolone 20 mg/kg for 5 d was initiated and continued with prednisolone 1 mg/kg per day.After this repeated pulse methylprednisolone treatment,surprisingly,diarrhoea subsided.Immunologic work-up was performed to rule out underlying immune deficiency with unremarkable results.CONCLUSION Unremitting diarrhoea from CMV esophago-enterocolitis subsided with antiviral and methylprednisolone therapy,implying the immune and NMDAR dysregulation in anti-NMDAR encephalitis.

Overlapping syndrome of recurrent anti-N-methyl-D-aspartate receptor encephalitis and anti-myelin oligodendrocyte glycoprotein demyelinating diseases:A case report

BACKGROUND Anti-N-methyl-D-aspartate receptor encephalitis(NMDARe)is capable of presenting a relapsing course and coexisting with myelin oligodendrocyte glycoprotein antibody disease,whereas it has been relatively rare.We describe a man with no history of tumor who successively developed anti-NMDARe and anti-myelin oligodendrocyte glycoprotein antibody disease.CASE SUMMARY A 29-year-old man was initially admitted with headache,fever,intermittent abnormal behavior,decreased intelligence,limb twitching and loss of consciousness on July 16,2018.On admission,examination reported no abnormality.During his presentation,he experienced aggravated symptoms,and the reexamination of cranial magnetic resonance imaging(MRI)indicated punctate abnormal signals in the left parietal lobe.External examination of cerebrospinal fluid and serum results revealed serum NMDAR antibody(Ab)(-),cerebrospinal fluid NMDAR-Ab(+)1:10 and Epstein-Barr virus capsid antigen antibody Ig G(+).Due to the imaging findings,anti-NMDARe was our primary consideration.The patient was treated with methylprednisolone and gamma globulin pulse therapy,mannitol injection dehydration to reduce intracranial pressure,sodium valproate sustained-release tablets for anti-epilepsy and olanzapine and risperidone to mitigate psychiatric symptoms.The patient was admitted to the hospital for the second time for“abnormal mental behavior and increased limb movements”on December 14,2018.Re-examination of electroencephalography and cranial MRI showed no abnormality.The results of autoimmune encephalitis antibody revealed that serum NMDAR-Ab was weakly positive and cerebrospinal fluid NMDAR-Ab was positive.Considering comprehensive recurrent anti-NMDARe,the patient was treated with propylene-hormone pulse combined with immunosuppressive agents(mycophenolate mofetil),and the symptoms were relieved.The patient was admitted for“hoarseness and double vision”for the third time on August 23,2019.Re-examination of cranial MRI showed abnormal signals in the medulla oblongata and right frontal lobe,and synoptophore examination indicated concomitant esotropia.The patient’s visual acuity further decreased,and the reexamination of cranial MRI+enhancement reported multiple scattered speckled and patchy abnormal signals in the medulla oblongata,left pons arm,left cerebellum and right midbrain,thalamus.The patient was diagnosed with an accompanying demyelinating disease.Serum antimyelin oligodendrocyte glycoprotein 1:10 and NMDAR antibody 1:10 were both positive.The patient was diagnosed with myelin oligodendrocyte glycoprotein antibody-related inflammatory demyelinating disease of the central nervous system complicated with anti-NMDARe overlap syndrome.The patient was successfully treated with methylprednisolone,gamma globulin pulse therapy and rituximab treatment.The patient remained asymptomatic and follow-up MRI scan 6 mo later showed complete removal of the lesion.CONCLUSION We emphasize the rarity of this antibody combination and suggest that these patients may require longer follow-up due to the risk of recurrence of two autoimmune disorders.

Anti-IgLON5 disease: a novel topic beyond neuroimmunology

Anti-IgLON5 disease is a recently defined autoimmune disorder of the nervous system associated with autoantibodies against IgLON5. Given its broad clinical spectrum and extremely complex pathogenesis, as well as difficulties in its early diagnosis and treatment, anti-IgLON5 disease has become the subject of considerable research attention in the field of neuroimmunology. Anti-IgLON5 disease has characteristics of both autoimmunity and neurodegeneration due to the unique activity of the antiIgLON5 antibody. Neuropathologic examination revealed the presence of a tauopathy preferentially affecting the hypothalamus and brainstem tegmentum, potentially broadening our understanding of tauopathies. In contrast to that seen with other autoimmune encephalitis-related antibodies, basic studies have demonstrated that IgLON5 antibody-induced neuronal damage and degeneration are irreversible, indicative of a potential link between autoimmunity and neurodegeneration in antiIgLON5 disease. Herein, we comprehensively review and discuss basic and clinical studies relating to anti-IgLON5 disease to better understand this complicated disorder.

Differentiating rhythmic high-amplitude delta with superimposed(poly)spikes from extreme delta brushes:limitations of standardized nomenclature and implications for patient management

Background Following the standardized nomenclature proposed by the American Clinical Neurophysiology Society(ACNS),rhythmic high-amplitude delta activity with superimposed spikes(RHADS)can be reported as an extreme delta brush(EDB).The clinical implications of similar electrographic patterns being reported as RHADS versus EDB are important to highlight.We aim to review the electrographic characteristics of RHADS,evaluate whether RHADS is seen in other neurological disorders,and identify the similar and unique characteristics between RHADS and EDB to ultimately determine the most accurate way to differentiate and report these patterns.We believe that the differentiation of RHADS and EDB is important as there is a vast difference in the diagnostic approach and the medical management of associated underlying etiologies.Data source We conducted an extensive search on MEDLINE and Pubmed utilizing various combinations of keywords.Searching for“gamma polymerase and EEG”,or“RHADS”or“Alpers syndrome and EEG”or“EEG”AND“Alpers–Huttenlocher syndrome”.Results Three articles were found to be focused on the description of“RHADS”pattern in Alpers Syndrome.No publication to date were found when searching for the terms“EDB”AND“children”,AND“infant”AND“adolescent”excluding“encephalitis”and“neonate”.Although RHADS and EDB appear as similar EEG patterns,meticulous analysis can differentiate them.RHADS is not exclusive to patients with Alpers–Huttenlocher syndrome and may manifest in regions beyond the posterior head region.Reactivity to eye-opening and response to anesthesia can be two other elements that help in the differentiation of these patterns.Conclusion RHADS is not exclusive to patients with AHS and may manifest in regions beyond the posterior head region.Reactivity to eye-opening and response to anesthesia are features that help in the differentiation of these patterns.

Autoimmune encephalopathies in children:diagnostic clues and therapeutic challenges

Neuronal surface antibody syndromes(NSAS)encompass a variety of disorders associated with“neuronal surface antibodies”.These share clinical and neuroradiological features that pose challenges related to their recognition and treatment.Recent epidemiological studies show a clear predominance for the glutamate-N-methyl-D-aspartate receptor encephalitis in both adults and pediatric population.Despite this,the overall NSAS’s incidence remains underestimated,and diagnosis persists to be not always easy to achieve.Based on current literature data,in this paper the authors propose a diagnostic pathway to approach and treat pediatric NSAS.An autoimmune etiology can be suggested through the integration of clinical,immunological,electrophysiological and neuroradiological data.On that basis,a target treatment can be started,consisting of corticosteroids and intravenous immunoglobulin or plasma exchange as a first-line immunotherapy,followed by second-line drugs including rituximab,cyclophosphamide or mycophenolate mophetil,if the case.In children a prompt diagnosis and a targeted treatment may lead to a better clinical outcome.Nevertheless further studies are required to assess the need of more tailored treatments according to long-term outcome findings and prognostic factors in different NSAS.