Search

Aim: Immune checkpoint inhibitor-induced encephalitis (ICI-iE) is a rare but life-threatening toxicity of immune checkpoint inhibitor treatment. We aim to identify the characteristics of ICI-iE and describe factors that discriminate it from herpes simplex virus (HSV)-1 encephalitis and anti-leucine-rich glioma-inactivated 1 (anti-LGI1) encephalitis, as two alternative entities of encephalitis. Methods: In this retrospective multicentre cohort study, we collected patients with ICI-iE reported to the Side Effect Registry Immuno-Oncology from January 2015 to September 2021 and compared their clinical features and outcome with 46 consecutive patients with HSV-1 or anti-LGI1 encephalitis who were treated at a German neurological referral centre. Results: Thirty cases of ICI-iE, 25 cases of HSV-1 encephalitis and 21 cases of anti-LGI1 encephalitis were included. Clinical presentation of ICI-iE was highly variable and resembled that of HSV-1 encephalitis, while impairment of consciousness (66% vs. 5%, p = .007), confusion (83% vs. 43%; p = .02), disorientation (83% vs. 29%; p = .007) and aphasia (43% vs. 0%; p = .007) were more common in ICI-iE than in anti-LGI1 encephalitis. Antineuronal antibodies (17/18, 94%) and MRI (18/30, 60%) were mostly negative in ICI-iE, but cerebrospinal fluid (CSF) showed pleocytosis and/or elevated protein levels in almost all patients (28/29, 97%). Three patients (10%) died of ICI-iE. Early immunosuppressive treatment was associated with better outcome (r = 0.43). Conclusions: ICI-iE is a heterogeneous entity without specific clinical features. CSF analysis has the highest diagnostic value, as it reveals inflammatory changes in most patients and enables the exclusion of infection. Early treatment of ICI-iE is essential to prevent sequelae and death.

Shan Qiao,1 Huai-kuan Wu,1 Ling-ling Liu,2 Mei-ling Wang,3 Ran-ran Zhang,4 Tao Han,5 Xue-wu Liu4 1Department of Neurology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong Province 250014, People’s Republic of China; 2Department of Neurology, Liaocheng People’s Hospital, Liaocheng, Shandong Province 252000, People’s Republic of China; 3Department of Neurology, Binzhou Medical University Hospital, Binzhou, Shandong Province 256603, People’s Republic of China; 4Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong Province 250012, People’s Republic of China; 5Department of Neurology, Shandong Provincial Hospital, Jinan, Shandong Province, People’s Republic of ChinaCorrespondence: Xue-wu LiuDepartment of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, No. 107 Wen Hua Xi Road, Jinan 250012, Shan Dong, People’s Republic of ChinaTel + 86 0531-82169114Email snlxw1966@163.comPurpose: To describe the clinical manifestation, immunotherapy, and long-term outcomes of anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis.Patients and Methods: This study was a retrospective analysis of 117 patients with a diagnosis of anti-LGI1 encephalitis identified from the databases of multiple clinical centers between September 2014 and December 2019. The clinical features, ancillary test results, and details of long-term outcomes were evaluated.Results: Among the 117 patients with anti-LGI1 encephalitis, 69.2% (81/117) were male and 30.8% (36/117) were female. The median age of all patients at the onset of the disease was 57 years (interquartile range [IQR], 52– 67). The median time from symptom onset to diagnosis was 8.7 weeks (IQR, 4.2– 25). The main clinical features identified were seizures, cognitive impairment, and mental and behavioral abnormalities. Of the 117 patients, 109 were treated with immunotherapy. Symptoms including memory, mental ability, and behavior improved in all 109 patients after 3– 5 days of treatment. The median time of follow-up for the treated patients was 33 months (IQR, 17– 42). Of the treated patients, 16.2% (19/117) experienced a relapse, with a median delay of 5 months (IQR, 2.1– 17) between onset and the first relapse. There were no mortalities over the follow-up period.Conclusion: The long-term outcome of patients with anti-LGI1 encephalitis was mostly favorable, although some patients continued to experience cognitive dysfunction. Early recognition is important for prompt initiation of immunotherapy that can improve clinical symptoms of anti-LGI1 encephalitis.Keywords: anti-LGI1 encephalitis, autoimmune epilepsy, follow-up, immunotherapy, relapse

Highlights • The semiological hallmark of anti-LGI-1 antibody encephalitis is 'FBDS'. • These seizures are not always dystonic in nature and sometimes of a mixed phenotype. • The case of a patient with faciobrachial tonic-myoclonic seizures is presented. • The phenotypes include tonic, clonic, dystonic and myoclonic +/- plus features. • ‘Faciobrachial motor seizures’ is a more apt description for these seizures., Autoimmune encephalitis associated with antibodies against leucine-rich glioma inactivated protein (LGI1) is classically associated with brief, recurrent, contractions of facial and upper limb muscles, typically on the same side. Commonly described as ‘faciobrachial dystonic seizures’ (FBDS), these seizures have become the semiological hallmark of anti-LGI1 encephalitis. However, the facial and upper limb contractions observed in patients with anti-LGI1 encephalitis associated seizures are not always dystonic in nature. Here, we briefly highlight the case of a patient who was admitted to our institution with faciobrachial tonic-myoclonic seizures to emphasize the fact that faciobrachial seizures in anti-LGI1 encephalitis are not always dystonic. We also review the literature on the semiology of these seizures in patients diagnosed with anti-LGI1 encephalitis and propose a more apt description for this phenomenon. Our case as well as the literature highlights that in anti-LGI1 encephalitis the typical seizure semiology of faciobrachial distribution includes tonic, clonic, dystonic, and myoclonic activity in isolation or combination with or without plus features. Given that accurate labelling of clinical phenomenology enables a better understanding of the underlying epileptic networks and precise diagnosis, we would suggest a more inclusive term ‘faciobrachial motor seizures’ instead of ‘faciobrachial dystonic seizures’ to describe the typical seizure semiology of anti-LGI1 encephalitis. Based on the presence or absence of specific clinical features, these seizures can be further sub-classified as focal aware faciobrachial motor seizures, focal impaired awareness faciobrachial motor seizures or focal faciobrachial motor plus seizures (aware or impaired awareness).

Creutzfeldt-Jakob Disease (CJD) is the prototypical cause of rapidly progressive dementia (RPD). Nonetheless, efforts to exclude reversible causes of RPD that mimic prion disease are imperative. The recent expanding characterization of neurological syndromes associated with antibodies directed against neuronal cell surface or sympathic antigens, namely autoimmune encephalitis is shifting paradigms in neurology. Such antigens are well known proteins and receptors involved in synaptic transmission. Their dysfunction results in neuropsychiatric symptoms, psychosis, seizures, movement disorders and RPD. Faciobrachial dystonic seizure (FBDS) is a novel characterized type of seizure, specific for anti-LGI1 encephalitis.In order to improve clinical recognition we report the cases of two Brazilian patients who presented with characteristic FDBS (illustrated by videos) and anti-LGI1 encephalitis.We have included all patients with FBDS and confirmed anti-LGI1 encephalitis and video records of FDBS in two tertiary Brazilian centers: Department of Neurology of Hospital das Clínicas, Sao Paulo University, Sao Paulo, Brazil and Hospital Geral de Fortaleza, Fortaleza, Brazil between January 1, 2011 and December 31, 2015.Both patients presented with clinical features of limbic encephalitis associated with FBDS, hyponatremia and normal CSF. None of them presented with tumor and both showed a good response after immunotherapy.FBDSs may be confounded with myoclonus and occurs simultaneously with rapid cognitive decline. Unawareness of FDBS may induce to misdiagnosing a treatable cause of RPD as CJD.A doença de Creutzfeldt-Jakob (DCJ) é o protótipo de demência rapidamente progressiva (DRP). No entanto, é imperativo que sejam excluídas causas reversíveis de DRPs que possam simular doença priônica. A recente caracterização de síndromes neurológicas associadas a anticorpos direcionados contra antígenos de superfície neuronal ou sinapse, assim denominadas de encefalites autoimunes, está mudando paradigmas em neurologia. Esses antígenos estão envolvidos na transmissão sináptica, sendo que as disfunções destes podem resultar em sintomas neuropsiquiátricos, psicose, crises epilépticas, distúrbios do movimento e DRP. A crise distônica faciobraquial (CDFB) é um tipo de crise recentemente caracterizada e específica da encefalite anti-LGI1.Para promover um melhor reconhecimento da doença relatamos os casos de 2 pacientes brasileiros que apresentaram CDFBs (ilustradas com vídeos) associadas à encefalite anti-LGI1.Foram incluídos todos os pacientes com CDFBs e encefalite anti-LGI1 confirmados em 2 centros brasileiros terciários: Departamento de Neurologia do Hospital das Clínicas da Universidade de São Paulo, São Paulo, Brasil e o Hospital Geral de Fortaleza entre 01 de janeiro de 2011 e 31 de dezembro de 2015.Ambos os casos apresentaram quadro clinico típico de encefalite límbica associada a CDFBs e exame do LCR sem alterações. Nenhum caso associou-se à presença de neoplasia e ambos apresentaram boa resposta à imunoterapia.A CDFB podem ser confundidas com mioclonias e ocorrer simultaneamente com rápido declínio cognitivo, o seu não reconhecimento pode induzir ao diagnóstico errôneo de uma causa potencialmente tratável de DRP como sendo DCJ.