Anti-leucine-rich Glioma Inactivated-1 Encephalitis Associated with Essential Thrombocythemia

Psychiatric manifestations of autoimmune encephalitis

Autoimmune encephalitis is increasingly recognized as a cause of psychiatric symptoms. A wide spectrum of psychiatric manifestations have been described which may precede, follow or occur independently of neurologic features. Patients typically respond to immunotherapy, however diagnosis is challenging due to phenotypic heterogeneity. The aim of this review is to provide an overview of the psychiatric features associated with encephalitis mediated by autoantibodies targeting neuronal cell-surface antigens and describe indicators of potential immunopathology underlying psychiatric manifestations.

Clinical Features and Therapeutic Effects of Anti-leucine-rich Glioma Inactivated 1 Encephalitis: A Systematic Review

Background: Clinical presentations and treatment programs about anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis still remain incompletely understood. Objective: This study analyzed the clinical features and therapeutic effects of anti-LGI1 encephalitis. Methods: PubMed, EMBASE, and the Cochrane Library were searched to identify published English and Chinese articles until April 2021. Data were extracted, analyzed, and recorded in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Results: A total of 80 publications detailing 485 subjects matched our inclusion criteria. Short-term memory loss (75.22%), faciobrachial dystonic seizures (FBDS) (52.53%), other seizures excluding FBDS (68.48%), psychiatric symptoms (57.67%), and sleep disturbances (34.30%) were the most frequently described symptoms in anti-LGI1 encephalitis. Hyponatremia (54.90%) was the most common hematologic examination change. The risk of incidence rate of malignant tumors was higher than in healthy people. The positive rate of anti-LGI1 in serum (99.79%) was higher than CSF (77.38%). Steroids (93.02%), IVIG (87.50%), and combined use (96.67%) all had a high remission rate in the initial visit. A total of 35 of 215 cases relapsed, of which 6/35 (17.14%) did not use first-line treatment, and 21 (60.00%) did not maintain long-term treatment. Plasma exchange (PE) could be combined in severe patients, immunosuppressant could be used for refractory patients or for recurrence and using an anti-epileptic drug to control seizures may benefit cognition. Conclusions: Short-term memory loss, FBDS, psychiatric symptoms, and hyponatremia were key features in identifying anti-LGI1 encephalitis. Serum and CSF antibody tests should be considered in diagnosis criteria. Steroids with IVIG should be recommended, PE was combined for use in severe patients, immunosuppressant therapy might improve outcomes if recurrence or progression occurred, and control seizures might benefit cognition. The useful ways to reduce relapse rate were early identification, clear diagnosis, rapid treatment, and maintaining long-term treatment. The follow-up advice was suggested according to the research of paraneoplastic syndrome, and concern about tumors was vital as well.

Electroencephalographic findings in antileucine-rich glioma-inactivated 1 (LGI1) autoimmune encephalitis: A systematic review

BACKGROUND

Antileucine-rich glioma-inactivated 1 (LGI1) autoimmune encephalitis is a distinct syndrome of early onset faciobrachial dystonic seizures (FBDS) and other focal seizures followed by neuropsychiatric symptoms. The electroclinical syndrome of this condition is yet to be fully understood. The main objective of this study was to determine the frequencies of electroencephalogram (EEG) findings in patients diagnosed with anti-LGI1 autoimmune encephalitis through a systematic review of published relevant articles.

METHODS

Major electronic healthcare databases were searched for relevant published articles until July 2020.

RESULTS

From 327 articles, 23 case reports and 14 case series were included in the review after satisfying the eligibility criteria. Data from a total of 151 cases of definite anti-LGI1 encephalitis were analyzed in this systematic review. Epileptiform discharges were the most frequent finding at 57.3%. Focal electroencephalographic abnormalities including slow wave (59.3%) and epileptiform activities (53.5%) most commonly arise from the temporal region. Faciobrachial dystonic seizures often have no ictal electroencephalographic correlate but would show electrodecremental events when seizure duration is prolonged.

CONCLUSION

Electroencephalogram abnormalities are seen in anti-LGI1 autoimmune encephalitis with epileptiform discharges as the most common finding followed by focal slowing. These findings were most frequently seen arising in the temporal region. Further studies using a standardized protocol focusing on electroencephalographic findings in anti-LGI1 encephalitis with clinical correlation to disease stage and treatment outcomes in terms of seizure control and memory and cognitive function are needed. Particular attention on ictal electrodecremental activity during FBDS should be done in studies with a larger sample size.