Anti-leucine-rich Glioma-inactivated 1 Protein-antibody Positive Encephalitis with Extensive Unilateral Cerebral Cortex and White Matter Lesions

Encephalitis caused by antibodies targeting the leucine-rich glioma-inactivated 1 protein receptor, which belongs to the anti-voltage-gated potassium channel receptor complex, is characterized by hyponatremia, progressive cognitive impairment, seizures, and psychiatric disorders. The patient initially presented with faciobrachial dystonic seizures and subsequently developed encephalopathy. Brain magnetic resonance imaging revealed atypical unilateral hyperintense signals in the cerebral cortex and white matter. Intravenous corticosteroid pulse therapy effectively improved faciobrachial dystonic seizures and brain lesions.

A rare case of antileucine-rich glioma-inactivated 1 encephalitis in a 14-year-old girl

BACKGROUND

Autoimmune limbic encephalitis in children occurs most frequently in those with antibodies against the N-methyl-D-aspartate glutamatergic receptor. We report the case of a 14-year-old girl who was diagnosed with antileucine-rich glioma-inactivated protein 1 limbic encephalitis.

CASE

A fourteen years old, previously healthy girl applied to the emergency department with suspicion of dystonic seizure, ataxia, gait disturbance and speech disorders. Serum sample of the patient was positive for leucine-rich glioma inactivated protein 1 IgG.

CONCLUSIONS

Although it is a rare disease in childhood, in the presence of new onset psychotic symptoms or altered mental state, concomittant hyponatremia and unique type of seizures, anti leucine-rich glioma inactivated protein 1encephalitis should be considered in differential diagnosis.

LGI-1 antibody encephalitis in a seven-year-old girl

LGI-1 antibody encephalitis is a rare autoimmune limbic encephalitis which has been reported predominantly in adults. Seizures in LGI-1 antibody encephalitis exhibit significant semiological variability. Faciobrachial dystonic seizures are characteristically seen in this condition and have so far been described only in adults. Other seizure types have also been reported. We describe the case of a seven-year-old girl with LGI-1 limbic encephalitis who presented with acute new-onset seizures, and rapidly deteriorated over the course of a few weeks with very frequent seizures and encephalopathy, becoming non-verbal and non-ambulatory. The electroclinical presentation of this child with LGI-1 encephalitis makes this case unique and further highlights the importance of a high index of suspicion for diagnosis in young children. Early diagnosis can lead to prompt and appropriate treatment with immunotherapy, and potential harmful treatments such as pharmacological coma can be avoided. To the best of our knowledge, this is the youngest case ever reporter. [Published with video sequences].

Clinical analysis of leucine-rich glioma inactivated-1 protein antibody associated with limbic encephalitis onset with seizures

We summarized the clinical characteristics of patients presenting with seizures and limbic encephalitis (LE) associated with leucine-rich glioma inactivated-1 protein antibody (LGI1) in order help recognize and treat this condition at its onset.We analyzed clinical, video electroencephalogram (VEEG), magnetic resonance imaging (MRI), and laboratory data of 10 patients who presented with LGI1-LE and followed up their outcomes from 2 to 16 (9.4 ± 4.2) months.All patients presented with seizures onset, including faciobrachial dystonic seizure (FBDS), partial seizure (PS), and generalized tonic-clonic seizure (GTCS). Four patients (Cases 3, 5, 7, and 8) had mild cognitive deficits. Interictal VEEG showed normal patterns, focal slowing, or sharp waves in the temporal or frontotemporal lobes. Ictal VEEG of Cases 4, 5, and 7 showed diffuse voltage depression preceding FBDS, a left frontal/temporal origin, and a bilateral temporal origin, respectively. Ictal foci could not be localized in other cases. MRI scan revealed T2/fluid-attenuated inversion recovery (FLAIR) hyperintensity and evidence of edema in the right medial temporal lobe in Case 3, left hippocampal atrophy in Case 5, hyperintensities in the bilateral medial temporal lobes in Case 7, and hyperintensities in the basal ganglia and frontal cortex in Case 10. All 10 serum samples were positive for LGI1 antibody, but it was only detected in the cerebrospinal fluid (CSF) of 7 patients. Five patients (Cases 2, 4, 6, 7, and 8) presented with hyponatremia. One patient (Case 2) was diagnosed with small cell lung cancer. While responses to antiepileptic drugs (AEDs) were poor, most patients (except Case 2) responded favorably to immunotherapy.LGI1-LE may initially manifest with various types of seizures, particularly FBDS and complex partial seizures (CPS) of mesial temporal origin, and slowly progressive cognitive involvement. Clinical follow-up, VEEG monitoring, and MRI scan are helpful in early diagnosis. Immunotherapy is effective for the treatment of both seizure and LE associated with LGI1 antibody. Although mostly nonparaneoplastic, tumor screening is recommended in some cases.