Drug resistant ADLTE and recurrent partial status epilepticus with dysphasic features in a family with a novel LGI1 mutation: electroclinical, genetic, and EEG/fMRI findings

Purpose: We characterized a family with autosomal dominant lateral temporal epilepsy (ADLTE) whose proband presented uncommon electroclinical findings such as drug-resistant seizures and recurrent episodes of status epilepticus with dysphasic features. Methods: The electroclinical characteristics and LGI1 genotype were defined in the family. In the proband, the ictal pattern was documented during video-EEG monitoring and epileptic activity was mapped by EEG/fMRI. Results: The affected members who were studied had drug-resistant seizures. In the proband, seizures with predominant dysphasic features often occurred as partial status epilepticus. The video-EEG-documented ictal activity and fMRI activation clearly indicated the elective involvement of the left posterior lateral temporal cortex. Sequencing of LGI1 exons revealed a heterozygous c. 367G>A mutation in exon 4, resulting in a Glu123Lys substitution in the protein sequence. Conclusions: The uncommon clinical pattern (high seizure frequency, drug-resistance) highlights the variability of the ADLTE phenotype and extends our knowledge of the clinical spectrum associated with LGI1 mutations.