Leucine-rich, glioma-inactivated 1 limbic encephalitis (LGI-1 LE) is a rare but devastating disorder. Early recognition and treatment is key in preventing long-term sequelae. Most cases respond to immunotherapy. However, this patient developed a refractory course of faciobrachial dystonic seizures (FBDS), neuropsychiatric symptoms, electrical shock-like sensations without electrographic correlates and secondary mesial temporal lobe epilepsy (MTLE).

This is a 76-year-old right-handed Caucasian male who presented with frequent (dozens daily) episodes of left facial spasms and ipsilateral dystonic movements of the arm that did not correlate on EEG, consistent with FBDS.

In addition, patient was experiencing worsening memory, balance and infrequent visual hallucinations. Altogether, his clinical presentation was suspicious for limbic encephalitis. Serum revealed positive LGI-1 antibodies. Patient underwent intravenous immunoglobulin (IVIG) therapy with drastic improvement in seizure frequency (once daily). Patient failed steroid maintenance due to hyperglycemia and psychosis. He was maintained on mycophenolate but transitioned to rituximab after acute exacerbation with hyponatremia. Despite aggressive immunosuppressive treatment with high dose IVIG and a few courses of plasmapheresis, patient had continued cognitive decline and developed new episodes of “chills down neck” without EEG correlates as well as automatisms and altered consciousness. This did correlate with electrographic seizures from right temporal region consistent with right MTLE. Repeat brain MRI demonstrated right hippocampal atrophy. Malignancy work up has been negative up to date.  

LGI-1 LE patients usually develop hippocampal T2-hyperintensities  in some cases associated with MTLE-like seizures that typically improve on immunotherapy without progression to “classic” MTLE. Our patient presented with FBDS that improved initially on immunosuppression but experienced progressive cognitive decline and hippocampal injury leading to right MTLE despite multiple immunotherapies. This case illustrates the need for early diagnosis and treatment to avoid injury to limbic structures and demonstrates that refractory cases may need further research in effective immunotherapy.