To discuss the different manifestations of seizures associated with LGI-1 encephalitis to achieve earlier recognition of the disease.
Seizures are the cardinal presenting sign of LGI-1 encephalitis, with faciobrachial dystonic seizures being pathognomonic for the disease. However, LGI-1 encephalitis can present with variable seizure types including focal motor seizures involving alternating limbs, as well as focal seizures with more difficult to recognize autonomic components. As such, the different manifestations of seizures in this disease can lead to misdiagnosis or delay in treatment. We present a case of LGI-1 encephalitis with dense anterograde amnesia, emotional lability, and various manifestations of tonic and dystonic semiologies captured throughout an epilepsy monitoring unit admission. On continuous video EEG, the patient was found to have occasional runs of left temporal theta slowing, at times with rhythmic appearance. Interictally, there were right and left anterior temporal epileptiform discharges. Repeat MRI brain w/wo contrast found asymmetric decreased size of the right hippocampus. Malignancy screening with CT chest/abdomen/pelvis with contrast was negative.
One patient with antibody proven LGI-1 encephalitis was evaluated throughout an Epilepsy Monitoring Unit admission, where all manifestations of seizures were captured using continuous video EEG.
Clinical manifestations of seizures associated with LGI-1 encephalitis.
Tonic:
⁃ Lower face pulling (>75%)
⁃ Eyebrow elevation
⁃ Arm and leg extension tonic
Dystonic:
⁃ Mouth opening
⁃ Mouth puckering
⁃ Grimacing
⁃ Fist clenching
⁃ Hand opening
It is important to recognize that LGI-1 encephalitis, while classically presenting with cluster of unilateral faciobrachial dystonic seizures, can also have alternating patterns and other manifestations of tonic seizures. Prompt diagnosis is of importance as the hallmark treatment of the disease is immunotherapy, which will treat seizures with better efficacy as compared to anti-seizure medications alone.