Two recent large cohorts of patients with anti-LGI1 encephalitis showed that mostpatients develop limbic encephalitis, clinically characterized by limbic amnesia,seizures or psychiatric symptoms associated with involvement of medial aspects oftemporal lobes on MRI, and CSF pleocytosis or EEG with epileptic or slow activityinvolving the temporal lobes.11,34 (Table 1) Hyponatremia is also an important clue for anti-LGI1autoimmunity, being present in 60-75% of patients.11,30,34 Both of our cases presented withunexplained hyponatremia. The gene discussed is LGI1; the disease is Hyponatremia.