Mercury Induced Autoimmunity: A Case of CASPR2/LGI1 Autoimmune Encephalitis in a 14-Month-old

Contactin-associated protein-like 2 (CASPR2) autoantibodies are among those associated with several syndromes with effects on both the central and peripheral nervous systems including neuropathy and encephalitis and is most commonly seen in middle-aged to elderly males. We present a case of autoimmune encephalitis in a 14-month-old female presenting with altered mental status, refusal to bear weight, and hypertension in the setting of mercury exposure. This is the youngest reported case of CASPR2/LGI1/VGKC antibody associated autoimmune encephalitis stimulated by mercury exposure.