This is a case of autoimmune limbic encephalitis. When an auto-antibody is found it is usually to either VGKC or NMDAR.

Antibodies to the voltage gated potassium (VGKC) channel interfere with peripheral neuromuscular and ganglionic transmission and may be associated with a number of neurological syndromes including limbic encephalitis, neuromyotonia and seizures. Anti VGKC antibodies are tested by radioimmunoassay.

NMDAR antibody (negative in this case) was first found in young female patients with ovarian tumors and prominent psychiatric symptoms, amnesia, seizures, dyskinesias, autonomic dysfunction and decreased levels of consciousness. The antibodies are now also found in males and females with no known tumor and in children. Their presence suggests an immunotherapy-responsive condition ¹.