Isaacs syndrome with LGI1 and CASPR2 antibodies after HPV vaccination: A case report

Isaacs syndrome is peripheral nerve hyperexcitability characterized by spontaneous muscle twitching and rigidity and is often associated with antibodies to CASPR2 (contactin-associated protein-like 2) and LGI1 (leucine-rich glioma-inactivated 1). But it is a rare Isaacs syndrome with LGI1 and CASPR2 antibodies after human papilloma virus (HPV) vaccination.

The patient presented with limb pain, muscle twitching, numbness in the extremities and around the mouth, and hand rash after the second dose of HPV vaccine.

Laboratory tests indicated positive for LGI1 antibodies, CASPR2 antibodies, anti-phosphatidylserine/prothrombin antibodies and anti-sulfatide antibodies, TPO and ATG, IgG E. The patient post-M-wave discharges were seen on F-wave examination of the posterior tibial nerve in both lower limbs. We diagnosis the patient with Isaacs syndrome.

Treatment with the intravenous immunoglobulin (IVIG) treatment, after 5 days of IVIG therapy (0.4 mg/kg/day), the rash on the hand disappeared, the pain was relieved, the sleep improved.

After 3 Courses of treatment, the clinical manifestations of the nervous system disappeared and negative responsibility antibodies profile.

This case report suggests a possible adverse reaction to HPV vaccination, which could be treated by attempting several periods of IVIG therapy. The underlying immune mechanisms need to be studied with further extensive data.