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

RATIONALE: 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. PATIENT CONCERNS: 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. DIAGNOSES: 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. INTERVENTIONS: 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. OUTCOMES: After 3 Courses of treatment, the clinical manifestations of the nervous system disappeared and negative responsibility antibodies profile. LESSONS: 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.