Stiff Person Syndrome: A Case Report with Sudden Onset and Coexistence of Sero-Positive Antibodies to Glutamic Acid Decarboxylase and Anti-SOX1 Antibodies

Abstract

Stiff Person Syndrome (SPS) is a rare neurological condition marked by muscle stiffness and painful spasms, which often progress slowly and can lead to significant disability. In approximately 80% of classic SPS cases, antibodies to glutamic acid decarboxylase (anti-GAD) are present. A subset of SPS, known as paraneoplastic syndrome, accounts for about 5% of cases and is associated with various malignancies, including those of the lung, thymus, breast, colon, and lymph nodes.

In this report, we present a case involving a 25-year-old Vietnamese female patient diagnosed with SPS who exhibited unusual clinical manifestations. Her symptoms included sudden onset and rapidly progressive rigidity in the spinal region, abdomen, and lower limbs, alongside painful spasms, autonomic disorders, and multiple severe bone fractures. Serological testing revealed high-titer anti-GAD antibodies, as well as anti-SOX1 antibodies, indicating the possibility of paraneoplastic SPS.

The primary treatment approach for this patient was intravenous immunoglobulin therapy, which resulted in a complete remission of her symptoms. This case underscores the complexities of SPS and highlights the importance of early diagnosis and treatment, particularly in cases presenting with atypical features.