A Case of Stiff Person Syndrome with Response to Methotrexate Therapy for Lymphoma
Zeinab Birjandian1, Jerome Graber2
1Neurology, University of Washington, 2University of Washington
Background:
Stiff person syndrome (SPS) is a rare neurologic disorder with prevalence of one to two patients per million, characterized by progressive muscle stiffness, rigidity, and spasm involving the axial muscles, resulting in impaired gait and balance. Most patients have autoantibodies against the glutamic acid decarboxylase (GAD) enzyme. Antibodies directed against GABA(A) receptor-associated protein, and the glycine-α1 receptor also occur. The paraneoplastic form of SPS usually is associated with lung, breast or lymphoma and are usually GAD antibody negative. Treatment is mainly focused on symptomatic relief by using benzodiazepines and immunomodulators (steroids, IVIg, rituximab, mycophenolate, plasma exchange), but optimal treatments for refractory cases are unclear.
Design/Methods:
We report a 57 yo woman who initially presented in 2015 with intermittent proximal RLE stiffness and pain that progressed to become constant and bilateral. Her gait and posture were affected with bent forward posture. She then developed full body spasms that were associated with severe pain, triggered by stress, startle, or certain movements. Brain and full spine MRI were normal, with positive glycine receptor antibodies. The patient received IVIG with partial improvement in symptoms in 2018 and rituximab was added in 2019, but she remained impaired, requiring a standing rollator to ambulate. She developed bilateral blurry vision with floaters in 2020. Vitrectomy found ocular lymphoma and brain MRI showed enhancement typical for lymphoma. She achieved complete remission with high dose methotrexate, rituximab and consolidative transplant and her SPS symptoms markedly improved during methotrexate monotherapy to the point of ambulating without assistive devices and remained stable six months after transplant.
Conclusions:
Methotrexate may have activity in refractory SPS, and transplant may achieve durable responses and is under current study.