1325 - The Use of Intrathecal Baclofen in the Management of Stiff Person Syndrome

Case Diagnosis: A 70-year-old female diagnosed in 1997 with GAD+ Stiff Person Syndrome(SPS).

Case Description: Her medications included Baclofen 20mg QID and Diazepam 5mg QID(later changed to Clonazepam 2mg BID). Despite these interventions, she reported daily somnolence and made numerous trips to the ED for painful muscle spasms, uncontrolled jerking, stiffness, gait impairment, and diffuse body pain. Additionally, she received several doses of IVIg in the hospital for symptom management. In 2021, she was counseled on intrathecal baclofen(ITB) to improve her symptoms and reduce her doses of sedating medications. After detailed discussions on risks, benefits, and alternatives with her previous treating neurologist, her ITB pump was implanted with no surgical complications. She was initiated on a dose of 50mcg which was slowly titrated to 147mcg. She also decreased her Baclofen dosage to 5mg QID and Clonazepam to 2mg daily.

Discussions: Stiff Person Syndrome is an autoimmune disorder resulting in painful muscle spasms, truncal stiffness, and generalized rigidity. The mainstay of treatment includes oral antispasmodics and benzodiazepines such as baclofen and clonazepam. However, these medications can have intolerable, systemic side effects. ITB can be used as a next line in therapy and previous case reports have shown patients experiencing significant clinical and functional improvements. Once our patient’s ITB dose was increased and oral medications decreased, she saw improvements in her spasms and a reduction in her sedation. She is on a multi-modal treatment plan including home physical and occupational therapy(PT/OT), which was initiated recently due to mobility impairments making regular outpatient PT/OT visits unfeasible. She reported feeling stronger allowing slightly more functional independence after only a few sessions.

Conclusions: This case report is intended to add to the growing body of evidence outlining the successful utilization of ITB to minimize pill burden and reduce the deleterious effects of high doses of oral medications in patients with SPS.