Improving Ambulation and Minimizing Disability with Therapeutic Plasma Exchange in a Stiff-person Syndrome Patient with Recurrent Falls

Abstract

Stiff-person syndrome (SPS) is a rare, autoimmune, neuromuscular disorder that manifests with axial and proximal muscle stiffness, rigidity, and painful muscle spasms, often causing progressive disability due to limited movement. First-line therapies comprise symptomatic management with γ-aminobutyric acid-modulating drugs such as benzodiazepines and baclofen. Patients resistant to these treatments are often given intravenous immunoglobulin (IVIg). Severe disease refractory to first-line therapy and IVIg may be treated with therapeutic plasma exchange (TPE) or immunomodulatory agents such as rituximab. Current evidence derived from case reports and case series has shown that roughly half of SPS patients treated with TPE report benefits. Here, we report the case of a 68-year-old man with a 20-year history of severe SPS and recurrent falls who was admitted to the emergency department for a traumatic hip fracture. He had significant rigidity in the axial and extremity muscles with persistent spasms of the quadriceps femoris muscle. Postoperatively, he was unable to participate in physical therapy (PT) due to these symptoms. He previously failed treatment with diazepam, baclofen, and monthly IVIg. Under our care, he underwent seven TPE treatments. By the end of treatment, he reported significant improvement in mobility with a resolution of muscle spasms and was able to be discharged to inpatient rehabilitation. This suggests that TPE may offer an effective, safe treatment modality for patients with severe refractory SPS that may significantly improve mobility and disability associated with the disease.

Keywords: stiff man syndrome; stiff person syndrome; therapeutic plasma exchange.

Figure 1. Pelvic X-ray of the displaced comminuted right intertrochanteric fracture (arrow)