2. Stiff person syndrome

Abstract

Background Stiff person syndrome (SPS) is a rare, insidiously progressive disease of central nervous system characterized by axial and limb rigidity with superimposed stimulus-sensitive spasms. SPS can be divided to classical generalized form, stiff limb syndrome, jerking SPS and progressive encephalomyelitis with rigidity and myoclonus (PERM). The incidence of SPS and its variant is about 1 per million in European population. Methods In this study of retrospective design we have evaluated all patients with muscle overactivity syndromes investigated in our EMG laboratory in last 6 years. Patient with SPS were further described and demographic data, EMG findings, laboratory results, auxiliary methods, therapy and improvement/progression were analyzed. Results During 6-year period (2007–2013) 5 patients with SPS were diagnosed and treated in Department of Neurology, PKN. There were 3 women and 2 men, 22–65 yrs. In 3 patients we were able to find a provoking factor (2 infectious diseases – tick-born encephalitis, herpes zoster; one patient was exposed to solvents during longer work in a garage). In all patients EMG was characterized by continuous muscle activity (normal motor unit potential), 3 with higher voltage of F-waves, in a woman constant retroflexion reaction. In 2 patients we found very high titers of anti-GAD in serum, in 1 in cerebrospinal fluid, and in another women increased titer of anti-amphiphysin. All patients were treated with immunosupression (steroids and later azathioprine or cyclosporin A), 3 patients treated with plasma exchange, 2 with high doses of intravenous immunoglobulins, and all by baclofen. Paraneoplastic SPS were in 2 (thymoma, multiple myeloma) and autoimmune type of SPS were in 3 patients. Conclusion SPS is one of the orphan diseases, which diagnosis and treatment demand experienced staff in EMG lab, broad spectrum of immunological laboratory methods, and neurologic intensive care unit for monitoring and treatment.