Document resource
Background Stiff person syndrome (SPS) is a heterogenous autoimmune condition. We describe a case series of patients presenting to a single clinic.Method Health records to a neurology clinic in Northern Sydney, Australia were retrospectively reviewed. We identified 10 patients between 2014 to 2024 who were managed as a SPS spectrum disorder. Their demographic data, investigations and treatment were collated and analysed.Results There were 8 female and 2 male patients, average age at onset of symptoms was 61 years (range 47–79). Clinical phenotype commonly involved gait dysfunction with episodic leg spasms with hyperreflexia, later spreading to involve paraspinals. Antibodies were detected to glutamic acid decarboxylase (GAD) in 3, to Contactin-Associated Protein-Like 2 (CASPR2) in 2 and seronegative in 5. 2 patients were presented within one month of a viral illness, 1 was paraneoplastic, the remaining 7 had no clear trigger. MRI of the neuroaxis and neurophysiology testing were generally unrevealing.Treatment with intravenous immunoglobulin (IV Ig) with steroids alone led to improvement and stability in 2 patients. IV rituximab was required in 7 patients for refractory cases leading to partial improvement in all. Additional plasma exchange was used transiently with 3 patients and mycophenolate in 2 patients with variable effect. IV tocilizumab was used in one relapsing case with no effect. Gabapentin, duloxetine, diazepam, baclofen, tizanidine and cannabinoid oils were helpful symptomatic adjuncts.Conclusion SPS spectrum disorder is complex to diagnose and treat with variable but definite response to immunotherapy.