Intrathecal Baclofen Pump Therapy for Medically Refractory Stiff Person Syndrome: A Multicenter Case Series

Objectives This study aimed to describe clinical outcomes, dosing, and safety of intrathecal baclofen (ITB) therapy in patients with medically refractory stiff person syndrome (SPS). Materials and Methods We retrospectively reviewed six patients with predominantly anti–glutamic acid decarboxylase (GAD)-positive SPS who underwent ITB pump implantation after inadequate response or intolerance to oral antispasticity medications and immunomodulatory therapies. Clinical features, prior treatments, ITB dosing, complications, and functional outcomes were analyzed. Results All the patients had severe stiffness and stimulus-sensitive spasms refractory to benzodiazepines, oral baclofen, and immunotherapy. Indications for ITB included respiratory compromise (n = 2), recurrent hip dislocations (n = 2), severe functional impairment (n = 6), and medication intolerance (n = 3). Maintenance ITB doses ranged from 365 to 650 μg/d. All patients experienced substantial reductions in stiffness and spasm frequency, with improved mobility or respiratory function. In one patient, postoperative septic shock developed, requiring temporary device removal; no long-term device failures occurred. Clinical benefit was sustained for 2.5 to four years of follow-up. Discussion ITB therapy may provide durable symptomatic improvement in severe, medically refractory SPS and should be considered in appropriately selected patients.