Ketamine for acute management of refractory stiff person syndrome: a case report.

Background: Stiff Person Syndrome (SPS) is a rare autoimmune neurological disorder characterized by progressive muscle rigidity and painful spasms. Standard treatments often yield variable responses, particularly in severe, refractory cases. This case report highlights the novel use of ketamine as an effective therapeutic agent for managing acute SPS exacerbations, underscoring its potential as a second-line treatment for patients unresponsive to conventional therapies.

Case presentation: A 22-year-old male with SPS, diagnosed via anti-glycine receptor antibodies, presented with an acute exacerbation of symptoms, including severe stiffness triggered by sensory stimuli. Initial management with high-dose benzodiazepines, baclofen, and intravenous methocarbamol failed to provide adequate relief. The patient was subsequently treated with intravenous ketamine, resulting in rapid and significant symptom resolution. Despite initial improvement, the patient experienced multiple recurrent flares requiring repeated ketamine administration. Over time, ketamine proved consistently effective in resolving acute symptoms when standard treatments were insufficient. The patient's management was complicated by anxiety, hypoxia, venous thromboembolism, and other comorbidities, highlighting the need for a multidisciplinary approach.

Conclusions: This case illustrates the potential utility of ketamine in managing acute and refractory SPS symptoms, providing rapid symptom resolution and reducing disease burden during severe flares. Ketamine's mechanism of action, including NMDA receptor antagonism and enhancement of GABAergic signaling, makes it a promising adjunct in SPS treatment protocols. This report emphasizes the importance of individualized, multidisciplinary care and the need for further research to establish ketamine's role in the long-term management of SPS.