A Pediatric Case of Stiff-Person Syndrome: Presentation and Comparative Analysis

Stiff-person syndrome (SPS) is a rare autoimmune neurological disorder characterized by progressive muscle rigidity and spasms. While it predominantly affects adults, pediatric cases are exceptionally rare, often leading to delayed diagnosis due to non-specific early clinical manifestations.

We report the case of an 11-year-old boy with progressive gait abnormalities and rigidity, initially misdiagnosed as an orthopedic disorder. The patient exhibited a forward-leaning posture, absent lumbar lordosis, and significant muscle tightness, leading to a primary surgical intervention. Despite initial improvement, symptom recurrence prompted further evaluation, ultimately raising suspicion of SPS. The absence of pyramidal or extrapyramidal signs complicated early diagnosis, highlighting the challenges in recognizing SPS in pediatric patients.

SPS diagnosis relies on clinical criteria, serological markers, and electromyography. Autoantibodies against glutamic acid decarboxylase (anti-GAD) are commonly associated, although other markers may be present in atypical forms. Pediatric SPS is often misdiagnosed as dystonia, metabolic myopathy, or an orthopedic disorder. The underlying pathophysiology involves autoimmune-mediated dysfunction of GABAergic inhibitory neurons, resulting in loss of muscle control. Treatment strategies include immunomodulatory therapies such as intravenous immunoglobulins and rituximab, alongside symptomatic management with baclofen and benzodiazepines. Long-term rehabilitation is essential to prevent complications and improve functional outcomes.

This case underscores the diagnostic complexity of pediatric SPS and the importance of multidisciplinary management. Early recognition is critical to prevent unnecessary surgical interventions and optimize therapeutic strategies. Greater awareness and further research are necessary to refine diagnostic approaches and treatment protocols in pediatric SPS.