Progressive bulbar dysfunction and respiratory failure in anti-IgLON5 disease.

A man in his 60s presented with progressive bulbar dysfunction, exertional dyspnoea and nocturnal respiratory disturbance. His symptoms began a decade earlier with throat clearing, mild dysphagia and sleep disruption, initially attributed to obstructive sleep apnoea treated with continuous positive airway pressure. Despite therapy, he developed worsening dysphagia, dream enactment, stridor and acute type II respiratory failure requiring emergency intubation and subsequent tracheostomy after repeated failed extubation attempts. Investigations revealed status dissociatus and agrypnia excitata on polysomnography, while serum studies confirmed high-titre anti-IgLON5 antibodies. Immunotherapy with corticosteroids, plasma exchange and rituximab achieved partial improvement, but tracheostomy dependence and bulbar symptoms persisted. He stabilised on nocturnal invasive ventilation and was discharged with coordinated multidisciplinary care. This case highlights the diagnostic pitfalls of attributing progressive neurological features to common mimics, the dual pathology of anti-IgLON5 disease that limits therapeutic response, and the importance of early airway intervention to prevent avoidable mortality.