Idiopathic sleep terror in an adult patient.

We report a case of a man in his 40s presenting with idiopathic adult-onset sleep terrors manifesting as nocturnal violent behaviour, including a concerning episode of attempted strangulation of his bed partner. Polysomnography documented an event during N3 sleep (slow-wave, deep non-rapid eye movement) with autonomic hyperactivation and complex motor behaviour. A detailed psychiatric evaluation did not reveal any diagnosable anxiety, mood or other psychiatric disorder, and there was no history of substance use, recent psychosocial stressors or sleep deprivation. Notably, there were no precipitating factors, though mild obstructive sleep apnoea without associated symptoms was detected. This case underscores the risk of violent behaviour in adult sleep terrors and emphasises the need for comprehensive evaluation and prompt intervention.