When are episodes of loss of consciousness life-threatening?

Episodic loss of consciousness is common in the paediatric population. While the majority of cases are due to benign conditions, life-threatening causes must be promptly identified. The present paper presents a case of recurrent loss of consciousness associated with convulsive activity and subsequent cardiac arrest due to a rare inherited ion channel disease known as Brugada syndrome. The case highlights the challenges of distinguishing epilepsy from convulsive syncope and the potentially disastrous consequences of an undiagnosed cardiac etiology. The most important paediatric causes of paroxysmal loss of consciousness and their salient features are reviewed. Clinical features suggesting a cardiac cause are emphasized because early recognition of these cases is critical.