Reflex anoxic seizures (‘RAS’) may present, as potentially life threatening events, but these are often preventable. They are most common in preschool children (but can occur in any age) and more so in females. As a cause of seizures they are not rare; one study estimated a frequency of 8 in 1000 preschool children1, but they are often misdiagnosed. The pathophysiology of RAS is vagally mediated – a noxious stimulus causes a supranormal vagal discharge resulting in bradycardia and then astystole2. This then results in cerebral under perfusion and hypoxia. During this time the patient is often noted to become very pale with dusky lips, initially flaccid and then tonic with rigid extension and clenched jaws. They may then have a generalised convulsion, often with rolling eyes and urinary incontinence. The patient spontaneously recovers (the whole episode lasting around 30 to 60 seconds) and will feel somnolent, often remaining pale for a while.
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