Paper indicates potential ways to protect epilepsy patients from sudden unexpected death
6 July 2011
People with epilepsy (who are otherwise healthy) are more than 20 times as likely to die suddenly from unexplained causes as the general population. However, there is little clear evidence for the beneficial effect of any particular intervention to prevent sudden unexpected death in epilepsy (SUDEP).
Recommendations from a Seminar published Online First in The Lancet suggest that reducing the occurrence of tonic-clonic seizures (the most common type of generalised seizure that affects the entire brain), less frequent or gradual changes to antiepileptic drugs (AEDs), night-time surveillance of high-risk patients, close supervision immediately after a seizure, and counselling patients about the risks and prevention strategies could help protect against SUDEP.
In this paper, Simon Shorvon from University College London Institute of Neurology, London, UK and Torbjorn Tomson from the Karolinska Institute, Stockholm, Sweden review the evidence for interventions to minimise the likelihood of sudden death and provide advice to clinicians managing patients with epilepsy.
Research suggests that experiencing a high number of generalised tonic-clonic seizures is the strongest predisposing factor for SUDEP: "Compared with patients with up to two seizures in the previous year, the relative risk [the number of times greater the risk is compared to the general population] of SUDEP is 7.21 in those with a history of three to 12 seizures, 8.64 in those with 13-50 seizures, and 10.16 in those with a history of more than 50."
Other risk factors include taking a combined regimen of AEDs (polytherapy), not taking AEDs as prescribed, sudden or frequent changes to AEDs, male sex, early onset of epilepsy (before the age of 16 years), having epilepsy for longer than 15 years, having seizures during sleep, and having seizures when alone.
The authors suggest that modifying such risk factors might reduce the possibility of sudden death. Key recommendations include controlling seizures through effective drug treatment and good compliance, changing treatment in a gradual, staged manner, and taking action over potential warning signs such as seizure-related severe bradycardia (abnormally slow resting heart rate below 60 beats per minute) or apnoea and seizures in people with pre-existing cardiac or respiratory impairment.
Other measures that might be useful range from supervision at night for high-risk patients, to choosing AEDs without associated cardiorespiratory adverse effects, and close observation of patients after a seizure until full consciousness is restored.
Shorvon and Tomson also examine the controversy surrounding whether and when to discuss the increased risk of sudden death with epilepsy patients. Some have argued that to inform all patients (even those at low risk) causes unnecessary stress and anxiety. But the authors urge: "We believe that most patients should have information about SUDEP, because although epilepsy is not usually a life-threatening condition, a small number of people do die in epileptic seizures from accidents and SUDEP, and the risk can be minimised by controlling tonic-clonic seizures. This information is best provided as part of comprehensive counselling about risks and prevention. Putting the risks in perspective is sometimes helpful-for example, comparing the risk of SUDEP (10-35 in 100 000 person-years) with the similar yearly risks of accidental death in a motor accident (about 18 in 100 000 cars or 55 per 100 000 motorcycles).
The paper also highlights the need for standardised autopsy protocols in all suspected SUDEP cases to enable data on the incidence of SUDEP in different regions, monitoring of time trends, and intervention strategies to be assessed.
Text sourced from The Lancet's press release