Prevention of Sudden Death in Patients With Epilepsy

Prevention of Sudden Death in Patients With Epilepsy

To the Editor: Sudden unexpected death in epilepsy (SUDEP) occurs sometimes in people with ictal disorders.1 The diagnosis does not require evidence of a seizure and excludes status epilepticus as a cause of death. The postmortem examination must not reveal any toxic or anatomic pathology, and death must not be due to trauma or drowning.

The prevalence of epilepsy in the United States is approximately 2.3 million in adults and 480,000 among children.1,2 One of 26 people in the United States and 1 of 103 people in Great Britain have epilepsy in their lifetime. The incidence of SUDEP is approximately 1-2 per 1,000 person years in patients with chronic epilepsy and 3-9 per 1,000 person years in severe, refractory seizures. There are more than 500 SUDEP deaths every year in Great Britain among the 600,000 individuals reported to have epilepsy.2 Postmortem studies indicate that up to 60% of all epilepsy-related deaths can be accounted for by SUDEP, making it the most common epilepsy-related cause of mortality.3

The risk of dying suddenly and unexpectedly for patients with epilepsy has been estimated to be more than 20 times greater than for the general population.1,2 The cause in two-thirds of the cases is unidentified. The most common risk factors for SUDEP are generalized tonic-clonic seizures, long-term epilepsy, male gender, polypharmacy, poor anticonvulsant drug compliance, and sleep deprivation.4

Case report. A 5-year-old girl, was treated in the pediatric neurology clinic. The diagnosis was severe, refractory seizures with a documented, recurrent myoclonic component of possible Dravet syndrome, according to ICD-9 diagnostic criteria. She had exhibited this convulsive disorder since the age of 3 years. Her epilepsy was managed with divalproex, temazepam, and a ketogenic diet. Despite pharmacotherapy, the child was never seizure free.

One morning, the child was found dead in her bed. The family reported no new illnesses, change in ictal status, trauma, or other concerns recently. A postmortem examination revealed no toxic or anatomic pathology. The cause of death was considered to be SUDEP, noting a higher frequency of such occurrences in children with Dravet syndrome.5

Integration of different mechanisms is proposed to explain SUDEP: cardiac arrythmias, respiratory depression, and cerebral or autonomic dysfunction.6 Neuronal networks activated during a seizure inhibit the respiratory centers in the medulla, leading to hypoventilation with an acid-base imbalance, which can induce bradycardia, asystole, and death.

Cardiorespiratory control by the brainstem is regulated via neurotransmitters like 5-hydroxytryptamine and adenosine.6 There is a rise in adenosine levels during convulsive activity that causes postictal hypoventilation, apnea, and arrhythmias. Serotonin decreases postictal hypoxemia, and reportedly in an animal experiment, selective serotonin reuptake inhibitor medications attenuated this influence.6

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Talking about SUDEP with patients and family at the initial onset of seizures is controversial; rather, it is advised that it be discussed after patients are more established in the clinic.7 Utilizing a SUDEP safety checklist can help clinicians in assessing the risk of sudden death in patients with epilepsy.2 Discussion is for higher-risk individuals. A preventative plan is provided to patients and family, hopefully to improve patient compliance with medications and facilitate changes in lifestyle.7 Such a plan targets diminishing prominent risk factors (Table 1).

References

1. Shorvon S, Tomson T. Sudden unexpected death in epilepsy. Lancet. 2011;378(9808):2028-2038. PubMed doi:10.1016/S0140-6736(11)60176-1

2. Shankar R, Cox D, Jalihal V, et al. Sudden unexpected death in epilepsy (SUDEP): development of a safety checklist. Seizure. 2013;22(10):812-817. PubMed doi:10.1016/j.seizure.2013.07.014

3. Waddell B, McColl K, Turner C, et al. Are we discussing SUDEP?—a retrospective case note analysis. Seizure. 2013;22(1):74-76.PubMed

4. Scorza FA, Duncan S, Cavalheiro EA, et al. Sleep tight, wake up bright: should sleep deprivation be included as a potential risk factor for SUDEP? Epilepsy Behav. 2014;33:75-76. PubMed doi:10.1016/j.yebeh.2014.02.004

5. Le Gal F, Korff CM, Monso-Hinard C, et al. A case of SUDEP in a patient with Dravet syndrome with SCN1A mutation. Epilepsia. 2010;51(9):1915-1918. PubMed doi:10.1111/j.1528-1167.2010.02691.x

6. Massey CA, Sowers LP, Dlouhy BJ, et al. Mechanisms of sudden unexpected death in epilepsy: the pathway to prevention. Nat Rev Neurol. 2014;10(5):271-282. PubMed doi:10.1038/nrneurol.2014.64

7. Miller WR, Young N, Friedman D, et al. Discussing sudden unexpected death in epilepsy (SUDEP) with patients: practices of health care providers. Epilepsy Behav. 2014;32:38-41. PubMed doi:10.1016/j.yebeh.2013.12.020

Murali K. Kolikonda, MD

[email protected]

Suneela Cherlopalle, MD

Vivek C. Shah, MD

Steven Lippmann, MD

Author affiliations: Department of Psychiatry, University of Louisville School of Medicine, Louisville, Kentucky.

Potential conflicts of interest: None reported.

Funding/support: None reported.

Published online: January 29, 2015.

Prim Care Companion CNS Disord 2015;17(1):doi:10.4088/PCC.14l01705

© Copyright 2015 Physicians Postgraduate Press, Inc.