NORD gratefully acknowledges Laura Gould Crandall, MA, Research Scientist and Orrin Devinsky, MD, Professor, Departments of Neurology, Neurosurgery and Psychiatry, Chief of Service, NYU Epilepsy Service, for assistance in the preparation of this report.
Sudden unexplained death in childhood (SUDC) is the sudden death of a child 12 months of age or older that remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history. These deaths elude our scientific understanding. SUDC cannot be predicted or prevented at this time. According to the U.S. Centers for Disease Control and Prevention, in 2018, 392 children between the ages of 1-18 years died suddenly without a clear cause of death determined. Most of these children were toddlers, aged 1-4 years; an incidence of 1.4 deaths per 100,000 toddler aged children. Research and awareness of SUDC remains limited.
Nearly all children with SUDC were thought to be sleeping before becoming unresponsive. Most were born as full-term singletons and their development was considered normal. Children were in their state of usual good health prior to death or had mild symptoms of illness such as cold symptoms or fever. Some children with SUDC had a history of febrile seizures, or a family history of febrile seizures.
A febrile seizure is a convulsion in a child that may be caused by a spike in body temperature, often from an infection. Children aged 3 months to 5 or 6 years may have febrile seizures and they occur in 2% to 5% of all children. There is a slight tendency for them to run in families. If a child’s parents, brothers or sisters, or other close relatives have had febrile seizures, the child is a bit more likely to have them.
By definition, the cause(s) of SUDC are unknown. However, due to the lack of standardizations of death investigations, consideration of undiagnosed cases of cardiac disorders affecting the heart rhythm that are often due to genetic abnormalities, infections, and neurological conditions should be considered and ruled out.
The history of febrile seizures in some children with SUDC, and their family members, demonstrate a possible correlation to sudden unexpected death In epilepsy (SUDEP) defined as the sudden, unexpected, non-traumatic, non-drowning death in an individual with epilepsy, witnessed or unwitnessed, in which the postmortem examination does not reveal an anatomical or toxicological cause for the death. Most children with witnessed SUDEP are associated with a terminal convulsion, called a tonic-clonic seizure.
Examinations of the brains in a subset of children after SUDC reveal subtle abnormal development of an area deep in the temporal lobe. It is unknown whether these are a cause of seizures, a result of past seizures, are a normal variant in development and whether they have a direct association with the death.
Children who die of SUDC are generally toddlers (60%), between 1 and 4 years of age, but older children can be affected. According to the CDC, non-Hispanic black/African American children have a >2-fold risk of SUDC versus non-Hispanic white, Asian or Pacific Islander, and American Indian/Alaska Native. Nearly 90% are born full-term and nearly half are first born.
SUDC is not a diagnosis but a category of death. SUDC describes the sudden death of a child greater than 12 months of age that has undergone a thorough investigation and does not reveal evidence of an unnatural death. Death investigations also vary widely and therefore the extent to which known causes of death have been ruled should be reviewed.
In 2019, the National Association of Medical Examiners Panel on Sudden Unexpected Death In Pediatrics published national guidelines regarding the investigation, certification and family needs associated with sudden death in children. (https://sudpeds.com/)
Clinical Testing and Work Up
The investigation of the child’s death should be comprehensive including investigation of the scene where the child was found unresponsive, interviews with caregivers, a review of the child medical history and their family medical history, a complete autopsy with ancillary testing as clinically indicated.
SUDC is a multidisciplinary problem and requires coordination among the professionals involved to effectively investigate a case of SUDC and also provide appropriate communication and effective medical follow-up for family members. Families need effective communication in regards to the ramifications of the child’s final cause of death and what screening recommendations are appropriate to consider. Asking your primary care physician to collaborate with the medical examiner or coroner who performed the death investigation can be an excellent way to streamline communication in an emotionally traumatic and confusing situation.
Since genetic disorders can contribute to sudden death, evaluation of family members is indicated. This can include but not limited to inherited heart arrhythmia seizure disorders, and metabolic disorders. It is valuable to confirm a family diagnosis and assess the risk in the living family members following an unexplained death. Clinical evaluation of family members following a sudden death may identify other affected members. First degree relatives (parents and siblings of the person who has died) should speak to their primary physician to obtain a referral to a cardiologist with expertise in electrophysiology and special training to evaluate genetic cardiac disorders and other referrals as clinically indicated.
SUDC is a category of death diagnosis of exclusion which means that it is only determined after the death and thorough investigation of the clinical history, scene of death and autopsy reveal no other cause. Because the determination of SUDC is made after death, there is no treatment.
SUDC Registry and Research Collaborative (SUDCRRC)
The purpose of the SUDCRRC is to increase the understanding of the characteristics, circumstances, medical histories and pathologies of children from ages 11 months through 18 years who have died suddenly and unexpectedly, and in some instances, without explanation. The SUDC Registry and Research Collaborative analyzes cases of sudden unexpected deaths in these children to understand risk factors and causes (including genetic studies on the child who died and both parents), and develop preventative measures. The SUDCRRC is available to review cases for evaluation through Dec 2023. For more information: https://sudc.org/research-and-medical-info/sudc-registry-research-collaborative
North American SUDEP Registry
NYU Comprehensive Epilepsy Center
223 East 34th St New York, NY 10016
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
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Some current clinical trials also are posted on the following page on the NORD website:
For information about clinical trials sponsored by private sources, in the main, contact:
For more information about clinical trials conducted in Europe, contact:
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