mother putting child to bed

Every year, thousands of American families lose a child to sudden unexplained death. These deaths mainly occur during sleep in infants less than 1 year old. But a smaller percentage of children experience sudden unexpected deaths in childhood (SUDC) after the first year of life, with most of these occurring before age 4. Now, a breakthrough study by researchers at the NYU Grossman School of Medicine and the NYU Comprehensive Epilepsy Center has found strong evidence that seizures may be linked to SUDC deaths.

In 2021, more than 200 children between ages 1 and 4 died from SUDC. The majority had no obvious heart problems, nervous system problems, or other health issues to explain their death. But children involved in SUDC cases do share one thing in common: they are 10 times more likely to have a history of febrile seizures. 

Febrile seizures are relatively common. About 1 in 25 children experience at least one febrile seizure, often triggered by fever from an illness such as the flu or an ear infection.  

Some experts already suspected a link between seizure history and SUDC, but it has been challenging to prove. For the study, the NYU researchers analyzed video footage of seven SUDC events in sleeping toddlers aged 13 to 27 months. Each of these children knew how to walk and had reached other normal milestones for their age. At the time of death, all of the toddlers were lying face down or had their faces obstructed by bedding. 

After careful analysis, researchers identified short seizures lasting less than a minute in all five videos with continuous footage. The remaining two children had motion-activated video footage. One child appeared to have had a seizure, and the other video was difficult to interpret. 

At least four of the children showed signs of life for several minutes after the seizure. The study authors noted that the seizures appeared to affect the children’s breathing. The seizures likely also dampened their reflexes, explaining why they remained face down instead of shifting positions to breathe better.

Seizures are notoriously hard to detect in an autopsy. “Our study, although small, offers the first direct evidence that seizures may be responsible for some sudden deaths in children, which are usually unwitnessed during sleep,” said Laura Gould, MSc, lead author and research assistant professor at NYU Langone.

This study was limited by imperfect video quality and few cases. However, the authors suspect that hidden seizures may be behind most SUDC cases. While just one of the toddlers in this study had a known history of febrile seizures, three of the children had changes to the brain similar to people with epilepsy.

Nighttime seizures may also be responsible for some toddler deaths attributed to other causes, such as infection or asphyxiation, and possibly even unexplained nighttime deaths in young adults. 

So far, there’s not enough evidence to say for sure that seizures cause SUDC events. However, this study is an important step forward in understanding and preventing these rare yet tragic cases. It may also help bring some closure to grieving families.

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4 Sources

  1. Gould, L., Reid, C. A., Rodriguez, A. J., Devinsky, O., & for SUDC Video Working Group (2024). Video analyses of sudden unexplained deaths in toddlers. Neurology, 102(3), article e208038.
  2. National Institute of Neurological Disorders and Stroke (2023, November 28). Febrile seizures., Retrieved January 15, 2024, from
  3. Barranco, R., Caputo, F., Molinelli, A., & Ventura, F. (2020). Review on post-mortem diagnosis in suspected SUDEP: Currently still a difficult task for Forensic Pathologists. Journal of Forensic and Legal Medicine, 70, 101920.
  4. NYU Langone News. (2024, January 4). Seizures identified as potential cause of sudden unexplained deaths in children.

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