Exploring Brain Activity in Sudden Unexpected Death in Epilepsy (SUDEP)
Epilepsy News From: Monday, March 18, 2019
Kommajosyula SP, Randall ME, Brozoski TJ, Odintsov BM, Faingold CL. Epilepsy Research, 135 (2017): 87-94.
The article “Specific subcortical structures are activated during seizure-induced death in a model of sudden unexpected death in epilepsy (SUDEP): A manganese-enhanced magnetic resonance imaging study” examined the changes of certain brain activities upon sudden unexpected death in epilepsy (SUDEP) in a mouse model.
Understanding cause or changes in a brain with SUDEP is an area of major concern. This study is the first one to use a special type of MRI (called MEMRI) for SUDEP research to look at the activity changes in specific brain structures.
- Sudden unexpected death in epilepsy (SUDEP) is likely the greatest single cause of death in people with epilepsy.
- Each year, about 1 in 1,000 people with epilepsy die from SUDEP.
- People with epilepsy have a 24-28 times higher risk of sudden death as compared to the general population.
- No one knows what causes SUDEP, but many areas are being looked at including problems with breathing, hearth rhythm, and brain function that occur with seizures.
- Imaging studies have found changes in brain activity in specific areas of the brain in people who passed away from SUDEP.
- The parts of the brain affected in SUDEP are mainly those that regulate the heart and the respiratory or breathing systems (i.e., cardio-respiratory functions). It is thought that the impaired cardio-respiratory functions would then lead to SUDEP.
- However, the specific structure of the brain where these neutral activity changes occurred is not yet known.
- A specialized MRI scan that uses a substance called manganese to detect brain activities in mice was used in this study. MEMRI can better track changes in brain activity and give images with higher brightness.
- A mouse model is commonly used to mimic human SUDEP. When given acoustical stimuli, the mice experience seizures, followed by seizure-induced respiratory arrest (S-IRA), which leads to sudden death. Images of brain activity are then done.
Description of Study
- Acoustic stimuli or sounds were used to trigger seizures and respiratory arrest in mice. Results were compared to a control group of mice who were not affected by the stimuli.
- Manganese-enhanced MRI (MEMRI) was used to measure the brain activity.
Summary of Study Findings
- A comparison of the patterns of MEMRI activation between DBA/1 mice with respiratory arrest after a seizure and controls showed increased activity levels in areas of the brain involved in controlling breathing.
- Respiratory arrest after a seizure was found to increase the activity in certain brain regions that contain a large number of serotonergic neurons. Loss of serotonergic signaling can predisopse mice to SUDEP.
What does this mean?
- These findings provide additional evidence that problems in the brain areas critical for regulating breathing through serotonin signaling are involved in SUDEP.
- In this paper, the scientists were able to successfully detect the specific brain structures that showed activity changes related to respiratory arrest after a seizure.
- More research is needed to investigate the electrical and chemical changes in these specific brain areas and if this can point to ways to prevent SUDEP.
Mingzhou Fu and Sloka Iyengar PhD
Daniel Friedman MD
Monday, March 18, 2019