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Published on: November 8, 2018
Early non-convulsive seizures are associated with the development of acute encephalopathy with biphasic seizures and
Azusa Maruyama1, Shoichi Tokumoto2, Hiroshi Yamaguchi2
1Department of Neurology, Hyogo Prefectural Kobe Children's Hospital, Japan.
Insights
Non-convulsive seizures (NCS) are common in children at high risk for acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). Early detection of NCS via cEEG is crucial as it is linked to worse neurological outcomes and AESD development.
Area of Science:
- Pediatric Neurology
- Neurophysiology
- Critical Care Medicine
Background:
- Febrile seizures and acute encephalopathy in children can present with seizures and fever of unknown etiology (SICF).
- Children with SICF, particularly those with refractory status epilepticus or prolonged neurological abnormalities, face a high risk of developing acute encephalopathy with biphasic seizures and late reduced diffusion (AESD).
- Non-convulsive seizures (NCS) are prevalent in critically ill children and contribute to excitotoxic neuronal injury.
Purpose of the Study:
- To determine the prevalence of NCS in the acute phase of high-risk pediatric patients for AESD.
- To investigate the association between acute-phase NCS and subsequent neurological outcomes, including AESD development.
Main Methods:
- A cohort of 137 children at high risk for AESD and presenting with SICF were studied.
- Continuous electroencephalogram monitoring (cEEG) was performed upon admission.
- Patient characteristics and outcomes were compared between those with and without NCS.
Main Results:
- NCS were detected in 30 out of 137 children, with 96.7% detected within 12 hours of admission.
- Neurological sequelae were significantly more common in children with NCS (20.0%) compared to those without (1.9%).
- AESD developed in 16.7% of NCS patients versus 2.8% of non-NCS patients.
Conclusions:
- The presence of NCS in the acute phase is a significant risk factor for neurological sequelae.
- NCS occurrence is strongly associated with the subsequent development of AESD in high-risk children.
Introduction:
Children with either febrile seizure or acute encephalopathy exhibit seizures and/or impaired consciousness accompanied by fever of unknown etiology (SICF). Among children with SICF, we previously reported those who have refractory status epilepticus or prolonged neurological abnormalities with normal AST levels are at a high risk for the development of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), considered to be caused by excitotoxicity. Non-convulsive seizures (NCS) are common in critically ill children and cause excitotoxic neuronal injury. The aim of this study was to elucidate the prevalence of NCS in the acute phase of children at a high risk for developing AESD and the relationship between NCS in the acute phase and neurological outcomes.
Methods:
We studied 137 children with SICF at a high risk for developing AESD and who underwent continuous electroencephalogram monitoring (cEEG) upon admission to a tertiary pediatric care center at Hyogo Prefectural Kobe Children's Hospital between October 2007 and August 2018. Patient characteristics and outcomes were compared between patients with NCS and without NCS.
Results:
Of the 137 children, NCS occurred in 30 children; the first NCS were detected in cEEG at the beginning in 63.3%, during the first hour in 90%, and within 12 h in 96.7%. Neurological sequelae were more common in NCS patients (20.0%) than in non-NCS patients (1.9%; p = 0.001). Five in 30 NCS patients (16.7%) and 3 in 107 non-NCS patients (2.8%) developed AESD (p = 0.013).
Conclusion:
The occurrence of NCS is associated with subsequent neurological sequelae, especially the development of AESD.
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